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Discussions and Knowledge Gaps

2

What determines whether a beryllium-sensitized individual progresses to chronic beryllium disease? Beryllium sensitization is necessary but not sufficient for organ disease, yet the host, exposure, and immunologic factors that convert the sub-clinical beryllium-specific T-cell response into progressive granulomatous lung disease are not defined.

KNOWLEDGE GAP OPEN gap_cbd_sensitization_to_disease_progression

Attached to

pathophysiology#Beryllium-Specific CD4+ T Cell Sensitization pathophysiology#Noncaseating Granuloma Assembly pathophysiology#Progressive Pulmonary Fibrosis and Restrictive Lung Disease

Roughly half of sensitized workers already have CBD at first evaluation, and in longitudinal follow-up a substantial minority of the remainder convert to disease over several years, with no consistent difference in age, sex, smoking, or measured exposure time between progressors and non-progressors. Because the beryllium-specific CD4+ Th1 response is present in both sensitization and disease, the step that tips a contained immune response into destructive, fibrosing granulomatous inflammation is the central unresolved question - relevant to whether early immunomodulation of sensitized but disease-free individuals could prevent CBD.

Proposed experiments

Longitudinal immunophenotyping of beryllium-sensitized workers to predict CBD conversion

exp_cbd_progression_immune_biomarkers

Prospectively follow a cohort of beryllium-sensitized but disease-free workers with serial bronchoalveolar lavage and blood sampling, tracking beryllium-specific CD4+ T-cell frequency, effector-memory/regulatory T-cell balance, IFN-gamma/TNF cytokine output, and HLA-DP Glu69 allele affinity, to identify immunologic determinants that predict progression to biopsy-proven granulomatous CBD versus stable sensitization.

Show evidence (2 references)

PMID:15374840 SUPPORT Human Clinical

"Disease developed in 17 sensitized individuals (31%) within an average follow-up period of 3.8 years (range, 1.0-9.5 years)."

Longitudinal evidence that a substantial minority of beryllium-sensitized individuals progress to CBD over a few years, framing progression determinants as an open question. Evidence source is HUMAN_CLINICAL (longitudinal patient cohort).

PMID:15374840 SUPPORT Human Clinical

"Approximately 50% of individuals with beryllium sensitization have chronic beryllium disease at the time of their initial clinical evaluation"

Documents that about half of sensitized individuals already have CBD at first evaluation, underscoring that sensitization precedes but does not guarantee disease. Evidence source is HUMAN_CLINICAL.

Does the HLA-DP2 transgenic mouse model of chronic beryllium disease, which reproduces beryllium-specific CD4+ T-cell responses and granulomatous inflammation, also faithfully reproduce the progressive interstitial fibrosis that drives human CBD morbidity - or is the fibrotic end stage the point of divergence between the animal model and human disease?

HUMAN MODEL MISMATCH OPEN mismatch_cbd_hla_dp2_transgenic_mouse_fibrosis

Attached to

pathophysiology#Beryllium-Specific CD4+ T Cell Sensitization pathophysiology#Noncaseating Granuloma Assembly pathophysiology#Progressive Pulmonary Fibrosis and Restrictive Lung Disease

The HLA-DP2 transgenic mouse is the flagship in-vivo model that links the HLA-DP Glu69 genetic lesion to a beryllium-specific CD4+ T-cell response and granulomatous lung inflammation, validating the upstream immunologic arm of the disease. However, the immunologic sensitization/granuloma steps are far better recapitulated in the model than the downstream, chronic fibrotic remodeling that determines long-term human outcome. Whether the fibrotic consequence node is model-faithful is therefore mechanistically important: if murine granulomas resolve or fail to progress to human-like fibrosis, the model is well suited to studying antigen recognition and early granuloma biology but a weaker platform for testing anti-fibrotic interventions in CBD.

Proposed experiments

Longitudinal fibrosis phenotyping of beryllium-exposed HLA-DP2 transgenic mice versus human CBD

exp_cbd_dp2_mouse_fibrosis_fidelity

Expose HLA-DP2 transgenic mice to beryllium oxide and follow them longitudinally with quantitative histologic fibrosis scoring, hydroxyproline collagen assays, and lung mechanics, benchmarking the trajectory against human CBD explant/biopsy fibrosis and pulmonary-function decline to determine whether and when the murine model diverges from the human fibrotic end stage.

Show evidence (1 reference)

PMID:26129650 SUPPORT Model Organism

"Using HLA-DP2 transgenic (Tg) mice, we developed a model of CBD that replicates the major features of the human disease."

Establishes the HLA-DP2 transgenic mouse as a model that replicates the major (chiefly immunologic) features of CBD, making the fidelity of its downstream fibrotic phenotype the open translational question. Evidence source is MODEL_ORGANISM.

⚙

Pathophysiology

9

Inhaled Beryllium Particle Deposition and Alveolar Macrophage Uptake

Inhaled beryllium particles deposit in the distal airways and alveoli, where they are taken up by alveolar macrophages and dendritic cells. Beryllium is a poorly soluble, biopersistent metal that the macrophage cannot degrade or clear, so it acts as a persistent indigestible stimulus that sustains a chronic, rather than self-limited, macrophage response - the disease-specific substitution for the generic persistent stimulus of the granuloma module.

alveolar macrophage CL:0000583 dendritic cell CL:0000451

chronic inflammatory response GO:0002544 ↑ INCREASED

Downstream

Beryllium-Modified Self-Peptide Neoantigen Formation

Show evidence (1 reference)

PMID:20356827 SUPPORT In Vitro

"Chronic beryllium disease (CBD) is a fibrotic lung disorder caused by beryllium (Be) exposure and is characterized by granulomatous inflammation and the accumulation of Be-responsive CD4(+) T cells in the lung."

Establishes inhaled beryllium as the cause of the CBD granulomatous response, i.e. the persistent stimulus. Support is PARTIAL because the snippet identifies beryllium as the causal stimulus but does not itself document alveolar deposition or macrophage uptake; those specifics are standard particle-clearance biology. Evidence source is IN_VITRO because this is a structural/biochemical study of the HLA-DP2 molecule.

Beryllium-Modified Self-Peptide Neoantigen Formation

Within the antigen-presenting cell, ionic beryllium (Be2+) is incorporated into the peptide-binding groove of HLA-DP class II molecules, coordinating with acidic residues of the HLA-DP beta chain and a bound self-peptide. Rather than acting as a classical hapten that modifies a protein covalently, beryllium is buried at the interface between the HLA-DP molecule and the peptide, altering the surface chemistry and conformation of the peptide-MHC complex so that it is seen as a neoantigen. This creates the antigenic determinant that beryllium-specific T cells recognize.

dendritic cell CL:0000451

antigen processing and presentation of peptide antigen via MHC class II GO:0002495 ↑ INCREASED

Downstream

HLA-DP Glu69-Restricted Antigen Presentation

Show evidence (2 references)

PMID:24995984 SUPPORT In Vitro

"the T cell ligand is created when a Be(2+) cation becomes buried in an HLA-DP2/peptide complex, where it is coordinated by both MHC and peptide acidic amino acids."

Directly demonstrates that beryllium forms a neoantigen by becoming buried in the HLA-DP2/peptide complex, coordinated by MHC and peptide acidic residues. Evidence source is IN_VITRO because it is a structural/biochemical study of the beryllium-loaded HLA-DP2 complex.

PMID:24995984 SUPPORT In Vitro

"the TCR does not interact with the Be(2+) itself, but rather with surface changes induced by the firmly bound Be(2+)"

Shows the T-cell receptor recognizes surface changes induced by bound beryllium rather than the cation itself, defining the neoantigenic determinant. Evidence source is IN_VITRO (structural study).

HLA-DP Glu69-Restricted Antigen Presentation

Presentation of the beryllium-modified neoantigen is restricted to HLA-DP molecules whose beta chain carries a glutamic acid (a negatively charged residue) at position 69 (HLA-DPB1 Glu69, e.g. HLA-DPB1*02:01, *06:01, *17:01). The Glu69 residue lines an acidic pocket that is required to coordinate the positively charged beryllium cation; HLA-DP molecules lacking Glu69 cannot bind beryllium and do not present it. This single genetic feature explains the dominant heritable susceptibility to sensitization and disease and is the molecular basis of the gene-environment interaction.

dendritic cell CL:0000451

antigen processing and presentation of peptide antigen via MHC class II GO:0002495 ↑ INCREASED

Downstream

Beryllium-Specific CD4+ T Cell Sensitization

Show evidence (3 references)

PMID:20356827 SUPPORT In Vitro

"an unusual solvent exposed acidic pocket formed between the peptide backbone and the HLA-DP2 beta-chain alpha-helix and containing three glutamic acids from the beta-chain, including betaGlu69"

The HLA-DP2 crystal structure reveals the acidic pocket containing betaGlu69 that is the proposed beryllium-coordination site. Evidence source is IN_VITRO (crystallographic study).

PMID:20356827 SUPPORT In Vitro

"mutation of any of the three glutamic acids in this pocket results in loss of the ability of DP2 to present Be to T cells."

Mutating the pocket glutamic acids abolishes beryllium presentation, establishing the Glu69 acidic pocket as required for presentation. Evidence source is IN_VITRO (mutagenesis of the HLA-DP2 molecule).

PMID:16272364 SUPPORT In Vitro

"a single amino acid residue of the MHC class II beta-chain dictates beryllium presentation and potentially, disease susceptibility."

Demonstrates that a single MHC class II beta-chain residue (Glu69) governs beryllium presentation. Evidence source is IN_VITRO because presentation was dissected in fibroblasts expressing mutated HLA-DP molecules.

Beryllium-Specific CD4+ T Cell Sensitization

Recognition of the HLA-DP/Glu69-presented beryllium neoantigen by the T-cell receptor of naive CD4+ T cells drives their clonal expansion into a beryllium-specific memory/effector population. This antigen-driven expansion is beryllium sensitization (BeS), the immunological state that precedes organ disease and is measured clinically by the beryllium lymphocyte proliferation test (BeLPT), in which a patient's blood or lung lymphocytes proliferate on exposure to beryllium salts in vitro. Sensitization is necessary but not sufficient for CBD.

beryllium-specific CD4+ T cell CL:0000624

T cell proliferation GO:0042098 ↑ INCREASED

Downstream

Beryllium-Specific Th1 Cytokine Response

Show evidence (3 references)

PMID:8105536 SUPPORT Human Clinical

"Chronic beryllium disease (CBD) is a lung disorder related to beryllium exposure and is characterized by the accumulation in the lung of beryllium-specific CD4+ major histocompatibility complex (MHC) class II-restricted T lymphocytes."

Documents accumulation of beryllium-specific, MHC-class-II-restricted CD4+ T cells in the lung - the sensitized effector population. Evidence source is HUMAN_CLINICAL (CBD patient cohort).

PMID:25398119 SUPPORT Other

"The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD"

The beryllium lymphocyte proliferation test detects the beryllium-specific T-cell proliferation that defines sensitization. Evidence source is OTHER (professional-society consensus statement).

PMID:26129650 SUPPORT Model Organism

"Using HLA-DP2 transgenic (Tg) mice, we developed a model of CBD that replicates the major features of the human disease."

An HLA-DP2 transgenic mouse model reproduces beryllium-specific CD4+ T-cell responses, recapitulating the sensitization step in vivo. Evidence source is MODEL_ORGANISM (HLA-DP2 transgenic mice).

Beryllium-Specific Th1 Cytokine Response

On re-encounter with beryllium in the lung, the expanded beryllium-specific CD4+ T cells polarize to a T-helper-1 effector phenotype and secrete interferon-gamma, tumor necrosis factor, and interleukin-2. These are predominantly effector-memory Th1 cells that accumulate in the bronchoalveolar space, producing the compartmentalized, beryllium-driven Th1 cytokine milieu that licenses macrophage activation and granuloma formation. This cytokine output is the disease-specific engine upstream of the conserved granuloma-formation amplifier.

beryllium-specific T-helper 1 cell CL:0000545

type II interferon production GO:0032609 ↑ INCREASED tumor necrosis factor production GO:0032640 ↑ INCREASED

Downstream

Th1 and TNF-Driven Macrophage Recruitment and Activation

Show evidence (1 reference)

PMID:16272364 SUPPORT In Vitro

"HLA-DP Glu69- and HLA-DR Glu71-expressing molecules are capable of inducing beryllium-specific proliferation and IFN-gamma expression by lung CD4+ T cells."

Beryllium presentation drives proliferation and interferon-gamma expression by lung CD4+ T cells, the Th1 cytokine output of this node. Evidence source is IN_VITRO (ex vivo lung CD4+ T cells stimulated in culture).

Th1 and TNF-Driven Macrophage Recruitment and Activation

Interferon-gamma and TNF from the beryllium-specific Th1 cells classically activate lung macrophages and recruit additional monocytes to the site. TNF is the non-redundant amplifier that organizes the granulomatous response. This activated, cytokine-rich macrophage compartment is the conserved amplifier step of the granuloma module, here driven specifically by the beryllium-antigen-specific T-cell response.

macrophage CL:0000235

macrophage activation GO:0042116 ↑ INCREASED

Downstream

Epithelioid Transformation and Multinucleated Giant Cell Formation

Show evidence (1 reference)

PMID:16272364 SUPPORT Other

"characterized by a CD4+ T cell alveolitis and granulomatous inflammation in the lung"

Characterizes CBD as a CD4+ T-cell alveolitis with granulomatous inflammation, linking the beryllium-specific T-cell response to macrophage granulomatous activation. Evidence source is OTHER because this is a background disease characterization within an immunology study.

Epithelioid Transformation and Multinucleated Giant Cell Formation

In the activated milieu the lung macrophages undergo the defining transformations of the granulomatous response: they differentiate into interdigitated epithelioid cells and fuse into multinucleated giant cells (including the asteroid- and Schaumann-body-containing giant cells seen in beryllium and sarcoid granulomas). This converts a diffuse mononuclear infiltrate into the organized cellular core of a granuloma.

epithelioid macrophage CL:0002150 multinucleated giant cell CL:0000647

syncytium formation by cell-cell fusion GO:0000768 ↑ INCREASED

Downstream

Noncaseating Granuloma Assembly

Show evidence (1 reference)

PMID:25007084 SUPPORT Other

"granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis, except through use of immunologic testing, such as the beryllium lymphocyte proliferation test"

CBD granulomas are histopathologically indistinguishable from sarcoidosis, i.e. compact epithelioid/giant-cell granulomas. Support is PARTIAL because the snippet establishes granulomatous histology but does not itself detail giant-cell fusion. Evidence source is OTHER (review).

Noncaseating Granuloma Assembly

The transformed macrophages assemble into compact, well-formed non-caseating granulomas - an epithelioid/giant-cell core cuffed by CD4+ T lymphocytes - distributed along the bronchovascular bundles and interlobular septa of the lung and in the hilar lymph nodes. Unlike the caseating granulomas of tuberculosis, CBD granulomas characteristically lack central caseous necrosis, matching the non-caseating pattern of sarcoidosis and making the two histologically indistinguishable.

macrophage CL:0000235 CD4+ T lymphocyte CL:0000624

inflammatory response GO:0006954 ↑ INCREASED

Downstream

Progressive Pulmonary Fibrosis and Restrictive Lung Disease

Show evidence (2 references)

PMID:25398119 SUPPORT Other

"BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD"

A granulomatous inflammatory response in the lung defines CBD, the organized-granuloma effector of this chain. Evidence source is OTHER (professional-society consensus statement).

PMID:25007084 SUPPORT Other

"granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis"

Confirms the mature CBD granuloma is a well-formed non-caseating granuloma matching sarcoidosis. Evidence source is OTHER (review).

Progressive Pulmonary Fibrosis and Restrictive Lung Disease

Because the beryllium stimulus cannot be cleared, the granulomatous response persists and, in a subset of patients, drives progressive interstitial fibrosis. Fibroblast recruitment and excessive collagen deposition around and between granulomas produce a restrictive ventilatory defect with impaired gas exchange, progressive dyspnea, and, in advanced disease, respiratory failure and cor pulmonale. This fibrotic end state is the pathological (destructive) arm of the granuloma module's containment-versus-destruction consequence.

fibroblast CL:0000057

collagen fibril organization GO:0030199 ↑ INCREASED

Show evidence (2 references)

PMID:20356827 SUPPORT In Vitro

"Chronic beryllium disease (CBD) is a fibrotic lung disorder caused by beryllium (Be) exposure"

Identifies CBD as a fibrotic lung disorder, the fibrotic end state of the granulomatous response. Evidence source is IN_VITRO (structural study whose abstract characterizes the disease).

PMID:25398119 SUPPORT Other

"Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline"

Progressive lung-function abnormality/decline is the clinical correlate of the fibrotic consequence. Evidence source is OTHER (consensus statement).

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

12

Cardiovascular 1

Mediastinal and hilar lymphadenopathy Mediastinal lymphadenopathy HP:0100721

Respiratory 4

Exertional dyspnea HP:0002094

Course: PROGRESSIVE

Chronic dry cough Nonproductive cough HP:0031246

Temporal: CHRONIC

Pulmonary fibrosis HP:0002206

Course: PROGRESSIVE

Restrictive ventilatory defect HP:0002091

Show evidence (1 reference)

PMID:25398119 SUPPORT Other

"Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline"

Documents the lung-function abnormality/decline that manifests as a restrictive ventilatory defect in CBD. Evidence source is OTHER (consensus statement).

Constitutional 2

Fatigue HP:0012378

Chest pain HP:0100749

Growth 1

Weight loss HP:0001824

Other 4

Non-caseating pulmonary granulomas Non-caseating epithelioid cell granulomatosis HP:0012220

Show evidence (1 reference)

PMID:25007084 SUPPORT Other

"granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis"

CBD produces non-caseating granulomas pathologically indistinguishable from sarcoidosis. Evidence source is OTHER (review).

Pulmonary granulomatosis HP:0030250

Interstitial pneumonitis HP:0006515

Digital clubbing Clubbing of fingers HP:0100759

🧬

Genetic Associations

1

HLA-DPB1

Gene: HLA-DPB1 hgnc:4940 relationship_type: SUSCEPTIBILITY

Show evidence (3 references)

PMID:8105536 SUPPORT Human Clinical

"Among CBD cases, 97 percent expressed the HLA-DPB1*0201-associated glutamic acid (unaffected population, 30 percent; P < 0.001) at residue 69"

The founding case-control observation that HLA-DPB1 glutamate-69 is markedly over-represented in CBD (97% vs 30%), establishing it as the dominant genetic susceptibility marker. Evidence source is HUMAN_CLINICAL.

PMID:31743304 SUPPORT Human Clinical

"BES and CBD were significantly associated with presence of DPβE69"

A later matched case-control study confirms the significant association of HLA-DP Glu69 with both sensitization and CBD. Evidence source is HUMAN_CLINICAL.

PMID:16272364 SUPPORT In Vitro

"Genetic susceptibility to this disease has been linked with HLA-DP alleles, particularly those possessing a glutamic acid at position 69 (Glu69) of the beta-chain"

Ties the genetic susceptibility to the Glu69-bearing HLA-DP alleles that present beryllium. Evidence source is IN_VITRO (mechanistic immunology study).

💊

Medical Actions

6

Beryllium exposure cessation

Action: therapeutic procedure Ontology label: Therapeutic Procedure NCIT:C49236

Removal from further beryllium exposure is the essential first intervention for anyone sensitized or with CBD, limiting antigen re-exposure that drives the beryllium-specific T-cell response.

Systemic corticosteroid therapy

Action: Pharmacotherapy NCIT:C15986

Agent: prednisone CHEBI:8382

Oral glucocorticoids (typically prednisone) are the mainstay pharmacotherapy for symptomatic or progressive CBD, suppressing the granulomatous inflammation and stabilizing or improving lung function.

Show evidence (1 reference)

PMID:25398119 SUPPORT Other

"Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline"

The ATS statement identifies corticosteroid therapy as the standard treatment for CBD with significant lung-function abnormality or decline. Evidence source is OTHER (consensus statement).

Steroid-sparing immunosuppression

Action: Pharmacotherapy NCIT:C15986

Agent: methotrexate CHEBI:44185

Methotrexate and other steroid-sparing immunosuppressants are used to reduce corticosteroid burden in patients requiring long-term therapy.

TNF inhibitor therapy

Action: Pharmacotherapy NCIT:C15986

Agent: anti-TNF monoclonal antibody NCIT:C20401

TNF-neutralizing biologics (e.g. infliximab) have been used in refractory granulomatous disease, targeting the TNF-driven macrophage activation that initiates and maintains the granuloma; benefit in CBD is less established than in sarcoidosis and infection risk is a concern.

Mechanism Target:

INHIBITS Th1 and TNF-Driven Macrophage Recruitment and Activation — TNF neutralization removes the non-redundant amplifier of the granulomatous response, impairing granuloma initiation and maintenance.

Show evidence (1 reference)

PMID:22974830 SUPPORT Human Clinical

"These changes suggest that infliximab therapy may decrease lung inflammation and the number of pathogenic, Be-responsive CD4+ cells recruited to the target organ."

A pilot clinical trial of the TNF inhibitor infliximab in CBD showed reduced lung inflammation and fewer beryllium-responsive CD4+ T cells, supporting TNF blockade of the macrophage-activation node. Evidence source is HUMAN_CLINICAL (placebo-controlled trial in CBD patients).

Lung transplantation

Action: organ transplantation Ontology label: Organ Transplantation NCIT:C15289

Lung transplantation is an option for end-stage fibrotic CBD with respiratory failure refractory to medical therapy.

Supportive care

Action: supportive care Ontology label: Supportive Care NCIT:C15747

Supportive measures - supplemental oxygen for hypoxemia, pulmonary rehabilitation, and management of comorbidities and complications such as pulmonary hypertension - address symptoms and functional impairment in progressive CBD independent of immunosuppression.

🌍

Environmental Factors

1

Occupational beryllium inhalation

Inhalation of airborne beryllium dust, fume, or particulate is the sole cause. At-risk work includes beryllium extraction and machining, aerospace and defense manufacturing, nuclear-weapons and reactor work, electronics, dental-alloy and ceramics fabrication, and metal recycling. Unlike the classic fibrogenic pneumoconioses, risk is not simply cumulative-dose dependent: even brief or low-level exposures can sensitize a genetically susceptible person, and particle size, solubility, and surface area modulate immunogenicity. Paraoccupational (take-home) and near-facility community exposures are also documented.

Show evidence (1 reference)

PMID:25398119 SUPPORT Other

"Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD)."

The official ATS statement establishes inhaled-beryllium exposure as the cause of sensitization and CBD. Evidence source is OTHER because this is a professional-society consensus statement.

Mechanism Target:

TRIGGERS Inhaled Beryllium Particle Deposition and Alveolar Macrophage Uptake — Airborne beryllium dust, fume, or particulate is the only route by which beryllium reaches the distal airways, so occupational inhalation is what places the persistent indigestible stimulus inside alveolar macrophages.

Show evidence (1 reference)

PMID:25398119 SUPPORT Other

"Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD)."

A professional-society consensus statement that beryllium exposure leads to sensitization and to chronic beryllium disease, which is the exposure arm this edge asserts. Evidence source is OTHER because the statement is consensus guidance rather than a primary study. No source cached for this entry documents the particle-deposition step itself.

📊

Prevalence

1

Beryllium-exposed workers

Point Prevalence 5500.0 per 100,000 (1000.0–10000.0) Unknown

CBD develops in roughly 1-10% of beryllium-exposed workers, varying widely with job task and exposure intensity; population-level prevalence in the unexposed general public is negligible. Rate is conditioned on the exposed working population, not the general population.

Show evidence (1 reference)

PMID:22974830 SUPPORT Human Clinical

"Chronic beryllium disease (CBD) is a granulomatous lung disorder that develops in 1–10% of beryllium-exposed workers"

Quantifies CBD occurrence as 1-10% among beryllium-exposed workers, an exposure-cohort-conditioned prevalence. Evidence source is HUMAN_CLINICAL.

📊

Related Datasets

1

Multi-omic signatures of Chronic Beryllium Disease bronchoalveolar lavage cells relate to T cell function and innate immunity geo:GSE206719

human MULTI OMICS n=144

PMID:35972918

Identified by GEO DataSets index search for Chronic Beryllium Disease (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

{ }

Source YAML

click to show

name: Chronic Beryllium Disease
creation_date: "2026-07-16T00:00:00Z"
category: Respiratory Disease
parents:
- Respiratory Disease
- Lung Disease
- Pneumoconiosis
disease_term:
  preferred_term: chronic beryllium disease
  term:
    id: MONDO:0015274
    label: chronic beryllium disease
description: >-
  Chronic beryllium disease (CBD, berylliosis) is a granulomatous interstitial
  lung disease caused by a beryllium-specific, cell-mediated (delayed-type,
  type IV) immune response to inhaled beryllium. It is the archetypal
  gene-environment disease: inhaled beryllium is presented by HLA-DP molecules
  carrying a glutamic acid at position 69 of the beta chain (HLA-DPB1 Glu69),
  which creates the acidic pocket that binds beryllium and displays a
  beryllium-modified self-peptide neoantigen to CD4+ T cells. The resulting
  beryllium-specific CD4+ T-helper-1 response (detected as beryllium
  sensitization by the beryllium lymphocyte proliferation test) drives
  interferon-gamma and TNF secretion, macrophage activation, and the assembly of
  non-caseating granulomas in the lung that progress to interstitial fibrosis.
  Beryllium sensitization precedes and is necessary but not sufficient for the
  organ disease; a subset of sensitized individuals progress to CBD. CBD is
  clinically and histologically nearly indistinguishable from sarcoidosis and is
  distinguished by a documented beryllium exposure plus a positive
  beryllium-specific lymphocyte response.
synonyms:
- berylliosis
- chronic berylliosis
- chronic beryllium lung disease
environmental:
- name: Occupational beryllium inhalation
  exposure_term:
    preferred_term: exposure to beryllium
    term:
      id: ECTO:9000941
      label: exposure to beryllium
  environment_context:
    preferred_term: beryllium-containing dust and fume
    term:
      id: ENVO:00002008
      label: dust
  chemicals:
  - beryllium
  description: >-
    Inhalation of airborne beryllium dust, fume, or particulate is the sole
    cause. At-risk work includes beryllium extraction and machining,
    aerospace and defense manufacturing, nuclear-weapons and reactor work,
    electronics, dental-alloy and ceramics fabrication, and metal recycling.
    Unlike the classic fibrogenic pneumoconioses, risk is not simply
    cumulative-dose dependent: even brief or low-level exposures can sensitize a
    genetically susceptible person, and particle size, solubility, and surface
    area modulate immunogenicity. Paraoccupational (take-home) and near-facility
    community exposures are also documented.
  evidence:
  - reference: PMID:25398119
    reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD)."
    explanation: >-
      The official ATS statement establishes inhaled-beryllium exposure as the
      cause of sensitization and CBD. Evidence source is OTHER because this is a
      professional-society consensus statement.
  influences_mechanisms:
  - target: Inhaled Beryllium Particle Deposition and Alveolar Macrophage Uptake
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      Airborne beryllium dust, fume, or particulate is the only route by which
      beryllium reaches the distal airways, so occupational inhalation is what
      places the persistent indigestible stimulus inside alveolar macrophages.
    evidence:
    - reference: PMID:25398119
      reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD)."
      explanation: >-
        A professional-society consensus statement that beryllium exposure
        leads to sensitization and to chronic beryllium disease, which is the
        exposure arm this edge asserts. Evidence source is OTHER because the
        statement is consensus guidance rather than a primary study. No source
        cached for this entry documents the particle-deposition step itself.
pathophysiology:
- name: Inhaled Beryllium Particle Deposition and Alveolar Macrophage Uptake
  role: trigger
  conforms_to: "granuloma_formation#Persistent Indigestible Stimulus"
  description: >-
    Inhaled beryllium particles deposit in the distal airways and alveoli, where
    they are taken up by alveolar macrophages and dendritic cells. Beryllium is a
    poorly soluble, biopersistent metal that the macrophage cannot degrade or
    clear, so it acts as a persistent indigestible stimulus that sustains a
    chronic, rather than self-limited, macrophage response - the disease-specific
    substitution for the generic persistent stimulus of the granuloma module.
  cell_types:
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  - preferred_term: dendritic cell
    term:
      id: CL:0000451
      label: dendritic cell
  biological_processes:
  - preferred_term: chronic inflammatory response
    term:
      id: GO:0002544
      label: chronic inflammatory response
    modifier: INCREASED
  evidence:
  - reference: PMID:20356827
    reference_title: "Crystal structure of HLA-DP2 and implications for chronic beryllium disease."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Chronic beryllium disease (CBD) is a fibrotic lung disorder caused by beryllium (Be) exposure and is characterized by granulomatous inflammation and the accumulation of Be-responsive CD4(+) T cells in the lung."
    explanation: >-
      Establishes inhaled beryllium as the cause of the CBD granulomatous
      response, i.e. the persistent stimulus. Support is PARTIAL because the
      snippet identifies beryllium as the causal stimulus but does not itself
      document alveolar deposition or macrophage uptake; those specifics are
      standard particle-clearance biology. Evidence source is IN_VITRO because
      this is a structural/biochemical study of the HLA-DP2 molecule.
  downstream:
  - target: Beryllium-Modified Self-Peptide Neoantigen Formation
- name: Beryllium-Modified Self-Peptide Neoantigen Formation
  role: mechanism
  description: >-
    Within the antigen-presenting cell, ionic beryllium (Be2+) is incorporated
    into the peptide-binding groove of HLA-DP class II molecules, coordinating
    with acidic residues of the HLA-DP beta chain and a bound self-peptide. Rather
    than acting as a classical hapten that modifies a protein covalently,
    beryllium is buried at the interface between the HLA-DP molecule and the
    peptide, altering the surface chemistry and conformation of the peptide-MHC
    complex so that it is seen as a neoantigen. This creates the antigenic
    determinant that beryllium-specific T cells recognize.
  cell_types:
  - preferred_term: dendritic cell
    term:
      id: CL:0000451
      label: dendritic cell
  biological_processes:
  - preferred_term: antigen processing and presentation of peptide antigen via MHC class II
    term:
      id: GO:0002495
      label: antigen processing and presentation of peptide antigen via MHC class II
    modifier: INCREASED
  evidence:
  - reference: PMID:24995984
    reference_title: "Structural basis of chronic beryllium disease: linking allergic hypersensitivity and autoimmunity."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "the T cell ligand is created when a Be(2+) cation becomes buried in an HLA-DP2/peptide complex, where it is coordinated by both MHC and peptide acidic amino acids."
    explanation: >-
      Directly demonstrates that beryllium forms a neoantigen by becoming buried
      in the HLA-DP2/peptide complex, coordinated by MHC and peptide acidic
      residues. Evidence source is IN_VITRO because it is a structural/biochemical
      study of the beryllium-loaded HLA-DP2 complex.
  - reference: PMID:24995984
    reference_title: "Structural basis of chronic beryllium disease: linking allergic hypersensitivity and autoimmunity."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "the TCR does not interact with the Be(2+) itself, but rather with surface changes induced by the firmly bound Be(2+)"
    explanation: >-
      Shows the T-cell receptor recognizes surface changes induced by bound
      beryllium rather than the cation itself, defining the neoantigenic
      determinant. Evidence source is IN_VITRO (structural study).
  downstream:
  - target: HLA-DP Glu69-Restricted Antigen Presentation
- name: HLA-DP Glu69-Restricted Antigen Presentation
  role: mechanism
  description: >-
    Presentation of the beryllium-modified neoantigen is restricted to HLA-DP
    molecules whose beta chain carries a glutamic acid (a negatively charged
    residue) at position 69 (HLA-DPB1 Glu69, e.g. HLA-DPB1*02:01, *06:01, *17:01).
    The Glu69 residue lines an acidic pocket that is required to coordinate the
    positively charged beryllium cation; HLA-DP molecules lacking Glu69 cannot
    bind beryllium and do not present it. This single genetic feature explains the
    dominant heritable susceptibility to sensitization and disease and is the
    molecular basis of the gene-environment interaction.
  cell_types:
  - preferred_term: dendritic cell
    term:
      id: CL:0000451
      label: dendritic cell
  biological_processes:
  - preferred_term: antigen processing and presentation of peptide antigen via MHC class II
    term:
      id: GO:0002495
      label: antigen processing and presentation of peptide antigen via MHC class II
    modifier: INCREASED
  evidence:
  - reference: PMID:20356827
    reference_title: "Crystal structure of HLA-DP2 and implications for chronic beryllium disease."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "an unusual solvent exposed acidic pocket formed between the peptide backbone and the HLA-DP2 beta-chain alpha-helix and containing three glutamic acids from the beta-chain, including betaGlu69"
    explanation: >-
      The HLA-DP2 crystal structure reveals the acidic pocket containing betaGlu69
      that is the proposed beryllium-coordination site. Evidence source is
      IN_VITRO (crystallographic study).
  - reference: PMID:20356827
    reference_title: "Crystal structure of HLA-DP2 and implications for chronic beryllium disease."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "mutation of any of the three glutamic acids in this pocket results in loss of the ability of DP2 to present Be to T cells."
    explanation: >-
      Mutating the pocket glutamic acids abolishes beryllium presentation,
      establishing the Glu69 acidic pocket as required for presentation. Evidence
      source is IN_VITRO (mutagenesis of the HLA-DP2 molecule).
  - reference: PMID:16272364
    reference_title: "Beryllium presentation to CD4+ T cells is dependent on a single amino acid residue of the MHC class II beta-chain."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "a single amino acid residue of the MHC class II beta-chain dictates beryllium presentation and potentially, disease susceptibility."
    explanation: >-
      Demonstrates that a single MHC class II beta-chain residue (Glu69) governs
      beryllium presentation. Evidence source is IN_VITRO because presentation was
      dissected in fibroblasts expressing mutated HLA-DP molecules.
  downstream:
  - target: Beryllium-Specific CD4+ T Cell Sensitization
- name: Beryllium-Specific CD4+ T Cell Sensitization
  role: mechanism
  description: >-
    Recognition of the HLA-DP/Glu69-presented beryllium neoantigen by the T-cell
    receptor of naive CD4+ T cells drives their clonal expansion into a
    beryllium-specific memory/effector population. This antigen-driven expansion
    is beryllium sensitization (BeS), the immunological state that precedes organ
    disease and is measured clinically by the beryllium lymphocyte proliferation
    test (BeLPT), in which a patient's blood or lung lymphocytes proliferate on
    exposure to beryllium salts in vitro. Sensitization is necessary but not
    sufficient for CBD.
  cell_types:
  - preferred_term: beryllium-specific CD4+ T cell
    term:
      id: CL:0000624
      label: CD4-positive, alpha-beta T cell
  biological_processes:
  - preferred_term: T cell proliferation
    term:
      id: GO:0042098
      label: T cell proliferation
    modifier: INCREASED
  evidence:
  - reference: PMID:8105536
    reference_title: "HLA-DPB1 glutamate 69: a genetic marker of beryllium disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chronic beryllium disease (CBD) is a lung disorder related to beryllium exposure and is characterized by the accumulation in the lung of beryllium-specific CD4+ major histocompatibility complex (MHC) class II-restricted T lymphocytes."
    explanation: >-
      Documents accumulation of beryllium-specific, MHC-class-II-restricted CD4+
      T cells in the lung - the sensitized effector population. Evidence source is
      HUMAN_CLINICAL (CBD patient cohort).
  - reference: PMID:25398119
    reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD"
    explanation: >-
      The beryllium lymphocyte proliferation test detects the beryllium-specific
      T-cell proliferation that defines sensitization. Evidence source is OTHER
      (professional-society consensus statement).
  - reference: PMID:26129650
    reference_title: "Metal-specific CD4+ T-cell responses induced by beryllium exposure in HLA-DP2 transgenic mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Using HLA-DP2 transgenic (Tg) mice, we developed a model of CBD that replicates the major features of the human disease."
    explanation: >-
      An HLA-DP2 transgenic mouse model reproduces beryllium-specific CD4+ T-cell
      responses, recapitulating the sensitization step in vivo. Evidence source is
      MODEL_ORGANISM (HLA-DP2 transgenic mice).
  downstream:
  - target: Beryllium-Specific Th1 Cytokine Response
- name: Beryllium-Specific Th1 Cytokine Response
  role: amplifier
  description: >-
    On re-encounter with beryllium in the lung, the expanded beryllium-specific
    CD4+ T cells polarize to a T-helper-1 effector phenotype and secrete
    interferon-gamma, tumor necrosis factor, and interleukin-2. These are
    predominantly effector-memory Th1 cells that accumulate in the bronchoalveolar
    space, producing the compartmentalized, beryllium-driven Th1 cytokine milieu
    that licenses macrophage activation and granuloma formation. This cytokine
    output is the disease-specific engine upstream of the conserved
    granuloma-formation amplifier.
  cell_types:
  - preferred_term: beryllium-specific T-helper 1 cell
    term:
      id: CL:0000545
      label: T-helper 1 cell
  biological_processes:
  - preferred_term: type II interferon production
    term:
      id: GO:0032609
      label: type II interferon production
    modifier: INCREASED
  - preferred_term: tumor necrosis factor production
    term:
      id: GO:0032640
      label: tumor necrosis factor production
    modifier: INCREASED
  evidence:
  - reference: PMID:16272364
    reference_title: "Beryllium presentation to CD4+ T cells is dependent on a single amino acid residue of the MHC class II beta-chain."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "HLA-DP Glu69- and HLA-DR Glu71-expressing molecules are capable of inducing beryllium-specific proliferation and IFN-gamma expression by lung CD4+ T cells."
    explanation: >-
      Beryllium presentation drives proliferation and interferon-gamma expression
      by lung CD4+ T cells, the Th1 cytokine output of this node. Evidence source
      is IN_VITRO (ex vivo lung CD4+ T cells stimulated in culture).
  downstream:
  - target: Th1 and TNF-Driven Macrophage Recruitment and Activation
- name: Th1 and TNF-Driven Macrophage Recruitment and Activation
  role: amplifier
  conforms_to: "granuloma_formation#Th1 and TNF-Driven Macrophage Recruitment and Activation"
  description: >-
    Interferon-gamma and TNF from the beryllium-specific Th1 cells classically
    activate lung macrophages and recruit additional monocytes to the site.
    TNF is the non-redundant amplifier that organizes the granulomatous response.
    This activated, cytokine-rich macrophage compartment is the conserved
    amplifier step of the granuloma module, here driven specifically by the
    beryllium-antigen-specific T-cell response.
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  biological_processes:
  - preferred_term: macrophage activation
    term:
      id: GO:0042116
      label: macrophage activation
    modifier: INCREASED
  evidence:
  - reference: PMID:16272364
    reference_title: "Beryllium presentation to CD4+ T cells is dependent on a single amino acid residue of the MHC class II beta-chain."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "characterized by a CD4+ T cell alveolitis and granulomatous inflammation in the lung"
    explanation: >-
      Characterizes CBD as a CD4+ T-cell alveolitis with granulomatous
      inflammation, linking the beryllium-specific T-cell response to macrophage
      granulomatous activation. Evidence source is OTHER because this is a
      background disease characterization within an immunology study.
  downstream:
  - target: Epithelioid Transformation and Multinucleated Giant Cell Formation
- name: Epithelioid Transformation and Multinucleated Giant Cell Formation
  role: central_effector
  conforms_to: "granuloma_formation#Epithelioid Transformation and Multinucleated Giant Cell Formation"
  description: >-
    In the activated milieu the lung macrophages undergo the defining
    transformations of the granulomatous response: they differentiate into
    interdigitated epithelioid cells and fuse into multinucleated giant cells
    (including the asteroid- and Schaumann-body-containing giant cells seen in
    beryllium and sarcoid granulomas). This converts a diffuse mononuclear
    infiltrate into the organized cellular core of a granuloma.
  cell_types:
  - preferred_term: epithelioid macrophage
    term:
      id: CL:0002150
      label: epithelioid macrophage
  - preferred_term: multinucleated giant cell
    term:
      id: CL:0000647
      label: multinucleated giant cell
  biological_processes:
  - preferred_term: syncytium formation by cell-cell fusion
    term:
      id: GO:0000768
      label: syncytium formation by cell-cell fusion
    modifier: INCREASED
  evidence:
  - reference: PMID:25007084
    reference_title: "Sarcoidosis and chronic beryllium disease: similarities and differences."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis, except through use of immunologic testing, such as the beryllium lymphocyte proliferation test"
    explanation: >-
      CBD granulomas are histopathologically indistinguishable from sarcoidosis,
      i.e. compact epithelioid/giant-cell granulomas. Support is PARTIAL because
      the snippet establishes granulomatous histology but does not itself detail
      giant-cell fusion. Evidence source is OTHER (review).
  downstream:
  - target: Noncaseating Granuloma Assembly
- name: Noncaseating Granuloma Assembly
  role: effector
  conforms_to: "granuloma_formation#Organized Granuloma Assembly"
  description: >-
    The transformed macrophages assemble into compact, well-formed
    non-caseating granulomas - an epithelioid/giant-cell core cuffed by CD4+ T
    lymphocytes - distributed along the bronchovascular bundles and interlobular
    septa of the lung and in the hilar lymph nodes. Unlike the caseating
    granulomas of tuberculosis, CBD granulomas characteristically lack central
    caseous necrosis, matching the non-caseating pattern of sarcoidosis and making
    the two histologically indistinguishable.
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  - preferred_term: CD4+ T lymphocyte
    term:
      id: CL:0000624
      label: CD4-positive, alpha-beta T cell
  biological_processes:
  - preferred_term: inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: INCREASED
  evidence:
  - reference: PMID:25398119
    reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD"
    explanation: >-
      A granulomatous inflammatory response in the lung defines CBD, the
      organized-granuloma effector of this chain. Evidence source is OTHER
      (professional-society consensus statement).
  - reference: PMID:25007084
    reference_title: "Sarcoidosis and chronic beryllium disease: similarities and differences."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis"
    explanation: >-
      Confirms the mature CBD granuloma is a well-formed non-caseating granuloma
      matching sarcoidosis. Evidence source is OTHER (review).
  downstream:
  - target: Progressive Pulmonary Fibrosis and Restrictive Lung Disease
- name: Progressive Pulmonary Fibrosis and Restrictive Lung Disease
  role: consequence
  conforms_to: "granuloma_formation#Tissue Containment versus Destruction and Fibrosis"
  description: >-
    Because the beryllium stimulus cannot be cleared, the granulomatous response
    persists and, in a subset of patients, drives progressive interstitial
    fibrosis. Fibroblast recruitment and excessive collagen deposition around and
    between granulomas produce a restrictive ventilatory defect with impaired gas
    exchange, progressive dyspnea, and, in advanced disease, respiratory failure
    and cor pulmonale. This fibrotic end state is the pathological (destructive)
    arm of the granuloma module's containment-versus-destruction consequence.
  cell_types:
  - preferred_term: fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  biological_processes:
  - preferred_term: collagen fibril organization
    term:
      id: GO:0030199
      label: collagen fibril organization
    modifier: INCREASED
  evidence:
  - reference: PMID:20356827
    reference_title: "Crystal structure of HLA-DP2 and implications for chronic beryllium disease."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Chronic beryllium disease (CBD) is a fibrotic lung disorder caused by beryllium (Be) exposure"
    explanation: >-
      Identifies CBD as a fibrotic lung disorder, the fibrotic end state of the
      granulomatous response. Evidence source is IN_VITRO (structural study whose
      abstract characterizes the disease).
  - reference: PMID:25398119
    reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline"
    explanation: >-
      Progressive lung-function abnormality/decline is the clinical correlate of
      the fibrotic consequence. Evidence source is OTHER (consensus statement).
phenotypes:
- name: Exertional dyspnea
  description: Progressive shortness of breath on exertion is the most common presenting symptom.
  phenotype_term:
    preferred_term: Dyspnea
    term:
      id: HP:0002094
      label: Dyspnea
    clinical_course: PROGRESSIVE
- name: Chronic dry cough
  description: A persistent nonproductive cough is a characteristic early symptom.
  phenotype_term:
    preferred_term: Nonproductive cough
    term:
      id: HP:0031246
      label: Nonproductive cough
    temporality: CHRONIC
- name: Fatigue
  description: Fatigue and reduced exercise tolerance are common constitutional symptoms.
  phenotype_term:
    preferred_term: Fatigue
    term:
      id: HP:0012378
      label: Fatigue
- name: Weight loss
  description: Unintentional weight loss occurs as a systemic feature of chronic granulomatous inflammation.
  phenotype_term:
    preferred_term: Weight loss
    term:
      id: HP:0001824
      label: Weight loss
- name: Chest pain
  description: Chest discomfort or pain may accompany the pulmonary involvement.
  phenotype_term:
    preferred_term: Chest pain
    term:
      id: HP:0100749
      label: Chest pain
- name: Non-caseating pulmonary granulomas
  description: >-
    Well-formed non-caseating epithelioid granulomas in the lung parenchyma and
    hilar lymph nodes are the pathological hallmark, indistinguishable from
    sarcoidosis.
  phenotype_term:
    preferred_term: Non-caseating epithelioid cell granulomatosis
    term:
      id: HP:0012220
      label: Non-caseating epithelioid cell granulomatosis
  evidence:
  - reference: PMID:25007084
    reference_title: "Sarcoidosis and chronic beryllium disease: similarities and differences."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis"
    explanation: >-
      CBD produces non-caseating granulomas pathologically indistinguishable from
      sarcoidosis. Evidence source is OTHER (review).
- name: Pulmonary granulomatosis
  description: Granulomatous inflammation distributed through the lung interstitium.
  phenotype_term:
    preferred_term: Pulmonary granulomatosis
    term:
      id: HP:0030250
      label: Pulmonary granulomatosis
- name: Interstitial pneumonitis
  description: Mononuclear interstitial inflammation accompanies the granulomatous response.
  phenotype_term:
    preferred_term: Interstitial pneumonitis
    term:
      id: HP:0006515
      label: Interstitial pneumonitis
- name: Pulmonary fibrosis
  description: Progressive interstitial fibrosis develops in advanced disease.
  phenotype_term:
    preferred_term: Pulmonary fibrosis
    term:
      id: HP:0002206
      label: Pulmonary fibrosis
    clinical_course: PROGRESSIVE
- name: Restrictive ventilatory defect
  description: >-
    Pulmonary function testing shows a restrictive pattern with reduced diffusing
    capacity as fibrosis advances; obstructive or mixed patterns also occur.
  phenotype_term:
    preferred_term: Restrictive ventilatory defect
    term:
      id: HP:0002091
      label: Restrictive ventilatory defect
  evidence:
  - reference: PMID:25398119
    reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline"
    explanation: >-
      Documents the lung-function abnormality/decline that manifests as a
      restrictive ventilatory defect in CBD. Evidence source is OTHER (consensus
      statement).
- name: Mediastinal and hilar lymphadenopathy
  description: Enlargement of hilar and mediastinal lymph nodes is a common radiographic finding.
  phenotype_term:
    preferred_term: Mediastinal lymphadenopathy
    term:
      id: HP:0100721
      label: Mediastinal lymphadenopathy
- name: Digital clubbing
  description: Clubbing of the fingers may occur in advanced fibrotic disease.
  phenotype_term:
    preferred_term: Clubbing of fingers
    term:
      id: HP:0100759
      label: Clubbing of fingers
genetic:
- name: HLA-DPB1
  gene_term:
    preferred_term: HLA-DPB1
    term:
      id: hgnc:4940
      label: HLA-DPB1
  relationship_type: SUSCEPTIBILITY
  notes: >-
    HLA-DPB1 alleles encoding a glutamic acid at position 69 of the beta chain
    (HLA-DPB1 Glu69) are the dominant genetic risk factor for beryllium
    sensitization and chronic beryllium disease. The Glu69 acidic pocket
    coordinates the beryllium cation and is required to present the
    beryllium-modified neoantigen to CD4+ T cells. Higher-affinity Glu69 alleles
    (e.g. HLA-DPB1*17:01, *02:01) confer greater risk, and gene copy/expression
    level further modulates susceptibility. This is a susceptibility locus, not a
    Mendelian cause: exposure is required for disease.
  evidence:
  - reference: PMID:8105536
    reference_title: "HLA-DPB1 glutamate 69: a genetic marker of beryllium disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Among CBD cases, 97 percent expressed the HLA-DPB1*0201-associated glutamic acid (unaffected population, 30 percent; P < 0.001) at residue 69"
    explanation: >-
      The founding case-control observation that HLA-DPB1 glutamate-69 is
      markedly over-represented in CBD (97% vs 30%), establishing it as the
      dominant genetic susceptibility marker. Evidence source is HUMAN_CLINICAL.
  - reference: PMID:31743304
    reference_title: "Lack of an Exposure Response and Interaction With HLA-DPβ1 and DRβ1 Polymorphisms in the Development of Beryllium Toxicity in a High Beryllium Exposure Cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "BES and CBD were significantly associated with presence of DPβE69"
    explanation: >-
      A later matched case-control study confirms the significant association of
      HLA-DP Glu69 with both sensitization and CBD. Evidence source is
      HUMAN_CLINICAL.
  - reference: PMID:16272364
    reference_title: "Beryllium presentation to CD4+ T cells is dependent on a single amino acid residue of the MHC class II beta-chain."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Genetic susceptibility to this disease has been linked with HLA-DP alleles, particularly those possessing a glutamic acid at position 69 (Glu69) of the beta-chain"
    explanation: >-
      Ties the genetic susceptibility to the Glu69-bearing HLA-DP alleles that
      present beryllium. Evidence source is IN_VITRO (mechanistic immunology
      study).
treatments:
- name: Beryllium exposure cessation
  description: >-
    Removal from further beryllium exposure is the essential first intervention
    for anyone sensitized or with CBD, limiting antigen re-exposure that drives
    the beryllium-specific T-cell response.
  treatment_term:
    preferred_term: therapeutic procedure
    term:
      id: NCIT:C49236
      label: Therapeutic Procedure
- name: Systemic corticosteroid therapy
  description: >-
    Oral glucocorticoids (typically prednisone) are the mainstay pharmacotherapy
    for symptomatic or progressive CBD, suppressing the granulomatous
    inflammation and stabilizing or improving lung function.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: prednisone
      term:
        id: CHEBI:8382
        label: prednisone
  evidence:
  - reference: PMID:25398119
    reference_title: "An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline"
    explanation: >-
      The ATS statement identifies corticosteroid therapy as the standard
      treatment for CBD with significant lung-function abnormality or decline.
      Evidence source is OTHER (consensus statement).
- name: Steroid-sparing immunosuppression
  description: >-
    Methotrexate and other steroid-sparing immunosuppressants are used to reduce
    corticosteroid burden in patients requiring long-term therapy.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: methotrexate
      term:
        id: CHEBI:44185
        label: methotrexate
- name: TNF inhibitor therapy
  description: >-
    TNF-neutralizing biologics (e.g. infliximab) have been used in refractory
    granulomatous disease, targeting the TNF-driven macrophage activation that
    initiates and maintains the granuloma; benefit in CBD is less established than
    in sarcoidosis and infection risk is a concern.
  therapeutic_modality: MONOCLONAL_ANTIBODY
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: anti-TNF monoclonal antibody
      term:
        id: NCIT:C20401
        label: Monoclonal Antibody
  target_mechanisms:
  - target: Th1 and TNF-Driven Macrophage Recruitment and Activation
    treatment_effect: INHIBITS
    description: >-
      TNF neutralization removes the non-redundant amplifier of the granulomatous
      response, impairing granuloma initiation and maintenance.
  evidence:
  - reference: PMID:22974830
    reference_title: "Infliximab therapy modulates an antigen-specific immune response in chronic beryllium disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These changes suggest that infliximab therapy may decrease lung inflammation and the number of pathogenic, Be-responsive CD4+ cells recruited to the target organ."
    explanation: >-
      A pilot clinical trial of the TNF inhibitor infliximab in CBD showed
      reduced lung inflammation and fewer beryllium-responsive CD4+ T cells,
      supporting TNF blockade of the macrophage-activation node. Evidence source
      is HUMAN_CLINICAL (placebo-controlled trial in CBD patients).
- name: Lung transplantation
  description: >-
    Lung transplantation is an option for end-stage fibrotic CBD with respiratory
    failure refractory to medical therapy.
  treatment_term:
    preferred_term: organ transplantation
    term:
      id: NCIT:C15289
      label: Organ Transplantation
- name: Supportive care
  description: >-
    Supportive measures - supplemental oxygen for hypoxemia, pulmonary
    rehabilitation, and management of comorbidities and complications such as
    pulmonary hypertension - address symptoms and functional impairment in
    progressive CBD independent of immunosuppression.
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
prevalence:
- population: Beryllium-exposed workers
  measure_type: POINT_PREVALENCE
  prevalence_class: UNKNOWN
  rate_per_100000: 5500.0
  rate_low: 1000.0
  rate_high: 10000.0
  notes: >-
    CBD develops in roughly 1-10% of beryllium-exposed workers, varying widely
    with job task and exposure intensity; population-level prevalence in the
    unexposed general public is negligible. Rate is conditioned on the exposed
    working population, not the general population.
  evidence:
  - reference: PMID:22974830
    reference_title: "Infliximab therapy modulates an antigen-specific immune response in chronic beryllium disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chronic beryllium disease (CBD) is a granulomatous lung disorder that develops in 1–10% of beryllium-exposed workers"
    explanation: >-
      Quantifies CBD occurrence as 1-10% among beryllium-exposed workers, an
      exposure-cohort-conditioned prevalence. Evidence source is HUMAN_CLINICAL.
discussions:
- discussion_id: gap_cbd_sensitization_to_disease_progression
  prompt: >-
    What determines whether a beryllium-sensitized individual progresses to
    chronic beryllium disease? Beryllium sensitization is necessary but not
    sufficient for organ disease, yet the host, exposure, and immunologic
    factors that convert the sub-clinical beryllium-specific T-cell response
    into progressive granulomatous lung disease are not defined.
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Beryllium-Specific CD4+ T Cell Sensitization
  - pathophysiology#Noncaseating Granuloma Assembly
  - pathophysiology#Progressive Pulmonary Fibrosis and Restrictive Lung Disease
  rationale: >-
    Roughly half of sensitized workers already have CBD at first evaluation, and
    in longitudinal follow-up a substantial minority of the remainder convert to
    disease over several years, with no consistent difference in age, sex,
    smoking, or measured exposure time between progressors and non-progressors.
    Because the beryllium-specific CD4+ Th1 response is present in both
    sensitization and disease, the step that tips a contained immune response
    into destructive, fibrosing granulomatous inflammation is the central
    unresolved question - relevant to whether early immunomodulation of sensitized
    but disease-free individuals could prevent CBD.
  proposed_experiments:
  - experiment_id: exp_cbd_progression_immune_biomarkers
    name: Longitudinal immunophenotyping of beryllium-sensitized workers to predict CBD conversion
    description: >-
      Prospectively follow a cohort of beryllium-sensitized but disease-free
      workers with serial bronchoalveolar lavage and blood sampling, tracking
      beryllium-specific CD4+ T-cell frequency, effector-memory/regulatory T-cell
      balance, IFN-gamma/TNF cytokine output, and HLA-DP Glu69 allele affinity, to
      identify immunologic determinants that predict progression to biopsy-proven
      granulomatous CBD versus stable sensitization.
  evidence:
  - reference: PMID:15374840
    reference_title: "Beryllium sensitization progresses to chronic beryllium disease: a longitudinal study of disease risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Disease developed in 17 sensitized individuals (31%) within an average follow-up period of 3.8 years (range, 1.0-9.5 years)."
    explanation: >-
      Longitudinal evidence that a substantial minority of beryllium-sensitized
      individuals progress to CBD over a few years, framing progression
      determinants as an open question. Evidence source is HUMAN_CLINICAL
      (longitudinal patient cohort).
  - reference: PMID:15374840
    reference_title: "Beryllium sensitization progresses to chronic beryllium disease: a longitudinal study of disease risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Approximately 50% of individuals with beryllium sensitization have chronic beryllium disease at the time of their initial clinical evaluation"
    explanation: >-
      Documents that about half of sensitized individuals already have CBD at
      first evaluation, underscoring that sensitization precedes but does not
      guarantee disease. Evidence source is HUMAN_CLINICAL.
- discussion_id: mismatch_cbd_hla_dp2_transgenic_mouse_fibrosis
  prompt: >-
    Does the HLA-DP2 transgenic mouse model of chronic beryllium disease, which
    reproduces beryllium-specific CD4+ T-cell responses and granulomatous
    inflammation, also faithfully reproduce the progressive interstitial fibrosis
    that drives human CBD morbidity - or is the fibrotic end stage the point of
    divergence between the animal model and human disease?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - pathophysiology#Beryllium-Specific CD4+ T Cell Sensitization
  - pathophysiology#Noncaseating Granuloma Assembly
  - pathophysiology#Progressive Pulmonary Fibrosis and Restrictive Lung Disease
  rationale: >-
    The HLA-DP2 transgenic mouse is the flagship in-vivo model that links the
    HLA-DP Glu69 genetic lesion to a beryllium-specific CD4+ T-cell response and
    granulomatous lung inflammation, validating the upstream immunologic arm of
    the disease. However, the immunologic sensitization/granuloma steps are far
    better recapitulated in the model than the downstream, chronic fibrotic
    remodeling that determines long-term human outcome. Whether the fibrotic
    consequence node is model-faithful is therefore mechanistically important:
    if murine granulomas resolve or fail to progress to human-like fibrosis, the
    model is well suited to studying antigen recognition and early granuloma
    biology but a weaker platform for testing anti-fibrotic interventions in CBD.
  proposed_experiments:
  - experiment_id: exp_cbd_dp2_mouse_fibrosis_fidelity
    name: Longitudinal fibrosis phenotyping of beryllium-exposed HLA-DP2 transgenic mice versus human CBD
    description: >-
      Expose HLA-DP2 transgenic mice to beryllium oxide and follow them
      longitudinally with quantitative histologic fibrosis scoring, hydroxyproline
      collagen assays, and lung mechanics, benchmarking the trajectory against
      human CBD explant/biopsy fibrosis and pulmonary-function decline to
      determine whether and when the murine model diverges from the human fibrotic
      end stage.
  evidence:
  - reference: PMID:26129650
    reference_title: "Metal-specific CD4+ T-cell responses induced by beryllium exposure in HLA-DP2 transgenic mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Using HLA-DP2 transgenic (Tg) mice, we developed a model of CBD that replicates the major features of the human disease."
    explanation: >-
      Establishes the HLA-DP2 transgenic mouse as a model that replicates the
      major (chiefly immunologic) features of CBD, making the fidelity of its
      downstream fibrotic phenotype the open translational question. Evidence
      source is MODEL_ORGANISM.
datasets:
- accession: geo:GSE206719
  title: Multi-omic signatures of Chronic Beryllium Disease bronchoalveolar lavage cells relate to T cell function and innate immunity
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: MULTI_OMICS
  sample_count: 144
  publication: PMID:35972918
  notes: Identified by GEO DataSets index search for Chronic Beryllium Disease (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

📚

References & Deep Research

Deep Research

1

Claude Code ▸

Chronic Beryllium Disease — Comprehensive Research Report

claude-haiku-4-5-20251001, claude-opus-4-8 13 citations 2026-07-16T23:32:56.655380

Chronic Beryllium Disease — Comprehensive Research Report

1. Disease Information

Chronic beryllium disease (CBD, "berylliosis") is a granulomatous interstitial lung disease driven by a beryllium-specific, cell-mediated (delayed-type, Type IV) immune response to inhaled beryllium. Think of it as the immune system deciding a chunk of metal is a permanent enemy it can't digest and building little fortified walls (granulomas) around it forever — a grudge that slowly stiffens the lung. It's the textbook gene-environment disease: you need both the exposure and the right immune-presentation genotype.

Key identifiers: - MONDO: MONDO:0015274 (chronic beryllium disease) — already in the entry. - MeSH: D001607 ("Berylliosis"). - ICD-10: J63.2 (Berylliosis). - ICD-11: under occupational/inorganic-dust pneumoconioses (CA60.1 region) — verify the exact leaf against the current ICD-11 browser; codings have shifted. - OMIM: No Mendelian OMIM entry — CBD is a complex susceptibility trait, not a single-gene disease. The relevant genetics live in HLA-DPB1 allele associations, not an OMIM disease number. - Orphanet: A rare-disease entry exists for berylliosis; confirm the ORPHA number in the current Orphadata pull rather than trusting memory.

Synonyms: berylliosis, chronic berylliosis, chronic beryllium lung disease, beryllium granulomatosis. (The entry's synonym list is good.)

Data derivation: Disease-level, aggregated. The knowledge here comes from occupational cohort studies (nuclear-weapons, aerospace, machining, ceramics workers), medical-surveillance registries (BeLPT screening programs at DOE facilities), immunology/structural-biology studies, and the 2014 ATS official statement — not from a single-patient EHR source.

2. Etiology

Primary cause (environmental): Inhalation of airborne beryllium — dust, fume, or fine particulate — is the sole necessary exposure. No beryllium, no CBD. It's an occupational/environmental toxicant acting as an immunogen (CHEBI: beryllium / beryllium(2+) cation; ECTO: exposure to beryllium). The entry correctly lists the at-risk industries: beryllium ore extraction and metal machining, aerospace/defense, nuclear-weapons and reactor work, electronics and semiconductors, dental-alloy and ceramics fabrication, and metal recycling.

Crucially, and unlike the classic fibrogenic pneumoconioses (silicosis, asbestosis), risk is not simply cumulative-dose-dependent. Even brief or low-level exposures can sensitize a genetically susceptible person; particle size, solubility, and surface area strongly modulate immunogenicity. Take-home ("paraoccupational") exposure on work clothes and near-facility community exposure are documented.

Genetic risk factors: - HLA-DPB1 Glu69 is the dominant heritable risk factor. Alleles encoding glutamic acid at position 69 of the DPβ chain (HLA-DPB102:01, 17:01, 06:01, etc.) markedly raise risk of both sensitization and disease. Richeldi et al. (Science 1993, PMID:8105536) — the founding observation: "97% [of CBD cases] expressed the HLA-DPB1*0201-associated glutamic acid (unaffected population, 30%; P < 0.001) at residue 69." - Higher-affinity Glu69 alleles (notably *17:01) and gene copy number / expression level further stratify risk (see McCanlies, Silveira, and the E69 genotype-exposure work, e.g. PMC8760148). - A minority susceptibility route via HLA-DR (glutamate at DRβ position 71, and an HLA-DRPheβ47 marker in Glu69-negative individuals; PMC1198259*) exists for the ~15–20% of patients lacking DP-Glu69.

Environmental/host modifiers: Higher airborne concentration, respirable particle fraction, and soluble beryllium salts increase risk; smoking is not a clear risk factor for CBD itself but suppresses BeLPT responses (see §10). Age, sex, and family history are not established independent risk factors beyond the HLA genetics.

Protective factors: Genetically, absence of a Glu69 allele is the main "protective" state — DP molecules lacking Glu69 cannot coordinate Be²⁺ and don't present it (mechanistic basis in §6). Environmentally, protection is entirely about exposure reduction: enclosed processes, wet machining, respiratory protection, and the lowered OSHA permissible exposure limit of 0.2 µg/m³ (8-hr TWA) under the 2017 final rule (PMID:28071878). No dietary/nutritional protective factor is established.

Gene–environment interaction: CBD is arguably the cleanest human example of a defined HLA-restricted gene × environment interaction — a specific MHC-II pocket residue (Glu69) is required to convert an inhaled metal into a T-cell antigen. Neither factor alone produces disease.

3. Phenotypes

CBD is insidious and adult-onset (occupational latency of years to decades). Severity and progression are variable. Suggested HP terms (the entry already carries most of these):

Phenotype	HP term	Type	Notes on frequency/course
Exertional dyspnea	HP:0002094 (Dyspnea)	Symptom	Most common presenting symptom; progressive
Chronic nonproductive cough	HP:0031246	Symptom	Characteristic early symptom; chronic
Fatigue / reduced exercise tolerance	HP:0012378	Symptom	Common constitutional
Unintentional weight loss	HP:0001824	Symptom	Systemic granulomatous feature
Chest pain/discomfort	HP:0100749	Symptom	Variable
Non-caseating pulmonary granulomas	HP:0012220	Histopathology	Pathological hallmark; indistinguishable from sarcoid
Pulmonary granulomatosis	HP:0030250	Histopathology	Interstitial distribution
Interstitial pneumonitis	HP:0006515	Histopathology	Mononuclear infiltrate
Pulmonary fibrosis	HP:0002206	Radiographic/histo	Advanced disease; progressive
Restrictive ventilatory defect (↓DLCO)	HP:0002091	Lab/PFT	Restrictive pattern with reduced diffusing capacity; obstructive/mixed also seen
Mediastinal/hilar lymphadenopathy	HP:0100721	Radiographic	Common; often less bulky than sarcoid
Digital clubbing	HP:0100759	Physical sign	Advanced fibrotic disease

Additional phenotypes worth considering for completeness: exercise-induced hypoxemia / reduced gas exchange (often the earliest physiologic abnormality, sometimes preceding resting PFT changes — cardiopulmonary exercise testing catches it first), skin granulomas / beryllium ulcers at sites of dermal beryllium implantation (a documented extrapulmonary manifestation), and in end-stage disease cor pulmonale / right heart failure (HP:0001648-ish pulmonary hypertension secondary to fibrosis). Beryllium can also produce contact dermatitis. Hepatic and other systemic granulomas are rare.

Onset/severity/progression: adult-onset; severity mild→severe and variable; course insidious then chronic-progressive in the subset that advances; frequency among affected individuals for the core respiratory phenotypes is high but the entry appropriately omits precise frequency: bands where quantitative support is thin.

Quality-of-life impact: progressive exertional limitation, oxygen dependence in advanced disease, and lifelong therapy burden. No CBD-specific validated QOL instrument is standard; generic respiratory/ILD tools (SF-36, St. George's Respiratory Questionnaire) are used in studies — flag as not-CBD-specific.

4. Genetic / Molecular Information

Susceptibility gene: HLA-DPB1 (HGNC — the entry uses hgnc:4940; verify this HGNC number resolves to HLA-DPB1, as HLA HGNC IDs are easy to transpose). Also HLA-DPA1 (the paired α chain), and HLA-DRB1 for the minority DR-restricted route.
Risk "variants": these are classical HLA alleles / polymorphic residues, not ClinVar-style pathogenic point mutations. The functional unit is the codon-69 residue of DPB1 (Glu69 = risk; non-Glu69 = low risk). This is a germline susceptibility polymorphism, not somatic, and not "pathogenic" in the ACMG/AMP sense — it's an immune-response allele. So most of the ClinVar/gnomAD/COSMIC machinery in the template is N/A; the right resources are the IMGT/HLA database and HLA allele-frequency references.
Functional consequence: gain of an antigen-presentation function — Glu69 creates an acidic pocket that binds Be²⁺. Mechanistically it's a "toxic gain of presentation," not loss-of-function.
Dose/copy effect: susceptibility scales with Glu69 allele copy number and DP surface expression (homozygotes and high-expressing haplotypes at higher risk).
Modifier genes: candidate immunogenetic modifiers include TNF-α promoter polymorphisms (−308), TGF-β1, and other cytokine variants associated with disease severity/progression in some cohorts, though replication is uneven — cite cautiously.
Epigenetics / chromosomal abnormalities: No established disease-defining DNA-methylation signature, and no aneuploidy/translocation involvement. Treat as not applicable / not established.

5. Environmental Information

Environmental factor: beryllium and beryllium-containing compounds (metal, oxide, alloys such as copper-beryllium, ceramics) as respirable dust/fume. CTD is a good structured source for beryllium–gene interactions.
Lifestyle: No causal lifestyle factor. Smoking is a notable confounder — cigarette smoke suppresses lymphocyte proliferation and can cause false-negative BeLPT, so it affects detection more than causation.
Infectious agents: None. CBD is non-infectious. (This is a key contrast with tuberculosis, whose caseating granulomas it superficially resembles.)

6. Mechanism / Pathophysiology

This is the heart of the entry and it's already modeled cleanly against the granuloma_formation module. The causal chain:

Step 1 — Deposition & uptake (trigger). Inhaled beryllium particles deposit in distal airways/alveoli and are engulfed by alveolar macrophages (CL:0000583) and dendritic cells (CL:0000451). Beryllium is poorly soluble and biopersistent — the macrophage cannot degrade or clear it, so it becomes the "persistent indigestible stimulus" that converts a normal, self-limited macrophage response into a chronic one. (Conforms to granuloma_formation#Persistent Indigestible Stimulus.) GO: chronic inflammatory response (GO:0002544).

Step 2 — Neoantigen formation (mechanism). Ionic Be²⁺ is incorporated into the peptide-binding groove of HLA-DP, coordinated by acidic residues of the DPβ chain and a bound self-peptide. This is the structural punchline from Clayton et al. (Cell 2014, PMID:24995984): "the T cell ligand is created when a Be2+ cation becomes buried in an HLA-DP2/peptide complex, where it is coordinated by both MHC and peptide acidic amino acids… the TCR does not interact with the Be2+ itself, but rather with surface changes induced by the firmly bound Be2+." So beryllium is not a classical covalent hapten — it's buried at the MHC–peptide interface, remodeling the surface into a neoantigen. This is what the paper means by "bridging allergic hypersensitivity and autoimmunity." GO: antigen processing and presentation via MHC class II (GO:0002495).

Step 3 — Glu69-restricted presentation (mechanism). Presentation is restricted to DP molecules bearing Glu69 (the acidic residue that coordinates the cation). Amicosante/Fontenot (PNAS 2000, PMID:11050177): beryllium presentation to CD4⁺ T cells "underlies disease-susceptibility HLA-DP alleles." Bill et al. (J Immunol 2005, PMID:16272364) pinned it to a single β-chain residue — "beryllium presentation… is dependent on a single amino acid residue of the MHC class II beta-chain" (Glu69 on DP, the homologous Glu71 on DR). The crystal structure of HLA-DP2 (PNAS 2010, PMID:20356827) showed the unique solvent-exposed acidic pocket.

Step 4 — CD4⁺ T-cell sensitization (mechanism). TCR recognition drives clonal expansion of beryllium-specific CD4⁺ memory/effector T cells (CL:0000545 T-helper 1 cell as the closest CL anchor). This expanded population is beryllium sensitization (BeS) — the state that precedes organ disease and is measured by the BeLPT. GO: T cell proliferation (GO:0042098). Sensitization is necessary but not sufficient for CBD.

Step 5 — Compartmentalized Th1 cytokine response (amplifier). On re-encounter in the lung, these cells polarize to Th1 and secrete IFN-γ, TNF, and IL-2; they accumulate as effector-memory Th1 cells in the bronchoalveolar space (Fontenot, JCI 2002 — target-organ localization of memory CD4⁺ T cells; Fontenot & Maier review, PMID:18317020). GO: type II interferon production (GO:0032609), tumor necrosis factor production (GO:0032640).

Step 6 — Macrophage recruitment & activation (amplifier). IFN-γ + TNF classically activate lung macrophages and recruit monocytes; TNF is the non-redundant organizer of the granulomatous response. (Conforms to granuloma_formation#Th1 and TNF-Driven Macrophage Recruitment and Activation.) GO: macrophage activation (GO:0042116).

Step 7 — Epithelioid/giant-cell transformation (central effector). Macrophages become epithelioid cells (CL:0002150) and fuse into multinucleated giant cells (CL:0000647) — the asteroid- and Schaumann-body-containing giant cells shared with sarcoid. GO: syncytium formation by cell-cell fusion (GO:0000768).

Step 8 — Non-caseating granuloma assembly (effector). Compact non-caseating granulomas — epithelioid/giant-cell core cuffed by CD4⁺ T cells — form along bronchovascular bundles, interlobular septa, and hilar nodes. No central caseous necrosis, which is what makes CBD histologically indistinguishable from sarcoidosis. (Conforms to granuloma_formation#Organized Granuloma Assembly.)

Step 9 — Progressive fibrosis (consequence). Because the stimulus can't be cleared, the response persists and, in a subset, drives interstitial fibrosis — fibroblast (CL:0000057) recruitment and collagen deposition (GO:0030199) → restrictive defect, impaired gas exchange, respiratory failure, cor pulmonale. (Conforms to granuloma_formation#Tissue Containment versus Destruction and Fibrosis.)

Regulatory arm worth noting: Regulatory T cells modulate granuloma intensity in the HLA-DP2 mouse model (PMID:24912188) — a mechanistic knob that partly explains why only some sensitized people progress.

Molecular profiling: BAL from CBD patients shows a compartmentalized Th1 signature (high IFN-γ, TNF, IL-2; oligoclonal TCR expansion, e.g. Vβ-restricted repertoires). No routine metabolomic/lipidomic/proteomic diagnostic signature is established; single-cell/BAL immunophenotyping is a research tool, not clinical.

7. Anatomical Structures Affected

Primary organ: lung (UBERON:0002048), specifically the pulmonary interstitium, alveoli/alveolar wall (UBERON:0002299 alveolus), distal airways, and bronchovascular bundles.
Regional lymphatics: hilar and mediastinal lymph nodes (UBERON:0002509 mesenteric-node is wrong — use thoracic/hilar lymph node terms; UBERON:0002509 not applicable; consider UBERON:0000029 lymph node with a mediastinal/hilar qualifier).
Body system: respiratory (with secondary cardiovascular involvement — pulmonary hypertension/cor pulmonale in advanced fibrosis).
Secondary/extrapulmonary: skin (granulomas, ulcers, contact dermatitis; UBERON:0002097), and rarely liver, spleen, myocardium, salivary glands, and other sites — systemic granulomatosis is uncommon but reported.
Tissue/cell level: epithelioid and multinucleated giant-cell macrophages, CD4⁺ Th1 lymphocytes, fibroblasts/myofibroblasts, alveolar macrophages, dendritic cells (CL terms as above).
Subcellular: antigen presentation is at the plasma-membrane MHC-II complex (GO:0042613 MHC class II protein complex); phagolysosomal handling of biopersistent particle in macrophages (GO:0005764 lysosome). No mitochondrial/ER-specific compartment is disease-defining.
Laterality: bilateral, diffuse, typically upper-and-mid-zone-predominant on imaging (like sarcoid), often with an upper-lobe fibrotic bias in advanced disease.

8. Temporal Development

Onset: adult; occupational. Latency is long and variable — months to >20–40 years after first exposure, with cases documented decades after exposure ceased.
Onset pattern: insidious/chronic. Acute beryllium disease (a distinct, high-dose chemical pneumonitis) is now essentially historical and mechanistically different — worth explicitly distinguishing from CBD in the entry if not already.
Stages: subclinical sensitization (BeS) → early granulomatous CBD (often asymptomatic, abnormal biopsy/BAL) → symptomatic granulomatous disease → fibrotic end-stage.
Progression rate: variable; BeS → CBD conversion runs roughly 6–8%/year in the Newman longitudinal cohort (PMID:15374840: 55 sensitized workers, mean follow-up 4.8 yr; ~31% developed CBD; the remaining ~69% stayed sensitized without disease), and a systematic review put progression at ~3.2–9.2%/year (PMID:22705916). Roughly half of sensitized individuals already have CBD at their first thorough evaluation.
Course: chronic, lifelong. Once fibrosis is established it is irreversible — corticosteroids don't reverse scar.
Remission: no spontaneous cure; treatment can stabilize/partially improve inflammation but disease "recrudesces with reduction of the corticosteroid dose," so relapse on tapering is characteristic.
Critical window: exposure cessation before fibrosis is the key intervention window; early identification via surveillance BeLPT is the point of maximum leverage.

9. Inheritance and Population

Epidemiology: CBD is uncommon and occupational. Cross-sectional prevalences among exposed worker cohorts: beryllium sensitization ~0.8–12% and CBD ~0.1–8%, depending on job/exposure intensity (machinists and ceramics workers highest; lower-exposure nuclear R&D sites ~2–3% sensitization). Population-level prevalence in the general (non-exposed) public is effectively negligible.
Inheritance pattern: Not Mendelian. It's a multifactorial/HLA-restricted susceptibility requiring environmental exposure. The heritable component is the HLA-DPB1 Glu69 (and minor DR) association — best modeled with relationship_type: SUSCEPTIBILITY, exactly as the entry does. Penetrance, expressivity, anticipation, mosaicism, founder effects, consanguinity, and carrier frequency in the classical genetics sense are N/A; the analogous concept is Glu69 allele frequency (~30–40% of the general population carries a Glu69 allele, vs ~80–97% of CBD patients — i.e., the allele is common but disease requires exposure + likely higher-affinity alleles/copy number).
Demographics: determined by occupation, not ethnicity — exposed workforces skew historically male, but that reflects the industries, not a biological sex effect. Geographic distribution tracks beryllium industry (US DOE nuclear-weapons complex, aerospace hubs, and beryllium-processing regions). No endemic geography in the infectious sense.

10. Diagnostics

The diagnostic dyad: documented beryllium exposure + demonstrated beryllium-specific immune sensitization + granulomatous pathology. Per the 2014 ATS official statement (PMID:25398119):

Beryllium Lymphocyte Proliferation Test (BeLPT) — the pivotal test. Patient blood (or BAL) lymphocytes are cultured with beryllium salts; proliferation indicates sensitization. Blood BeLPT single-test sensitivity ~61.5%, specificity ~90.8%; split-sample (duplicate) testing raises sensitivity to ~76% at some cost to specificity. BAL BeLPT is more sensitive for organ disease but can be falsely negative in smokers or the immunosuppressed. This is the test that distinguishes CBD from sarcoidosis (which is BeLPT-negative).
Bronchoscopy with transbronchial (or surgical) biopsy — to demonstrate non-caseating granulomas / mononuclear interstitial infiltrate; BAL typically shows a lymphocytosis with elevated CD4:CD8 ratio and a positive BAL BeLPT.
Imaging: chest CT/HRCT — upper/mid-zone nodular and reticular opacities, ground-glass, septal thickening, hilar/mediastinal adenopathy; can be normal early. RadLex terms apply.
Pulmonary function testing: restrictive (or obstructive/mixed) pattern with reduced DLCO; cardiopulmonary exercise testing detects gas-exchange abnormality earliest.
Genetic testing: HLA-DPB1 Glu69 typing is used in research and risk stratification but is not a stand-alone diagnostic — the allele is too common in the general population. It supports susceptibility, not diagnosis.
Differential diagnosis: sarcoidosis (the big one — clinically/histologically identical; the exposure history + BeLPT is what separates them), tuberculosis and other infectious granulomas (caseating), hypersensitivity pneumonitis, other pneumoconioses, granulomatosis with polyangiitis.
Screening: workplace medical-surveillance BeLPT programs (DOE, aerospace) for asymptomatic exposed workers — the standard secondary-prevention tool. LOINC codes exist for BeLPT-type lymphocyte proliferation results.

Omics/liquid-biopsy diagnostics: not clinically applicable; research only.

11. Outcome / Prognosis

Natural history: variable — some patients remain stable for years with no treatment; a subset progresses to fibrotic, disabling disease and respiratory failure.
Mortality: CBD can be fatal in advanced fibrotic disease (respiratory failure, cor pulmonale); it is a compensable occupational disease with documented excess mortality in exposed cohorts, but it is not uniformly lethal. No clean 5-/10-year survival figure applies across the disease spectrum — flag as "variable, stage-dependent."
Morbidity/disability: progressive exertional limitation, oxygen dependence, and lifelong immunosuppressive therapy burden drive substantial disability in progressors.
Complications: pulmonary fibrosis, pulmonary hypertension, cor pulmonale, respiratory failure, corticosteroid/immunosuppression side effects, and (rarely) systemic granulomatous involvement.
Recovery: inflammation is partially reversible with therapy; fibrosis is not. Exposure cessation improves the trajectory but doesn't erase established sensitization.
Prognostic factors: degree of fibrosis at diagnosis, DLCO/exercise gas exchange, extent of granulomatous burden, and continued vs ceased exposure. TNF-α and severity-associated cytokine polymorphisms are candidate molecular prognostics (unvalidated for clinical use).

12. Treatment (MAXO/NCIT terms noted)

The entry's treatment block is solid. Detail:

Beryllium exposure cessation — the essential first step for anyone sensitized or diseased; removes the antigen driving the T-cell response. (Not a drug — best captured as removal-from-exposure; NCIT:C49236 Therapeutic Procedure is a reasonable anchor; there isn't a crisp MAXO "exposure avoidance" term.)
Systemic corticosteroids (prednisone) — mainstay pharmacotherapy for symptomatic/progressive disease. Typically 3–6 months then reassess PFTs/gas exchange and taper to lowest effective dose. Suppresses granulomatous inflammation; cannot reverse fibrosis; disease recrudesces on taper, so therapy is often lifelong. (CHEBI:8382 prednisone; NCIT:C15986 Pharmacotherapy; MAXO could anchor to corticosteroid/anti-inflammatory therapy.)
Steroid-sparing immunosuppressants — methotrexate (e.g., 7.5 mg weekly with folic acid) and azathioprine, adapted from sarcoidosis management, to reduce steroid burden (Current Treatment of CBD review, PMC2774897). (CHEBI:44185 methotrexate.)
TNF-α inhibitors (infliximab) — used in refractory granulomatous disease; targets the non-redundant TNF amplifier. Maier et al. (PMID:22974830) showed infliximab "modulates an antigen-specific immune response in chronic beryllium disease." Benefit is less established than in sarcoidosis and infection risk (reactivation TB, etc.) is a real concern. The entry correctly links this to the Th1 and TNF-Driven Macrophage Recruitment and Activation node with INHIBITS. (NCIT:C20401 Monoclonal Antibody / better: infliximab-specific term if available.)
Supportive care — supplemental oxygen (MAXO:0000950 supportive care), pulmonary rehabilitation, vaccination, comorbidity management.
Lung transplantation — for end-stage fibrotic CBD refractory to medical therapy (MAXO:0010039 organ transplantation).

Pharmacogenomics: none clinically actionable specific to CBD. Experimental/tolerizing approaches — antigen-specific tolerance strategies (e.g., recombinant HLA-DP2 tolerizing beryllium-specific pathogenic T cells, PMID region ~16951350 / Falta group) are preclinical and mechanistically interesting but not clinical. No approved gene/cell/RNA therapy.

13. Prevention

Primary prevention: exposure control is everything — engineering controls (enclosure, local exhaust, wet processing), the OSHA 0.2 µg/m³ PEL (2017 final rule, PMID:28071878), respiratory protection, dermal protection, and hygiene to prevent take-home exposure. This is the only truly effective lever.
Secondary prevention: medical-surveillance BeLPT screening of exposed workers to catch sensitization early and remove sensitized individuals from further exposure before organ disease develops.
Tertiary prevention: in diagnosed CBD, exposure removal + monitoring to slow progression and prevent fibrotic complications.
Genetic screening: HLA-DPB1 Glu69 pre-employment screening is ethically contentious and not standard — it risks genetic discrimination, the allele is common, and it has poor positive predictive value. Worth flagging as a live policy debate rather than a recommendation.
Immunization / public-health / vector control: N/A (non-infectious).

14. Other Species / Natural Disease

Natural disease: No meaningful naturally-occurring CBD in companion animals or wildlife — beryllium exposure is essentially an anthropogenic occupational phenomenon. OMIA has no CBD entry.
Comparative biology: the disease is defined by human HLA-DP presentation, which doesn't have a direct wild-animal counterpart. Beryllium toxicity can be induced experimentally in animals, but the HLA-restricted immune disease is human-specific.
Zoonosis / cross-species transmission: N/A.

15. Model Organisms

Flagship model — HLA-DP2 transgenic mouse (Mucosal Immunology 2015, PMID:26129650): intratracheal beryllium oxide induces lung mononuclear infiltrates and a CD4-dependent, beryllium-specific adaptive immune response in lung and spleen, recapitulating the major features of human CBD; beryllium-responsive CD4⁺ T cells were largely TCR Vβ6⁺, and the group defined HLA-DP2-binding mimotopes recognized by beryllium-specific T cells even without beryllium present. This is the model that ties the human Glu69 genetics to an in-vivo granulomatous phenotype — evidence_source MODEL_ORGANISM.
Regulatory-T-cell modulation in the same HLA-DP2 model (PMID:24912188) — Tregs tune granuloma intensity, a mechanistic model for variable progression.
In vitro / cellular models: patient BAL and blood lymphocyte cultures (the BeLPT itself is a functional cellular assay), beryllium-specific CD4⁺ T-cell clones, and recombinant soluble HLA-DP2 for structural/binding work (PNAS 2010, Cell 2014) — evidence_source IN_VITRO.
Model limitations: mouse models require the human HLA-DP2 transgene to work at all (mouse MHC-II doesn't present beryllium the human way), and murine granulomas don't fully reproduce human fibrotic end-stage disease — a legitimate HUMAN_MODEL_MISMATCH candidate for a discussion block if you want to flag translational caveats. Resources: MGI for the transgenic lines.

Key citations (verify snippets before committing, per the DR/anti-hallucination SOP)

PMID	What it anchors	Evidence source
8105536	Richeldi, Science 1993 — HLA-DPB1 Glu69 as genetic marker (97% vs 30%)	HUMAN_CLINICAL
11050177	Amicosante/Fontenot, PNAS 2000 — Be presentation to CD4⁺ underlies DP susceptibility	IN_VITRO
16272364	Bill, J Immunol 2005 — single β-chain residue (Glu69/Glu71) dependence	IN_VITRO
20356827	HLA-DP2 crystal structure, PNAS 2010 — the acidic solvent-exposed pocket	IN_VITRO
24995984	Clayton, Cell 2014 — buried Be²⁺ neoantigen; allergy↔autoimmunity bridge	IN_VITRO
18317020	Fontenot & Maier — Immunology of CBD review	(review)
25398119	ATS 2014 official statement — diagnosis/management, BeLPT performance	HUMAN_CLINICAL
15374840	Newman, AJRCCM 2005 — BeS→CBD progression ~6–8%/yr	HUMAN_CLINICAL
22705916	Systematic review — progression 3.2–9.2%/yr	HUMAN_CLINICAL
17474035	Exposure-response, beryllium machining plant	HUMAN_CLINICAL
28071878	OSHA 2017 final rule — 0.2 µg/m³ PEL	(regulatory)
22974830	Maier — infliximab modulates antigen-specific response in CBD	HUMAN_CLINICAL
26129650	HLA-DP2 transgenic mouse model, Mucosal Immunol 2015	MODEL_ORGANISM
24912188	Tregs modulate granulomatous inflammation, HLA-DP2 model	MODEL_ORGANISM

Sources consulted: Richeldi Science 1993, Amicosante PNAS 2000, Bill J Immunol 2005, Clayton Cell 2014, ATS 2014 statement, Newman AJRCCM 2005, systematic review PMID 22705916, HLA-DP2 mouse model, Treg mouse model, infliximab in CBD, OSHA final rule, Current Treatment of CBD, E69 genotype-exposure.

Bottom line for the curation entry: the existing Chronic_Beryllium_Disease.yaml is already in genuinely good shape — the 9-node pathophysiology chain conforms correctly to granuloma_formation, the HLA-DPB1 susceptibility modeling is right, and the treatment/target_mechanisms links are sound. The main gaps I'd consider adding, if you want to push completeness: (1) a BeLPT diagnostic representation and the CD4:CD8 BAL lymphocytosis, (2) explicit skin granuloma / beryllium ulcer and pulmonary hypertension/cor pulmonale phenotypes, (3) a prevalence block (BeS 0.8–12%, CBD 0.1–8% in exposed cohorts; MEASURE_TYPE POINT_PREVALENCE, condition on exposed population in notes), (4) an HLA-DP2 transgenic mouse model/animal block with evidence_source: MODEL_ORGANISM, and (5) maybe a HUMAN_MODEL_MISMATCH discussion noting the transgene requirement and incomplete fibrosis in mice. Two small things to double-check mechanically: the HGNC id for HLA-DPB1 (hgnc:4940) and the hilar/mediastinal lymph node UBERON term if you add anatomy — those are the kind of easy-to-transpose identifiers the term validator will catch.

Want me to fold any of those additions into the YAML and run the validation stack, or keep this as a research reference for now?

Chronic Beryllium Disease

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Chronic Beryllium Disease — Comprehensive Research Report

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic / Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome / Prognosis

12. Treatment (MAXO/NCIT terms noted)

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Key citations (verify snippets before committing, per the DR/anti-hallucination SOP)