Cadmium Poisoning: Comprehensive Disease Characteristics Research Report

1. Disease Information

Overview. Cadmium (Cd) poisoning encompasses the acute and chronic toxic effects of exposure to cadmium and its compounds, a non-essential, non-biodegradable heavy metal with no known physiological function in humans. Cadmium is released into the environment from mining, smelting, electroplating, battery (Ni-Cd) manufacture, pigment/plastic stabilizer production, and fossil-fuel combustion, and enters the food chain because certain crops (notably rice, leafy vegetables, shellfish, and organ meats) readily accumulate it from contaminated soil and water. The two principal exposure routes are inhalation (occupational fume/dust exposure, cigarette smoking) and ingestion (contaminated food and water). Cadmium has an exceptionally long biological half-life in humans (10–30 years), accumulating primarily in the renal cortex and liver, which is why chronic low-dose environmental exposure — rather than single high-dose events — dominates the global disease burden (StatPearls: Cadmium Toxicity, NBK536966; ATSDR Toxicological Profile for Cadmium).

Clinically, cadmium poisoning presents in two distinct syndromes: - Acute (high-dose) poisoning — typically occupational fume inhalation (welding/brazing cadmium-containing alloys, smelting) causing chemical pneumonitis and pulmonary edema, or ingestion causing severe gastroenteritis. - Chronic (low-dose) poisoning — the dominant global pattern, causing irreversible proximal tubular nephropathy, osteomalacia/osteoporosis (classically Itai-itai disease in Japan), pulmonary emphysema, and is classified by IARC as a Group 1 human carcinogen (lung cancer, with evidence for kidney, prostate, breast, and bladder).

Key identifiers: - ICD-10-CM: T56.3 (Toxic effect of cadmium and its compounds); T56.3X1A (accidental, initial encounter); Y96 codes for occupational exposure context - ICD-11: NE61 (Toxic effect of cadmium or its compounds) — falls under Chapter 22, "Injury, poisoning or certain other consequences of external causes" - MeSH: D002104 (Cadmium Poisoning); D002103 (Cadmium) - MONDO ID: A specific, verified MONDO CURIE for "cadmium poisoning" was not confirmed through direct ontology lookup during this research pass; MONDO's disease hierarchy contains toxic/chemically-induced disease branches (e.g., under "poisoning by heavy metal" concepts) that a curator should resolve via runoak against the local MONDO adapter before binding a disease_term. Itai-itai disease itself may warrant a distinct MONDO entity as a specific historical cadmium-poisoning cohort/syndrome — this should be confirmed rather than assumed. - OMIM: Not applicable — cadmium poisoning is an acquired/environmental toxic disorder, not a monogenic Mendelian condition (though genetic polymorphisms modulate susceptibility; see Etiology). - Orphanet: Not indexed as a distinct rare disease entity (cadmium poisoning is common-exposure, not rare-disease scoped), though Itai-itai disease historically appears in some toxicology/rare-disease compendia.

Synonyms/alternative names: Cadmium intoxication; chronic cadmium nephropathy; cadmium fume fever; Itai-itai disease (痛い痛い病, "ouch-ouch disease" — the chronic cadmium-induced osteomalacia/osteoporosis syndrome first described in the Jinzu River basin, Toyama Prefecture, Japan, in the 1950s–60s).

Evidence base composition: The literature is a mixture of (1) aggregated population-level exposure-outcome studies (NHANES, EFSA dietary surveys, occupational cohorts), (2) individual clinical case reports/series (acute fume poisoning, Itai-itai patients), and (3) mechanistic in vitro/animal studies. Unlike a monogenic disease entry, cadmium poisoning evidence is dominated by epidemiological dose-response relationships rather than individual EHR-derived case phenotyping.

2. Etiology

Disease Causal Factor

Cadmium poisoning is environmental/toxicological, not genetic or infectious, in its primary causation: it is caused directly by absorption of cadmium (Cd²⁺) from an external source, exceeding the body's detoxification (metallothionein-binding) and excretory capacity. There is no infectious agent and no single causal gene; genetic factors instead act as modifiers of susceptibility and toxicokinetics (absorption efficiency, renal handling, antioxidant capacity), not as sufficient or necessary causes.

Risk Factors

Environmental/occupational risk factors: - Occupational exposure: smelting, battery manufacturing (Ni-Cd), electroplating, pigment/plastics production, welding/brazing of cadmium alloys, phosphate fertilizer production, e-waste recycling. - Cigarette smoking — the single largest environmental determinant of cadmium body burden in non-occupationally-exposed populations. Tobacco leaves hyperaccumulate cadmium from soil; a smoker inhales roughly 1–2 µg of cadmium per cigarette, absorbing ~10% via the lung (much higher bioavailability than the ~5% GI absorption from food). A geometric mean blood cadmium of ~1.58 µg/L has been reported in heavy smokers versus a U.S. population mean of ~0.38 µg/L (ATSDR Toxicological Profile for Cadmium). - Diet: rice, shellfish, offal (kidney, liver), cocoa/chocolate, and leafy vegetables grown on contaminated or naturally cadmium-rich (often phosphate-fertilized) soils are the dominant dietary sources. EFSA's Panel on Contaminants in the Food Chain set the Tolerable Weekly Intake (TWI) at 2.5 µg/kg body weight/week, and notes that dietary exposure in some EU subgroups (children, vegetarians, residents of contaminated areas) approaches or exceeds this TWI, with cereals, vegetables, nuts/pulses, starchy roots, and meat products the largest dietary contributors. - Contaminated drinking water and soil near mining/smelting sites — the etiologic exposure route for Itai-itai disease (irrigation of rice paddies with mine-tailings-contaminated water from the Kamioka mine on the Jinzu River). - Iron deficiency markedly increases intestinal cadmium absorption, because cadmium is taken up via iron-transport pathways (DMT1) when body iron stores are low — a key reason why women (who have lower iron stores, especially premenopausally) show higher gastrointestinal cadmium absorption efficiency (up to ~2×) than men for a matched dietary dose. - Age: cumulative, lifelong bioaccumulation means body burden and toxic risk rise with age; children and the elderly show heightened vulnerability windows. - Low dietary calcium and zinc status enhance cadmium absorption and toxicity by competing for shared transport pathways.

Genetic risk factors (modifiers of toxicokinetics, not causal in the Mendelian sense): - Metal transporter gene variants governing intestinal/renal cadmium uptake: DMT1/SLC11A2 (divalent metal transporter 1) — the intronic IVS4+44C/A polymorphism's CA genotype has been associated with elevated urinary cadmium, suggesting susceptibility to prolonged accumulation; SLC39A8 (ZIP8) and SLC39A14 (ZIP14) — zinc/bicarbonate symporters expressed in the proximal tubule S3 segment that mediate cadmium uptake from the apical membrane; siRNA knockdown of ZIP8, ZIP14, or DMT1 in kidney proximal tubule cells significantly reduces cadmium uptake, and no single transporter dominates — TRPV6 and TRPM7 calcium channels also contribute (Fujishiro et al., Metallomics 2012, PMID:22437713 region of literature). - Metallothionein (MT1A/MT2A) promoter polymorphisms affecting the individual's capacity to sequester cadmium as the relatively inert Cd-MT complex, thereby modulating the balance between "safe storage" and free-ion toxicity. - Glutathione S-transferase (GSTM1/GSTT1) null genotypes and antioxidant enzyme polymorphisms (SOD, catalase, GPX1) — reduce detoxification of cadmium-induced reactive oxygen species (ROS), increasing individual susceptibility to oxidative damage. - VDR (vitamin D receptor) gene polymorphisms — plausibly modify individual susceptibility to cadmium-induced bone loss given cadmium's interference with vitamin D activation, though human data are more limited than for the transporter genes above.

Protective Factors

Adequate iron, zinc, and calcium nutritional status — competitively reduces intestinal cadmium absorption via shared transporters (DMT1, calcium channels), the best-established dietary protective mechanism.
Selenium — forms cadmium-selenide complexes that may reduce cadmium bioavailability/toxicity in some experimental models, though human protective evidence is less robust.
High dietary fiber and certain plant polyphenols — modestly reduce GI cadmium bioavailability in some studies.
Metallothionein induction (e.g., by prior low-dose zinc exposure) — upregulates the endogenous Cd-sequestering protein, a preconditioning-type protective mechanism demonstrated mainly in animal models.
No specific protective genetic variant is well-replicated in human GWAS to date; this remains an area with limited direct evidence (flag as KNOWLEDGE_GAP if curated in dismech).

Gene-Environment Interactions

The clearest documented gene-environment interaction is iron status × DMT1/transporter genotype × dietary cadmium exposure: individuals who are iron-deficient (environmental/nutritional factor) upregulate DMT1 expression at the intestinal brush border, which increases cadmium co-absorption; a DMT1 polymorphism further modulates the magnitude of this effect, meaning genetically susceptible, iron-deficient individuals absorb proportionally more cadmium from an identical dietary dose than iron-replete individuals with a lower-risk genotype. Similarly, GST-null genotype × oxidative-stress-inducing co-exposures (smoking, other pro-oxidant xenobiotics) likely potentiates cadmium's oxidative renal and vascular injury, though this remains an area needing more targeted human interaction studies (CTD, PheGenI databases catalog these gene-chemical relationships).

3. Phenotypes

A. Acute high-dose exposure phenotypes

Table (click to expand)

Phenotype	Type	HPO suggestion	Onset/Course	Notes
Chemical pneumonitis	Clinical sign	HP:0410048 (Pneumonitis) / consider HP:0002090 (Pneumonia)	Acute, 8h–7 days post-exposure, progressive	Follows fume inhalation; can be fatal (PMID:5928153 — 5 cases, 1 death from renal necrosis)
Pulmonary edema	Clinical sign	HP:0100598 (Pulmonary edema)	Acute, days	Leading cause of acute-exposure mortality
Metal fume fever (flu-like syndrome)	Symptom	HP:0001945 (Fever) + HP:0025406 (Chills)	Acute, self-limited if exposure ceases early	Initial, often reversible phase
Acute tubular necrosis	Lab/clinical	HP:0000083 (Renal insufficiency)	Acute, can be irreversible	Cause of fatality in severe cases
Severe gastroenteritis (ingestion route)	Symptom	HP:0002018 (Nausea)/HP:0002014 (Diarrhea)/HP:0030157 (Abdominal pain)	Acute, hours	From ingestion of highly contaminated food/beverage

B. Chronic low-dose exposure phenotypes

Renal: - Proximal tubular dysfunction (the hallmark chronic lesion) — HP:0000121 (Nephropathy) / consider a Fanconi-syndrome-pattern term; presents as low-molecular-weight proteinuria (β2-microglobulinuria, retinol-binding-protein-uria), glucosuria, aminoaciduria, and phosphaturia. Progressive, generally irreversible even after exposure cessation; frequency approaches 100% in heavily exposed occupational/Itai-itai cohorts at sufficiently high cumulative dose. - Decreased glomerular filtration rate / chronic kidney disease — HP:0012622 (Chronic kidney disease); later-stage, progressive complication of sustained tubular injury. - Nephrolithiasis — HP:0000787 (Nephrolithiasis); reported at elevated frequency in cadmium-exposed cohorts secondary to hypercalciuria from tubular calcium leak.

Skeletal (Itai-itai disease spectrum): - Osteomalacia — HP:0002753 (Osteomalacia); severe bone pain, multiple pseudofractures (Looser zones), and characteristic waddling "duck gait." Onset typically in postmenopausal, multiparous women with chronic dietary cadmium exposure and pre-existing calcium/vitamin D insufficiency; severe, chronic, progressive. - Osteoporosis — HP:0000939 (Osteoporosis); often coexists with osteomalacia in the same patients. - Bone pain — HP:0002653 (Skeletal pain) — the eponymous "itai-itai" (ouch-ouch) symptom. - Pathological/spontaneous fractures — HP:0002816 (Pathologic fracture); can occur with minimal trauma or even coughing in severe cases. - Decreased bone mineral density — measurable, dose-related, documented even in general (non-Itai-itai) cadmium-exposed populations at moderate exposure.

Pulmonary (chronic, mainly occupational/smoking-related): - Emphysema/chronic obstructive pulmonary disease — HP:0002088 (Abnormal pulmonary interstitial morphology)/consider HP:0006510 (Chronic pulmonary obstruction); progressive, associated with cumulative fume exposure, and now recognized as an important, underappreciated component of cadmium's contribution to tobacco-related lung disease. - Restrictive/decreased pulmonary function — reduced FEV1/FVC documented in occupational cohorts. - Anosmia — HP:0000458 (Abnormal nasal morphology)/consider olfactory dysfunction terms; reported in cadmium-exposed workers from nasal mucosal damage.

Cardiovascular: - Hypertension — HP:0000822 (Hypertension); a 2024 dose-response meta-analysis (26 studies, 2005–2023) found a significant positive correlation between cadmium exposure and risk of heart failure, stroke, and coronary heart disease (PMID:38295933); a 2023 AHA scientific statement similarly implicates chronic low-level cadmium (with lead and arsenic) in elevated cardiovascular disease risk. - Increased cardiovascular mortality — dose-dependent association across multiple cohort studies.

Reproductive/endocrine: - Hormonal disruption (estrogen-mimetic effects) — cadmium binds and activates estrogen receptor alpha (ERα), forming an ERα–c-Jun transcriptional complex that drives proliferative gene programs; termed a "metalloestrogen" (PMID:20219890). - Reduced fertility / adverse pregnancy outcomes — associated with cadmium exposure in multiple epidemiological studies (reduced birth weight, altered placental function). - Testicular damage — HP:0000034 (Abnormal testis morphology); classic acute high-dose animal toxicology finding, with more limited direct human occupational evidence.

Neurological/psychiatric: - Cognitive impairment / neurotoxicity — cadmium accumulates in brain over prolonged low-dose exposure; the nervous system is described as particularly vulnerable to chronic low-dose cadmium (2023 review, DOI:10.3390/ijms242316558). - Depression — recent NHANES cross-sectional analyses found each incremental unit of blood cadmium associated with a ~33% rise in depression prevalence. - Chronic pain — elevated blood cadmium is a documented risk factor for chronic pain in NHANES 1999–2004 data (PMC11148299). - Peripheral neuropathy — reported in some heavily exposed occupational cohorts.

Oncologic (chronic, latency of years-decades): - Lung cancer — HP:0100526 (Neoplasm of the lung); IARC Group 1 carcinogen designation is substantially based on this association, strongest in occupational cohorts. - Bladder, prostate, pancreatic, breast, kidney, endometrial cancers — variably supported associations; a 2024 systematic review of biological-sample cadmium and cancer risk (9 meta-analyses + 57 original articles) concluded consistent evidence for a causal role in pancreas, lung, and bladder carcinogenesis, and positive correlation between biological cadmium and total cancer risk/mortality. Prostate cancer evidence is weaker/mixed (2024 updated meta-analysis: pooled effect size 1.11, 95% CI 0.85–1.45 — not statistically significant).

Quality of life impact: Chronic phenotypes — especially Itai-itai-type osteomalacia with severe bone pain and pathologic fractures, and progressive CKD — carry substantial disability burden (mobility loss, chronic pain, dialysis dependence in advanced nephropathy). Dedicated disease-specific QOL instrument data for cadmium poisoning specifically are sparse in the literature; QOL burden is typically inferred from generic CKD/osteoporosis QOL literature (EQ-5D, SF-36) rather than cadmium-specific cohorts.

4. Genetic/Molecular Information

Cadmium poisoning is fundamentally an acquired toxic disorder, so there is no single causal gene (no OMIM Mendelian entry). The relevant genetics concern (a) toxicokinetic modifier genes and (b) the molecular targets cadmium acts upon.

Toxicokinetic/susceptibility genes (modifier, not causal): - SLC11A2 (DMT1) — HGNC:10908; intestinal/renal divalent metal transporter; IVS4+44C/A intronic polymorphism CA genotype associated with elevated urinary cadmium in exposed populations. - SLC39A8 (ZIP8) — HGNC:20862; zinc/bicarbonate symporter; the A391T variant reduces cellular uptake of zinc, cadmium, and iron via reduced plasma membrane expression, and is separately associated with hypotension and insulin resistance (PMC9240775). - SLC39A14 (ZIP14) — HGNC:20858; kidney proximal tubule S3-segment metal/bicarbonate symporter mediating cadmium and manganese uptake. - MT1A, MT2A (metallothioneins) — HGNC:7393, HGNC:7407; low-molecular-weight, cysteine-rich metal-binding proteins that sequester cadmium; promoter polymorphisms modulate individual sequestration capacity. - GSTM1, GSTT1 (null genotypes) — reduced glutathione-conjugation-based detoxification capacity. - VDR — vitamin D receptor; plausible modifier of bone susceptibility given cadmium's vitamin D interference (limited direct human replication).

Molecular targets / mechanisms of cadmium action (not "pathogenic variants" in the classical sense, but the molecular lesions cadmium itself produces): - Calcium channel mimicry — cadmium enters cells via voltage-gated calcium channels, TRPV6, and TRPM7, in addition to the ZIP8/ZIP14/DMT1 metal-transporter routes, disrupting intracellular Ca²⁺ signaling. - Zinc-finger protein displacement — cadmium displaces zinc from zinc-finger DNA-binding domains (transcription factors, DNA-repair enzymes such as XPA, PARP), impairing DNA repair fidelity and contributing to genotoxicity/carcinogenicity. - Enzyme inhibition — direct inhibition of DNA repair enzymes and antioxidant enzymes (catalase, superoxide dismutase) by binding to sulfhydryl (-SH) groups. - Epigenetic dysregulation — cadmium alters DNA methylation patterns and histone modifications genome-wide; implicated as a contributing carcinogenic mechanism (2024 Toxics review, PMID:38922068).

Variant classification / allele frequency databases: Because there is no single causal locus, ClinVar/gnomAD-style pathogenic-variant curation does not apply in the standard Mendelian sense. gnomAD is, however, relevant as a source of population allele frequencies for the modifier polymorphisms above (DMT1, ZIP8, GST-null genotypes) if fine-grained susceptibility modeling is desired.

Chromosomal abnormalities: Not a feature of cadmium poisoning etiology; cadmium is, however, itself clastogenic/aneugenic in vitro and in occupationally exposed cohorts (chromosomal aberration and micronucleus frequency increases reported), which is a downstream genotoxic effect of exposure rather than a causal chromosomal lesion.

5. Environmental Information

Environmental factors (primary etiologic category — see also Etiology above): - Occupational cadmium fume/dust (smelting, welding, battery manufacture, electroplating, pigment production) — ECTO-type exposure term suggestion: "occupational exposure to cadmium" / "exposure to cadmium fumes." - Contaminated soil/water from mining and smelting — the documented cause of Itai-itai disease via irrigation-water and rice-paddy contamination downstream of the Kamioka zinc mine. - Ambient air pollution near industrial/smelting sites and from fossil fuel/waste combustion. - Contaminated food — rice (especially in parts of Asia grown on cadmium-enriched soils), leafy vegetables, shellfish/crustaceans (which bioaccumulate cadmium strongly), organ meats (kidney, liver), cocoa/chocolate products, and phosphate-fertilized crops. EFSA notes cereals, vegetables, nuts/pulses, starchy roots, and meat products are collectively the largest dietary contributors in EU populations. - E-waste recycling (informal/artisanal recycling of Ni-Cd batteries and electronics) — an emerging exposure source, especially in low- and middle-income countries.

Lifestyle factors: - Cigarette smoking — the dominant modifiable lifestyle risk factor in non-occupational populations; smokers show roughly double the blood cadmium level of non-smokers. - Second-hand smoke exposure. - Dietary pattern — high consumption of cadmium-accumulating foods, low intake of protective minerals (iron, zinc, calcium). - Alcohol use — some studies suggest interactive hepatotoxic/nephrotoxic effects with chronic cadmium exposure, though evidence is less robust than for smoking.

Infectious agents: Not applicable — cadmium poisoning has no infectious etiology.

6. Mechanism / Pathophysiology

Overview of the causal chain

Cadmium exposure (inhalation/ingestion) → systemic absorption bound to albumin/metallothionein → hepatic and, predominantly, renal cortical accumulation → intracellular free Cd²⁺ release → oxidative stress, Ca²⁺ signaling disruption, zinc-finger protein displacement, mitochondrial dysfunction → proximal tubular epithelial cell injury/death → chronic tubular dysfunction (Fanconi-like proximal tubulopathy) → impaired renal 1α-hydroxylation of vitamin D and phosphate wasting → secondary/associated osteomalacia and osteoporosis, with parallel direct osteotoxic effects on osteoblasts → systemic complications (CVD, carcinogenesis, endocrine disruption) via oxidative stress and ERα mimicry in extra-renal tissues.

Molecular pathways

Oxidative stress is described as "the pivotal mechanism" underlying cadmium toxicity across virtually all target organs: cadmium disrupts the pro-oxidant/antioxidant balance (depleting glutathione, inhibiting catalase and superoxide dismutase via -SH group binding), generating reactive oxygen species (ROS) that damage lipids, proteins, and DNA, and trigger apoptosis (PMID:38922068; PMID:39771090; PMID:24117228).
Ca²⁺ signaling disruption — cadmium is a molecular mimic of calcium, entering cells through voltage-gated calcium channels, TRPV6, and TRPM7, and dysregulating downstream Ca²⁺-dependent signaling cascades. GO term suggestion: GO:0007204 (positive regulation of cytosolic calcium ion concentration) — perturbed.
Epigenetic modification — genome-wide DNA methylation changes and histone modifications are increasingly recognized as contributing to both chronic tissue injury and carcinogenesis.
DNA repair interference — cadmium inhibits nucleotide excision repair and mismatch repair enzymes (many of which are zinc-finger proteins), a key mechanism underlying its genotoxic/carcinogenic potential despite cadmium itself being a weak direct mutagen.

Cellular processes

Apoptosis and necrosis of proximal tubular epithelial cells (renal), alveolar type I cells with type II cell hyperplasia (acute pulmonary injury), osteoblasts (via a documented ROS → SIRT1/PGC-1α/p53 signaling axis in a 2023 rat model of cadmium-induced osteoporosis), and germ cells (testicular toxicity in animal models).
Chronic inflammation — acute inhalation triggers neutrophilic pulmonary inflammation (demonstrated in rat inhalation models); chronic low-dose exposure is associated with systemic low-grade inflammatory activation contributing to cardiovascular risk.
Impaired autophagy/mitochondrial dysfunction — increasingly implicated in cadmium-induced proximal tubular cell injury.

Protein/enzyme dysfunction

Cadmium inhibits proteins via thiol-group binding (broad mechanism affecting many enzymes, including antioxidant enzymes) and displaces zinc from zinc-finger transcription factors and DNA-repair proteins, producing loss-of-function-like effects without altering the underlying gene sequence.
Renal proximal tubular uptake occurs via megalin:cubilin receptor-mediated endocytosis at the apical brush border. The classical model held that Cd²⁺–metallothionein-1 complexes (filtered freely at the glomerulus given the ~7 kDa size of MT-1) are endocytosed via megalin/cubilin and then released intracellularly in the endosomal/lysosomal compartment, producing free Cd²⁺-driven toxicity. A revised model (2019, PMC6566203) argues that cadmium bound to β2-microglobulin, albumin, and lipocalin-2, rather than metallothionein specifically, is the primary driver of megalin:cubilin-dependent proximal tubular toxicity — an active area of mechanistic revision.

Tissue damage mechanisms

Renal: diffuse proximal tubular atrophy, basement membrane thickening, and mild interstitial fibrosis in the renal cortex (autopsy-confirmed in Itai-itai patients, PMID:10997741).
Bone: osteomalacia in cadmium poisoning is driven substantially indirectly, via renal tubular dysfunction → impaired proximal-tubule 1α-hydroxylase activity → reduced active vitamin D (1,25-dihydroxyvitamin D) → impaired intestinal calcium absorption and mineralization defect, compounded by direct renal phosphate wasting. Direct toxic effects of cadmium on osteoblasts (impairing calcification at the ossification front) are a proposed, evidence-supported second mechanistic arm; the field notes "the exact mechanism underlying this bone disease remains unresolved," making this a genuine, citable knowledge gap suitable for a KNOWLEDGE_GAP discussion if curated (PMID:23095355; PMID:1303956).
Lung (acute): alveolar type I cell necrosis with type II cell hyperplasia, interstitial thickening, hemorrhage, edema, and macrophage inhibition following high-dose fume inhalation.

Biochemical abnormalities

Elevated urinary β2-microglobulin, N-acetyl-β-D-glucosaminidase (NAG), and retinol-binding protein — biomarkers of proximal tubular injury (see Diagnostics).
Hypophosphatemia, glucosuria, generalized aminoaciduria — Fanconi-syndrome-like tubular leak pattern.
Reduced serum 1,25-dihydroxyvitamin D.

Molecular profiling

Transcriptomics: altered gene expression signatures in kidney and bone tissue following cadmium exposure, documented in animal models (GEO-deposited datasets exist for cadmium nephrotoxicity/osteotoxicity studies).
Epigenomics: genome-wide DNA methylation alteration is an active 2023–2024 research area (see Mechanisms/Pathways review, PMID:38922068).
microRNA dysregulation: cadmium nephrotoxicity is associated with altered microRNA expression in the rat renal cortex (PMC5874789), a mechanistic link between cadmium exposure and post-transcriptional dysregulation of injury-response genes.

Suggested ontology terms for pathophysiology nodes

GO (biological process): GO:0006979 (response to oxidative stress); GO:0034605 (cellular response to heat) [analogous stress-response framework]; GO:0006974 (DNA damage response); GO:0006914 (autophagy); GO:0097190 (apoptotic signaling pathway); GO:0030282 (bone mineralization) — decreased.
GO (molecular function): GO:0046872 (metal ion binding); GO:0005385 (zinc ion transmembrane transporter activity) — for ZIP8/ZIP14.
GO (cellular component): GO:0005739 (mitochondrion); GO:0005634 (nucleus) — for zinc-finger displacement effects; GO:0005886 (plasma membrane) — transporter localization.
CL (cell type): CL:1001106 (kidney proximal straight tubule epithelial cell) / CL:1000838 (kidney proximal convoluted tubule epithelial cell); CL:0000062 (osteoblast); CL:0001056 (alveolar type I cell) and alveolar type II cell; CL:0000359 (vascular endothelial cell) for cardiovascular effects.

7. Anatomical Structures Affected

Organ level: - Primary target organs: Kidney (proximal tubule — the dose-limiting critical organ for chronic exposure) and Lung (acute high-dose route of entry and target organ for inhalational disease). - Secondary/complication organs: Bone (osteomalacia/osteoporosis, secondary to renal dysfunction plus direct effects), Liver (accumulation site, hepatic dysfunction in severe chronic poisoning — documented pathologically in Itai-itai autopsies with metallothionein expression), Cardiovascular system (hypertension, atherosclerosis-associated events), Testis/reproductive organs, Peripheral/central nervous system, Breast/endocrine tissue (ERα-mediated effects). - Body systems involved: Renal/urinary, Respiratory, Skeletal, Cardiovascular, Endocrine/reproductive, Nervous, and (as a chronic carcinogenic consequence) multiple organ systems via oncogenesis.

Tissue and cell level: - Renal proximal tubular epithelium (S1–S3 segments) — primary cellular target (CL:1000838 / CL:1001106). - Osteoblasts and osteoclasts — bone remodeling cells directly and indirectly affected. - Alveolar epithelium (Type I and Type II pneumocytes) — acute inhalational injury. - Vascular endothelium — implicated in cadmium-associated hypertension/atherosclerosis. - Hepatocytes — accumulation and metallothionein-expression site.

Subcellular level (GO Cellular Component): - Mitochondria — site of oxidative stress generation and dysfunction. - Lysosomes/endosomes — site of Cd-metallothionein/Cd-protein complex release following megalin:cubilin-mediated endocytosis. - Nucleus — site of zinc-finger transcription factor and DNA-repair-enzyme interference. - Plasma membrane — site of transporter-mediated (ZIP8/ZIP14/DMT1/TRPV6/TRPM7) cellular entry.

Localization (UBERON terms): - UBERON:0004134 (kidney proximal tubule) or UBERON:0001225 (proximal tubule) - UBERON:0002048 (lung) - UBERON:0001474 (bone element) / UBERON:0002481 (bone tissue) - UBERON:0002107 (liver) - UBERON:0001981 (blood vessel) — cardiovascular involvement

Lateralization: Not applicable — cadmium toxicity is systemic/bilateral in its organ effects (bilateral renal tubulopathy, bilateral/diffuse osteomalacia).

8. Temporal Development

Onset: - Acute poisoning: onset within hours (inhalation — flu-like/metal-fume-fever symptoms) to days (progression to chemical pneumonitis/pulmonary edema, 8 hours–7 days post-exposure in severe cases); ingestion-related acute gastroenteritis has onset within hours. - Chronic poisoning: insidious onset over years to decades of cumulative low-dose exposure; there is no defined "typical age of onset" in the congenital-disease sense — onset is exposure-duration- and cumulative-dose-dependent. Itai-itai disease classically presented in adults, especially multiparous, postmenopausal women in their 40s–60s in the endemic Jinzu River basin cohort, reflecting decades of chronic dietary exposure compounded by pregnancy/lactation-related calcium demands and postmenopausal bone loss.

Progression: - Renal: proximal tubular dysfunction is typically slowly progressive and, once an injury threshold is crossed, often irreversible even after exposure cessation — a critical prognostic feature distinguishing cadmium nephropathy from many other toxic nephropathies. - Skeletal: progressive osteomalacia/osteoporosis with worsening bone pain and increasing fracture risk over time in the absence of exposure cessation and mineral/vitamin D repletion. - Pulmonary (acute): staged progression — mild flu-like phase (hours) → possible progression to pneumonitis/edema (days) → potential fibrosis or death in severe unresolved cases; if the patient survives the acute phase without progressing after 1–2 days, prognosis is generally favorable, though "interstitial pneumonitis after cadmium exposure" reversibility itself has been specifically questioned in case reports. - Carcinogenesis: long latency (years to decades) typical of chemical carcinogenesis, consistent with cadmium's classification based predominantly on chronic occupational cohort follow-up data.

Patterns: - Remission: chronic renal tubular dysfunction generally does not remit even after exposure cessation, unlike many other toxic exposures — this "point of no return" characteristic is one of the more clinically important, distinguishing features of chronic cadmium nephropathy. - Critical periods: pregnancy/lactation (increased maternal bone turnover interacting with cadmium-impaired mineralization) and iron-deficient states (childhood, menstruating/pregnant women) represent windows of heightened absorption and vulnerability.

9. Inheritance and Population

Epidemiology: - Cadmium poisoning is not a rare/orphan disease in exposure terms — low-level chronic exposure is nearly universal in industrialized populations via diet and, for smokers, tobacco. Clinically significant chronic poisoning (nephropathy, osteomalacia) is concentrated in occupationally exposed workers and populations in historically or currently contaminated regions (the Jinzu River basin in Japan being the paradigmatic example, with several thousand affected individuals historically identified and hundreds of confirmed Itai-itai cases). - Blood cadmium in the general U.S. adult population (NHANES 1999–2008): geometric mean 0.376 µg/L (age ≥20 years); slightly higher in females (0.331 µg/L) than males (0.299 µg/L) in some analyses, reflecting sex differences in GI absorption efficiency (see below) partially offset by occupational exposure patterns. - Newer NHANES cycles (August 2021–August 2023) have updated blood cadmium reference data available via CDC, though a full updated geometric-mean summary was not directly retrieved in this pass.

Inheritance pattern: Not applicable in the Mendelian sense — cadmium poisoning is an acquired toxic/environmental disease. The relevant "genetic" dimension is polygenic susceptibility modification (transporter and detoxification gene polymorphisms described in Etiology/Genetics above), not a discrete inheritance pattern, penetrance, or expressivity in the classical genetic-disease sense.

Population demographics: - Affected populations: historically, agricultural communities in cadmium-mining-affected river basins (Japan — Jinzu River/Toyama; other documented cadmium-contaminated regions in China); currently, occupationally exposed industrial workers (battery, smelting, electroplating industries) worldwide, and — for the low-grade chronic exposure relevant to cardiovascular/cancer/bone endpoints — the general population, especially smokers. - Geographic distribution: strongly tied to industrial/mining activity and to regional soil cadmium content affecting crop uptake (parts of East Asia with cadmium-contaminated paddy soils are particularly notable); e-waste recycling hotspots in parts of Africa and Asia represent an emerging geographic risk pattern. - Sex ratio: Itai-itai disease specifically showed strong female predominance, attributed to lower iron stores (hence higher cadmium GI absorption efficiency), pregnancy/lactation-related bone calcium demand, and postmenopausal bone loss compounding cadmium's skeletal effects — a well-documented sex-specific vulnerability pattern rather than a sex-linked genetic mechanism. - Age distribution: chronic disease manifestations (nephropathy, osteomalacia, cancer) cluster in middle-aged to older adults reflecting cumulative exposure; acute poisoning can occur at any age given sufficient single/short-term high-dose exposure (predominantly working-age adults in occupational settings).

10. Diagnostics

Clinical/laboratory tests: - Blood cadmium (BCd) — reflects recent/ongoing exposure (biological half-life in blood ~3–4 months); standard biomonitoring test (NHANES reference method). - Urinary cadmium (UCd, typically creatinine-corrected, µg/g creatinine) — reflects cumulative body burden/kidney cadmium content given cadmium's long renal half-life; the standard biomarker for chronic exposure assessment and the basis of most occupational and environmental exposure limits (LOINC terms exist for both blood and urine cadmium assays). - Urinary β2-microglobulin (Uβ2-MG) — a classic marker of proximal tubular dysfunction; "currently the most widely used assay for detecting kidney dysfunction" in cadmium-exposed workers, though its relative sensitivity versus NAG is debated across studies (some show UCd correlates more closely with NAG at UCd <10 µg/g creatinine; more recent work suggests Uβ2-MG is more sensitive for detecting renal dysfunction per se). Also linked to hypertension risk in chronically exposed populations (PMC12029079). - Urinary N-acetyl-β-D-glucosaminidase (NAG) — lysosomal enzyme marker of tubular cell injury; simple, inexpensive, reliable, but less sensitive than retinol-binding protein (RBP) or β2-microglobulin per some assessments, and recent work questions how tightly NAG actually tracks nephron destruction. - Urinary retinol-binding protein (RBP) — another low-molecular-weight protein biomarker of proximal tubular reabsorptive dysfunction. - Serum creatinine/eGFR — for later-stage, established CKD assessment (a late marker relative to tubular biomarkers). - Urinary calcium, phosphate; serum 1,25-dihydroxyvitamin D, phosphate — for the osteomalacia workup. - Bone mineral density (DXA) — for skeletal complication assessment; documented dose-related decreases in cadmium-exposed populations.

Imaging: - Plain radiography for pseudofractures (Looser zones), a classic osteomalacia finding in advanced Itai-itai disease. - Chest imaging (CXR/CT) for acute inhalational pneumonitis/pulmonary edema assessment.

Genetic testing: Not applicable in the diagnostic sense (no causal gene to sequence); research-context genotyping of transporter/detoxification polymorphisms (DMT1, ZIP8, GST) is investigational for susceptibility stratification, not clinical diagnosis.

Clinical diagnostic criteria: - Diagnosis of chronic cadmium poisoning/nephropathy rests on a combination of (a) documented exposure history (occupational or environmental), (b) elevated urinary and/or blood cadmium, and (c) the characteristic proximal tubular dysfunction biomarker pattern (β2-MG, NAG, RBP, glucosuria, aminoaciduria) ± osteomalacia findings. Itai-itai disease has established historical diagnostic criteria from Japanese public health authorities (exposure-area residence + tubular proteinuria + bone lesions), a useful ESTABLISHED_CRITERIA framework if curated as a definitions block. - Differential diagnosis: other causes of Fanconi-like proximal tubulopathy (Wilson disease, cystinosis, Dent disease, other heavy metal nephropathies — lead, mercury), other causes of adult-onset osteomalacia (vitamin D deficiency, hypophosphatemic disorders, celiac disease), and other occupational pneumonitides for the acute inhalational presentation.

Screening: Occupational biological monitoring programs (OSHA's cadmium standard, 29 CFR 1910.1027, mandates biological monitoring of blood and urinary cadmium plus urinary β2-microglobulin in exposed workers) represent the primary organized screening framework; there is no population-wide newborn or carrier screening analog given the acquired, non-genetic nature of the disease.

11. Outcome/Prognosis

Survival and mortality: - Acute high-dose fume poisoning carries meaningful mortality risk from pulmonary edema/respiratory failure in severe, unresolved cases (case series document fatalities, e.g., PMID:5928153). - Chronic exposure is associated with increased all-cause and cardiovascular mortality in dose-response fashion across multiple cohort and NHANES-based analyses, and with increased site-specific cancer mortality (lung, and evidence trending for pancreas/bladder) per the 2024 systematic review of biological cadmium and cancer risk/mortality.

Morbidity and function: - Chronic cadmium nephropathy, once tubular injury has occurred, is generally irreversible — a key prognostic feature — leading to lifelong low-molecular-weight proteinuria and, in advanced cases, progression to overt CKD. - Itai-itai-pattern osteomalacia produces substantial disability: chronic debilitating bone pain, waddling gait, and susceptibility to pathological fractures with minimal trauma, historically causing severe functional impairment and reduced quality of life in affected Japanese cohorts. - Emphysema/reduced pulmonary function from chronic fume exposure contributes to long-term respiratory morbidity, compounding smoking-related lung disease risk in exposed smokers.

Complications: - Progression to end-stage renal disease in severe/prolonged exposure. - Recurrent pathological fractures. - Increased cardiovascular events (heart failure, stroke, coronary heart disease). - Malignancy (lung primarily; possibly bladder, pancreatic, other sites).

Recovery potential: - Acute exposure: substantial recovery potential if exposure is promptly terminated and the patient survives the acute pneumonitis/edema phase without progressing to severe respiratory failure. - Chronic exposure: recovery of renal tubular function after exposure cessation is generally poor/absent once injury has occurred — this is one of the more clinically distinctive and consequential features of the disease, in contrast to some other reversible toxic nephropathies. Skeletal disease can improve somewhat with calcium/vitamin D repletion and exposure cessation, but severe deformity/fracture sequelae are often permanent.

Prognostic factors: Cumulative dose (duration × intensity of exposure), baseline nutritional status (iron, calcium, vitamin D), sex (female sex historically associated with more severe skeletal disease in the Itai-itai cohort), age at exposure, and smoking status (compounding pulmonary and cardiovascular risk) are the principal prognostic modifiers identified in the literature. Urinary β2-microglobulin/NAG/RBP levels also function as prognostic biomarkers for the likelihood of progression to overt renal impairment.

12. Treatment

There is no proven disease-modifying cure for established chronic cadmium nephropathy or osteomalacia. Management is fundamentally exposure cessation plus supportive/symptomatic care; chelation therapy — the mainstay for lead and some other heavy-metal poisonings — has notably limited and time-dependent efficacy for cadmium and carries specific safety concerns.

Primary intervention: - Removal from exposure source (occupational reassignment, dietary source identification/avoidance, environmental remediation) — NCIT term suggestion: NCIT:C15747 (Supportive Care) or a more specific environmental-modification concept if available.

Pharmacotherapy — chelation (limited/investigational efficacy, use with caution): - EDTA (ethylenediaminetetraacetic acid, e.g., CaNa₂EDTA) — binds cadmium and enhances urinary excretion; in animal models, cadmium cytotoxicity was completely inhibited by co-administered EDTA, but chelator efficacy for cadmium is markedly time-critical: only administration immediately (versus delayed) after cadmium exposure significantly reduced tissue (kidney/liver) cadmium concentrations in experimental models, with immediate-treatment animals excreting 50–75% of the cadmium dose in urine within 24 hours versus ~0.1% in untreated controls. NCIT/CHEBI suggestion: CHEBI:64118 (edetic acid) as therapeutic_agent under a Pharmacotherapy treatment_term (NCIT:C15986). - DMSA (dimercaptosuccinic acid, succimer) — removed cadmium more effectively than DMPS in some mouse studies, but was reported ineffective against cadmium cytotoxicity in at least one direct study, illustrating that chelator efficacy for cadmium does not parallel its established efficacy for lead. - DMPS (2,3-dimercapto-1-propanesulfonic acid) — used experimentally, generally less effective than DMSA for cadmium removal in comparative animal studies. - Safety caveat: chelation for cadmium carries a documented risk of aggravating renal tubular damage rather than ameliorating it, particularly with delayed or high-dose administration — this is a critical, clinically important limitation distinguishing cadmium chelation from lead chelation, and underlies why chelation is not a routine standard-of-care intervention for established chronic cadmium nephropathy in humans. Combination with methionine has shown improved outcomes over chelators alone in restoring cadmium-induced hepatic/renal transaminase changes in animal studies, but this remains experimental.

Supportive/symptomatic care: - Calcium and vitamin D (active/activated forms, e.g., calcitriol) supplementation — for osteomalacia management, addressing the downstream mineralization defect even though it does not reverse the underlying renal tubular lesion. - Phosphate repletion as needed for tubular phosphate wasting. - Management of acute pulmonary injury: supplemental oxygen, corticosteroids (used empirically in some case reports of cadmium-induced pneumonitis), and mechanical ventilatory support for severe pulmonary edema/respiratory failure — NCIT:C15747 (Supportive Care). - Analgesia for the severe chronic bone pain characteristic of Itai-itai disease. - Standard CKD management (blood pressure control, dietary modification, and progression to renal replacement therapy/dialysis in advanced cases) for those who progress to overt chronic kidney disease.

Experimental/investigational: - Antioxidant supplementation (e.g., N-acetylcysteine, selenium) has been explored in animal models to mitigate cadmium-induced oxidative injury, but robust human clinical trial evidence supporting a specific antioxidant regimen for established cadmium poisoning was not identified in this research pass — flag as an evidence gap if curated. - No cadmium-specific agents are registered in ClinicalTrials.gov as approved disease-modifying therapies at the time of this report; most relevant trials concern chelation pharmacokinetics/biomonitoring methodology rather than definitive efficacy trials for cadmium poisoning specifically.

Treatment outcomes: Given the largely irreversible nature of established tubular injury, the primary "treatment outcome" measured in the literature is prevention of further exposure/progression rather than reversal of existing damage; formal treatment-response-rate data (in the sense used for pharmacotherapy trials) are sparse for this indication.

13. Prevention

Primary prevention: - Occupational exposure controls: engineering controls (ventilation, enclosed processes), personal protective equipment, and regulatory exposure limits (e.g., OSHA's cadmium standard 29 CFR 1910.1027, setting permissible exposure limits and mandating biological monitoring) in cadmium-using industries. - Environmental/agricultural controls: soil remediation in contaminated areas, restrictions on irrigation with contaminated water (the direct historical lesson of Itai-itai disease, which prompted major Japanese public-health and environmental-remediation programs), and monitoring/limiting cadmium content in fertilizers. - Food safety regulation: maximum permitted cadmium levels in foods (EU/Codex Alimentarius regulatory limits for rice, cereals, vegetables, offal, cocoa products), informed by EFSA's Tolerable Weekly Intake of 2.5 µg/kg body weight. - Tobacco control: smoking cessation and reduction in smoking initiation is arguably the single most impactful primary-prevention lever for population-level cadmium body burden reduction, given tobacco's outsized contribution to non-occupational exposure. - Nutritional adequacy programs: ensuring adequate dietary iron, zinc, and calcium intake (particularly in women of reproductive age) to reduce the enhanced intestinal cadmium absorption associated with deficiency states.

Secondary prevention (screening/early detection): - Occupational biological monitoring (blood cadmium, urinary cadmium, urinary β2-microglobulin) in exposed worker populations, enabling early detection of tubular dysfunction before progression to irreversible injury — this is the most evidence-supported secondary-prevention intervention. - Environmental biomonitoring of at-risk populations near contaminated sites.

Tertiary prevention: - Early exposure cessation upon detection of biomarker abnormalities, before progression to overt osteomalacia or CKD, is the principal tertiary strategy given the largely irreversible nature of established chronic cadmium nephropathy. - Calcium/vitamin D supplementation and fracture-prevention strategies in individuals with established skeletal disease.

Immunization: Not applicable — cadmium poisoning is not an infectious/immunization-preventable disease.

Genetic counseling: Not applicable in the classical sense (no Mendelian transmission), though risk communication regarding individual susceptibility (e.g., iron-deficiency-related enhanced absorption) may have a role in targeted public health messaging for high-risk groups (e.g., women of reproductive age).

Public health interventions: - Site remediation and contamination monitoring at former mining/smelting locations. - Public health surveillance systems (e.g., NHANES biomonitoring in the U.S., similar national programs elsewhere) tracking population-level cadmium body burden trends over time. - International/regulatory harmonization of food cadmium limits (Codex Alimentarius, EU regulations) given the global nature of food-trade-mediated exposure.

14. Other Species / Natural Disease

Taxonomy: Cadmium toxicity is a broadly conserved phenomenon across vertebrate (and many invertebrate) species, reflecting cadmium's fundamental biochemical mimicry of essential divalent cations (zinc, calcium) rather than a species-specific mechanism.

Naturally occurring/environmental exposure in other species: - Wildlife: cadmium bioaccumulation and toxicity are well-documented in wildlife inhabiting contaminated environments, particularly species with long lifespans and high trophic-level bioaccumulation potential (e.g., raptors, marine mammals accumulating cadmium from shellfish/crustacean prey — cadmium is strongly bioaccumulated in mollusks and crustaceans, which show naturally high tissue cadmium even in relatively unpolluted marine environments). - Domestic/companion animal and livestock exposure: livestock grazing on contaminated pasture or fed contaminated feed can develop cadmium-related renal and skeletal pathology analogous to the human disease; veterinary case reports of environmental cadmium toxicosis exist, though this is not as systematically cataloged (e.g., in OMIA, which is primarily oriented toward Mendelian veterinary genetic disease) as inherited veterinary conditions.

Comparative biology: - The proximal tubular megalin:cubilin-mediated uptake mechanism central to human cadmium nephrotoxicity is evolutionarily conserved across mammals, which is precisely why rodent models (rat, mouse) are considered reasonably faithful models of the human renal lesion (see Model Organisms below). - Avian species (notably relevant to wildlife toxicology) show comparable cadmium-induced renal and skeletal pathology, though avian calcium metabolism differences (egg-laying-related calcium mobilization) introduce some species-specific nuance to skeletal outcome comparisons.

Zoonotic potential/transmission: Not applicable — cadmium poisoning is a toxic exposure phenomenon, not an infectious or transmissible disease; there is no zoonotic transmission concept relevant here, though shared dietary/environmental exposure sources (e.g., a contaminated water/food source affecting both livestock and the human population consuming them) represent a shared-exposure rather than transmission pathway.

15. Model Organisms

Rodent models (the dominant experimental system): - Mouse: chronic low-dose environmentally-relevant cadmium exposure models demonstrate early renal proximal tubular damage that is not well-predicted by blood or urine cadmium levels alone — an important translational finding suggesting tissue-level injury can precede/exceed what conventional biomarkers capture (ScienceDirect, chronic mouse exposure study). Mouse models are also used to study cadmium's estrogen-mimetic effects on uterine and mammary gland growth, supporting the ERα-mediated endocrine-disruption mechanism. - Rat: extensively used for both renal (subcutaneous/drinking-water cadmium exposure models showing dose- and duration-dependent proximal tubular injury, histomorphological/ultrastructural precancerous lesions, and altered renal cortical microRNA expression) and skeletal toxicity modeling — a 2023 rat study specifically implicated the ROS → SIRT1/PGC-1α/p53 signaling pathway in cadmium-induced osteoblast apoptosis underlying osteoporosis pathogenesis. Rat models using dual-energy X-ray absorptiometry (DXA) have quantified dose-related bone mineral density reductions in cadmium-exposed animals, directly modeling the Itai-itai skeletal phenotype. Rat inhalation models have also been used to study acute cadmium-induced neutrophilic pulmonary inflammation and to test protective agents (e.g., tiotropium/budesonide) against this acute lung injury phenotype. - Periodontal bone models: subcutaneous cadmium injection in rats produces significant periodontal bone loss, proposed as a translational model for periodontal disease association with cadmium exposure in humans.

Genetic models: - Transporter knockout/knockdown models (siRNA-mediated knockdown of ZIP8, ZIP14, and DMT1 in cultured mouse kidney proximal tubule cells) have been used to dissect the relative contribution of each metal-transport pathway to cellular cadmium uptake, establishing that no single transporter pathway predominates (a polygenic-uptake model with direct relevance to interpreting human transporter-gene susceptibility polymorphisms). - Conditional/tissue-specific transporter knockouts in mouse are a logical extension for future mechanistic dissection, though a comprehensive knockout-model literature specific to cadmium (analogous to, e.g., IMPC-cataloged single-gene disease models) was not comprehensively retrieved in this pass.

In vitro/cell-based models: - Cultured renal proximal tubule cell lines (human and rodent-derived) are the standard system for studying megalin:cubilin-dependent cadmium-protein complex uptake and cytotoxicity mechanisms, including the classical Cd-metallothionein model and the revised Cd-β2-microglobulin/albumin/lipocalin-2 model. - Human breast cancer cell lines (T47D, and ERα+/ERα− comparator lines) are the standard system for dissecting cadmium's estrogen-receptor-mediated mechanisms.

Phenotype recapitulation and limitations: - Rodent renal and skeletal models recapitulate the proximal tubular injury and mineralization-defect phenotypes of human chronic cadmium poisoning with reasonably high fidelity, given the conserved megalin:cubilin uptake mechanism and shared vitamin-D-activation pathway. - Limitations: rodent lifespan and cadmium accumulation kinetics differ substantially from the multi-decade human chronic exposure pattern underlying diseases like Itai-itai, so rodent models are generally better suited to modeling the mechanism of injury than the full decades-long natural history; species differences in calcium/bone metabolism (and the specific postmenopausal/multiparous-female risk profile of human Itai-itai disease) are not fully captured by standard rodent designs unless specifically modeled (e.g., ovariectomized rat models combined with cadmium exposure, mimicking postmenopausal bone vulnerability). - Applications: rodent and cell-based models remain the primary tools for mechanistic dissection (transporter biology, oxidative stress pathways, chelation pharmacokinetics/efficacy testing) and are essential to interpreting the chelation-efficacy time-dependence findings summarized in the Treatment section, which derive substantially from these animal studies rather than human clinical trial data.

Summary of Key Ontology Term Suggestions for KB Curation

Table (click to expand)

Category	Suggested terms
MeSH	D002104 (Cadmium Poisoning), D002103 (Cadmium)
ICD-10-CM	T56.3
Key genes (modifier)	SLC11A2/DMT1 (hgnc:10908), SLC39A8/ZIP8 (hgnc:20862), SLC39A14/ZIP14 (hgnc:20858), MT1A (hgnc:7393), MT2A (hgnc:7407)
Key phenotypes (HP)	HP:0002753 (Osteomalacia), HP:0000939 (Osteoporosis), HP:0000121 (Nephropathy), HP:0012622 (Chronic kidney disease), HP:0410048/HP:0002090 (Pneumonitis/Pneumonia), HP:0100598 (Pulmonary edema), HP:0000822 (Hypertension), HP:0002816 (Pathologic fracture), HP:0100526 (Neoplasm of the lung)
Key GO processes	GO:0006979 (response to oxidative stress), GO:0006974 (DNA damage response), GO:0097190 (apoptotic signaling pathway), GO:0030282 (bone mineralization)
Key CL cell types	CL:1000838/CL:1001106 (proximal tubule epithelial cell), CL:0000062 (osteoblast), CL:0001056 (alveolar type I cell)
Key UBERON	UBERON:0004134 (kidney proximal tubule), UBERON:0002048 (lung), UBERON:0001474 (bone element)
Key CHEBI	CHEBI:22977 (cadmium atom/ion), CHEBI:64118 (edetic acid / EDTA)
Key NCIT (treatment)	NCIT:C15986 (Pharmacotherapy), NCIT:C15747 (Supportive Care)

Note on evidence gaps requiring curator judgment: (1) the exact molecular mechanism of cadmium-induced osteoblast/bone toxicity remains explicitly unresolved in the primary literature; (2) the megalin:cubilin cargo-protein model (metallothionein vs. β2-microglobulin/albumin/lipocalin-2) is under active mechanistic revision; (3) a verified MONDO CURIE for this entity should be confirmed via direct ontology lookup rather than assumed from this report.

Sources

Reference Validation

Checked with linkml-reference-validator 0.2.1.

Table (click to expand)

Outcome	Count
References checked	32
Resolved	32
Unresolved (possible confabulation)	0
Unverifiable	0
References weighed for topical relevance	32
On topic	19
Off topic	1

References that may not be about this subject

These identifiers resolve, so they are not fabrications, but the records they resolve to share almost none of this report's vocabulary. That is a clue and not a verdict - a paper can be relevant in ways its title and abstract do not spell out - so read them before deciding:

PMID:22437713 (1 mention) - A two-dimensional polymer prepared by organic synthesis.
shared terms: none

Weighed against this report's own most characteristic terms: cadmium, exposure, renal, disease, poisoning, chronic, tubular, proximal, bone, calcium, injury, itai-itai, acute, osteomalacia, kidney, effect, cell, via, mechanism, risk.

All extracted references resolved successfully. Resolving is not the same as being relevant, though - see the references listed above as possibly off topic.