Rheumatoid Arthritis

name: Rheumatoid Arthritis
creation_date: '2025-12-04T16:57:31Z'
updated_date: '2026-02-16T20:19:38Z'
category: Complex
parents:
- Autoimmune Disease
- Inflammatory Arthritis
definitions:
- name: "OHDSI Phenotype Library: Earliest event of Rheumatoid Arthritis"
  definition_type: PHENOTYPE_ALGORITHM
  description: >-
    OHDSI cohort definition that indexes the first ever rheumatoid arthritis
    event in history, using a concept set spanning condition and observation
    domains, with cohort exit at the end of continuous observation.
  scope: OMOP CDM (OHDSI)
  criteria_sets:
  - name: Earliest event of rheumatoid arthritis
    description: Index on the first RA event in history.
    inclusion_criteria:
    - preferred_term: Rheumatoid arthritis concept set (condition + observation)
      description: OHDSI RA concept set of 15 concepts used in condition and observation domains.
    - preferred_term: First occurrence in history
      description: Index date is the first RA event in the patient's history.
    - preferred_term: Cohort exit at end of observation
      description: Cohort end is the end of continuous observation.
  - name: More specific RA cohort (confirmation)
    description: Requires confirmation to improve specificity.
    inclusion_criteria:
    - preferred_term: Rheumatoid arthritis concept set (condition + observation)
      description: OHDSI RA concept set of 15 concepts used in condition and observation domains.
    - preferred_term: Confirming RA event
      description: Second RA diagnosis or observation code 31 to 365 days after index.
    - preferred_term: Cohort exit at end of observation
      description: Cohort end is the end of continuous observation.
  notes: >-
    Source: OHDSI forum phenotype submission "Rheumatoid Arthritis" (logic description
    and evaluation notes); imported to the OHDSI Phenotype Library (expected id 858).
has_subtypes:
- name: Seropositive RA
  display_name: Seropositive Rheumatoid Arthritis
  description: Characterized by the presence of rheumatoid factor (RF) and/or anti-cyclic citrullinated peptide (anti-CCP) antibodies.
  evidence:
  - reference: PMID:28451788
    reference_title: "The role of autoantibodies in the pathophysiology of rheumatoid arthritis."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation. The presence of autoantibodies in the sera of RA patients has provided many clues to the underlying disease pathophysiology. Based on the presence of several autoantibodies like rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA)... RA can be subdivided into seropositive and seronegative disease.
    explanation: The literature indicates that RA can be subdivided into seropositive and seronegative types based on the presence of RF and/or ACPAs in the sera of the patients, which supports the given statement.
- name: Seronegative RA
  display_name: Seronegative Rheumatoid Arthritis
  description: Absence of both RF and anti-CCP antibodies, but with typical clinical features of RA.
  evidence:
  - reference: PMID:33329548
    reference_title: "Adult-Onset Anti-Citrullinated Peptide Antibody-Negative Destructive Rheumatoid Arthritis Is Characterized by a Disease-Specific CD8+ T Lymphocyte Signature."
    supports: SUPPORT
    snippet: Traditionally, RA is divided into seropositive (SP) and seronegative (SN) disease forms, the latter consisting of an array of unrelated diseases with joint involvement.
    explanation: This study discusses SN-RA as a form characterized by the absence of anti-citrullinated peptide antibody (ACPA) and rheumatoid factor (RF), supporting the statement.
  - reference: PMID:3266362
    reference_title: "What is seronegative rheumatoid arthritis?"
    supports: SUPPORT
    snippet: We became increasingly concerned with the problem of defining properly patients with seronegative RA. Both the statement of seronegativity with regard to rheumatoid factors (RF), the diagnosis of RA, and particularly the exclusion of cases of seronegative arthritis other than RA were difficult.
    explanation: This study acknowledges the existence of seronegative RA defined by the absence of RF.
  - reference: PMID:32678001
    reference_title: "Presence of autoantibodies in \"seronegative\" rheumatoid arthritis associates with classical risk factors and high disease activity."
    supports: PARTIAL
    snippet: Rheumatoid arthritis (RA) is classified as seropositive or seronegative, depending on the presence/absence of rheumatoid factor (RF), primarily IgM RF, and/or anti-citrullinated protein antibodies (ACPA), commonly detected using anti-cyclic citrullinated peptide (CCP) assays.
    explanation: This supports the seronegative classification based on the absence of RF and anti-CCP antibodies but points out the complexity and variability within seronegative RA.
  - reference: PMID:38251565
    reference_title: "Autoantibody-negative rheumatoid arthritis: still a challenge for the rheumatologist."
    supports: SUPPORT
    snippet: The subset of rheumatoid arthritis that does not have autoantibodies (such as rheumatoid factor and anti-citrullinated protein autoantibodies) remains less well defined in its pathogenic mechanisms.
    explanation: Refers to RA without autoantibodies, supporting the statement that such a subtype exists.
- name: JIA
  display_name: Juvenile Idiopathic Arthritis (JIA)
  description: Onset of arthritis before the age of 16, persisting for at least 6 weeks.
  evidence:
  - reference: PMID:35087087
    reference_title: "Juvenile idiopathic arthritis."
    supports: PARTIAL
    snippet: Juvenile idiopathic arthritis (JIA) is an umbrella term for arthritis of unknown origin, lasting for >6 weeks with onset before 16 years of age.
    explanation: The literature specifies that JIA is defined as arthritis lasting for more than 6 weeks with onset before 16 years, aligning with the statement. However, JIA is not a subtype of Rheumatoid Arthritis but rather a distinct condition.
  - reference: PMID:23763801
    reference_title: "Juvenile rheumatoid arthritis."
    supports: NO_EVIDENCE
    snippet: To determine the spectrum of clinical presentation, laboratory parameters and drug therapy in patients with Juvenile Rheumatoid Arthritis (JRA).
    explanation: The study focuses on Juvenile Rheumatoid Arthritis (JRA), a term which is sometimes used synonymously with Juvenile Idiopathic Arthritis (JIA) but does not explicitly define it as a subtype of Rheumatoid Arthritis.
  - reference: PMID:37700346
    reference_title: "Childhood-onset rheumatoid arthritis at a tertiary hospital in Senegal, West Africa."
    supports: PARTIAL
    snippet: Childhood-onset rheumatoid arthritis (CORA), known as rheumatoid factor (RF)-positive juvenile idiopathic arthritis is a type of juvenile idiopathic arthritis that shares the same genetic factors and clinical features as adult-onset rheumatoid arthritis.
    explanation: This literature mentions that RF-positive juvenile idiopathic arthritis is a type of JIA sharing features with adult RA. It confirms that JIA has clinical overlap with RA but does not support that JIA is a subtype of RA.
  - reference: PMID:8465574
    reference_title: "[Polyarthritis in the elderly]."
    supports: NO_EVIDENCE
    snippet: Ten to thirty-three per cent of all cases of rheumatoid arthritis (RA) develop after sixty years of age. Late-onset RA patients are more likely to be male, to have faster onset of symptoms...
    explanation: The literature provided does not discuss JIA or its relation as a subtype of RA.
prevalence:
- population: Global
  percentage: 0.5-1.0
  evidence:
  - reference: PMID:24217093
    reference_title: "Rheumatoid arthritis."
    supports: PARTIAL
    snippet: A study in the UK found the population minimum prevalence of RA is 1.16% in women and 0.44% in men. In Australia, the estimated prevalence is 0.6%.
    explanation: While the prevalence of RA in the UK and Australia provides values that fall both below and slightly within the stated range (0.5-1.0%), it does not consistently support the global prevalence within that range.
  - reference: PMID:32712723
    reference_title: "Is Axial Spondyloarthritis More Common Than Rheumatoid Arthritis?"
    supports: REFUTE
    snippet: According to the most recently published systematic reviews, pooled prevalence estimates for RA are 0.38% in North America, and 0.21 to 0.25% in European subregions.
    explanation: The prevalence estimates for North America and European subregions are significantly below the stated range (0.5-1.0%), thus not supporting the statement.
progression:
- phase: Onset
  evidence:
  - reference: PMID:15588970
    reference_title: "Does early rheumatoid arthritis exist?"
    supports: NO_EVIDENCE
    snippet: It suggests that the term 'early rheumatoid arthritis' is not appropriate and that patients either have established rheumatoid arthritis or an undifferentiated inflammatory arthritis.
    explanation: This reference argues against the categorization of 'early rheumatoid arthritis' and suggests that RA should be considered either as established or undifferentiated inflammatory arthritis, providing no evidence about the progression specifically at the onset phase.
  - reference: PMID:23926091
    reference_title: "Symptom complexes at the earliest phases of rheumatoid arthritis: a synthesis of the qualitative literature."
    supports: NO_EVIDENCE
    snippet: However, little is known about the characteristics of symptoms at the onset of a disease that eventually progresses to RA
    explanation: This study highlights the lack of comprehensive knowledge on the characteristics and progression of RA in its earliest phases, thus providing no evidence regarding the progression of RA specifically at the onset phase.
- age_range: 30-60
  evidence:
  - reference: PMID:29039317
    reference_title: "Progression pattern of rheumatoid arthritis: A study of 500 Pakistani patients."
    supports: PARTIAL
    snippet: The disease severity increases with increase in the age and reaches to its peak in above 60 years of age (p=0.001). The pattern of progression of RA in the Pakistani patients is almost consistent with other relevant studies conducted on European and European derived populations.
    explanation: This study indicates that the progression of rheumatoid arthritis increases with age and is most severe in patients above 60. This indirectly supports the statement that progression can be observed in the age range of 30-60, by confirming its increase towards the upper end of this range.
  - reference: PMID:34894251
    reference_title: "Should we reconsider the definition of elderly-onset rheumatoid arthritis in an ageing society?"
    supports: NO_EVIDENCE
    snippet: Patients with all EORA features were more numerous with age and almost exclusively older than 65 years.
    explanation: This supports the idea that progression features become more prominent with age. As such, rheumatoid arthritis progression can be inferred for the age range of 30-60.
  - reference: PMID:24217093
    reference_title: "Rheumatoid arthritis."
    supports: NO_EVIDENCE
    snippet: A study in the UK found the population minimum prevalence of RA is 1.16% in women and 0.44% in men.
    explanation: Prevalence indicates the presence of the disease, which includes its progression over time. This supports the existence of progression within the age range specified.
  - reference: PMID:31899521
    reference_title: "Secular changes in the progression of clinical markers and patient-reported outcomes in early rheumatoid arthritis."
    supports: PARTIAL
    snippet: This study demonstrates improvements in inflammatory markers over time in early RA, in line with improved treatment strategies.
    explanation: The discussion about the progression of clinical and inflammatory markers over time implies that progression happens in various age groups including those within 30-60 years.
pathophysiology:
- name: Autoimmune Response
  description: The immune system mistakenly attacks the body's own tissues, particularly the synovial membrane lining the joints.
  cell_types:
  - preferred_term: Th17 Cell
    term:
      id: CL:0000899
      label: T-helper 17 cell
  biological_processes:
  - preferred_term: T-helper 17 type immune response
    term:
      id: GO:0072538
      label: T-helper 17 type immune response
  - preferred_term: Inflammatory Response
    term:
      id: GO:0006954
      label: inflammatory response
  evidence:
  - reference: PMID:22608255
    reference_title: "Autoimmune arthritis: the interface between the immune system and joints."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) is an autoimmune disease, characterized by chronic inflammation and synovial hyperplasia in the joints that ultimately lead to cartilage and bone destruction. A wealth of research has shown that CD4(+) T cells, especially IL-17 producing helper T (Th17) cells, play an important role in RA development.
    explanation: This reference supports the statement that Th17 cells are involved in the autoimmune response in RA, particularly affecting the joints.
  - reference: PMID:30572135
    reference_title: "Th17 cells in renal inflammation and autoimmunity."
    supports: SUPPORT
    snippet: These pro-inflammatory T-cells are also key players in autoimmunity and a pathogenic role has been demonstrated in several diseases such as rheumatoid arthritis or psoriasis.
    explanation: The cited literature indicates that Th17 cells play a significant role in the autoimmune response and inflammation characteristic of RA.
  - reference: PMID:31895885
    reference_title: "The metabolic signature of T cells in rheumatoid arthritis."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) is a prototypic autoimmune disease manifesting as chronic inflammation of the synovium and leading to acceleration of cardiovascular disease and shortening of life expectancy.
    explanation: This reference corroborates that RA is an autoimmune disease affecting the synovium, aligning with the statement.
- name: Inflammatory Cytokine Production
  description: Overproduction of inflammatory cytokines like TNF-α, IL-1, and IL-6 leads to joint inflammation and damage.
  biological_processes:
  - preferred_term: cytokine production
    term:
      id: GO:0001816
      label: cytokine production
  locations:
  - preferred_term: synovial membrane
    term:
      id: UBERON:0002018
      label: synovial membrane of synovial joint
  evidence:
  - reference: PMID:9836373
    reference_title: "Role of pro-inflammatory cytokines in rheumatoid arthritis."
    supports: PARTIAL
    snippet: Rheumatoid arthritis (RA) is well known to be a chronic autoimmune/inflammatory disease which leads to progressive joint damage and destruction.
    explanation: The abstract explicitly states that RA leads to progressive joint damage and inflammation, which aligns with the statement that overproduction of inflammatory cytokines leads to joint inflammation and damage.
  - reference: PMID:34688020
    reference_title: "Systemic effects of IL-6 blockade in rheumatoid arthritis beyond the joints."
    supports: SUPPORT
    snippet: This pleiotropic cytokine [IL-6] is a key factor in the pathogenesis of rheumatoid arthritis (RA) and is involved in many extra-articular manifestations that accompany the disease.
    explanation: IL-6 is mentioned as a key factor in the pathogenesis of RA, supporting the notion that overproduction of inflammatory cytokines like IL-6 contributes to RA.
  - reference: PMID:32830085
    reference_title: "Mechanistic insights into the role of pyroptosis in rheumatoid arthritis."
    supports: PARTIAL
    snippet: The pro-inflammatory mediators released via interaction of intracellular kinases direct the development of Rheumatoid arthritis.
    explanation: The abstract clearly states that pro-inflammatory mediators direct the development of RA, which supports the statement about the role of cytokines like TNF-α, IL-1, and IL-6 in joint inflammation and damage.
  - reference: PMID:33692806
    reference_title: "Role of the IL-23/IL-17 Pathway in Rheumatic Diseases: An Overview."
    supports: PARTIAL
    snippet: IL-23/IL-17 axis activation contributes to the development of several inflammatory diseases, such as ... Rheumatoid Arthritis.
    explanation: Although focusing on IL-23/IL-17, the review also discusses other inflammatory cytokines such as IL-6 and TNF-α and their role in RA, which supports the statement.
- name: Synovial Hyperplasia
  description: The synovial membrane becomes thickened and inflamed, leading to the formation of pannus tissue that invades cartilage and bone.
  cell_types:
  - preferred_term: Synoviocyte
    term:
      id: CL:0000214
      label: synovial cell
  - preferred_term: Macrophage
    term:
      id: CL:0000235
      label: macrophage
  locations:
  - preferred_term: synovial membrane
    term:
      id: UBERON:0002018
      label: synovial membrane of synovial joint
  downstream:
  - target: Cartilage and Bone Destruction
    description: Synovial hyperplasia and pannus formation lead to progressive destruction of articular cartilage and bone.
    evidence:
    - reference: PMID:32071294
      reference_title: "NR1D1 modulates synovial inflammation and bone destruction in rheumatoid arthritis."
      supports: SUPPORT
      snippet: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial hyperplasia, pannus formation, and cartilage and bone destruction.
      explanation: This paper establishes that synovial hyperplasia leads to pannus formation which directly causes cartilage and bone destruction in RA.
  evidence:
  - reference: PMID:15353290
    reference_title: "Synovial activation in rheumatoid arthritis."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) is a chronic inflammatory disease with progressive articular damage. Activated cells of the synovium produce pro-inflammatory and matrix-degrading effector molecules, which maintain the inflammation and lead to the destruction of the involved joints. In addition to macrophages and T- and B-cells, fibroblast-like synoviocytes must be considered key cells in driving the pathological processes. They can be distinguished by their transformed-appearing phenotype and their invasion into adjacent cartilage and bone.
    explanation: The literature describes that fibroblast-like synoviocytes and macrophages play a key role in the inflammation and invasion of cartilage and bone in RA, supporting the statement.
  - reference: PMID:35958604
    reference_title: "Synovial Macrophages: Past Life, Current Situation, and Application in Inflammatory Arthritis."
    supports: PARTIAL
    snippet: Synovial hyperplasia often presents when joints become inflamed due to immune cell infiltration. Synovial membrane... interact with synovial fibroblasts (SFs), T cells, B cells, and other inflammatory cells to promote the production of a variety of pro-inflammatory cytokines and chemokines, such as TNF-alpha, IL-1beta, IL-8, and IL-6, which are involved in the pathogenic process of inflammatory arthritis.
    explanation: This source confirms the role of synovial fibroblasts and macrophages in the inflammatory process associated with synovial hyperplasia in RA.
  - reference: PMID:29287304
    reference_title: "The Tumor-Like Phenotype of Rheumatoid Synovium: Molecular Profiling and Prospects for Precision Medicine."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by destructive hyperplasia of the synovium. Fibroblast-like synoviocytes (FLS) are a major component of synovial pannus and actively participate in the pathologic progression of RA.
    explanation: The source supports the role of fibroblast-like synoviocytes in the hyperplasia of the synovium and formation of pannus tissue in RA.
- name: Cartilage and Bone Destruction
  description: Chronic inflammation and pannus formation lead to the erosion of articular cartilage and underlying bone.
  locations:
  - preferred_term: synovial joint
    term:
      id: UBERON:0002217
      label: synovial joint
  - preferred_term: articular cartilage
    term:
      id: UBERON:0010996
      label: articular cartilage of joint
  evidence:
  - reference: PMID:28597065
    reference_title: "Cellular and molecular pathways of structural damage in rheumatoid arthritis."
    supports: SUPPORT
    snippet: Structural damage of cartilage and bone tissue is a hallmark of rheumatoid arthritis (RA). The resulting joint destruction constitutes one of the major disease consequences for patients... These factors result in an inflammatory milieu in the affected joints which leads to an increased development and function of osteoclasts.
  - reference: PMID:17634141
    reference_title: "Erosive arthritis."
    supports: PARTIAL
    snippet: Chronic inflammatory arthritis not only leads to inflammatory bone loss but it also involves local erosion of articular bone. This osteo-destructive feature of chronic inflammatory arthritis is a major cause of disability in patients with rheumatoid arthritis.
  - reference: PMID:24217093
    reference_title: "Rheumatoid arthritis."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterised by joint swelling, joint tenderness and destruction of synovial joints, leading to severe disability.
  - reference: PMID:35273387
    reference_title: "Effects of targeted therapies on bone in rheumatic and musculoskeletal diseases."
    supports: SUPPORT
    snippet: Rheumatoid arthritis can involve localized, periarticular bone erosion...The RANK-RANKL-osteoprotegerin axis and the Wnt-beta-catenin signalling pathway...have been implicated in inflammatory bone loss.
- name: JAK/STAT Signaling
  description: The JAK/STAT pathway serves as a central conduit for IL-6 and interferon signaling, driving both immune cell activation and stromal responses in synovium.
  biological_processes:
  - preferred_term: cytokine-mediated signaling pathway
    term:
      id: GO:0019221
      label: cytokine-mediated signaling pathway
  cell_types:
  - preferred_term: Fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  - preferred_term: Macrophage
    term:
      id: CL:0000235
      label: macrophage
  locations:
  - preferred_term: synovial membrane
    term:
      id: UBERON:0002018
      label: synovial membrane of synovial joint
  notes: Targeted by JAK inhibitors in clinical practice
  evidence:
  - reference: PMID:35367240
    reference_title: "Underpinning IL-6 biology and emphasizing selective JAK blockade as the potential alternate therapeutic intervention for rheumatoid arthritis."
    supports: SUPPORT
    snippet: the JAK-STAT pathway has been majorly implicated in RA disease progression upon IL-6 stimulation
    explanation: This review demonstrates that JAK-STAT signaling is central to IL-6 mediated pathogenesis in rheumatoid arthritis, and that JAK inhibitors are clinically effective in treating RA by abrogating this signaling pathway.
- name: NF-κB Activation
  description: NF-κB transcriptional activation drives proinflammatory cytokine production and cell survival signals in immune and fibroblast cells.
  biological_processes:
  - preferred_term: immune response
    term:
      id: GO:0006955
      label: immune response
  - preferred_term: cytokine production
    term:
      id: GO:0001816
      label: cytokine production
  cell_types:
  - preferred_term: Fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  - preferred_term: Macrophage
    term:
      id: CL:0000235
      label: macrophage
- name: Neutrophil Extracellular Trap Formation
  description: Neutrophils release extracellular traps containing citrullinated histones and autoantigens via PAD4-mediated citrullination, amplifying autoimmunity.
  cell_types:
  - preferred_term: Neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: immune response
    term:
      id: GO:0006955
      label: immune response
  notes: NETs provide source of citrullinated antigens that serve as ACPA targets
- name: B Cell and Plasma Cell Responses
  description: B cells and plasma cells generate autoantibodies (ACPA, RF) locally within synovium and at mucosal sites, forming ectopic lymphoid structures.
  cell_types:
  - preferred_term: B cell
    term:
      id: CL:0000236
      label: B cell
  - preferred_term: Plasma cell
    term:
      id: CL:0000786
      label: plasma cell
  locations:
  - preferred_term: synovial membrane
    term:
      id: UBERON:0002018
      label: synovial membrane of synovial joint
  notes: B cell-rich synovitis predicts better response to rituximab
- name: Mucosal Origins and Dysbiosis
  description: Aberrant immune activation in lung, oral, and gut mucosa precedes systemic autoimmunity, driven by dysbiosis, epithelial barrier dysfunction, and local citrullination.
  locations:
  - preferred_term: respiratory system mucosa
    term:
      id: UBERON:0004785
      label: respiratory system mucosa
  - preferred_term: oral mucosa
    term:
      id: UBERON:0003343
      label: mucosa of oral region
  - preferred_term: intestinal mucosa
    term:
      id: UBERON:0001242
      label: intestinal mucosa
  notes: Mucosal IgA autoantibodies can precede clinical arthritis; Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans implicated
- name: Epigenetic Dysregulation of T Cell Function
  description: >
    Aberrant chromatin remodeling and histone modifications alter T cell gene
    expression programs, promoting autoreactive T cell activation and loss of
    immune tolerance. Changes in DNA methylation and histone acetylation at
    immune gene loci contribute to disease susceptibility and chronicity.
  cell_types:
  - preferred_term: T-helper 17 cell
    term:
      id: CL:0000899
      label: T-helper 17 cell
  - preferred_term: CD4-positive helper T cell
    term:
      id: CL:0000492
      label: CD4-positive helper T cell
  biological_processes:
  - preferred_term: Chromatin Remodeling
    term:
      id: GO:0006338
      label: chromatin remodeling
  - preferred_term: Epigenetic Regulation of Gene Expression
    term:
      id: GO:0040029
      label: epigenetic regulation of gene expression
  - preferred_term: T Cell Differentiation
    term:
      id: GO:0030217
      label: T cell differentiation
  downstream:
  - target: Autoimmune Response
    description: Epigenetic dysregulation promotes autoreactive T cell programs that drive the autoimmune response
  notes: Cluster 38 (MLL2 complex; DOT1L, MEN1) and Cluster 59 (RNF20, HDAC7) from Zhu/Dann T cell Perturb-seq show broad autoimmune GWAS enrichment via epigenetic regulatory programs
phenotypes:
- category: Musculoskeletal
  name: Symmetric Polyarthritis
  frequency: VERY_FREQUENT
  diagnostic: true
  sequelae:
  - target: Joint Deformity
  - target: Reduced Mobility
  evidence:
  - reference: PMID:29848426
    reference_title: "Spectrum of Joint Deformities in Children with Juvenile Idiopathic Arthritis."
    supports: PARTIAL
    snippet: More than 50% patients with JIA have joint deformities. Joint deformities are more likely to be seen in children with long-standing disease, those with polyarthritis JIA and seropositive patients.
    explanation: This supports the association between polyarthritis and joint deformity, but it is specific to Juvenile Idiopathic Arthritis (JIA) and does not fully address symmetric polyarthritis in RA.
  - reference: PMID:37410796
    reference_title: "Initial presentation of early rheumatoid arthritis."
    supports: SUPPORT
    snippet: Incident RA presents mainly as symmetric arthritis.
    explanation: This literature clearly supports that RA often presents as symmetric arthritis, aligning with the statement.
  - reference: PMID:37158761
    reference_title: "Patterns of Involvement of the Hand Joints in Classical Rheumatoid Arthritis."
    supports: SUPPORT
    snippet: Symmetrical involvement of the hand joints is described as characteristic of rheumatoid arthritis (RA).
    explanation: This reference reinforces that symmetric polyarthritis is characteristic of RA, supporting the statement.
  - reference: PMID:22035393
    reference_title: "Rheumatoid arthritis of the cervical spine--clinical considerations."
    supports: PARTIAL
    snippet: Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder affecting multiple organ systems, joints, ligaments, and bones and commonly involves the cervical spine.
    explanation: While this reference mentions systemic and joint involvement, it does not specifically address symmetric polyarthritis or its frequency.
  - reference: PMID:11358413
    reference_title: "What is the natural history of rheumatoid arthritis?"
    supports: NO_EVIDENCE
    snippet: RA is now thought to be associated with a conserved sequence of amino acids in a number of HLA-DRB1 alleles, called the RA shared epitope
    explanation: This suggests a genetic predisposition to more severe and chronic forms of RA, which could include symmetric polyarthritis, thus supporting the statement.
  phenotype_term:
    preferred_term: Symmetric Polyarthritis
    term:
      id: HP:0040311
      label: Symmetric polyarthritis
- category: Musculoskeletal
  name: Morning Stiffness
  frequency: FREQUENT
  evidence:
  - reference: PMID:26403254
    reference_title: "The importance of assessment and management of morning stiffness in Asian patients with rheumatoid arthritis: Recommendations from an expert panel."
    supports: PARTIAL
    snippet: These recommendations serve to guide rheumatologists and other stakeholders on the assessment and management of morning stiffness.
    explanation: The literature states that morning stiffness is a significant symptom in rheumatoid arthritis (RA) and is commonly associated with functional disability and pain. This supports the statement that morning stiffness is a common phenotype in RA.
  - reference: PMID:36544060
    reference_title: "Perspectives of colon-specific drug delivery in the management of morning symptoms of rheumatoid arthritis."
    supports: SUPPORT
    snippet: Rheumatoid arthritis symptoms follow a 24 h circadian rhythm and exhibit high thresholds of pain, functional disability, and stiffness predominantly early in the morning.
    explanation: This excerpt confirms that morning stiffness is a frequent and notable symptom in rheumatoid arthritis, aligning with the frequency and naming attributes in the statement.
  - reference: PMID:30936222
    supports: NO_EVIDENCE
    snippet: ''
    explanation: The reference does not provide relevant information regarding morning stiffness as a phenotype or its commonality in rheumatoid arthritis.
  - reference: PMID:25437284
    supports: NO_EVIDENCE
    snippet: ''
    explanation: While the reference discusses early symptoms of RA, it does not specifically mention morning stiffness as a common phenotype.
  - reference: PMID:24461540
    reference_title: "Polymyalgia rheumatica--diagnosis and classification."
    supports: NO_EVIDENCE
    snippet: The typical symptoms are bilateral aching of the shoulder girdle, associated with morning stiffness.
    explanation: The reference notes that morning stiffness is a symptom associated with polymyalgia rheumatica and also mentions its relevance in diagnosing inflammatory rheumatic diseases, which includes RA.
  phenotype_term:
    preferred_term: Morning Stiffness
    term:
      id: HP:0005197
      label: Generalized morning stiffness
- category: Systemic
  name: Fatigue
  frequency: FREQUENT
  evidence:
  - reference: PMID:25005390
    reference_title: "Rheumatoid arthritis and fatigue."
    supports: SUPPORT
    snippet: Many of these people experience pain, inflammation, stiffness, reduced mobility and joint function, and fatigue.
    explanation: The literature supports that fatigue is a common symptom experienced by people with rheumatoid arthritis.
  - reference: PMID:26803313
    reference_title: "Metabolomics study of fatigue in patients with rheumatoid arthritis naïve to biological treatment."
    supports: NO_EVIDENCE
    snippet: Fatigue occurs in all chronic inflammatory diseases, in cancer, and in some neurological conditions.
    explanation: This supports the notion that fatigue is a common systemic phenotype in rheumatoid arthritis.
  - reference: PMID:38643104
    reference_title: "Predictors of quality of life, functional status, depression and fatigue in early arthritis: comparison between clinically suspect arthralgia, unclassified arthritis and rheumatoid arthritis."
    supports: PARTIAL
    snippet: Patients with RA reported worse outcomes for all PROMs than those with CSA or UA.
    explanation: This study highlights the high burden of fatigue among patients with RA, supporting fatigue as a common systemic phenotype.
  phenotype_term:
    preferred_term: Fatigue
    term:
      id: HP:0012378
      label: Fatigue
- category: Extra-articular
  name: Rheumatoid Nodules
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:15163106
    reference_title: "Epidemiology of extra-articular manifestations in rheumatoid arthritis."
    supports: SUPPORT
    snippet: Extra-articular RA (ExRA) includes a wide variety of disease manifestations... ExRA manifestations are not uncommon, explain excess mortality in RA and are predicted by smoking and autoantibodies.
    explanation: The abstract mentions that extra-articular manifestations are not uncommon in RA, suggesting that these phenotypes occur occasionally.
  - reference: PMID:17544962
    reference_title: "Rheumatoid nodule."
    supports: SUPPORT
    snippet: Rheumatoid nodules are the most common extra-articular manifestation of rheumatoid arthritis.
    explanation: Rheumatoid nodules are identified as the most common extra-articular manifestation, reinforcing their occurrence in RA.
  - reference: PMID:27151711
    reference_title: "Rheumatoid nodules and quality of life in rheumatoid arthritis females - complex assessment."
    supports: SUPPORT
    snippet: Rheumatoid nodules (RNs) are one of the most frequent extra-articular manifestations of RA.
    explanation: The abstract indicates that rheumatoid nodules are among the most frequent extra-articular manifestations, supporting their occasional presence as noted in the given statement.
  - reference: PMID:7354699
    reference_title: "Laryngeal rheumatoid arthritis."
    supports: PARTIAL
    snippet: Rheumatoid nodules were seen in two cases and granulomatous areas surrounding cricothyroid joints were noted in two others.
    explanation: The study reports instances of rheumatoid nodules, demonstrating their occurrence as extra-articular manifestations, albeit not specifying frequency.
  - reference: PMID:8465574
    reference_title: "[Polyarthritis in the elderly]."
    supports: PARTIAL
    snippet: Late-onset RA patients ... are less likely to develop rheumatoid nodules, extraarticular manifestations, positive serologic tests, or unfavorable outcomes.
    explanation: The abstract notes that rheumatoid nodules occur less frequently in late-onset RA, which indirectly supports their occasional prevalence in the general RA population.
  - reference: PMID:37740125
    reference_title: "Rheumatoid arthritis with pulmonary accelerated rheumatoid nodules treated by baricitinib: a case-based review."
    supports: PARTIAL
    snippet: Pulmonary accelerated rheumatoid nodules (ARN) represent a rare occurrence within the context of rheumatoid arthritis (RA)... multiple bilateral pulmonary nodules.
    explanation: The review provides specific cases of pulmonary rheumatoid nodules, confirming their occasional manifestation as an extra-articular feature.
- category: Extra-articular
  name: Interstitial Lung Disease
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:15163106
    reference_title: "Epidemiology of extra-articular manifestations in rheumatoid arthritis."
    supports: PARTIAL
    snippet: Extra-articular RA (ExRA) includes a wide variety of disease manifestations... ExRA manifestations are not uncommon, explain excess mortality in RA and are predicted by smoking and autoantibodies.
    explanation: The reference confirms that extra-articular manifestations in RA are common, but does not specifically address the frequency of interstitial lung disease.
  - reference: PMID:38411210
    reference_title: "Updates on interstitial lung disease and other selected extra-articular manifestations of rheumatoid arthritis."
    supports: PARTIAL
    snippet: RA-associated interstitial lung disease (RA-ILD) is a major contributor to mortality, with no decline in incidence and scant therapeutic options.
    explanation: The reference confirms RA-ILD as a significant extra-articular manifestation, but it does not detail its specific frequency.
  - reference: PMID:31376890
    reference_title: "Thoracic Manifestations of Rheumatoid Arthritis."
    supports: PARTIAL
    snippet: The most common intrathoracic manifestations of RA include interstitial lung disease, airway disease, pleural disease, rheumatoid nodules, and drug-induced toxicity.
    explanation: The reference indicates that interstitial lung disease is a common pulmonary manifestation of RA, but does not quantify how often it occurs.
- category: Musculoskeletal
  frequency: FREQUENT
  name: Boutonniere Deformity
  notes: Flexion contracture of PIP joint with hyperextension of DIP joint
  evidence:
  - reference: PMID:2661577
    reference_title: "Boutonniere deformities in rheumatoid arthritis."
    supports: SUPPORT
    snippet: The pathology of the boutonniere begins with a synovitis of the joint, followed by elongation al the central slip, subluxation of the later bands, and contracture of the retinacular ligaments.
    explanation: The reference describes the occurrence of boutonniere deformity in the context of rheumatoid arthritis, supporting the statement that it is a frequent musculoskeletal issue associated with this condition.
  - reference: PMID:34628456
    reference_title: "Frequency and risk factor analyses of bone erosion of the distal interphalangeal joint in patients with rheumatoid arthritis: a cross-sectional study."
    supports: SUPPORT
    snippet: Bone erosion can be observed at the DIP joint in patients with RA, and these cases frequently shows bone erosions of other finger joints, such as PIP joint.
    explanation: The study indicates that bone erosions, including those leading to deformities like boutonniere, are common in rheumatoid arthritis patients.
  - reference: PMID:19474183
    reference_title: "The working space of the hand in rheumatoid arthritis: its impact on disability."
    supports: SUPPORT
    snippet: The average working space volume was 4921 cc in rheumatoid patients with no visible hand deformity and 1154 cc in the presence of combined finger deformities (P < 0.005).
    explanation: This reference discusses the prevalence of hand deformities in rheumatoid arthritis, indicating that such deformities, including boutonniere, significantly impact the working space of the hand.
- category: Musculoskeletal
  frequency: OCCASIONAL
  name: Swan-neck Deformity
  notes: Hyperextension of PIP joint with flexion of DIP joint
  evidence:
  - reference: PMID:2661576
    reference_title: "The rheumatoid swan-neck deformity."
    supports: SUPPORT
    snippet: It is important to evaluate each swan-neck deformity to determine the mobility and radiographic condition of the PIP joint.
    explanation: The reference discusses the evaluation and treatment of swan-neck deformity in the context of rheumatoid arthritis, supporting the association between rheumatoid arthritis and swan-neck deformity.
- category: Extra-articular
  frequency: OCCASIONAL
  name: Sicca Syndrome
  notes: Dry eyes and mouth due to secondary Sjogren's syndrome
  evidence:
  - reference: PMID:33346115
    reference_title: "Beyond the joints, the extra-articular manifestations in rheumatoid arthritis."
    supports: PARTIAL
    snippet: Secondary Sjögren's syndrome and pulmonary manifestations are observed in almost 10% of patients, also in the early disease
    explanation: The statement claims that Sicca Syndrome (secondary Sjogren's syndrome) is an occasional extra-articular manifestation of Rheumatoid Arthritis. However, the literature indicates that it occurs in almost 10% of RA patients, suggesting it is not merely occasional but more common.
  - reference: PMID:27424016
    reference_title: "Secondary Sjogren's Syndrome in 83 Patients With Rheumatoid Arthritis."
    supports: PARTIAL
    snippet: Our results demonstrated that the prevalence of sSS was 5.9% (CI:0.6%-10.5%). Number of 27.7% of RA patients positively responded to at least one question about sicca symptoms.
    explanation: The study found that secondary Sjogren's syndrome (sSS) has a prevalence of 5.9% among RA patients, and 27.7% of RA patients reported sicca symptoms. This indicates that sSS is not just an occasional manifestation but occurs with a higher frequency.
- category: Extra-articular
  frequency: OCCASIONAL
  name: Scleritis
  notes: Inflammation of the sclera of the eye
  evidence:
  - reference: PMID:20559644
    reference_title: "[Diseases of the outer eye in rheumatoid arthritis]."
    supports: SUPPORT
    snippet: The main spectrum of eye involvement comprises keratoconjunctivitis sicca, episcleritis and scleritis as well as ulcerative keratitis.
    explanation: This reference indicates that scleritis is part of the spectrum of eye involvement in rheumatoid arthritis, supporting the statement.
  - reference: PMID:37344292
    reference_title: "[Scleritis and episcleritis]."
    supports: SUPPORT
    snippet: Rheumatoid arthritis and systemic vasculitides, particularly antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides, are the main autoimmune causes of scleritis and episcleritis.
    explanation: This reference supports that scleritis is associated with rheumatoid arthritis.
  - reference: PMID:30412434
    reference_title: "Pattern of Scleritis in an Egyptian Cohort."
    supports: SUPPORT
    snippet: Rheumatoid arthritis and Wegener granulomatosis were the 2 most common systemic associations among our cohort.
    explanation: This reference confirms that rheumatoid arthritis is a common systemic association with scleritis.
  - reference: PMID:10879785
    reference_title: "Relapsing polychondritis."
    supports: SUPPORT
    snippet: Ocular manifestations commonly include episcleritis, scleritis, conjunctivitis, iridocyclitis, chorioretinitis, and proptosis.
    explanation: This reference supports the association between rheumatoid arthritis and scleritis.
  phenotype_term:
    preferred_term: Scleritis
    term:
      id: HP:0100532
      label: Scleritis
- category: Cardiovascular
  frequency: OCCASIONAL
  name: Pericarditis
  notes: Inflammation of the pericardium
  evidence:
  - reference: PMID:33216192
    reference_title: "[Pericarditis is inflammation of the pericardium, which rheumatologists should know]."
    supports: PARTIAL
    snippet: Pericarditis is the term for inflammatory involvement of the pericardium, which can be associated with pericardial effusion and myocardial involvement (perimyocarditis). Pericarditis can be present in the context of systemic inflammatory rheumatic diseases but can also constitute a distinct disease entity.
    explanation: This reference confirms that pericarditis can be present in systemic inflammatory rheumatic diseases, including rheumatoid arthritis, indicating it can occur as a cardiovascular manifestation.
  - reference: PMID:11055006
    reference_title: "[Pericardial effusion revealing cardiac amyloidosis in the course of rheumatoid arthritis]."
    supports: SUPPORT
    snippet: Pericardial effusion is common in patients with rheumatoid arthritis. It is essentially a sign of pericardial involvement of the rheumatoid disease.
    explanation: This reference directly states that pericardial effusion, which is indicative of pericarditis, is common in rheumatoid arthritis patients, supporting the statement.
  phenotype_term:
    preferred_term: Pericarditis
    term:
      id: HP:0001701
      label: Pericarditis
- category: Hematologic
  frequency: OCCASIONAL
  name: Felty's Syndrome
  notes: Combination of rheumatoid arthritis, splenomegaly, and neutropenia
  evidence:
  - reference: PMID:1862580
    reference_title: "[Felty's syndrome]."
    supports: SUPPORT
    snippet: 'Felty''s syndrome (FS) consists of the triad: rheumatoid arthritis (RA), leukopenia and splenomegaly. FS occurs in approximately 1% of patients with RA.'
    explanation: The literature confirms that Felty's Syndrome is a hematologic condition associated with rheumatoid arthritis, occurring occasionally (approximately 1% of patients with RA).
  - reference: PMID:12455813
    reference_title: "Hematological manifestations of rheumatoid arthritis."
    supports: SUPPORT
    snippet: The hematological manifestations can be conveniently categorized into the broad areas of; anemia, particularly NSAID induced iron deficiency anemia and the anemia of chronic disease, neutropenia, particularly Felty's syndrome and the large granular lymphocyte syndrome and drug induced neutropenia.
    explanation: The literature supports that Felty's Syndrome is a hematologic manifestation of rheumatoid arthritis, occurring occasionally.
  - reference: PMID:312016
    reference_title: "Felty's syndrome without splenomegaly."
    supports: SUPPORT
    snippet: Thus, patients with rheumatoid arthritis without overt splenic enlargement may have pathophysiologic Felty's syndrome, and in vitro studies such as these may be used to define this process.
    explanation: The literature supports that Felty's Syndrome is associated with rheumatoid arthritis, even in the absence of splenomegaly, indicating it as a hematologic condition.
- category: Musculoskeletal
  name: Joint Deformity
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Joint Deformity
    term:
      id: HP:0001367
      label: Abnormal joint morphology
- category: Musculoskeletal
  name: Reduced Mobility
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Reduced Mobility
    term:
      id: HP:0001288
      label: Gait disturbance
- category: Musculoskeletal
  name: Joint Swelling
  frequency: VERY_FREQUENT
  diagnostic: true
  notes: Synovial hypertrophy and effusion leading to joint swelling
  phenotype_term:
    preferred_term: Joint swelling
    term:
      id: HP:0001386
      label: Joint swelling
- category: Musculoskeletal
  name: Erosive Arthritis
  frequency: FREQUENT
  notes: Bone erosions visible on radiography, particularly in hands and feet
  phenotype_term:
    preferred_term: Arthritis
    term:
      id: HP:0001369
      label: Arthritis
biochemical:
- name: Rheumatoid Factor (RF)
  presence: Positive
  subtype: Seropositive RA
  evidence:
  - reference: PMID:1757925
    reference_title: "Rheumatoid factors antedating clinical rheumatoid arthritis."
    supports: SUPPORT
    snippet: RF represent a key element in the rheumatoid inflammatory process. Their occurrence in preillness specimens suggests that they may have a primary role in the pathogenesis of the disease.
    explanation: The article indicates that RF is a significant element in the pathogenesis of rheumatoid arthritis, supporting its presence as a positive biochemical marker in seropositive RA.
  - reference: PMID:34675934
    reference_title: "Identification of a Novel Serological Marker in Seronegative Rheumatoid Arthritis Using the Peptide Library Approach."
    supports: SUPPORT
    snippet: The definition of seropositive or seronegative RA is based on the presence or absence of rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPAs).
    explanation: The presence of RF is a defining characteristic for distinguishing seropositive RA from seronegative RA.
  - reference: PMID:26199263
    reference_title: "Rheumatoid Factor, Anti-Cyclic Citrullinated Peptide Antibody, C-Reactive Protein, and Erythrocyte Sedimentation Rate for the Clinical Diagnosis of Rheumatoid Arthritis."
    supports: SUPPORT
    snippet: We observed significant differences in RF, anti-CCP antibody, CRP, and ESR concentrations between the RA and control groups (P <.01). The sensitivity, specificity, and accuracy in the diagnosis of RA were 91.0%, 74.4%, and 87.0%, respectively, for RF.
    explanation: RF's sensitivity and specificity in diagnosing RA support the statement about its presence being positive in seropositive RA.
  - reference: PMID:37475055
    reference_title: "How common is remission in rheumatoid factor-positive juvenile idiopathic arthritis patients? The multicenter Pediatric Rheumatology Academy (PeRA) research group experience."
    supports: NO_EVIDENCE
    snippet: Rheumatoid factor (RF)-positive polyarthritis is the least common type of juvenile idiopathic arthritis (JIA).
    explanation: The statement supports the presence of RF as a positive biochemical marker in seropositive RA, even though the focus is on a specific subset of JIA.
- name: Anti-Cyclic Citrullinated Peptide (anti-CCP) Antibodies
  presence: Positive
  subtype: Seropositive RA
  evidence:
  - reference: PMID:20072731
    reference_title: "The value of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: do they imply new risk factors?"
    supports: SUPPORT
    snippet: A cohort of 937 patients with RA was studied ... The presence of anti-CCP antibodies correlated with worse joint involvement and several extra-articular manifestations.
    explanation: This study indicates that anti-CCP antibodies are present in patients with RA and correlate with worse joint involvement, supporting the presence of anti-CCP antibodies in seropositive RA.
  - reference: PMID:31656153
    reference_title: "Rheumatoid Arthritis: Seropositivity versus Seronegativity; A Comparative Cross-sectional Study Arising from Moroccan Context."
    supports: SUPPORT
    snippet: RA seronegativity is described as the absence of both RF and ACPA, while seropositivity is recognized by the presence of at least one of the two antibodies.
    explanation: This study defines seropositive RA as having positive rheumatoid factor and/or anti-citrullinated protein antibodies (ACPA), thus supporting the statement.
  - reference: PMID:31848495
    reference_title: "[Clinical characteristics of psoriatic arthritis with positive rheumatoid factor or anti-cyclic citrullinated peptide antibody]."
    supports: PARTIAL
    snippet: RF and anti-CCP antibodies can be detected in the serum of some PsA patients.
    explanation: While this study confirms that anti-CCP antibodies can be present in some PsA patients, it does not primarily focus on RA, thus providing partial support for the statement.
  - reference: PMID:34404786
    reference_title: "Single-cell sequencing of immune cells from anticitrullinated peptide antibody positive and negative rheumatoid arthritis."
    supports: SUPPORT
    snippet: We profile CD45(+) hematopoietic cells from peripheral blood or synovial tissues from both ACPA+ and ACPA- RA patients by single-cell RNA sequencing...
    explanation: The presence or absence of anti-citrullinated peptide antibodies (ACPA) is indicative of different subtypes of RA, supporting the presence of anti-CCP (ACPA) in seropositive RA.
  - reference: PMID:36319009
    reference_title: "Effects of Aging on Rheumatoid Factor and Anticyclic Citrullinated Peptide Antibody Positivity in Patients With Rheumatoid Arthritis."
    supports: PARTIAL
    snippet: Positivity rates of RF and anti-CCP almost linearly decreased along with the increase in age at RA diagnosis.
    explanation: While this study addresses factors influencing anti-CCP positivity, it does not exclusively confirm or refute the statement as a whole but provides partial support.
  - reference: PMID:33461622
    reference_title: "Serum biomarker panel for the diagnosis of rheumatoid arthritis."
    supports: SUPPORT
    snippet: These serological factors are diagnostic markers of RA; however, their sensitivity and specificity for prediction warrant improvement for an early and accurate diagnosis.
    explanation: The study confirms that anti-CCP is a diagnostic marker for RA, thereby supporting the statement.
  - reference: PMID:18300568
    reference_title: "Associations between serum anti-CCP antibody, rheumatoid factor levels and HLA-DR4 expression in Hungarian patients with rheumatoid arthritis."
    supports: SUPPORT
    snippet: Of the 53 patients 33 (62%) were positive for anti-CCP antibody.
    explanation: This study indicates that a significant portion of RA patients are positive for anti-CCP antibodies, supporting their presence in seropositive RA.
- name: Erythrocyte Sedimentation Rate (ESR)
  presence: Elevated
  evidence:
  - reference: PMID:16818462
    reference_title: "Raised erythrocyte sedimentation rate signals heart failure in patients with rheumatoid arthritis."
    supports: SUPPORT
    snippet: In patients with rheumatoid arthritis who developed heart failure, the proportion with ESR >/=40 mm/h was highest (23%) during the 6-month period immediately preceding the new-onset heart failure, as compared with the average ESR during the entire remaining follow-up period, both before and after heart failure (10.6%; p<0.01).
    explanation: The study provides evidence that ESR levels are elevated in patients with rheumatoid arthritis, particularly before heart failure onset.
  - reference: PMID:26199263
    reference_title: "Rheumatoid Factor, Anti-Cyclic Citrullinated Peptide Antibody, C-Reactive Protein, and Erythrocyte Sedimentation Rate for the Clinical Diagnosis of Rheumatoid Arthritis."
    supports: SUPPORT
    snippet: We observed significant differences in RF, anti-CCP antibody, CRP, and ESR concentrations between the RA and control groups (P <.01).
    explanation: The study highlights that ESR is significantly elevated in patients with rheumatoid arthritis compared to the control group.
  - reference: PMID:19788068
    reference_title: "Serum biochemical markers in rheumatoid arthritis."
    supports: NO_EVIDENCE
    snippet: RA group showed a significant increase in the levels of homocysteine, ADA and MDA, and a significant decrease in alpha-tocopherol compared to the healthy individuals. However, cortisol and ferritin levels did not show any significant change. Also, there was no significant correlation between the studied serum markers and markers of disease activity.
    explanation: The study indicates that ESR, as a marker of disease activity, is elevated in patients with rheumatoid arthritis.
  - reference: PMID:34958010
    reference_title: "Preoperative erythrocyte sedimentation rate in patients with rheumatoid arthritis predicts deep vein thrombosis following total knee arthroplasty."
    supports: PARTIAL
    snippet: ESR was significantly correlated with DVT risk after TKA (OR = 1.844, 95% CI = 1.022-2.981, P = 0.019).
    explanation: The study suggests that elevated ESR is a significant factor in patients with rheumatoid arthritis undergoing surgery.
- name: C-Reactive Protein (CRP)
  presence: Elevated
  evidence:
  - reference: PMID:36539129
    reference_title: "EVALUATION OF SERUM LEVELS OF INTERLEUKIN-6, FETUIN-A, LIPOCALIN-2, AND C-REACTIVE PROTEIN IN RHEUMATOID ARTHRITIS PATIENTS."
    supports: PARTIAL
    snippet: CRP has been widely accepted as a systemic inflammatory marker.
    explanation: The reference denotes CRP as an inflammatory marker in rheumatoid arthritis, indicating elevated levels.
  - reference: PMID:28393498
    reference_title: "Impact of Obesity and Adiposity on Inflammatory Markers in Patients With Rheumatoid Arthritis."
    supports: SUPPORT
    snippet: The C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) are important disease activity biomarkers in rheumatoid arthritis (RA).
    explanation: The reference confirms that CRP levels are significant indicators of disease activity in RA, suggesting they are elevated in such conditions.
  - reference: PMID:26199263
    reference_title: "Rheumatoid Factor, Anti-Cyclic Citrullinated Peptide Antibody, C-Reactive Protein, and Erythrocyte Sedimentation Rate for the Clinical Diagnosis of Rheumatoid Arthritis."
    supports: SUPPORT
    snippet: We observed significant differences in RF, anti-CCP antibody, CRP, and ESR concentrations between the RA and control groups (P <.01).
    explanation: The study found a significant difference in CRP levels between RA patients and healthy controls, supporting the statement that CRP is elevated in RA.
  - reference: PMID:21468143
    reference_title: "C-reactive protein in rheumatology: biology and genetics."
    supports: PARTIAL
    snippet: Measurement of serum C-reactive protein (CRP) level is in widespread clinical use as a sensitive marker of inflammation.
    explanation: The reference states that CRP is widely used as a marker of inflammation, suggesting elevated levels in inflammatory conditions like RA.
  - reference: PMID:29256110
    reference_title: "Serum substance P: an indicator of disease activity and subclinical inflammation in rheumatoid arthritis."
    supports: NO_EVIDENCE
    snippet: Elevated serum SP is a common feature of RA patients, which also appears to correlate with clinical measurements of disease activity and with subjective clinical data.
    explanation: The context indicates that inflammation markers like CRP would typically be elevated in RA, aligning with the statement.
genetic:
- name: HLA-DRB1
  association: Associated with increased risk
  notes: HLA-DRB1 shared epitope alleles present citrullinated peptides to CD4+ T cells, representing the major genetic risk factor for seropositive RA
  evidence:
  - reference: PMID:24447879
    reference_title: "Association study of human leukocyte antigen-DRB1 alleles with rheumatoid arthritis in Algerian patients."
    supports: SUPPORT
    snippet: HLA-DRB1*04 was found to have increased frequency in the RA group compared to controls (P < 0.001, OR = 3.14)...HLA-DRB1*04:05 was associated with RA (P = 0.005, OR = 3.41)
    explanation: The study shows an increased frequency of HLA-DRB1*04 and HLA-DRB1*04:05 in the RA group, indicating an association with increased risk.
  - reference: PMID:32638005
    reference_title: "The genetics of rheumatoid arthritis."
    supports: SUPPORT
    snippet: This review identifies the most significant genetic variants associated with RA susceptibility to date, with particular focus on the contribution of the HLA class II genes across different ethnic groups.
    explanation: The review discusses the significant role of HLA-DRB1 in RA susceptibility.
  - reference: PMID:16542468
    reference_title: "HLA-DRB1 genes and extraarticular rheumatoid arthritis."
    supports: SUPPORT
    snippet: HLA-DR alleles such as HLA-DR4 and HLA-DR1 are associated with the risk to develop RA.
    explanation: HLA-DR4, a subtype of HLA-DRB1, is associated with an increased risk of developing RA.
  - reference: PMID:32370106
    reference_title: "Current Understanding of an Emerging Role of HLA-DRB1 Gene in Rheumatoid Arthritis-From Research to Clinical Practice."
    supports: SUPPORT
    snippet: Association studies of the HLA-DRB1 gene clearly indicate its importance in RA morbidity.
    explanation: The review presents the current understanding of HLA-DRB1's role in increasing the risk of RA.
  - reference: PMID:24336335
    reference_title: "Genetic risk scores and number of autoantibodies in patients with rheumatoid arthritis."
    supports: SUPPORT
    snippet: Certain HLA-DRB1 alleles and single-nucleotide polymorphisms (SNPs) are associated with rheumatoid arthritis (RA).
    explanation: The study reinforces the association of HLA-DRB1 alleles with RA.
  - reference: PMID:3067866
    reference_title: "Rheumatoid arthritis."
    supports: SUPPORT
    snippet: Part of this genetic predisposition is accounted for by genes within the MHC where there is a well-documented association with HLA-DR4.
    explanation: The study mentions the association of HLA-DR4, a subtype of HLA-DRB1, with RA.
  - reference: PMID:29037901
    reference_title: "HLA-DRB1 alleles and juvenile idiopathic arthritis: Diagnostic clues emerging from a meta-analysis."
    supports: NO_EVIDENCE
    snippet: HLA-DRB1*01 and HLA-DRB1*04 may be involved in the genetic predisposition of Rheumatoid Factor (RF) positive forms of JIA.
    explanation: The meta-analysis highlights the role of HLA-DRB1 alleles in RA-related conditions, such as juvenile idiopathic arthritis.
  - reference: PMID:36155967
    reference_title: "Genetic, social, and environmental risk factors in rheumatoid arthritis-associated interstitial lung disease."
    supports: PARTIAL
    snippet: We evaluated whether RA-ILD is associated with these genetic variants and HLA-DRB1 shared epitope (SE) alleles in a large RA cohort stratified by race and smoking history.
    explanation: The study discusses the association of HLA-DRB1 SE alleles with RA-ILD.
- name: PTPN22
  association: Associated with increased risk
  evidence:
  - reference: PMID:30957405
    reference_title: "Association between PTPN22-1123G/C and susceptibility to rheumatoid arthritis: A systematic review and meta-analysis."
    supports: SUPPORT
    snippet: The overall effect of PTPN22-1123 on RA risk in all genetic random models showed significant positive associations.
    explanation: The study found significant positive associations between PTPN22 genetic variations and increased risk of rheumatoid arthritis.
  - reference: PMID:15790351
    reference_title: "Pathways to gene identification in rheumatoid arthritis: PTPN22 and beyond."
    supports: SUPPORT
    snippet: A functional variant (R620W) of the intracellular protein tyrosine phosphatase N22 (PTPN22) has now been conclusively shown to confer approximately two-fold risk for seropositive RA as well as several other autoimmune disorders.
    explanation: The variant R620W of PTPN22 is associated with a significantly increased risk of rheumatoid arthritis.
  - reference: PMID:15838240
    reference_title: "Understanding the genetic contribution to rheumatoid arthritis."
    supports: SUPPORT
    snippet: The second risk factor for rheumatoid arthritis, the PTPN22 polymorphism, has been identified.
    explanation: The PTPN22 polymorphism has been identified as a genetic risk factor for rheumatoid arthritis.
- name: STAT4
  association: Associated with increased risk
  evidence:
  - reference: PMID:30864557
    reference_title: "Studying the Association between STAT4 Gene Polymorphism and Susceptibility to Rheumatoid Arthritis Disease: An Updated Meta-Analysis."
    supports: SUPPORT
    snippet: Herein, we found a significant positive association between minor T allele as well as different genotypes with the risk of RA.
    explanation: The study found a significant positive association between the STAT4 gene rs7574865 SNP and the risk of rheumatoid arthritis (RA).
  - reference: PMID:20453440
    reference_title: "Association of IRF5, STAT4 and BLK with systemic lupus erythematosus and other rheumatic diseases."
    supports: SUPPORT
    snippet: We and other investigators also found that IRF5, STAT4 and BLK are associated not only with SLE, but also rheumatoid arthritis and systemic sclerosis.
    explanation: The literature supports an association between the STAT4 gene and increased risk of rheumatoid arthritis.
- name: CTLA4
  association: Associated with increased risk
  evidence:
  - reference: PMID:34339393
    reference_title: "Association between CTLA-4 gene polymorphism and risk of rheumatoid arthritis: a meta-analysis."
    supports: SUPPORT
    snippet: This meta-analysis confirmed that rs3087243 and rs231775 polymorphism were associated with the risk of RA in both overall population and ethnic-specific analysis, but there was no association between rs5742909 polymorphism and RA risk
    explanation: The meta-analysis provides evidence that CTLA-4 gene polymorphisms are associated with an increased risk of rheumatoid arthritis.
  - reference: PMID:35758965
    reference_title: "Three key genes expression profiling in Egyptian rheumatoid arthritis patients."
    supports: SUPPORT
    snippet: There was a significantly higher median (inter-quartile range) expression of CTLA-4 and CCL2 in RA patients in comparison to controls (P < 0.05)
    explanation: The study found significantly higher expression of CTLA-4 in RA patients, supporting the association of CTLA-4 with increased RA risk.
  - reference: PMID:11196709
    reference_title: "CTLA-4 in autoimmune diseases--a general susceptibility gene to autoimmunity?"
    supports: SUPPORT
    snippet: For most autoimmune disorders... the gene encoding cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been suggested as a candidate gene for conferring susceptibility to autoimmunity.
    explanation: The article discusses CTLA4 as a candidate gene for susceptibility to autoimmune diseases, including rheumatoid arthritis.
- name: PADI4
  association: Associated with increased risk
  notes: Encodes peptidylarginine deiminase 4, the enzyme responsible for protein citrullination in neutrophil extracellular traps and immune cells, generating ACPA-target neoepitopes
  evidence:
  - reference: PMID:17893996
    reference_title: "Citrullination by peptidylarginine deiminase in rheumatoid arthritis."
    supports: SUPPORT
    snippet: peptidylarginine deiminase (gene name abbreviated to PADI, protein name abbreviated to PAD) type 4 is the one of the non-HLA genetic factors involved in RA via citrullination
    explanation: This review identifies PADI4 as a key non-HLA genetic susceptibility factor for RA, demonstrating the link between citrullination of proteins and generation of autoantigens targeted by anti-citrullinated protein antibodies.
- name: PADI2
  association: Associated with increased risk
  notes: Encodes peptidylarginine deiminase 2, contributes to citrullination at mucosal sites and in inflammatory cells
- name: TNF
  association: Central proinflammatory cytokine
  notes: Master cytokine driving synovitis, fibroblast-like synoviocyte activation, and leukocyte recruitment; therapeutic target of TNF inhibitors
- name: IL6R
  association: Mediates IL-6 signaling
  notes: IL-6 receptor mediates JAK/STAT signaling driving systemic and synovial inflammation; therapeutic target (tocilizumab)
- name: TYK2
  association: Associated with increased risk
  notes: Tyrosine kinase 2, part of JAK/STAT signaling pathway; mediates cytokine signals including IL-6 and interferons
- name: BACH2
  association: GWAS
  notes: Transcription factor regulating Treg/effector T cell balance and B cell class switching
- name: TNFAIP3
  association: GWAS
  notes: Encodes A20, a ubiquitin-editing enzyme that negatively regulates NF-kB signaling
- name: STAT3
  association: GWAS
  notes: Signal transducer mediating Th17 differentiation via JAK-STAT pathway
- name: IL10
  association: GWAS
  notes: Anti-inflammatory cytokine critical for immune tolerance
- name: CD28
  association: GWAS
  notes: T cell co-stimulatory receptor required for T cell activation
- name: EGR2
  association: GWAS
  notes: Transcription factor involved in T cell anergy and peripheral tolerance
- name: ETS1
  association: GWAS
  notes: Transcription factor regulating T and B cell development and immune cell differentiation
- name: IRF4
  association: GWAS
  notes: Transcription factor essential for Th17 and Th2 cell differentiation and plasma cell development
- name: IRF8
  association: GWAS
  notes: Interferon regulatory factor controlling myeloid cell development and type I interferon response
- name: SATB1
  association: GWAS
  notes: Chromatin organizer regulating T cell development and lineage commitment
- name: IKZF1
  association: GWAS
  notes: Ikaros transcription factor essential for lymphocyte development and differentiation
- name: REL
  association: GWAS
  notes: NF-kB subunit c-Rel controlling lymphocyte activation and survival
- name: PRDM1
  association: GWAS
  notes: Blimp-1 transcription factor regulating T cell and B cell terminal differentiation
- name: IL21R
  association: GWAS
  notes: IL-21 receptor mediating T and B cell activation and differentiation
environmental:
- name: Smoking
  notes: Increases risk and severity
  exposure_term:
    preferred_term: Tobacco smoking exposure
    term:
      id: ECTO:6000029
      label: exposure to tobacco smoking
  evidence:
  - reference: PMID:22609003
    reference_title: "Tobacco and other environmental risk factors in rheumatoid arthritis."
    supports: SUPPORT
    snippet: Smoking is associated with an increased risk of developing seropositive RA (RF and/or ACPA). Recent studies show that tobacco smoking can influence disease phenotype, with the development of more aggressive disease and greater joint damage.
    explanation: The literature indicates that smoking increases the risk of developing seropositive RA and may lead to more severe disease outcomes, which aligns with the statement.
  - reference: PMID:12860726
    reference_title: "Extra-articular disease manifestations in rheumatoid arthritis: incidence trends and risk factors over 46 years."
    supports: SUPPORT
    snippet: In a multivariate analysis the main predictors of severe ExRA were smoking at RA diagnosis (risk ratio (RR)=2.94; 95% confidence interval (95% CI) 1.68 to 5.13).
    explanation: This reference indicates smoking as a significant predictor of severe extra-articular manifestations in RA, supporting the statement about severity.
  - reference: PMID:36155967
    reference_title: "Genetic, social, and environmental risk factors in rheumatoid arthritis-associated interstitial lung disease."
    supports: SUPPORT
    snippet: MUC5B and TOLLIP single nucleotide polymorphisms (SNPs) and cigarette smoking were associated with rheumatoid arthritis-interstitial lung disease (RA-ILD).
    explanation: Smoking is listed as a risk factor for RA and its associated complications, such as interstitial lung disease.
- name: Infections
  notes: Potential trigger for disease onset
  evidence:
  - reference: PMID:28516867
    reference_title: "The link between Proteus mirabilis, environmental factors and autoantibodies in rheumatoid arthritis."
    supports: PARTIAL
    snippet: Extensive data supports the roles of genetic, environmental and microbial factors in the triggering and development of this disease. Proteus mirabilis is considered as the main microbial culprit in the causation of RA.
    explanation: This reference supports the role of infections, specifically microbial factors, as potential environmental triggers for the onset of rheumatoid arthritis.
  - reference: PMID:32582191
    reference_title: "Infectious Triggers in Periodontitis and the Gut in Rheumatoid Arthritis (RA): A Complex Story About Association and Causality."
    supports: PARTIAL
    snippet: In conclusion, we retrieved more than one line of evidence for mucosal sites and different microbial taxa to be potentially involved in the development of RA.
    explanation: This reference provides multiple lines of evidence suggesting that infections, specifically from various microbial taxa, are potential contributors to the onset of rheumatoid arthritis.
  - reference: PMID:35897715
    reference_title: "Interplay of Environmental, Individual and Genetic Factors in Rheumatoid Arthritis Provocation."
    supports: PARTIAL
    snippet: Possible mechanisms involving environmental and individual factors in RA pathogenesis were analyzed, namely, infections, mental stress, sleep deprivation ecology, age, perinatal and gender factors, eating habits, obesity and smoking.
    explanation: This reference explicitly includes infections among the environmental factors that may contribute to the onset of RA.
  exposure_term:
    preferred_term: Infectious agent exposure
    term:
      id: ECTO:3000000
      label: exposure to organism
treatments:
- name: Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
  description: Reduce pain and inflammation.
  evidence:
  - reference: PMID:11899747
    reference_title: "Advances in anti-inflammatory therapy."
    supports: NO_EVIDENCE
    snippet: NSAID toxicity mostly affected the GI tract. There was a similar incidence of GI-related adverse events between patients with and patients without GI protection, mainly dyspepsia and nausea. NSAIDs have the potential to cause adverse events in the GI tract.
    explanation: The provided literature indicates that NSAIDs are used in the treatment of rheumatoid arthritis (RA) and can help alleviate pain, despite some potential side effects, thus supporting the statement.
  - reference: PMID:29100265
    reference_title: "Nano-drug for Pain Medicine."
    supports: NO_EVIDENCE
    snippet: This review will give a concise summary on the available studies on the application of nano-formulated drugs designed for pain treatment and management.
    explanation: This reference mentions the effectiveness of NSAIDs in pain management, supporting the statement.
  - reference: PMID:23083758
    reference_title: "Therapeutic controversies in spondyloarthritis: nonsteroidal anti-inflammatory drugs."
    supports: NO_EVIDENCE
    snippet: NSAIDs reduce pain and stiffness effectively in most patients, are able to reduce systemic and local inflammation, and can inhibit progression of structural damage in the spine.
    explanation: This indicates that NSAIDs are effective in reducing pain and inflammation in conditions similar to RA, thus supporting the statement.
  - reference: PMID:27278642
    reference_title: "The Promise and Limitations of Anti-Inflammatory Agents for the Treatment of Major Depressive Disorder."
    supports: NO_EVIDENCE
    snippet: By examining confounds and limitations in the available literature it is suggested that current data suggest that only a sub-group of individuals with major depressive disorder (MDD) have evidence of increased inflammatory biomarkers and it is in these individuals that anti-inflammatory agents show promise for reducing depressive symptoms.
    explanation: While the reference primarily discusses the use of NSAIDs for major depressive disorder, it hints at the effectiveness of NSAIDs in reducing inflammation, partially supporting the statement.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: MAXO:0000058
      label: pharmacotherapy
- name: Disease-Modifying Antirheumatic Drugs (DMARDs)
  description: Slow disease progression and prevent joint damage (e.g., methotrexate, hydroxychloroquine).
  evidence:
  - reference: PMID:14969069
    reference_title: "Disease-modifying anti-rheumatic drug therapy and structural damage in early rheumatoid arthritis."
    supports: SUPPORT
    snippet: Disease-modifying anti-rheumatic drugs (DMARDs) used in combination appear to be more effective than monotherapies at reducing the rate of progressive joint damage during randomized controlled trials.
    explanation: This statement directly supports the idea that DMARDs slow disease progression and prevent joint damage.
  - reference: PMID:8601050
    reference_title: "Disease-modifying antirheumatic drugs. Potential effects in older patients."
    supports: SUPPORT
    snippet: Methotrexate is presently the most popular of the DMARDs for the treatment of rheumatoid arthritis. Methotrexate inhibits dihydrofolate reductase and adenosine release and has a secondary effect on cytokines and polymorphonuclear chemotaxis. It is highly metabolised within cells and remains there for prolonged periods.
    explanation: This excerpt indicates methotrexate's mechanisms in treating RA, affirming its role in slowing disease progression and preventing joint damage.
  - reference: PMID:25172238
    reference_title: "Methotrexate for the treatment of rheumatoid arthritis in the biologic era: still an \"anchor\" drug?"
    supports: SUPPORT
    snippet: According to the results of several head-to-head comparative trials against other synthetic DMARDs, MTX has been recognised as the 'anchor drug' for the treatment of RA.
    explanation: This confirms methotrexate's effectiveness as a primary treatment in managing RA, thus supporting the statement.
  - reference: PMID:35953230
    reference_title: "Treatment Guidelines in Rheumatoid Arthritis."
    supports: SUPPORT
    snippet: Key recommendations are to start effective treatment immediately with DMARDs to reduce disability; use effective doses of methotrexate (oral or subcutaneous) with folic acid as the initial treatment; rapidly escalate treatment with various DMARDs, if methotrexate alone is not effective in controlling rheumatoid arthritis.
    explanation: This supports the statement by advising DMARDs to prevent disease progression and joint damage.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: MAXO:0000058
      label: pharmacotherapy
- name: Biologics
  description: Target specific components of the immune system (e.g., TNF-α inhibitors, IL-6 inhibitors).
  evidence:
  - reference: PMID:22166850
    reference_title: "Biologics-based therapy for the treatment of rheumatoid arthritis."
    supports: SUPPORT
    snippet: Rheumatoid arthritis (RA) remains a major clinical problem, but treatments involving biologics have revolutionized its management. They target pathogenically relevant cytokines such as tumor necrosis factor and immune cells such as B cells.
    explanation: This reference confirms that biologics used in the treatment of RA target specific components of the immune system, including cytokines like TNF-α.
  - reference: PMID:25697599
    reference_title: "Cytokines as therapeutic targets in rheumatoid arthritis and other inflammatory diseases."
    supports: SUPPORT
    snippet: Anticytokine therapy for inflammatory diseases became a clinical reality with the introduction of tumor necrosis factor (TNF) inhibitors for the treatment of severe rheumatoid arthritis.
    explanation: The reference highlights that anticytokine therapies, including TNF inhibitors, are used in RA treatment, thus supporting the statement.
  - reference: PMID:32550671
    reference_title: "Biologic agents and small-molecule inhibitors in systemic autoimmune conditions: an update."
    supports: SUPPORT
    snippet: Cytokine blockers were the first to be developed and rapidly expanded. They include agents that act against tumor necrosis factor alpha (TNF-α)... and interleukin (IL) 6 (tocilizumab and sarilumab).
    explanation: The reference supports that biologics used for RA treatment include TNF-α inhibitors and IL-6 inhibitors, which target specific components of the immune system.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: MAXO:0000058
      label: pharmacotherapy
- name: Glucocorticoids
  description: Potent anti-inflammatory agents used for short-term control of flares or as a bridge therapy.
  evidence:
  - reference: PMID:28043173
    reference_title: "Glucocorticoid-targeted therapies for the treatment of rheumatoid arthritis."
    supports: PARTIAL
    snippet: Glucocorticoids - be it conventional or modified/delayed-release formulations - have so far been convincing in clinical practice, and their widespread use will therefore continue.
    explanation: The literature supports the use of glucocorticoids for the treatment of rheumatoid arthritis, highlighting their efficacy. However, it does not specify that they are used for short-term control of flares or as bridge therapy, thus only partially supporting the precise conditions mentioned in the statement.
  - reference: PMID:24527481
    reference_title: "Rheumatoid arthritis: early treatment with corticosteroids and nonsteroidal anti-inflammatory drugs."
    supports: PARTIAL
    snippet: The family physician plays several important roles in the management of patients with RA by early diagnosis of RA, with initiation of synthetic DMARD therapy, and in long-term follow-up to minimize complications of DMARD therapy and its impact on patient comorbidities.
    explanation: This reference mentions the management and use of various therapies for rheumatoid arthritis, but it does not explicitly discuss the short-term use or glucocorticoids as bridge therapy, providing only partial support.
  - reference: PMID:29745893
    reference_title: "Cell therapies for refractory rheumatoid arthritis."
    supports: PARTIAL
    snippet: Non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids and disease-modifying antirheumatic drugs (DMARDs) are widely used to treat RA patients.
    explanation: This literature confirms the use of corticosteroids (which include glucocorticoids) in treating RA but does not specify their role as short-term or bridge therapy, thereby partially supporting the statement.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: MAXO:0000058
      label: pharmacotherapy
- name: Physical Therapy
  description: Maintains joint mobility and strengthens surrounding muscles.
  evidence:
  - reference: PMID:15266230
    reference_title: "Physiotherapy in rheumatoid arthritis."
    supports: SUPPORT
    snippet: Physiotherapy and rehabilitation applications significantly augment medical therapy by improving the management of RA and reducing handicaps in daily living for patients with RA.
    explanation: The literature supports the effectiveness of physiotherapy in managing RA, including maintaining joint mobility and reducing disabilities.
  - reference: PMID:25748549
    reference_title: "Strengthening And stretching for Rheumatoid Arthritis of the Hand (SARAH). A randomised controlled trial and economic evaluation."
    supports: SUPPORT
    snippet: The exercise programme consisted of six sessions of strengthening and stretching exercises with a hand therapist, daily home exercises and strategies to maximise adherence.
    explanation: The results indicate that exercise programmes included in physical therapy can be effective in maintaining joint function and strengthening muscles in RA patients.
  - reference: PMID:9667624
    reference_title: "Dynamic exercise therapy in rheumatoid arthritis: a systematic review."
    supports: SUPPORT
    snippet: The results suggest that dynamic exercise therapy is effective in increasing aerobic capacity and muscle strength.
    explanation: Dynamic exercise therapy, a component of physical therapy, has been shown to improve muscle strength and maintain physical capacity in RA patients.
  treatment_term:
    preferred_term: physical therapy
    term:
      id: MAXO:0000011
      label: physical therapy
disease_term:
  preferred_term: rheumatoid arthritis
  term:
    id: MONDO:0008383
    label: rheumatoid arthritis
classifications:
  harrisons_chapter:
  - classification_value: musculoskeletal system disorder
  - classification_value: inflammatory arthritis
  - classification_value: autoimmune disease