Table 1 The main clinical and laboratorial characteristics of JIA subtypes based on International League of Associations for Rheumatology (ILAR) classification criteria. ANA – antinuclear antibodies, Anti-CCP – Anti-Cyclic Citrullinated Peptide, CRP - C-reactive protein, ERA - enthesitis-related arthritis, HLA - human leukocyte antigen system, RF – rheumatoid factor, sJIA – systemic JIA
From: Juvenile idiopathic arthritis: from aetiopathogenesis to therapeutic approaches
Subtype | Oligoarticular JIA | Polyarticular JIA RF- | Polyarticular JIA RF+ | ERA | Psoriatic JIA | Systemic sJIA |
|---|---|---|---|---|---|---|
Characteristic of arthritis | • ≤4 joints affected• Mainly large joints• Asymmetric, often only a single joint (knee) | • ≥5 joints affected• Symmetric or asymmetric• Small and large joints• Sometimes a cervical spine and/or temporomandibular joint | • ≥5 joints affected• Symmetric• Mainly small joints (metacarpophalangeal joints and wrists)• Erosive• Aggressive symmetric polyarthritis | • Lower limb joints affected more common• Axial involvement: sacroiliac joint, hip or shoulder | • Asymmetric arthritis• Small and large joints | • Usually arthralgias;• 30–50% chronic arthritis - slowly developed• Mostly wrists, knees, ankles joints or asymptomatic temporomandibular arthritis |
Systemic manifestation | 30% uveitis | 10% uveitis | • Rheumatoid nodules• 10% uveitis | • Acute anterior uveitis• EnthesitisGut inflammation | • Psoriasis• Dactylitis• Onycholysis• Nail pitting• Uveitis (10–15%) | • Spiking fever• Generalized lymphadenopathy• Migratory salmon-pink rash• Serositis (pericarditis most common, then pleuritic and peritonitis)• Hepatosplenomegaly• MAS |
Sex predominance | Female | Female | Female | Male | Equal | Equal |
HLA genetic pre-disposition | Associated with• A2• DRB1*11• DRB1*08• DPB1*0201• DRB1*15*01• DQA1*04• DQB1*04• DRB1*13 for persistent• DRB1*01 for extended variant | Associated with• A2• DRB1*08• DPB1:03• DQA1*04• DRB1*15*01• DPB1*02*01 | Associated with• DRB1*04• DRB1*01• DRB1*08• DQA1*03 | Associated with• B27• DRB1*01• DQA1*01• DQB1*05 | Associated with• DRB1*01• DRB1*11• DRB1*12• HLA-C*06 - biomarker for skin involvement• B27 – for sacroileitis (mostly in older age) | Associated with• DRB1:04• DQA1*01• DQB1*04• DRB1*01 |
Biomarkers | 60% ANA+ | 40% ANA+ | • RF+• Anti-CCP+• ANA+ in 40% | 45–85% HLA-B27+ | 50% ANA+ | Elevating level of• CRP• Ferritin• Platelets |
Adult equivalent | – | Potential Seronegative Rheumatoid Arthritis | RF-positive Rheumatoid Arthritis | Spondyloarthropathies | Psoriatic Arthritis | Adult Onset Still’s Disease |