Initial Blood Work for a Patient with Hand Pain and Family History of Rheumatoid Arthritis
Core Laboratory Tests
- The European League Against Rheumatism recommends that initial blood work for a patient with hand pain and family history of rheumatoid arthritis should include ESR, CRP, RF, and ACPA testing, along with complete blood count, liver function tests, and renal function assessment 1, 2, 3
- Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP) should be performed at baseline for both diagnostic and prognostic purposes in patients with suspected inflammatory arthritis 2, 3
- Rheumatoid Factor (RF) is essential for evaluation as it is predictive of RA diagnosis and prognosis 3, 4
- Anti-Citrullinated Protein Antibodies (ACPA) should be tested alongside RF as it increases diagnostic certainty for RA and provides prognostic information 3, 4
Diagnostic Value of Autoantibody Testing
- The presence of RF and/or ACPA significantly increases the probability of developing RA, though negative tests do not exclude progression to RA 3
- RF and ACPA have strong predictive value for RA diagnosis 3, 1
- The presence of these antibodies also correlates with increased probability of developing persistent synovitis and worse radiographic outcomes 1
Additional Considerations
- Additional autoantibody tests should be considered if non-RA systemic inflammatory disorders are suspected 3
- Plain radiographs of hands and wrists should be performed at baseline as they provide important complementary information 3, 5
- Laboratory tests should be repeated when clinically relevant to assess disease activity and treatment response 3
Common Pitfalls to Avoid
- Laboratory tests should complement, not replace, careful clinical examination 6
- Failing to order both RF and ACPA reduces diagnostic sensitivity 3