Which of the following laboratory markers is the MOST specific for the diagnosis of rheumatoid arthritis?

• A Rheumatoid factor (IgM)
• B Antinuclear antibody
• C Anti-cyclic citrullinated peptide (anti-CCP) antibodies ✓
• D Elevated C-reactive protein

Explanation

Anti-CCP antibodies have a specificity for rheumatoid arthritis of about 95 percent, higher than IgM rheumatoid factor, whose specificity is roughly 75 to 85 percent and which is also positive in Sjogren syndrome, chronic hepatitis B, SLE, sarcoidosis and ageing. Anti-CCP positivity also correlates with erosive disease and worse prognosis. ANA is nonspecific and CRP is a generic marker of inflammation found in many conditions.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.