Anticyclic citrullinated peptide antibody and rheumatoid factor in south Tunisian patients with rheumatoid arthritis: association with disease activity and severity

Abstract

Objective: To explore relationships between immunological status, clinical features, radiographic damage, disease activity, and functional disability in Tunisian patients with rheumatoid arthritis (RA).

Materials and methods: The study was carried out in 112 patients with RA. Demographic characteristics, disease duration, disease activity score 28 (DAS28), the Health Assessment Questionnaire (HAQ), and the Sharp/van der Heijde score were collected. Anticyclic citrullinated peptide antibody (anti-CCP) and rheumatoid factor (RF) were performed.

Results: We found that anti-CCP positivity was associated with longer disease duration (P = 0.001), presence of RF (P = 4.89 × 10(-8) ), and night pain positivity (P = 0.025). Patients with positive RF had more night pain and higher anti-CCP positivity (for all P ≤ 0.05). Anti-CCP titer was correlated with disease duration (P = 0.034) and Sharp total score (P = 1.2 × 10(-4) ). Moreover, there was a significant correlation between RF and anti-CCP antibodies titers (P = 0.011). Indeed, DAS28 correlated with HAQ (P = 1.8 × 10(-7) ) and morning stiffness duration (P = 0.045). In multivariate regression analysis, the main factors associated with anti-CCP titers were radiographic damage (P = 1.625 × 10(-4) ) and RF (P = 0.013). For DAS28, only HAQ (P = 2.9 × 10(-4) ) was associated.

Conclusion: These findings suggest that anti-CCP antibodies are associated with RF and more severe joint damage. Moreover, disease activity is associated with functional disability.

Keywords: DAS28; anti-CCP antibodies; rheumatoid arthritis; rheumatoid factor.