To determine the prevalence and the associations of anti-neutrophil cytoplasmic antibodies (ANCA) and subtypes with clinical, biological, and radiological findings in patients with rheumatoid arthritis (RA).
This is a transversal study of 85 patients with RA (followed in Ibn-i Sina Hospital, Ankara University School of Medicine) with disease duration of 8.7 +/- 6.4 years. Besides clinical, biological, and radiological disease activity parameters, ANCA and ANCA against myeloperoxidase (MPO) and proteinase 3 (PR3) were examined.
The prevalence of ANCA, perinuclear ANCA (p-ANCA) and atypical ANCA (a-ANCA) were 18% (15/85 patients), 6% and 12%, respectively. Anti-MPO was found in six patients while anti-PR3 was not found. No significant association could be found between clinical, biological, and radiological disease activity assessments and ANCA (including indirect immunoflorescence subtypes). Similarly, ANCA were not associated with features suggestive of underlying vasculitis (noticed in 11/85 patients), and/or other extra-articular features.
Our results confirm that ANCA of various specificities (mainly a-ANCA) occur in a minority of RA. However, those ANCA were not associated with more severe RA, including the 6/85 patients positive for MPO (who were all free from vasculitis). The over-representation in RA sera of a-ANCA, as compared to p-ANCA, should be further studied.