Anti-Ro/SSA antibodies in rheumatoid arthritis (RA)

Background

AntiRo are found in 5–15% of RA. Significant associations were reported with sicca, vasculitis, hypergammaglobulins, ANA, high-titer RF, toxicity to D-penicillamine and gold salts treatment. Aim of the study: to evaluate clinical features, radiologic progression and response to disease-modifying antirheumatic drugs (DMARDs) in antiRo-RA patients.

Patients and methods

We studied 210 patients with RA: antiRo were determined by CIE, with human spleen extract, and by ELISA with recombinant Ro proteins (Pharmacia). Cutoff values for ELISA were determined testing 177 sera from routine.

Results

AntiRo were detected in 27 patients (F:M 12.5:1). Two groups (antiRo⁺ and antiRo^-) did not show any difference with regard to disease duration, arthritis onset and articular erosions. AntiRo were associated with xerophthalmia (P < 0.0000001), xerostomia (P = 0.0012), oral ulcers (P = 0.0067), scleritis (P = 0.0067) and amyloidosis (P = 0.042). Rheumatoid factor, antiperinuclear factor and anticitrulline were recorded in 70% in both groups; hypergammaglobulinemia, ANA, anti-dsDNA and AMA were frequently detected in antiRo⁺ patients. Patients were given a mean of 3.93 DMARDs, with no statistical difference between antiRo⁺ and antiRo^-: hydroxychloroquine, methotrexate and gold salts are the most frequently used. Patients who were antiRo^- were more frequently treated with hydroxychloroquine and infliximab, while D-penicillamine was used more frequently in those who were antiRo⁺. DMARD toxicity was detected in 9.3% of antiRo⁺, with no statistically significant difference between the two groups.

Conclusion

AntiRo, found in 12.8% of patients with RA, is associated with extra-articular features and with an autoantibody profile unusual for RA. No difference with respect to DMARD toxicity was found in anti-Ro⁺ patients.