The effect of infliximab on rheumatoid factor and anti-citrullinated cyclic peptide antibodies

Background

Rheumatoid arthritis (RA) patients are successfully treated with infliximab (anti-TNF-α therapy). This therapy may induce autoantibodies like anti-dsDNA antibodies.

Objectives

To investigate the effect of infliximab on rheumatoid factor (RF) and anti-citrullinated cyclic peptide antibodies (anti-CCP antibodies).

Patients and methods

62 patients with refractory RA were treated with infliximab in an early access program. They received 3 mg/kg infliximab IV at week 0, 2, 6 and every 8 weeks thereafter in combination with MTX. Serum samples were obtained at baseline and week 30. Samples were tested for RF Waaler-Rose (SERODIA-RA, Fujirebio Inc), RF Latex Fixation (DifcoLaboratories) and anti-CCP antibodies ELISA (Euro-Diagnostica).

Results

At baseline, 41/62 RA patients were positive for RF Waaler-Rose, 39/62 RA patients were positive for RF Latex Fixation and 41/62 RA patients had a positive test result for anti-CCP antibodies ELISA. After infliximab treatment, 33/62 RA patients were positive for RF Waaler-Rose, 31/62 RA patients were positive for RF Latex Fixation and we observed a positive test result for anti-CCP antibodies in the same 41/62 RA patients. McNemar test revealed a significant paired difference for RF Waaler-Rose (P = 0.039) and for RF Latex Fixation (P = 0.021), but not for anti-CCP antibodies (P = 1.0). Wilcoxon Signed Rank Test showed a significant decrease for RF Waaler-Rose (P < 0.001) and for RF Latex Fixation (P = 0.035). No significant difference was observed for anti-CCP antibodies (P = 0.744).

Conclusion

In RA patients, infliximab treatment results in a decrease of RF Waaler-Rose and RF Latex Fixation. No difference considering the anti-CCP antibodies is seen.