Infliximab treatment-induced formation of autoantibodies is common in Behçet's disease.

OBJECTIVE: To study autoantibody formation in patients with Behcet's disease (BD) who received long-term treatment with the anti-TNF monoclonal antibody infliximab. METHODS: Serial sera from infliximab-treated patients (5 mg/kg at weeks 0, 4, 8, and every 6-8 weeks thereafter) were tested for various autoantibodies, using commercially available methods, at baseline and at 6 months (n = 20), at 12 months (n = 16), and at 18 months post-baseline (n = 12). Thirty-five age- and sex-matched BD patients, not treated with infliximab, served as controls. RESULTS: Autoantibodies were rarely seen in controls, as well as in infliximab treated patients at baseline. Formation of antinuclear antibodies (ANA) at low titers was evident in 13/20 (65%) patients at 6 months post-baseline; one additional patient developed anti-beta2 glycoprotein-I IgM antibodies (anti-beta(2)GPI). Of the 13 ANA-positive sera, low titers-IgM of anti-dsDNA or anti-beta(2)GPI were detected in 7 (35%) and 6 (30%) patients, respectively. Additional measurements at 12 and 18 months showed that the persistence and/or increasing titers of these autoantibodies depended on continuation of treatment. Antibodies to extractable nuclear antigens (anti-RNP, anti-SS-A/Ro, anti-SS-B/La, anti-Sm), rheumatoid factors, anti-cyclic citrullinated peptide antibodies and antineutrophil cytoplasmic antibodies, were never detected. No antibody-related symptoms, lupus-like disease, or thrombosis were observed in any patient up to 18 months of follow-up. CONCLUSION: Early induction of ANA and specific autoantibodies is common in BD patients treated with infliximab, including low titers of non-pathogenic anti-dsDNA and anti-Beta 2 GPI antibodies. A possible clinical significance of these findings needs to be documented in further studies, including more patients and longer follow-up periods.