Objective: Infliximab, a monoclonal antibody to tumor necrosis factor-α, is effective in patients with ankylosing spondylitis (AS), who have not responded to conventional therapy. There were no data on the efficacy and side effect of infliximab in patients with AS in Korea. The objective of this study is to observe the efficacy and adverse effect of infliximab retrospectively in Korean patients with AS. Methods: We reviewed the medical records of thirty-three AS patients. The patients were enrolled to fulfill the modified New York criteria of AS and be in active disease state and resist to conventional therapy. Patients were given 3∼5 mg/kg of infliximab infusions at weeks 0, 2, 8 and 16. Information on C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and antinuclear antibody (ANA) test was collected at each infusion. The paired t-test was used for comparison between the visits. Results: There were 29 male and 4 female patients. The mean age at first infliximab treatment was 34.6⁑9.8 years. All patients were HLA-B27 positive. ESR and CRP decreased significantly from baseline to 16 weeks after treatment (p＜0.001, respectively). The mean ESR was 76.1⁑36.5 mm/h at baseline and 21.3⁑31.6 mm/h at 16 weeks. The mean CRP was 6.4⁑4.8 mg/dL at baseline and 1.3⁑2.1 mg/dL at 16 weeks. Only 1 out of 33 patients got worse. All patients were tested negative for ANA at baseline. After 16 weeks of therapy, the induction of ANA was observed in 8 patients, but no patients have lupus-like symptoms. Conclusion: Infliximab is an effective therapy with non-specific adverse effect in AS non-responsive to conventional therapy in Korea.

Keywords: Infliximab, Ankylosing spondylitis