Treatment of active ankylosing spondylitis with leflunomide and methotrexate:a prospective controlled clinical trial

Objective To assess the efficacy and safety of leflunomide in active ankylosing spondylitis.Methods Totally 62 cases of active ankylosing spondylitis were included,and divided randomly into leflunomide group(n=26)and methotrexate group(n=36).The patients in leflunomide group received an oral leflunomide loading dose of 50 mg or 40 mg once daily for the first 3 days followed by a maintenance dose of 50 mg or 40 mg once weekly,according to whether the bodyweight was more than 50 kg or less than 50 kg,respectively.The patients in methotrexate group were prescribed oral methotrexate 5 mg once in the first week,10 mg once in the second week,15 mg once in the third week and thereafter weekly.Sulfasalazine was prescribed 0.75 three times daily in both groups.The Bath Ankylosing Spondylitis Disease Activity Index(BASDAI)and The Bath Ankylosing Spondylitis Metrology Index(BASIM)scoring instruments were used to assess the responsiveness to leflunomide and methotrexate at entry,three months,six months,twelve months and eighteen months after treatment,respectively.Laboratory data including peripheral blood counts(WBC,HGB,RBC),erythrocyte sedimentation rates(ESR),liver enzymes,serum creatinine,urinary sediments were detected at the same time.Sacroiliac joints CT scan and other involved joints x-ray radiograph examinations were taken at entry,six months,twelve months and eighteen months after treatment,respectively.Results Twenty-two cases in leflunomide group and 29 cases in methotrexate group were followed up to eighteen months.BASDAI in leflunomide group was significantly lower(P0.01)compared with MTX group from six months.As to BASMI and ESR,there were no differences between the two groups at three months,six months,twelve months and eighteen months.No deterioration with sacroiliac joints on CT scan and the involved joints on x-ray radiographs in the two groups was found.The incidence rate of adverse events were higher in MTX group than LEF group.Conclusion Leflunomide shows the same efficacy as methotrexate in active ankylosing spondylitis,while the adverse effects are mild compared with methotrexate.