Risk factors for relapse in patients with bullous pemphigoid in clinical remission: a multicenter, prospective, cohort study.

OBJECTIVE To identify prognostic factors for relapse in the first year after cessation of therapy in bullous pemphigoid (BP). DESIGN Prospective, multicenter, cohort study (January 1, 2000, through December 31, 2006). SETTING Fifteen French dermatology departments. Patients Patients with BP in remission under low doses of topical or systemic corticosteroids. Interventions Cessation of corticosteroid treatment (day 0) followed by a systematic clinical and immunologic follow-up. MAIN OUTCOME MEASURES The end point was clinical relapse within the first year after cessation of therapy. Associations of clinical, biological, and immunologic (including direct immunofluorescence, serum anti-basement membrane zone autoantibodies, and serum BP180 autoantibodies by enzyme-linked immunosorbent assay [ELISA] on day 0) variables with clinical relapse were assessed by means of univariate and multivariate analyses. RESULTS On day 0, 30 of 114 patients (26.3%) still had a positive result of direct immunofluorescence, 63 of 112 (56.3%) had circulating anti-basement membrane zone autoantibodies, and 34 of 57 (60%) had anti-BP180 antibodies by ELISA. At month 12, 22 patients were dead (n = 11) or lost to follow-up (n = 11), 51 were in remission, and 45 had had relapses (mean interval to relapse, 3.2 months). Factors predictive of relapse within 12 months after cessation of therapy were a positive result of direct immunofluorescence microscopy (P = .02), a greater age (P = .01), and high-titer ELISA scores (P = .02) on day 0. In multivariate analysis, the only factor independently predictive of relapse was a high-titer ELISA score on day 0 (odds ratio, 11.00; 95% confidence interval, 1.29-93.76). CONCLUSIONS High-titer anti-BP180 ELISA score and, to a lesser degree, a positive direct immunofluorescence finding are good indicators of further relapse of BP. At least 1 of these tests should be performed before therapy is discontinued.