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.