Importance: Although predisposing factors for bullous pemphigoid (BP) have been recently established, no clinical or immunologic factors have yet been identified to predict disease outcome.
Objective: To identify risk factors for BP relapse during the first year of treatment.
Design, setting, and participants: Multicenter prospective study of 120 consecutive patients with newly diagnosed BP in 8 French dermatology departments. Baseline and 6 follow-up visits were planned to record disease activity and collect blood samples for measurement of serum anti-BP180 and anti-BP230 levels by means of enzyme-linked immunosorbent assay (ELISA).
Main outcomes and measures: The end point was clinical relapse within the first year of therapy. Associations of clinical and immunologic (including serum levels of anti-BP180 and anti-BP230 autoantibodies) parameters with clinical relapse were assessed using univariate and multivariate analyses.
Results: During the 1-year follow-up, 35 patients (29.2%) experienced relapse, whereas anti-BP180 and anti-BP230 ELISA results were similar at baseline between patients who did and did not experience relapse. Factors at baseline independently associated with relapse were extensive disease at inclusion (hazard ratio [HR], 2.37 [95% CI, 1.2-4.8]) and an associated dementia (HR, 2.09 [95% CI, 1.0-4.2]). Use of superpotent topical corticosteroids alone (by 100 patients [83.3%]) induced a dramatic, early decrease in serum levels of anti-BP180 and anti-BP230 autoantibodies. Mean early decreases in autoantibody levels between baseline and day 60 were lower in patients with relapse compared with patients with ongoing remission (-10.0% and -45.2%, respectively, for anti-BP180 levels [P < .001] and -11.8% and -35.4%, respectively, for anti-BP230 levels [P = .046]). A higher serum level of anti-BP180 at day 150, with a cutoff of 23 U/mL, provided 84.2% sensitivity, 44.8% specificity, 33.3% positive predictive value, and 89.7% negative predictive value for the occurrence of relapses between days 150 and 360.
Conclusions and relevance: The pronounced decrease in the level of anti-BP180 autoantibodies and, to a lesser extent, those directed against BP230 confirmed the use of superpotent topical corticosteroids alone as a reference BP treatment. Furthermore, our study suggests that neurological diseases play a major role in BP, not only as a predisposing but also as a prognostic factor.