Clinical and Immunologic Factors Associated With Bullous Pemphigoid Relapse During the First Year of Treatment

Abstract

Although predisposing factors for bullous pemphigoid (BP) have been recently established, no clinical or immunologic factors have yet been identified to predict disease outcome. To identify risk factors for BP relapse during the first year of treatment. 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). 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. 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. 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.