Anti-BP180 autoantibodies as a marker of poor prognosis in bullous pemphigoid: a cohort analysis of 94 elderly patients

Abstract

The prognosis of bullous pemphigoid (BP), a disorder which usually affects elderly patients, is not well established and conflicting data have been reported about the mortality rate of the disease. Our objective in this study was to assess the clinical and immunological factors determining survival in a prospective series of 94 patients with BP. A cohort of 94 consecutive patients with BP (mean age +/- SD: 81 +/- 4 years) was studied over an 8-year period (1987-94) in one department and patients followed up for at least 1 year. The diagnosis of BP was made on clinical criteria (using a standardized questionnaire), direct immunofluorescence (IF) findings (i.e. linear deposits of IgG and/or C3 along the basement membrane zone) and confirmed by direct immunoelectron microscopy and/or Western immunoblotting. Our analysis (median duration of follow-up: 5 years) showed that 37% of BP patients were dead within a year of starting treatment. The clinical or immunological factors which may influence the prognosis of BP were studied according to the criterion of death or survival by the end of the first year of treatment. None of the following factors was found to be significantly linked to the prognosis in BP: age, sex, extent of skin lesions at presentation, presence of mucosal lesions, blood eosinophilia, or the presence of circulating basement membrane zone autoantibodies by indirect IF. An impaired general condition and a history of coronary artery disease indicated a bad prognosis. The presence of circulating autoantibodies against BP180 autoantigen but not autoantibodies against BP230, as detected by immunoblotting on epidermal extracts, was found to be significantly more frequent (60% vs. 25%) in BP patients who died within the first year of treatment (P < 0.01). We conclude that the presence of circulating autoantibodies against BP180 represents the first intrinsic prognostic factor that has been demonstrated in BP. This result supports the growing body of evidence for the pathophysiological importance of the anti-BP180 autoantibodies.