Clinical and immunological features of bullous pemphigoid: A single-centre retrospective study

Background: Bullous pemphigoid (BP) is an autoimmune blistering disorder predominantly affecting the elderly. This study aimed to characterize the clinical and immunological profiles of BP patients diagnosed in a single dermatology unit over a 10-year period. Material and methods: A retrospective analysis was conducted on 19 patients with confirmed BP, based on clinical criteria, direct immunofluorescence (DIF), and detection of circulating autoantibodies via indirect immunofluorescence (IIF). ELISA or biochip assays were not available. Clinical data, histopathological findings, and serological correlations were analyzed. Results: The predominant DIF pattern was co-deposition of IgG, IgA, and complement component 3 (C3) (68.4%). Two patients exhibited IgA and C3 deposition without IgG, raising the possibility of linear IgA bullous dermatosis (LABD), though clinical features did not warrant reclassification. A statistically significant association was observed between BP180 autoantibody positivity and both type 2 diabetes and amlodipine use. Conclusions: This study highlights an atypically high prevalence of IgA deposits in BP tissue and supports the potential link between calcium channel blockers — especially amlodipine — and BP180 autoantibody development. Limitations include the small cohort size, retrospective design, and lack of ELISA testing. Further multicenter studies are needed to validate these findings and explore immunological variants of BP.