The impact of lesional inflammatory cellular infiltrate on the phenotype of bullous pemphigoid

Background The influence of cutaneous cellular infiltration on the phenotype bullous pemphigoid (BP) remains to be established. Objectives To evaluate main histopathological characteristics patients with BP and assess association between composition lesional inflammatory infiltrate various clinical, immunological immunopathological aspects disease. Methods Retrospective study encompassing diagnosed throughout years 2009–2020 in a specialized tertiary referral centre. Results encompassed 136 BP, whom 27 (19.9%) demonstrated cell-poor skin specimens. Overall, 78 (57.4%), 71 (52.2%) 5 (3.7%) specimens were found include eosinophil-predominant, lymphocyte-predominant neutrophil-predominant infiltrates, respectively. Relative remaining those an eosinophil-predominant had higher (90.8% vs. 77.2%; P = 0.030) whilst lower (70.3% 88.7%; 0.017) seropositivity anti-BP180 NC16A IgG. latter subgroup presented prevalence mucosal involvement (25.9% 8.3%; 0.011) non-inflammatory clinical (50.0% 17.1%; 0.041). Patients manifested severity BPDAI scores frequency subtype (11.1% 36.4%; 0.035), neutrophilic mean (SD) levels IgG [269.3 (227.6) 722.7 (1499.6) U/mL; 0.003]. Conclusions Eosinophil-predominance high cellularity are associated increased Lymphocyte-predominant infiltrates predict more severe phenotype, pointing towards pathogenic role autoreactive lymphocytes.