Clinical Features of Chinese Patients With Bullous Pemphigoid Induced by Immune Checkpoint Inhibitors.

Objective To explore the clinical features and treatments of Chinese patients with bullous pemphigoid (BP) induced by immune checkpoint inhibitors (ICI). Methods A retrospective analysis was conducted on 18 Chinese patients with ICI-induced BP treated in the Peking Union Medical College Hospital and 14 Chinese patients with this disease reported in the literature.Furthermore,the research data of non-Chinese patients were used for comparison to outline the clinical features and treatment responses of the Chinese patients. Results A total of 32 patients (21 males and 11 females) were enrolled,and all of them presented BP induced by programmed death-1/programmed death ligand-1 inhibitors.Compared with non-Chinese patients,the Chinese patients with ICI-induced BP showed low average ages [(65.2±9.5) years vs. (69.9±10.3) years,P=0.020],increased proportion of BP induced by tislelizumab (28.1% vs. 0,P<0.001),decreased proportions of BP induced by pembrolizumab (18.8% vs. 39.4%,P=0.029) and nivolumab (3.1% vs. 52.8%,P<0.001),and decreased proportion of primary malignant melanoma (9.4% vs. 43.3%,P<0.001).The incidence of pruritus (96.9% vs. 66.1%,P<0.001) and mucosal involvement (59.4% vs. 15.7%,P<0.001) in the Chinese patients were higher than those in the non-Chinese patients.The proportions of the Chinese patients treated with tripterygium glycosides (9.4% vs. 0,P=0.008),dupilumab (18.8% vs. 0.8%,P<0.001),and topical corticosteroids (87.5% vs. 53.5%,P<0.001) were higher than those of non-Chinese patients. Conclusions The Chinese patients with ICI-induced BP tend to have a younger age and a higher probability of BP induced by tislelizumab than the non-Chinese patients.Unlike that in the non-Chinese patients,the primary tumor in the Chinese patients with ICI-induced BP is predominantly lung cancer.Pruritus is more obvious,and mucosal involvement is more common in the Chinese patients.Systemic corticosteroid therapy is the international standard treatment for ICI-induced BP,while tripterygium glycosides and dupilumab are characteristic therapies in China.