HLA alleles associated to susceptibility to gliptin‐associated bullous pemphigoid in Italian patients

Bullous pemphigoid (BP), although a rare disease, is the most frequent subepidermal autoimmune disorder. Treatment with gliptins, used for type 2 diabetes, was reported as associated with BP onset. To identify HLA alleles that may reflect a higher susceptibility to BP in the Italian population, we analysed 30 patients affected by idiopathic bullous pemphigoid (IBP) and 86 gliptin‐associated BP (GABP) patients. A significant association between HLA‐DQB1*03:01 allele and IBP and GABP patients was found. Of note, both IBP and GABP were significantly associated with one of the following haplotypes: DRB1*11:01 , DRB3*02:02 , DQA1*05:05 , DQB1*03:01 or DRB1*11:04 , DRB3*02:02 , DQA1*05:05 and DQB1*03:01 . These data identify, for the first time, potential markers of susceptibility to BP in the Italian population, especially when associated with gliptin intake.