Kridin K, et al. – In this study, experts assessed the correlation between dipeptidyl-peptidase 4 (DPP-4) inhibitor exposure and the development of bullous pemphigoid (BP). They also characterized the clinical features and history of patients with DPP-4 inhibitor–associated BP. Findings suggested an association of vildagliptin and, to a lesser extent, linagliptin with an increased risk of BP. The increasing incidence of BP in Israel may be partly explained by this. They recommended considering the discontinuation of DPP-4 inhibitor treatment in patients with diabetes when BP is diagnosed.

Methods

• In a tertiary care referral center for autoimmune bullous diseases in northern Israel, researchers conducted this retrospective case-control study of the intake of different DPP-4 inhibitor agents and metformin and occurrence of BP among patients with diabetes.
• Between January 1, 2011, and December 31, 2017, they included 82 consecutive patients with diabetes and immunopathologically validated BP, as well as 328 age-, sex-, and ethnicity-matched control participants with diabetes but BP-free.
• They followed up the patients with diabetes and BP and exposure to DPP-4 inhibitors for a median of 2.0 years and compared with other patients with diabetes and BP who were not exposed to DPP-4 inhibitors regarding clinical and immunological features, laboratory analyses, treatments, and clinical outcomes.

Results

• Overall, they noted an association of DPP-4 inhibitor intake with a threefold increased risk for BP.
• For vildagliptin and linagliptin, the adjusted ORs were 10.7 and 6.7, respectively.
• A link of DPP-4 inhibitor use was noted with BP independent of the use of metformin.
• This association was stronger among male vs female patients and strongest in patients younger than 70 years of age.
• Higher mucosal involvement (22.2% vs 6.5%; P =0.04) and lower mean (SD) peripheral eosinophil counts (399.8 [508.0] vs 1,117.6 [1,847.6] cells/μL; P=0.01) were presented by the patients with DPP-4 inhibitor–associated BP vs those with BP who had not been exposed to DPP-4 inhibitor.
• Improved clinical outcomes followed the discontinuation of DPP-4 inhibitor treatment.