The effect of dipeptidyl peptidase-4 inhibitor on incidence and clinical course in bullous pemphigoid patients in a tertiary medical center.

Several studies have reported an association between dipeptidyl peptidase 4 inhibitor (DPP4i), a commonly prescribed second-line oral antihyperglycemic drug, and bullous pemphigoid (BP). However, the benefits of DPP4i withdrawal in patients with BP remain controversial. This study primarily aimed to evaluate the clinical severity of DPP4i-associated BP by comparing it to those without Type 2 diabetes mellitus (DM). The secondary objective was to determine whether cessation of DPP4i is necessary for all patients with BP. This retrospective case-control study included 83 patients. The participants were divided into three groups according to their diabetic status and the status of discontinuance or continuance of DPP4i. The 12-month follow-up of the monthly dosage of systemic steroids per body weight (kg) and the percentage of systemic steroid off-therapy in these participants were recorded since the diagnosis of BP. Compared to patients with BP without DM, the 1st, 3rd, and 12th systemic prednisolone doses were significantly lower in the DPP4i group (p = 0.01684, 0.02559, and 0.009336, respectively). The 12th systemic prednisolone dose was significantly lower in patients who discontinued DPP4i (p = 0.0338). Nevertheless, several spontaneous remissions with systemic steroid off-therapy were also noted in the DPP4i-continuance group within 12 months of follow-up. This article supports the favorable impact of DPP4i withdrawal in patients with BP and shows that DPP4i may incite or aggravate BP, resulting in a milder disease course.