Bullous Pemphigoid Associated with Dipeptidyl Peptidase 4 Inhibitors for the Treatment of Type 2 Diabetes: A Multicenter Study in Istanbul.

Objectives: Recent studies have revealed an association between dipeptidyl peptidase 4 inhibitors (DPP4i) and development of bullous pemphigoid (BP). The main aim of our study is to evaluate the association between DPP4i treatment and BP development. The secondary endpoints were to evaluate clinical characteristics and biochemical parameters of the DPP4i associated BP cases and determine the differences of DPP4i associated BP disease than non-DPP4i associated BP cases.

Methods: We designed a retrospective case-control study, comparing type 2 diabetic 58 BP cases to 75 type 2 diabetic controls. Data were collected from three dermatological departments in Istanbul/Turkey, from November 1, 2008, to January 1, 2019. Medical records of each patient's demographic, clinical characteristics, drugs used, and laboratory data were reviewed.

Results: There was no statistical difference in age and gender between the patient and control group. The most common prescribed oral antidiabetic for both groups was metformin. The most commonly prescribed DPP4i was vildagliptin. Fourteen (24.1%) out of 58 diabetic patients with BP were using vildagliptin, 12 (20.7%) out of 58 diabetic BP patients were using linagliptin, 6 (10.3%) out of 58 diabetic BP patients were using sitagliptin, and 1 (1.7%) out of 58 diabetic BP patients were using saxagliptin. There was no significant difference between the two groups regarding the DPP4 is use (using DPPi at the time of diagnosis and not). Both groups had similar clinical characteristics, localizations, disease severity, comorbidities, treatment responses, and biochemical parameters. BP patients using DPP4i had statistically less mucosal involvement than BP patients not using DPP4i (p=0.044).

Conclusion: Even though there was no difference between two groups, when BP develops in diabetic patients, DPP4 is should be questioned and with cooperation with clinician's consideration of change may be planned.