More Severe Erosive Phenotype Despite Lower Circulating Autoantibody Levels in Dipeptidyl Peptidase-4 Inhibitor (DPP4i)-Associated Bullous Pemphigoid: A Retrospective Cohort Study.

backgroundThe clinical and immunological profile of patients with dipeptidyl peptidase-4 inhibitor (DPP4i)-associated bullous pemphigoid (BP) is inconsistent in the current literature.

objectivesThe aims were to investigate the clinical and immunological features of patients with DPP4i-associated BP and to examine whether there are intraclass differences between different DPP4i agents.

methodsA retrospective cohort study was conducted, including all consecutive patients diagnosed with BP throughout the years 2009-2019 in a tertiary referral center.

resultsThe study encompassed 273 patients with BP (mean age at diagnosis 79.1 ± 9.9 years), of whom 24 (8.8%) were associated with DPP4i. Sitagliptin was the prescribed agent for 17 patients (70.8%), and vildagliptin was prescribed in seven patients (29.2%). Relative to other patients with BP, patients with DPP4i-associated BP had more prominent truncal involvement (95.8% vs. 73.9%; P = 0.017), greater erosion/blister Bullous Pemphigoid Disease Area Index (BPDAI) subscore (29.8 ± 17.4 vs. 20.6 ± 14.4; P = 0.018), and lower levels of anti-BP180 NC16A (279.2 ± 346.1 vs. 572.2 ± 1352.0 U/ml; P = 0.009) and anti-BP230 (25.5 ± 47.8 vs. 128.6 ± 302.9 U/ml; P = 0.009) antibodies. Relative to patients with sitagliptin-associated BP, those with vildagliptin-associated BP had a lower seropositivity rate (57.1% vs. 94.1%, P = 0.031) and lower levels (96.7 ± 139.0 vs. 354.5 ± 376.5; P = 0.023) of anti-BP180 NC16A antibodies, and tended to present with higher erosion/blister BPDAI subscore (36.3 ± 9.6 vs. 25.8 ± 19.7; P = 0.095).

conclusionsDPP4i-associated BP is characterized by a more severe blistering and erosive presentation despite lower levels of typically pathogenic antibodies.