Association between chronic kidney disease and risk of bullous pemphigoid: a nationwide population-based cohort study

Background: Studies have shown that bullous pemphigoid (BP) occurs in patients with chronic kidney disease (CKD). However, the risk of developing BP in patients with CKD remains inconclusive. Objective: To investigate whether CKD increases the risk of BP. Methods: Participants were recruited from the National Health Insurance Database of Taiwan between 2007 and 2018. Overall, 637,664 newly diagnosed patients with CKD and 637,664 age-, sex-, and comorbidity-matched non-CKD participants were selected. A competing risk model was used to evaluate the risk of development of BP. Results: After adjusting for age, sex, and comorbid diseases in the multivariate model, CKD was a significant risk factor for BP (adjusted hazard ratio [aHR]: 1.29; 95% confidence interval [CI]: 1.17–1.42; p < 0.001). CKD patients were classified into the dialytic or non-dialytic groups and compared to non-CKD participants, and this revealed that patients with dialysis-dependent CKD had the highest risk of BP (aHR 1.75; 95% CI 1.51–2.03), followed by patients with non-dialysis-dependent CKD (aHR 1.20; 95% CI 1.08–1.32). Limitations: We lacked detailed laboratory data on the severity of CKD. Conclusions: Compared with individuals without CKD, those with CKD had a 1.3-fold increased risk of BP. Patients with dialysis-dependent CKD had an even higher BP risk (1.8-fold).