PD-1/PD-L1 Checkpoint Inhibition Associated Bullous Pemphigoid: A Propensity Matched Retrospective Cohort Study

This letter illustrates a comparison of the BP-free survival probability in patients starting PD-1/PD-L1 inhibitors and DPP-4 inhibitors that has not been previously demonstrated in other studies. A propensity matched retrospective cohort study performed on TriNetX participants showed a significantly increased risk of BP in patients starting PD-1/PD-L1 inhibitors, especially for patients who are male and/or over the age of 65.