Cotrimoxazole as a Preventative Intervention for Pneumocystis Pneumonia in Pemphigus Patients Treated with Rituximab: A Retrospective Study

IntroductionPneumocystis jirovecii pneumonia (PJP) is a severe, life-threatening complication in patients treated with rituximab. However, there is no consensus on the primary prophylaxis for it in rituximab-treated pemphigus patients. Therefore, we sought to investigate the prophylactic efficacy and safety profile of cotrimoxazole for reducing the risk of developing PJP in pemphigus patients receiving rituximab.MethodsThis single-center retrospective study investigated 148 pemphigus patients undergoing a first cycle of rituximab between 2008 and 2021 at a tertiary referral center in northern Taiwan. Patients were divided into the prophylaxis group (N = 113) and the control group (N = 35) according to whether or not cotrimoxazole was administered. The primary outcome was the 1-year incidence of PJP in the two groups, while the secondary outcome was the incidence of cotrimoxazole-related adverse events.ResultsOf the 148 patients enrolled in this study, three patients, all in the control group, developed PJP during the 1-year follow-up. The incidence of PJP (8.6%) in the control group was significantly higher than that in the prophylaxis group (0%) (p = 0.012). The incidence of cotrimoxazole-related adverse events was 2.7%, and none of the cases were associated with life-threatening conditions. In addition, the cumulative prednisolone dose was associated with a trend of a higher risk of PJP (p = 0.0483).ConclusionsProphylactic cotrimoxazole significantly reduces the risk of PJP in a certain high-risk population and has a tolerable safety profile.

Automated summary

We conducted a single-centered retrospective study on pemphigus patients treated with rituximab, investigating the prophylactic efficacy and safety profile of cotrimoxazole. The results showed that the incidence of PJP in the prophylaxis group was significantly lower than that in the control group, and the adverse reactions of cotrimoxazole were tolerable.