Risk Factors for Mortality in Pneumocystis jirovecii Pneumonia in Patients with Inflammatory Bowel Disease

Abstract

Background: Pneumocystis jirovecii pneumonia (PJP) is highly fatal once infection is established. In this study, we investigated the risk of PJP mortality in patients with inflammatory bowel disease (IBD). Methods: We conducted a retrospective observational study of case data from IBD patients who developed PJP, compiled from 17 collaborating institutions. Parameters such as age, sex, medications used, and blood test results were analyzed to identify risk factors for mortality. Results: The mortality rate among the 28 IBD patients who developed PJP was 17.9%. A low serum albumin level at the start of IBD treatment was identified as a risk factor for mortality and showed the following association with probability of death (P): P = 1/[1 + exp(-5.5 + 2.4 × Alb). The probability of death exceeded 0.5 when serum albumin was 2.2 g/dL or lower. Conclusion: Patients with IBD who develop PJP have a high mortality rate and often cannot continue treatment with medication alone. Therefore, it is necessary to pay attention to albumin levels at the start of immunosuppressive therapy when creating a treatment plan.