Increased Risk of Pneumocystis Jiroveci Pneumonia Among Patients with Inflammatory Bowel Disease

Objectives: Patients with inflammatory bowel disease (IBD) may be at increased risk for pneumocystis jiroveci pneumonia (PCP). Our aims were (1) to determine the incidence and relative risk of PCP in IBD and (2) to describe medication exposures in patients with IBD with PCP. Methods: We performed a retrospective cohort study and a case series using administrative data from IMS Health Inc, LifeLink Health Plan Claims Database. In the cohort, patients with IBD were matched to 4 individuals with no IBD claims. PCP risk was evaluated by incidence rate ratio and adjusted Cox proportional hazards modeling. The demographics and medication histories of the 38 cases of PCP in patients with IBD were extracted. Results: The cohort included 50,932 patients with Crohn's disease, 56,403 patients with ulcerative colitis, and 1269 patients with unspecified IBD; matched to 434,416 individuals without IBD. The crude incidence of PCP was higher in the IBD cohort (10.6/100,000) than in the non-IBD cohort (3.0/100,000). In the adjusted analyses, PCP risk was higher in the IBD versus non-IBD cohort (hazard ratio, 2.96; 95% confidence interval, 1.75-4.29), with the greatest risk in Crohn's disease compared with non-IBD (hazard ratio, 4.01; 95% confidence interval, 1.88-8.56). In the IBD case series of PCP cases (n = 38), the median age was 49 (interquartile range, 43-57). A total of 20 individuals (53%) were on corticosteroids alone or in combination with other immunosuppression. Conclusions: Although the overall incidence of PCP is low, patients with IBD are at increased risk. Patients with IBD with PCP are predominantly on corticosteroids alone or in combination before PCP diagnosis.