Pneumocystis Pneumonia in Inflammatory Bowel Disease: The Costs of Immunosuppression

Patients with inflammatory bowel disease (IBD) are subject to a spectrum of immunosuppressive agents including corticosteroids, immunomodulators, and biological therapies. Despite the benefits of these therapies and their ability to induce remission, they increase the risk of infectious complications with various organisms including Pneumocystis jiroveci pneumonia (PCP), which is associated with significant morbidity and mortality. Although PCP infection is typically associated with HIV-infected populations, the risk is increased in patients with IBD. Inflammatory autoimmune diseases like IBD account for as high as 20% of PCP infection in HIV-negative patients with greater than 50% mortality. Despite this, there are no clear guidelines for PCP prophylaxis in IBD. PCP should be considered in the differential when an IBD patient on immunosuppression presents with fever and respiratory symptoms. Here we review the existing literature regarding PCP risk in inflammatory bowel disease, the role of tumor necrosis alpha-inhibitors, and considerations for prophylaxis.