Prevention of Pneumocystis pneumonia in patients with inflammatory bowel disease based on the detection of Pneumocystis colonization

To the Editor: The review of Poppers and Scherl1 raises an important issue concerning the prophylaxis against Pneumocystis pneumonia (PcP) in patients with inflammatory bowel disease (IBD) treated with immunosuppressive drugs. Currently, there are no guidelines and no standard of care for the chemoprophylaxis against PcP for IBD patients undergoing immunosuppressive therapies. PcP prophylaxis remains a case-by-case clinical decision balancing risk and benefits for each individual patient. Effective and relatively safe chemoprophylaxis for PcP is available, but it should be used with discretion to avoid exposing patients to unnecessary adverse side effects. Trimethoprim-sulfamethoxazole (co-trimoxazole) is the agent of choice for the prevention of PcP. Co-trimoxazole is generally well tolerated by patients without HIV infection, although rash, fever, and myelosuppression occur occasionally. Alternative regimens of prophylaxis are available for patients with documented intolerance to co-trimoxazole, but they are less effective, as has been shown for HIV-infected persons.2 In IBD patients the issue is to whom should PcP prophylaxis be given and for how long. At present, a top priority could be identifying risk factors for PcP in IBD patients treated with immunosuppressive drugs; this would allow physicians to make an individual risk assessment based on objective parameters in order to select patients for prophylactic treatment. In this sense, the authors cited1 suggest that it is reasonable to consider chemoprophylaxis for those patients with severe or fulminant disease, requiring corticosteroids and long-standing immunosuppressive or biological agents. Also, they think that other factors that might favor PcP prophylaxis include advanced patient age, medical comorbidities such as HIV infection, more extensive disease, and longer disease duration. However, the authors did not consider a major risk factor for PcP development, such as Pneumocystis colonization.3