High incidence of Pneumocystis jirovecii pneumonia in patients receiving biweekly rituximab and cyclophosphamide, adriamycin, vincristine, and prednisone.

The risk of infection with Pneumocystis jirovecii pneumonia (PCP) in patients undergoing chemotherapy is closely related to the intensity of corticosteroid exposure. PCP is uncommon with classical (3-weekly) R-CHOP, but the risk may be higher with biweekly R-CHOP (R-CHOP-14) due to the increased frequency of prednisolone pulses. Among 47 consecutive patients treated with R-CHOP-14 at our institution, five (11%) developed microbiologically proven PCP, with a further two (4%) having classical clinical and radiological features of PCP, but without microbiological confirmation. None of these patients were HIV-positive or had additional risk factors for PCP. Our experience suggests that PCP prophylaxis should be considered in institutions using R-CHOP-14 for the treatment of patients with aggressive lymphomas.