Pneumocystis jirovecii pneumonia in Diffuse Large B-Cell Lymphoma Treated with R-CHOP.

BACKGROUND The aim of this study was to estimate the incidence of and risk factors for Pneumocystis pneumonia (PCP) infection in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). METHODS The medical records of 739 DLBCL patients who received R-CHOP between May 2004 and January 2019 were retrospectively evaluated. Patients were divided into two groups: those who received primary PCP prophylaxis (prophylaxis group) and those who did not (control group). The incidence rate of PCP in each group was calculated, and risk factors for PCP were evaluated in the control group. RESULTS Baseline characteristics were significantly different between the two groups. Compared to the 602 patients who did not receive prophylaxis, the prophylaxis group (n = 137) had poor prognostic factors of older age, high lactate dehydrogenase (LDH) levels, advanced Ann Arbor stage, and high International Prognostic Index (IPI) risk scores. None of the patients receiving PCP prophylaxis developed PCP, while the incidence of PCP in the control group was 8.1% (definite cases 5.5% and probable cases 2.7%). Out of the 49 patients who developed PCP, 10 patients (20.4%) were admitted to the intensive care unit, and the PCP-related death rate was 16.3% (8/49). CONCLUSION This study showed that PCP prophylaxis is highly effective against PCP infection and may help guide prevention of PCP during R-CHOP treatment in DLBCL patients.