Risk factors for Pneumocystis jirovecii pneumonia in patients with lymphoproliferative disorders

Guidelines for primary Pneumocystis jirovecii pneumonia (PCP) prophylaxis for patients with hematologic malignancy (HM) are still lacking. Our objective was to identify risk factors for PCP among patients with HM to help recognize patients who would benefit from primary PCP prophylaxis.

We performed a case-control study of adult patients with HM and negative for human immunodeficiency virus and with confirmed PCP by using cytology or histopathology from 2 medical centers over an 11-year period. Each case was matched with 4 patients without PCP by type of HM and year of treatment. We compared demographic, clinical, and laboratory data among cases and controls. Data were analyzed by using SPSS version 18.0.

Fourteen cases and 56 controls were included in the study period. No significant differences were seen in demographics between both groups. All identified patients had lymphoproliferative HM, the majority of patients (93%) had either non-Hodgkin lymphoma or chronic lymphocytic leukemia. Autoimmune diseases were more frequent in cases vs. controls (28.6% vs. 5.4% P = .01). The receipt and duration of chemotherapy were similar in both groups. Among chemotherapeutic agents, including steroids, only fludarabine was associated with increased risk for PCP (50% vs. 17.9%; P = .02). No difference was found in total or lymphocyte percentage in cases at the time of PCP diagnosis vs. nadir values in controls.

Patients with lymphoproliferative HM, specifically chronic lymphocytic leukemia and non-Hodgkin lymphoma, who are receiving fludarabine and with autoimmune disorders are at increased risk for PCP and should be considered for PCP primary prophylaxis.