LISTERIOSIS IN PATIENTS WITH CHRONIC LYMPHOCYTIC-LEUKEMIA WHO WERE TREATED WITH FLUDARABINE AND PREDNISONE

Objective. To determine whether therapy with fludarabine plus prednisone in patients with chronic lymphocytic leukemia increases the risk for developing listeriosis. Design: Retrospective cohort study based on hospital surveillance data. Setting: Referral cancer center. Participants: A total of 795 patients with chronic lymphocytic leukemia who received care at The University of Texas M. D. Anderson Cancer Center between 1980 and 1990. Interventions: Patients were treated with fludarabine alone or fludarabine and prednisone. Measurements: The listeriosis attack rate was analyzed according to the type of treatment received. Results: Seven of 408 patients in the fludarabine group developed listeriosis (1.7%; 95% Cl, 0.2% to 6%) compared with 0 of 387 patients who received conventional chemotherapy alone (0% to 0.9%; P = 0.015). The 7 patients were among 248 patients who were treated with both fludarabine and prednisone; none of 160 patients treated with fludarabine alone developed listeriosis (P = 0.045 by the Fisher exact test). A dramatic reduction in CD4 counts occurred in patients after fludarabine and prednisone treatment and coincided with the development of listeriosis. Conclusion: The administration of fludarabine plus prednisone is associated with an increased incidence of listeriosis in patients with chronic lymphocytic leukemia. The depletion of CD4 cells may underlie the pathogenesis.