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.