Incidence and Risk Factors for Leukopenia in Kidney Transplant Recipients Receiving Valganciclovir for Cytomegalovirus Prophylaxis
Multi-Organ Transplant Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
Meeting: 2013 American Transplant Congress
Abstract number: B963
Background: Cytomegalovirus (CMV) is a major cause of morbidity and mortality after kidney transplantation. Valganciclovir is primarily used for CMV prophylaxis but is known to induce leukopenia, rendering the patients more susceptible to other infections. Risk factors for leukopenia among those who receive valganciclovir prophylaxis remain poorly understood.
Methods: This retrospective cohort study examined 524 recipients of kidney transplants from 1 Jan 2003 to 31 Dec 2010 (followed until 31 Dec 2011). Leukopenia was defined as white blood cell count (WBC) < 3 x 10^9/L. Recipient WBC was measured weekly up to the end of the third month post-transplant, then every two weeks up to the end of the sixth month. The appropriateness of valganciclovir dosage was determined relative to recipient kidney function (Cockcroft-Gault formula). Cox proportional hazards models were fitted to examine the association of baseline (at prophylaxis start date) and time-varying valganciclovir dosage with the time to first leukopenia episode, while adjusting for other covariates.
Results: A total of 202 new-onset leukopenia events were observed during prophylaxis. The cumulative incidence of leukopenia was 40.6% at 6-months post-transplant. The probability of developing leukopenia over study follow-up was significantly associated with low baseline WBC (log rank P < 0.001) and time-varying appropriateness of valganciclovir dosage (log rank P = 0.03). In both baseline and time-varying Cox proportional hazards models, low baseline WBC was significantly associated with an increased risk of leukopenia (P < 0.01). Valganciclovir dosage below recommended value (P = 0.01), higher recipient BMI (P = 0.04), and higher recipient eGFR (P = 0.02) were significantly associated with a decreased risk of leukopenia in the time-varying model.
Conclusions: Our results suggest that baseline WBC and the risk of leukopenia are inversely related. The time-varying models suggest a protective effect against leukopenia for a lower dosage of valganciclovir, higher BMI, and higher eGFR. Further study is required to confirm and explore these associations in other kidney transplant populations.
To cite this abstract in AMA style:
Liang C, Famure O, Li Y, Kim J. Incidence and Risk Factors for Leukopenia in Kidney Transplant Recipients Receiving Valganciclovir for Cytomegalovirus Prophylaxis [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/incidence-and-risk-factors-for-leukopenia-in-kidney-transplant-recipients-receiving-valganciclovir-for-cytomegalovirus-prophylaxis/. Accessed June 7, 2025.« Back to 2013 American Transplant Congress