Risk Factors for Late-Onset Cytomegalovirus Infection or Disease in Kidney Transplant Recipients

BACKGROUND CMV-D+/R- serostatus is the only well-established risk factor for late-onset cytomegalovirus (CMV) infection/disease (i.e., incident CMV infection/disease after cessation of prophylactic antiviral therapy). This study aimed to explore other potential risk factors for late-onset CMV infection/disease in kidney transplant recipients. METHODS We conducted a retrospective cohort study of 641 kidney transplant recipients in Toronto, Canada, from January 1, 2003, to December 31, 2010. The cumulative incidence of late-onset CMV infection/disease was assessed using the Kaplan-Meier product-limit method. Potential risk factors for late-onset CMV infection/disease were examined using Cox proportional hazards regression models. RESULTS Cumulative incidence estimates for CMV infection/disease after prophylaxis cessation in D+/R- versus D+/R+ versus D-/R+ patients were 26.2% versus 7.4% versus 3.1% at 6 months and 30.0% versus 7.7% versus 3.7% at 1 year, respectively. D+/R- serostatus (vs. R+ serostatus) and an estimated glomerular filtration rate of less than 45 mL/min (vs. ≥ 60 mL/min) at prophylaxis cessation were independently associated with late-onset CMV infection/disease (hazard ratio, 4.04 [95% confidence interval, 2.39-6.83]; and hazard ratio, 2.03 [95% confidence interval, 1.07-3.88], respectively). CONCLUSIONS Patients with lower estimated glomerular filtration rate at prophylaxis cessation may be at an increased risk of late-onset CMV infection/disease and should be considered for more intensive CMV viral load monitoring, particularly within the first year after prophylaxis cessation.