Background: Late cytomegalovirus (CMV) infection can occur after cessation of viral prophylaxis in kidney transplant recipients, yet, timing of infection is unclear and longer duration of prophylaxis may be warranted.
Methods: We conducted a retrospective cohort study of 86 children (35 CMV donor seropositive, recipient seronegative [D + R-] and 51 CMV recipient seropositive [R+]) younger than 18 years who received a kidney transplant between January 2002 and June 2014 and were treated with antiviral prophylaxis for 3 months after transplantation. Incidence of CMV DNAemia and CMV disease was determined using Kaplan-Meier analyses and risk factors were assessed using Poisson regression.
Results: Of the 86 children, 61.6% were male and median age at transplant was 13.4 years (interquartile range [IQR], 8.9-15.6) with a median follow-up of 35.2 months (IQR, 18.0-54.5). Incidence of CMV DNAemia within the first 3 months after prophylaxis cessation in CMV D + R- and CMV R+ children was 22.9% and 23.5% and incidence of CMV disease was 11.4% and 0%, respectively. Cumulative incidence of CMV DNAemia in both groups was similar (31.4%). Children who received antithymocyte globulin were more likely to develop CMV DNAemia compared with those who received anti-IL-2 (IRR, 2.98; 95% confidence interval, 1.41-6.30) after controlling for age, sex, Epstein-Barr Virus serostatus and rejection.
Conclusions: This study demonstrates a high incidence of CMV infection after cessation of antiviral prophylaxis. These results support extension of antiviral prophylaxis beyond 3 months and/or intensive viral load monitoring to reduce risk of CMV infection in D + R- and R+ children, especially those receiving antithymocyte globulin.