LAUSR

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.