The Role of Valacyclovir on Epstein–Barr Virus Viral Loads in Pediatric Liver Transplantation Patients

Abstract

Epstein-Barr virus (EBV) infection occurring in the postoperative period represents a significant risk for pediatric transplant recipients. It presents in various manners, including a mononucleosis-like syndrome, hepatitis, encephalopathy, or posttransplant lymphoproliferative disease (PTLD). Valacyclovir has in vitro activity against EBV. We sought to review our experience with valacyclovir on peripheral blood EBV viral loads among a group of EBV-infected patients after liver transplantation (OLT). Twelve children of ages 6-36 months (median, 12 months), underwent OLT. Eight (66%) were EBV immunoglobulin (Ig)G seronegative at the time of the operation. Eight patients developed primary infection and 4 patients developed reactivation of a post primary infection. Valacyclovir was prescribed immediately to 3 patients when we detected an acute-primary EBV infection. Valacyclovir was prescribed for 2 patients who had primary EBV infections followed by PTLD. Three patients who had primary EBV infection were administered valacyclovir after they became chronically EBV PCR positive for more than 1 year. Four out of 12 cases (33%) were EBV seropositive at the time of OLT, and underwent postprimary EBV reactivation displaying chronic EBV carrier state for 8-10 months before valacyclovir treatment. Peripheral blood EBV viral loads were tested every 2 months. The primary outcome was the proportion of subjects with EBV viremia who had a >or=2 log 10 decrease in EBV copies/mL after valacyclovir treatment. The duration of valacyclovir treatment was a median of 10 months (range, 8-11 months). At the beginning of the treatment period the median level of EBV viral load was 1.1 x 10(4) (range, 1 x 10(4) to 1 x 10(7)). EBV virus was cleared in only 1 patient with primary acute EBV infection. EBV viral loads did not change in 7 of 12 patients and decreased only 1 log 10 (n = 2) or 2 log 10 (n = 2). In this small, non-placebo-controlled study, valacyclovir treatment was not effective to decrease peripheral blood EBV viral loads.