Response of elevated Epstein-Barr virus DNA levels to therapeutic changes in pediatric liver transplant patients: 56-month follow up and outcome.

Background: Posttransplant lymphoproliferative disease (PTLD) is a serious complications after liver transplantation. Epstein-Barr virus (EBV) load measured by quantitative competitive polymerase chain reaction (PCR) has been used as an early marker for the development of PTLD and a guide for initiating preemptive therapy. The aim of this study is to report the results of EBV DNA PCR screening in a transplant population and to examine the risk factors for developing elevated EBV DNA PCR and the effect of interventions for reducing EBV DNA levels.

Methods: Medical records of 44 children who underwent liver transplantation and EBV DNA PCR screening during a 3-year period were reviewed, and the patients were prospectively followed up for another 2 years. Eleven patients who developed elevated EBV DNA PCR levels, defined as >/=40 genomes/105 peripheral blood lymphocytes (PBL) in pretransplant EBV-seronegative patients and >/=200 genomes/105 PBL in pretransplant-seropositive patients, were treated. The initial intervention was reduction of immunosuppression and initiation of anti-viral therapy in all patients, with administration of cytomegalovirus immunoglobulin (CMV-IgG) in two patients. CMV-IgG was then given to five of the patients who did not respond to the initial intervention.

Results: The initial intervention resulted in the reduction of EBV DNA PCR levels to below threshold values in 4 of 11 patients. Five patients who did not respond to the initial interventions were subsequently given intravenous CMV-IgG. The EBV DNA PCR level fell in all five of these patients during the course of treatment with CMV-IgG, with a significant reduction (to threshold levels or by two dilutions) in four of the five patients. No episodes of graft rejection were observed.

Conclusion: Eleven patients (25%) developed elevated EBV DNA PCR after liver transplantation. There were no identifiable risk factors for developing elevated EBV DNA PCR. A combination of reducing immunosuppression, adding antiviral agents, and initiating CMV-IgG resulted in a significant reduction of EBV DNA levels in nine (82%) patients during the follow-up period.