NEW YORK (Reuters Health) - Reactivation of Epstein-Barr virus (EBV) may play a role in renal allograft rejection, according to German researchers.

In 23 patients undergoing kidney transplants, researchers at the University of Lubeck School of Medicine correlated the onset and frequency of EBV reactivation with episodes of acute rejection.

In the November 1st issue of The Journal of Infectious Diseases, lead author Dr. Wolfram J. Jabs and his colleagues explain that while cytomegalovirus infection is known to be associated with rejection, "a possible role for EBV in the context of early rejection events has not been systematically studied until now."

Thirteen of the 23 kidney recipients had reactivation of the virus, all within the first week posttransplant. This frequency of reactivation was "unexpectedly high," the authors report. Ten of these 13 developed rejection at a median of 5 days after reactivation.

In contrast, among the 10 patients without viral reactivation, only 1 experienced an episode of rejection.

The small study size made it difficult to determine "whether any particular immunosuppressive medication correlated with the incidence of EBV reactivation," the researchers add.

It may be, they speculate, that reactivation of the virus in the immunosuppressed transplant recipients "increases antigen load and induces the clonal expansion of EBV-specific T cell memory either to lytic or latent cycle antigens of the virus and that allo-cross-reactive components within this expanding response exceed the threshold needed for the promotion of rejection."

Dr. Jabs' group suggests that "EBV reactivation may induce a T cell response that, through the phenomenon of allo-cross-reactivity, could play a critical role in graft rejection."

J Infect Dis 2004;190:1600-1604.

Copyright © 2003 Reuters Limited. All rights reserved. Republication or redistribution of Reuters Limited content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters Limited. Reuters Limited shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.