HHV-6 DNA in peripheral blood mononuclear cells after liver transplantation

Abstract

Background Human herpesvirus-6 (HHV-6) infections have been reported after liver transplantation. In this study, the detection of HHV-6 DNA in peripheral blood mononuclear cells (PBMC) was compared with HHV-6 antigenemia in liver transplant patients. Objectives Forty-three adult liver recipients were frequently monitored by HHV-6 antigenemia test, which detects the viral antigens in PBMC, but is rather qualitative than quantitative. Study Design From the same PBMC specimens HHV-6 DNA was demonstrated by in situ hybridization using a biotinylated probe and quantified as positive cells/10, 000 PBMC. Altogether 330 blood specimens were analyzed. Results During the first 6 months (mean 12 days) after transplantation, 35/43 patients developed HHV-6 antigenemia. Concurrently, HHV-6 DNA-positive cells with mean peak number of 661(±574)/10, 000 were detected in 33/35 patients. Seven patients received ganciclovir treatment because of concurrent CMV infection with mean peak number of HHV-6 DNA-positive cells 381(±336) before and 34(±59)/10, 000 after the treatment (p = 0.03). All CMV infections responded to ganciclovir, but HHV-6 DNAemia disappeared slowly, within 79 days (mean 36 days). Without antivirals, HHV-6 DNAemia/antigenemia lasted usually longer. Conclusions Detection of HHV-6 DNA in PBMC correlated well with HHV-6 antigenemia, and may be used in the monitoring of transplant patients.