Human herpesvirus 6 infection in adult living related liver transplant recipients.

To analyze human herpesvirus 6 (HHV-6) infection in adult living related liver transplantation, we performed a virological analysis, including viral isolation, serological assay, and real-time polymerase chain reaction, of serially collected blood samples from 67 recipients. In addition, cytokine levels were measured to determine their role in viral reactivation. HHV-6 was isolated from only 4 recipients (6.0%), and viral DNA was detected in 15 (22.4%) of the 67 recipients. A significant increase in HHV-6 immunoglobulin G antibody titers was observed in 19 (28.4%) of the 67 recipients. Finally, 26 recipients (38.8%) had HHV-6 reactivation 2-6 weeks after transplantation. HHV-6 associated clinical features were analyzed in the 17 recipients presenting with either viremia or DNAemia. Two recipients with viremia and 3 recipients with DNAemia had unexplained fever at the time of viral infection. An increase in aminotransferase levels was observed in 2 recipients with viremia and 3 recipients with DNAemia. Recipients with liver cirrhosis caused by hepatitis B virus or hepatitis C virus infection as the underlying disease were more likely to have HHV-6 infection (P = 0.025). Mortality at the last follow-up in recipients with HHV-6 reactivation was significantly higher than in those without viral reactivation (P = 0.0118). Plasma interleukin-6 levels were significantly higher in the recipients with HHV-6 viremia than in the recipients without viremia at 4 weeks post-transplant (P = 0.0411). Moreover, tumor necrosis factor alpha levels were also higher in recipients with HHV-6 viremia (P < 0.0001) or reactivation (P = 0.0011) than in recipients without viremia or reactivation 4 weeks post-transplant.