HHV-6 reactivation is often associated with CMV infection in liver transplant patients

Human herpesvirus 6 (HHV-6) infection has been recently reported in liver transplant patients. HHV-6 is closely related to cytomegalo-virus (CMV), and some interaction between the viruses has been suggested. In this study, the post-transplant HHV-6 antigenemia was investigated in relation to symptomatic CMV infections in adult liver transplant patients. CMV infections were diagnosed by the pp65 antigenemia test and by viral cultures. HHV-6 infections were demonstrated by the HHV-6 antigenemia test and by serology. Significant symptomatic CMV infection was diagnosed in 42 of 75 patients during the first 6 months after transplantation. All CMV infections were successfully treated with ganciclovir. Concurrent HHV-6 antigenemia was detected in 21 (50%) of 42 patients with CMV infection. All HHV-6 infections were reactivations. HHV-6 also responded to the antiviral treatment, but with less clear effect. In conclusion, HHV-6 reactivation is often associated with CMV infection in liver transplant patients. The results support the suggestion that CMV and HHV-6 may have interactions.