CMV Co-infection (HHV5) and Human Herpes Virus 6 (HHV6) in renal transplant recipients

Abstract

Purpose: The aim of this study was to assess the occurrence of co-infection of CMV-HHV6 bearers among 25 kidney transplant patients. Methods: Inclusion criteria were CMVPCR negative at the time of transplantation, which became positive during follow-up. Three consecutive blood samples were selected from each patient and analyzed both for HHV6 PCR and nested PCR for CMV. Results: At transplantation, 30% of patients were positive for HHV6PCR. During follow up, 11 additional patients had at least one HHV6PCR positive, resulting in a total of 80% HHV6 viremia in this series. As some authors suggest that both HHV6 and HHV7 may aggravate the clinical picture of CMV infection, medical records of those patients were analyzed. Asymptomatic CMV viremia was found in 9 patients. Remaining 16 patients had isolated leukopenia (n = 8) or symptomatic CMV treatment with ganciclovir (n = 8). While HHV6 PCR positive or negative was comparable between patients with asymptomatic CMV viremia or associated with transient leukopenia in the group treated with CMV disease, the prevalence of HHV6 positive blood was 100%. No differences in renal function were observed during the viremia. However, after a year monitoring, there was a trend for higher levels of creatinine in the group positive for HHV6, which became significant after five years (2.5 vs. 1.2 mg / dl, p <0.05). Conclusion, CMV/HHV6 co-infection is associated with more pronounced clinical symptoms and the need for antiviral treatment. The decline of renal function in group HHV6 positive can present a most serious consequence for CMV infection, a temporary immunosuppressive reduction or subclinical acute rejection episodes. Prospective studies are needed to answer these questions.