Human Herpes Virus 6 and 7 Co-infections with Cytomegalovirus in patients with kidney transplantation

Abstract

Organ transplants imply the use of immunosuppressant drugs to avoid graft rejection, cytomegalovirus (CMV) is among the most common opportunistic viruses reactivated in renal transplant recipients (RTR), and it might be associated with the other two members of betaherpesviruses; Human herpesvirus-6 and -7 (HHV-6 and -7). Reactivation of these two viruses increases the risk of CMV-associated renal allograft loss and morbidity in RTRs. The objectives of this study are to study the frequency of these betaherpesviruses co-infections in RTR, and to determine the effect of these viruses on RTR morbidity and allograft functions.Patients and Methods: This case-control study included 53 RTR, 11 females, 43 males, and 53 age and sex-matched donors as controls, after 3 months a second blood sample was taken from the 53 RTR. Serum samples were subjected for viral DNA extraction and detection of CMV, HHV-6 and -7 by quantitative real time-PCR, and for serological study of anti-CMV and HHV-7 IgG. Results: The frequency of CMV was 28.30% and 5.7% (p=0.035), HHV-6 was 20.75 and 3.8% (p=0.015), and HHV-7 was positive in 22.64% and 3.8% (p=0.007) in patients and controls respectively.In addition, (30.19%) 16/53 of RTR had single viral infection in comparison to controls that had only (5.7%), and 9.4% of patients had double viral infections while only 3.8% of the controls had double viral infections, and 7.6% of RTRs had triple viremia with none in the control group, p˂0.001. Statistically at the second sampling CMV viral load is significantly increasing, and is significantly correlated with the VL of both roseola viruses. Also, HHV-6 VL is significantly increasing after three months, and it is also significantly increasing with that of HHV-7. Mean serum creatinine is higher in triple infections (p=0.043). Out of the 53 RTR; 20 patients had renal allograft rejection. Among the total CMVpositive patients (9/15) 60% and three out of four patients who had triple viral reactivations had allograft rejection. The seroprevalence rates of CMV and HHV-7 were 97.7% and 32% in RTR patients, the values of anti-CMV IgG antibody are decreased during CMV reactivation, and also in patients with triple viral reactivation as investigated by QPCR. Quantitative ELISA study found no significant correlation with viral loads which makes ELISA less valuable in diagnosing CMV or HHV-7 in RTR.In conclusion, the present study found a higher frequency of single, triple and double betaherpesviruses infections in RTR than normal controls. These co-infections increased the risk of nephropathy and allograft rejection. Also roseola viruses increase the frequency and pathological effect of CMV infection in RTR.