[Cytomegalovirus effects in solid organ transplantation and the role of antiviral prophylaxis]. / Effets du cytomégalovirus en transplantation et place de la prophylaxie antivirale.

Cytomegalovirus (CMV) belongs to ß-Herpesviridae family. Morbidity related to this infectious agent remains a serious concern in the context of immunosuppression. Occurence of CMV infection within the first 3 months post-renal transplantation without any antiviral prophylaxis is about 70% of patients. Direct and indirect effects of CMV infection in the setting of organ transplantation are described in this review. A 3 to 6 months course of prophylaxis with valganciclovir is advised concerning high-risk transplant recipients (D+/R-) but recommendation regarding intermediate-risk transplant recipients (CMV-seropositive patients) is still unclear. Recent studies highlight a benefit of long time prophylaxis (until 6 months) in terms of CMV disease occurence among D+/R- patients. News assays that measures IFNγ responses to a variety of CMV epitopes (Quantiferon(®) and Elispot IFNγ) are developped to predict CMV disease onset after discontinuation of antiviral prophylaxis. These assays could contribute to adapt prophylaxis to each recipient.

Treatment of chronic hepatitis C virus infection in dialysis patients: an update.

Hepatitis C virus (HCV) infection is a blood-borne infection and its prevalence used to be elevated in hemodialysis (HD) patients. Its main mode of contamination relies on nosocomial transmission. HCV infection is frequently associated in HD patients with normal liver enzymes whereas liver histology can display some degree of HCV-related lesions. The assessment of HCV-related lesions, even in HD dialysis patients, can be done via noninvasive tests. After kidney transplantation, HCV-related lesions can worsen; however, in this setting antiviral treatment harbors the risk of acute rejection. Therefore, it is recommended to implement antiviral treatment while the patient is receiving dialysis therapy. In this setting, the rate of viral clearance is usually high. In case of sustained virological response, no relapse occurs after kidney transplantation, despite heavy immunosuppression.