[Viral infections in renal transplantation].

KIDNEY TRANSPLANTATION IN HIV-POSITIVE SUBJECTS: To date, HIV+ patients have generally been excluded from transplantation programs. Encouraging results have however been obtained in 6 patients suggesting that transplantation and the accompanying immunosuppression are feasible in selected HIV-positive patients. HUMAN POLYOMAVIRUS INFECTIONS: Polyomavirus BK has been implicated as the pathogenic agent causing tubulointerstitial nephropathies in less than 5% of all kidney graft recipients. Polyomavirus JC, the causal agent of progressive multifocal leucoencephalitis, appears to be a co-infectant with the BK virus. Its pathogenic potential remains to be elucidated. POLYOMAVIRUS-LINKED PROBLEMS: It is very difficult to make the histological diagnosis of polyomavirus nephropathy due to the presence of several disease stages: the basic question is to distinguish between acute rejection and BK virus nephropathy. Excessive immunosuppression appears to be an predominant factor leading to BK virus infection of the kidney graft, sometimes leading to loss of the graft. It is thus a general rule to reduce the immunosuppression in patients with BK virus nephropathy. EPSTEIN-BARR VIRUS INFECTIONS: Epstein-Barr infections often lead to posttransplantation lymphoproliferative disorders that can be diagnosed early using quantitative polymerase chain reaction (PCR). PCR is also useful for measuring viral load and for adapting treatment.