title: Place of mTOR inhibitors in management of BKV infection after kidney transplantation.
abstract: BACKGROUND
  BK virus (BKV) viremia and BKV-associated nephropathy (BKVAN) have become a serious nuisance to kidney transplant (KT) patients since the mid-nineties, when the incidence of this disease has increased significantly.
  
  
  METHODS
  Directory of open access journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science have been searched.
  
  
  RESULTS
  Many hypothesis have been made as to why this phenomenon has developed; it is of general opinion that a more potent immunosuppression is at the core of the problem. The use of the association of tacrolimus (TAC) with mycophenolic acid (MPA) has gained momentum in the same years as the increase in BKV viremia incidence making it seem to be the most likely culprit. m-TOR inhibitors (m-TORIs) have been shown to have antiviral properties in vitro and this fact has encouraged different transplant teams to use these agents when confronted with BKV infection (viremia or nephropathy). However, the results are mitigated. There had been conflicting results for example when converting from TAC-to sirolimus-based immunosuppression in the setting of established BKVAN.
  
  
  CONCLUSIONS
  In order to prevent BKV infection we have to minimize to some extent immunosuppression, but it is not always possible, e.g. in high immunological risk patients. Conversely, we could use m-TORIs associated with low-dose calcineurin inhibitors (CNIs). This could be actually the key to a safe immunosuppression regimen both from the immunological stand point and from the viral one.
authors.affiliation: Clinique Universitaire de Néphrologie, CHU Grenoble, France ; Université Grenoble Alpes, Grenoble, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jouve
authors.affiliation: Clinique Universitaire de Néphrologie, CHU Grenoble, France ; Université Grenoble Alpes, Grenoble, France ; Department of Nephrology and Organ Transplantation, CHU Rangueil, Université Paul Sabatier, Toulouse, France ; INSERM U563, IFR-BMT, CHU Purpan, Toulouse, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Rostaing
authors.affiliation: Clinique Universitaire de Néphrologie, CHU Grenoble, France.
authors.forename: Paolo
authors.initials: P
authors.lastname: Malvezzi
keywords: BK virus infection; BKV-associated nephropathy; Everolimus; Immunosuppression; Kidney transplantation; Sirolimus