title: Polyomavirus-associated nephropathy: update on BK virus-specific immunity.
abstract: The human polyomavirus type 1, also called BK virus (BKV), causes polyomavirus-associated nephropathy (PVAN) in 1-10% of renal transplant recipients, with graft loss in over 50% of cases. The risk factors for PVAN are not conclusively defined and likely involve complementing determinants of recipient, graft, and virus. A central element seems to be the failing balance between BKV replication and BKV-specific immune control, which can result from intense triple immunosuppression, HLA-mismatches, prior rejection and anti-rejection treatment, or BKV-seropositive donor/seronegative recipient pairs. Consistent with this general hypothesis, the timely reduction of immunosuppression in kidney transplant recipients reduced graft loss to less than 10% of cases. However, the BKV-specific humoral and cellular immune response is not well characterized. Recent work from several groups suggest that changes in antibody titers and BKV-specific CD4+ and CD8+ T cells may help to better define the risk and the course of PVAN in renal transplant patients.
authors.affiliation: Transplant Immunology and Pediatric Hematology/Oncology, IRCCS Policlinico San Matteo, Pavia, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Comoli
authors.forename: S
authors.initials: S
authors.lastname: Binggeli
authors.forename: F
authors.initials: F
authors.lastname: Ginevri
authors.forename: H H
authors.initials: HH
authors.lastname: Hirsch
mesh_terms: D001739:BK Virus / Q000276:immunology*; D006801:Humans; D007674:Kidney Diseases / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D016030:Kidney Transplantation; D027601:Polyomavirus Infections / Q000453:epidemiology / Q000276:immunology* / Q000821:virology