移植技術と研究

BK Virus Screening and Management Following Kidney Transplantation: An Update

Abstract

Phuong-Thu Pham, Joanna Schaenman and Phuong-Chi Pham

BK virus is a ubiquitous human virus with a peak incidence of primary infection in children 2-5 years of age and a seroprevalence rate of greater than 60-90% among the adult population worldwide. Following primary infection, BK virus preferentially establishes latency within the genitourinary tract and frequently reactivates in the setting of immunosuppression. In renal transplant recipients, BK virus is associated with a range of clinical syndromes including asymptomatic viruria with or without viremia, ureteral stenosis and obstruction, interstitial nephritis, and BK allograft nephropathy (BKN). BKN most commonly presents with an asymptomatic rise in serum creatinine between 2 to 60 months after engraftment (median 9 months). A definitive diagnosis requires an allograft biopsy. Over the last two decades, BKN has been recognized as an important cause of allograft dysfunction and graft loss in kidney transplant recipients. Nonetheless, there is currently no standardized protocol for the management of BK viremia or established BKN. In this article, a brief overview of the literature on the various treatment strategies for BK-associated clinical spectrum is presented followed by the authors’ suggested approach for posttransplant screening and monitoring for BK virus replication. Suggested treatment strategies are also discussed.