BK Virus-Associated Nephropathy in Adult Patients Post Kidney Transplantation: What Progress in 30 Years of History?

Abstract

Completely unknown before the 90s and exceptional up to the 2000s, BK virus nephropathy (BKvN), usually known as polyomavirus-associated nephropathy, has emerged as a significant and severe viral complication in kidney transplantation (KT). More than twenty years after Gardner's discovery of BKv in 1971, Purighalla described, in 1995, the first case of BKvN. Four years later in 1999, Nickeleit et al. published a first series of five cases of BKvN and made very precious and pertinent contributions to understanding this new entity. It has been well established that in post-KT, 30 to 50% of kidney transplant recipients are positive for BK viruria, of whom approximately one-third will develop BK viremia and, without intervention, could progress in 1 to 10% of cases to BKvN, leading to kidney graft failure in more than half of the cases. For now, there is no preventive antiviral treatment for BKvN; only a strategy of rapid, efficient screening allows for the preservation of renal graft function. The only effective and sure treatment measure is to reduce the intensity of total immunosuppression, including immunosuppressive drugs and corticosteroids. Based on the current data, this review describes the physiopathology, diagnosis, and management of BKvN in adult KTRs. It presents the results of the fifty most important studies published during the last two decades.