Renal Function Impairment in Kidney Transplantation: Importance of Early BK Virus Detection.

Abstract

BACKGROUND\nBK virus allograft nephropathy is a major complication of kidney transplantation that markedly reduces graft survival (50% graft failure 24 months after being diagnosed). BK virus replication can occur at any time posttransplantation. Viruria detection is a signal of virus reactivation and precedes viremia. Only viremia has been related to BK nephropathy. Early detection appears to be important in the prevention of BK nephropathy.\n\n\nMETHODS\nUsing serial follow-up of BK infection, we sought to determine the association of BK virus infection with kidney function impairment. We included all solitary kidney recipients transplanted between February 1, 2010 and December 31, 2014 and followed for at least 1 year. Viruria at >107 copies/mL, viremia at >104 copies/mL, or biopsy-proven BK nephropathy were indicative of positivity. Various recipient, donor, and transplant characteristics were registered. Creatinine level was measured at 3, 6, 9, and 12 months and while virus replication was detected. P\xa0< .05 was considered statistically significant.\n\n\nRESULTS\nTwo hundred fifty-four kidney recipients were included. Viruria was detected in 73 of them (28.74%), of whom 32 (12.6%) also had viremia. Of the 32 recipients with viremia, 7 had biopsy-proven nephropathy. Only viremia positivity had a negative effect on kidney function (P\xa0< .01). One of 32 viremia-positive recipients had graft loss (3.1%).\n\n\nCONCLUSION\nSerial monitoring for BK virus replication is important for detection of BK infection. Early BK detection appears crucial to prevent impairment of kidney function and subsequent graft loss.