High-level viruria as a screening tool for BK virus nephropathy in renal transplant recipients

Abstract

BackgroundAlthough early monitoring of BK virus infection in renal transplant patients has led to improved outcomes over the past decade, it remains unclear whether monitoring for viremia is the best screening tool for BK virus nephropathy (BKVN).MethodsWe conducted a retrospective review of the medical records of 368 renal transplant recipients who had a minimum of 18 months of posttransplantation follow-up. The relationship between the presence of BK viruria and a composite end point of BK viremia/BKVN was established, and the predictive value of high-grade BK viruria for development of viremia/BKVN was determined.ResultsHigh grade of BK viruria was present in 110 (30.1%) of the renal transplant recipients. BK viremia/BKVN was present in 64 (17.4%) patients and was 50 times more likely to be present in patients with high-grade BK viruria. The risk of developing BK viremia/BKVN was 3 times higher in high-grade viruria patients, and viruria preceded viremia by nearly 7 weeks.ConclusionThe presence of high-grade viruria is an early marker for developing BK viremia/BKVN. Detection of high-grade viruria should prompt early allograft biopsy and/or preemptive reduction in immunosuppression.

Polyomavirus Nephropathy: Ten-Year Experience

“…Therapeutic strategies often promote resolution of infection and prevent further decline in the kidney allograft function, but the damage from BKVN may not be reversed, leading to chronic allograft dysfunction [1]. In fact, the results demonstrated that even after strategies had been implemented, a significant percentage of patients had progressive allograft dysfunction.…”

“…B K VIRUS (BKV) is a non-enveloped DNA virus of the polyomaviridae family, and 80% to 90% of the general population is seropositive for BKV [1]. Primary infection usually occurs in the first decade of life, probably by respiratory or oral transmission, and then becomes latent mainly in the urinary tract [2].…”

BK virus-induced renal allograft nephropathy

“…At the minimum, high levels of PCR-BKV viruria (≥2.5 x 10 7 copies/mL) may be an early marker of BKV viraemia or BKVN (ref. 54 ). If BKV viruria develops in early post-transplant period, risk for BKVN development is higher compared to later occurrence.…”

Efficacy and adverse effects of cidofovir for treatment of BK virus infection in kidney transplant recipients

“…Approximately 30% to 60% of post-transplant recipient has developed BK viruria, and 10% to 20% has BK viremia (11). About 1% to 10% has developed BK-VAN during the first year after transplant (5,12,13). During BK virus replication, BK viruria usually precedes BK viremia by a median of ~4 weeks.…”