BKV-infection in kidney graft dysfunction

Abstract

Introduction: BKV nephropathy (BKN) causes kidney graft loss, whose specifi c diagnosis is invasive and might be predicted by the early detection of active viral infection. Objective: Determine the BKV-infection prevalence in late kidney graft dysfunction by urinary decoy cell (DC) and viral DNA detection in urine (viruria) and blood (viremia; active infection). Methods: Kidney recipients with >1 month follow-up and creatinine >1.5 mg/dL and/or recent increasing >20% (n = 120) had their urine and blood tested for BKV by semi-nested PCR, DC searching, and graft biopsy. PCR-positive patients were classifi ed as 1+, 2+, 3+. DC, viruria and viremia prevalence, sensitivity, specifi city, and likelihood ratio (LR) were determined (Table 2x2). Diagnosis effi cacy of DC and viruria were compared to viremia. Results: DC prevalence was 25%, viruria 61.7%, and viremia 42.5%. Positive and negative patients in each test had similar clinical, immunossupressive, and histopathological characteristics. There was no case of viremia with chronic allograft nephropathy and, under treatment with sirolimus, patients had a lower viruria prevalence (p = 0.043). Intense viruria was the single predictive test for active infection (3+; LR = 2.8).

Detection of BK virus in urine from renal transplant subjects by mass spectrometry

“…Screening for BK virus in kidney transplant recipients is usually carried out by the detection of virally infected cells in urine or viral nucleic acid in urine or blood [7]. Urine cytology is often used as a screening test for active viral infection by looking for decoy cells; urothelial cells with an enlarged nucleus containing a single large basophilic intra-nuclear inclusion [8].…”

Urine analysis in microfluidic devices

“…For example, for renal transplant recipients, high levels of the BK virus (BKV, named after the initials of a renal transplant patient and is a member of the polyomavirus family) may cause graft dysfunction, graft loss, and/or reduced patient survival rates. 85,86 BKV infection is common in children after renal transplantation, and reactivation of the virus initially results in asymptomatic viruria (virus present in urine) and progresses to viremia (virus present in blood), subclinical nephritis and eventually BKV-associated interstitial nephritis or nephropathy. In the absence of a proven antiviral therapy, early identification of patients at risk of BKV-associated interstitial nephritis or nephropathy and subsequent modification of immunosuppressive regimens may significantly reduce the damage.…”