Prospective study of infection and nephropathy due to BK and JC polyomavirus in 76 kidney transplant recipients

Nephropathy due to polyomavirus is usually diagnosed by renal biopsy after worsening of renal function. This is normally at an advanced stage of the disease.

To study the early detection of the presence of BK and JC polyomavirus in urine by monthly real-time quantitative polymerase chain reaction (PCR) assay.

The study included 76 kidney transplant recipients from cadaveric donors between August 2005 and July 2006 with a 1-year follow-up.

Viruria was positive in 31 patients (40.7%) and viremia in 7 (9.2%), three of whom (3.9%) developed nephropathy. After reduction of the immunosuppression, the viruria became negative in 32.0% and the viremia in 42.8% of the patients. Renal function (creatinine clearance, aMDRD) at 1 year was 49.2 mL/min/1.73 m(2) in the patients with nephropathy and 64.3 mL/min/1.73 m(2) in the others. One-year patient and graft survival was 96%. No patient lost the graft due to nephropathy.

The detection of BK and JC polyomavirus by protocolized PCR enabled an early diagnosis of nephropathy, preventing graft loss with good renal function at 1 year.