Introduction: 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.
Aim: 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.
Material and methods: The study included 76 kidney transplant recipients from cadaveric donors between August 2005 and July 2006 with a 1-year follow-up.
Results: 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.
Conclusions: 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.