Long-term outcome of screening for polyoma BK virus infection in kidney transplant recipients

Abstract

BK virus (BKV) infection was studied prospectively in 50 unselected consecutive patients who had undergone kidney transplantation. Infection was monitored for one year after transplantation. Viral DNA in urine (viruria) and plasma (viremia) samples was detected by nested, qualitative polymerase chain reaction. BKV screening data was available for 92% (n = 46) of patients enrolled in the study. Four groups of patients were distinguished: uninfected patients (group 1, n = 30), patients with viruria (group 2, n = 3), patients with viremia (group 3, n = 6) and patients with developed BKV nephropathy (group 4, n = 7). Infection was observed starting form the first month, and the maximum number of patients with active BKV infection occurred at six months after transplantation. Five-year graft survival was 69% for patients with any evidence of BKV infection, compared with 80.0% (P = NS) for patients without BKV infection. The best graft function was observed in group one patient (mean serum creatinine 130 mkmol/l and glomerular filtration rate (GFR) 60.9 ml/min) and the worst in group 4 (mean serum creatinine 180 mkmol/l and GFR 52.31 ml/min) at five years after transplantation. Five-year patient survival was 82.6% and was not affected by presence of BKV infection.