Kidney graft loss associated with JC polyomavirus nephropathy.

This is the first case of documented treatment failure of JCV nephritis, despite a reduction of immunosuppressive agents and the use of antiviral therapy. We consistently detected high levels of JCV viremia, which correlated with the progressive deterioration of the graft and caused the final loss of the kidney, suggesting that JCV plays an etiological role in the onset of severe nephropathy in kidney transplant patients.