Nephritic-nephrotic syndrome as a presentation of BK virus infection.

BK virus (BKV) is increasingly found as an important cause of allograft nephropathy. Nephrotic syndrome is not a usual manifestation of BKV nephropathy. Here, we report a 12-year-old boy, a case of end-stage renal disease due to nephronophthisis, who got the kidney transplanted from a 16-year-old cadaver, and after 18 months of uneventful transplantation on triple immunosuppressive therapy (mycophenolate mofetil (MMF), cyclosporin and prednisolone), presented with nephrotic feature (edema, heavy proteinuria, hypoalbuminemia and hyperlipidemia). Kidney biopsy was in favor of BKV infection and eventually ended in graft failure.