Abstract

BACKGROUND
BK virus nephropathy (BKVN) is an emerging problem as a consequence of the use of potent immunosuppressive agents. Because optimal detection methods for the diagnosis of BKVN are required clinically, we compared the results of renal allograft biopsy, urine cytology, and urine and blood viral loads.
METHODS
Four hundred sixty two case notes from 2004 to 2009 at Seoul St. Mary's Hospital were reviewed. During that period, 286 cases of urine cytology for decoy cells, 938 cases of urine BKV reverse transcription-polymerase chain reaction (RT-PCR), and 1,029 cases of blood BKV RT-PCR were performed. All diagnostic methods were performed in 85 cases.
RESULTS
A histological diagnosis of BKVN was made in 2.4% of cases (11/462). Urine cytology for decoy cells was positive in 26.2% (75/286). BKV RT-PCR revealed viruria in positivity of 22.1% (207/938) and viremia in 5.2% (54/1,029). In cases of BKVN, the sensitivities of urine and blood BKV RT-PCR were all 100% and the specificities were 69% and 94.5%, respectively. In cases with positive urine decoy cells, the sensitivities of urine and blood BKV RT-PCR were 50% and 27.7%, with specificities of 77.7% and 100%, respectively.
CONCLUSIONS
BKV screening by RT-PCR assays may be a clinically useful noninvasive test to identify renal recipients with concurrent BKVN.

• Keywords: Kidney transplantation;BKV-associated nephropathy;Real-time PCR;Decoy cells;Urine cytology;