Polyomaviruses BK And JC-DNA quantitation in kidney allograft biopsies

Background: Polyomavirus-associated nephropathy(PVAN) is one of the most common viral disease affecting renal allograft, with BK being the most frequent causal agent and JCV being considered responsible in < 3% of the cases. Objectives: To quantify polyomaviruses BK and JC load by real-time TaqMan PCR in tissue specimens (renal and ureteral) from kidney transplant recipients. Study design and methods: One-hundred-thirty-eight specimens (125 kidneys, 13 ureters) obtained from 109 patients were evaluated by quantitative real-time PCR for the detection of BKV- and JCV-DNA. Demographic, virological, and histopathological data were collected. Results: BKV-DNA was positive in 32 of 109 patients (29.6%) and JCV-DNA in 20 of 109 patients (18.3%). The highest BK viral loads (> 10(4) genome equivalents/cell) were found in two renal samples with histopathologically confirmed PVAN; while JC viral load was > 10(4) genome equivalents/cell in one ureteral sample. Conclusions: Although quantitation of viral DNA on renal allograft biopsies could be complementary to histopathological evaluation and the highest viral load are detectable in renal specimens with PVAN, the identification of a diagnostic cut-off should require further studies. (c) 2008 Elsevier B.V. All rights reserved.