Abstract for presentation at Australia and New Zealand Society of Nephrology Annual Scientific Conference

Detection of BK virus cDNA in renal transplant biopsies precedes the development of histological changes of BK virus nephropathy

  • Dr Kathryn Wiggins, University of Melbourne & St. Vincent's Hospital, Australia
  • Ms Renae Gow, University of Melbourne & St. Vincent's Hospital, Australia
  • Dr John Kanellis, Monash Medical Centre, Australia
  • Dr Prue Hill, St. Vincent's Hospital, Australia
  • Dr Alison Skene, Monash Medical Centre, Australia
  • Dr David Goodman, St. Vincent's Hospital, Australia
  • A/Prof Robyn Langham, University of Melbourne and St. Vincent's Hospital, Australia

    • Purpose: BK virus nephropathy (BKVN) affects up to 10% of renal transplants. Early detection permits intervention and improves prognosis. At present diagnosis is based on characteristic histological features of the transplant biopsy that have limited sensitivity. We investigated the application of molecular biological techniques to detect mRNA in transplant biopsies as a more sensitive method of BKV detection. BKV cDNA was retrospectively measured in archival transplant biopsies from patients who subsequently developed clear histological changes of BKVN.
    Methods: RNA was extracted from scraped 6 micron sections of biopsy tissue. cDNA was measured using real-time polymerase chain reaction. 2 implantation and 11 serial post-transplant renal biopsies from 3 patients with classical features of BKVN were analysed.
    Results: BKV cDNA was not detected in implantation biopsies. cDNA was demonstrated in 9 of 11 post-transplant biopsies from 3 patients a mean of 56.3 (range 24-110) days post-transplantation. Detection of cDNA preceded diagnosis of BKVN by 8.7 (range 2.0-17.0) months, at which time serum creatinine was lower (186.7±11.5 vs 237.0±67.1 µmol/L). BKV was detected in 2 biopsies reported as having acute rejection. The relative quantity of cDNA was highest at the time of the peak creatinine, and decreased after intervention.
    Conclusions: We have demonstrated that archival human tissue provides a valuable resource for molecular diagnosis of BKVN, which can be demonstrated before histological changes develop. While these findings require validation in a larger population, implementation of molecular analysis may facilitate earlier diagnosis, measuring response to treatment and improve prognosis.

    Conference Organiser - ICMS Pty Ltd