Prospective Monitoring of BK Viremia and Early Protocol Biopsies: Impact on the Evolution of BK Polyomavirus Associated Nephropathy (BKPVAN). A Kidney Transplantation Center Experience
Mathieu Latour, Edith Renoult, Michel Paquet, Catherine Girardin, Gilles St-Louis, Rene Levesque, Heloise Cardinal, Marie-Claude Fortin, Marie-Josee Hebert, Walter Schurch. Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
Background: BKPVAN is a major cause of renal allograft dysfonction. The timing of the initial diagnosis is critical for therapeutic success and a good outcome.
Design: A pre-emptive strategy based on prospective monitoring of BK viremia during the first year and allograft biopsies, as part of protocol surveillance at 3 and 6 months, were established in our institution since 2008. We retrieved all cases of BKPVAN diagnosed on biopsy with SV40 positivity from 2004 to 2010. Clinical and histopathological findings were analysed between cases diagnosed before and after 2008.
Results: 21 cases were identified. 11 cases before 2008 (A group) and 10 cases after 2008 (B group). Seven cases were diagnosed on protocol biopsy: 1 in A group and 6 in B group. Time between graft and BKPVAN diagnosis decreased significantly (p=0.0004) after 2008 with an average of 515 days (169-1005) in A group and 143 days (75-243) in B group. eGFR at the time of diagnosis was not statistically different between A and B group (34.9±18.7 and 39.84±12.9). However, one year after BKPVAN diagnosis, eGFR was significantly (p=0.02) better in B group (39.82±14.48) compared to A group (24±12.5). 8 cases in A group have lost more than 20% of renal function compared to only 2 in B group (p=0.03). The majority (7 out of 10) of cases diagnosed after 2008 were staged as early infection (class A).
Conclusions: The introduction of a pre-emptive strategy based on prospective monitoring of BK viremia during the first year and allograft biopsies, as part of protocol surveillance, have modified the evolution of BKPVAN. BKPVAN are now diagnosed earlier with a better outcome. However, some cases still have an aggresive behavior.
Category: Kidney (does not include tumors)
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 272, Wednesday Afternoon