BK polyomavirus seroreactivity of kidney donors predicts viremia and nephropathy in recipients

H.F. Wunderink, E. van der Meijden, C.S. van der Blij-de Brouwer, M.J.K. Mallat, G. Haasnoot, E.W. van Zwet, E.C.J. Claas, H.J.W. de Fijter, A.C.M. Kroes, F. Arnold, A. Touzé, F.H.J. Claas, J.I. Rotmans, M.C. Feltkamp

Chair(s): dr. Marije C. Baas, nefroloog, Radboudumc, Nijmegen & dr. Dries E. Braat, chirurg, LUMC

Thursday 10 march 2016

14:10 - 14:20h at Zaal 1 & 2

Categories: Parallelsessie (klinisch)

Parallel session: Parallelsessie XII - Klinisch

Background:
Kidney transplant (KTx) donors are not implicated in predicting BK polyomavirus (BKV) infection in the immunocompromised recipient. It has been suggested, however, that BKV-infection originates from the kidney allograft. Since BKV-seroreactivity correlates with BKV-replication and, therefore, may mirror the infectious potential, we investigated whether baseline BKV-seroreactivity of KTx-donors predicts viremia and BKV-associated nephropathy (BKVAN) in recipients.

Methods:
In a retrospective cohort of 407 living kidney allograft donor-recipient pairs, transplanted between 2003-2013, pre-KTx donor and recipient sera were tested for BKV IgG-levels. Baseline IgG-levels were correlated with the occurrence of BKV-viremia and BKVAN during the first year after transplantation.

Results:
Baseline BKV-seroprevalence of both donors and recipients was high, ≥ 95%. A strong, statistically significant association was observed between donor BKV-IgG level and occurrence of viremia and BKVAN. This resulted in a sevenfold increased hazard ratio for BKV-viremia, which increased even further in case of a low BKV-seroreactive recipient. Baseline recipient BKV-seroreactivity as such was not associated with viremia or BKVAN. Multivariate analysis showed donor BKV-seroreactivity to be the strongest baseline factor associated with BKV-viremia and BKVAN.

Conclusion:
Donor level of BKV-IgG is a strong predictor of BKV-infection in KTx-recipients. The proportional relation between donor BKV-seroreactivity and recipient infection suggests that donor BKV-seroreactivity reflects the infectious load of the kidney allograft. This finding promotes the use of BKV-serological testing pre-KTx, in order to assess the risk of BKVAN and to personalize BKV-plasma load-monitoring. Furthermore, it emphasizes the relevance of strategies aimed to increase BKV-immunity in kidney allograft-recipients.