Exploring TTV as a potential biomarker of infection in renal transplant recipients

A.L. van Rijn, H.F. Wunderink, C.S. de Brouwer, J.I. Rotmans, M.C.W. Feltkamp

Thursday 14 march 2019

13:37 - 13:39h at Tropentheater

Categories: Klinisch/Basaal, Parallelsessie

Parallel session: Parallelsessie XV – Basaal / Klinisch 2

Background: Torque teno virus (TTV) is an ubiquitous, non-pathogenic and highly prevalent virus. TTV load has been proposed as a biomarker of immunity, for instance in solid organ transplant recipients. In kidney transplantation (KTx) patients, over immunosuppression increases the risk of infection, for instance with BK polyomavirus (BKPyV), whereas under-immunosuppression might result in allograft rejection. The aim of this study was to explore whether TTV loads can predict BKPyV viremia in KTx recipients.

Methods: Development of BKPyV viremia was retrospectively assessed in a cohort of 389 Dutch KTx recipients, with one-year follow up. BKPyV as well as TTV viral load were determined using real-time PCR in plasma and serum samples taken at baseline, and 1.5, 3, 6, and 12 months after KTx. Survival analysis was performed in R software v. 3.5.1.

Results: During follow-up, 105 (27%) recipients developed BKPyV viremia. TTV detection increased from 84% at baseline (mean 2.2 * 10³TTV copies/ml) to 97% 3 months after transplantation (8.3* 10⁶copies/ml). KTx recipients who already tested TTV positive prior to KTx had a 2-fold increased risk (HR of 2.0; CI: 1.0-4.0) for developing BKPyV viremia. Longitudinal TTV loads in association with development of BKPyV are currently being analyzed.

Conclusions: TTV positivity and load correspond to risk of BK viremia in KTx recipients. Further evaluation of TTV as a potential biomarker of infection in KTx recipients is needed.