Pretransplant numbers of CD16+ monocytes as a novel biomarker to predict acute rejection after kidney transplantation; a pilot study

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T.P.P. van den Bosch, L.B. Hilbrands, R. Kraaijeveld, N.H.R. Litjens, F. Rezaee, D. Nieboer, E.W. Steyerberg, J.A. van Gestel, C.C. Baan, A.T. Rowshani

Chair(s): dr. D.A. Hesselink

Thursday 9 march 2017

12:30 - 12:45h

Categories: Poster - Klinisch

Parallel session: Postersessie - Klinisch 1

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Acute rejection is one of the major immunological determinants of kidney graft function and survival. Early biomarkers to predict rejection are lacking. Emerging evidence reveals a crucial role for the monocyte-macrophage lineage cells in the pathogenesis of rejection. We hypothesized that higher pre-transplant numbers of proinflammatory CD16+ monocytes can predict rejection.

The study cohort consisted of 104 kidney transplant recipients (58 non-rejectors and 46 biopsy-proven rejectors), and 33 healthy individuals. Posttransplant median±IQR follow up time was 14.7 (0.3-34) months. Pretransplantation blood samples were analyzed by flow cytometry for monocyte immunophenotypes. Groups were compared by Cox regression models for the occurrence of acute rejection.

We documented a significantly increased absolute number of pretransplant CD16+ monocytes in patients who developed biopsy proven rejection after transplantation compared to non-rejectors and healthy individuals (Hazard Ratio [HR], 1.60; 95% Confidential Interval [CI], 1.28 to 2.00; p<0,001 and HR, 1.47; CI, 1.18 to 1.82, p<0,001). In parallel,  significantly less absolute numbers of CD16- monocytes were observed at pretransplant time point  in rejectors vs non-rejectors (HR, 0.74; CI, 0.58 to 0.94; p<0,014).

A higher pre-transplant number of CD16+ monocytes is significantly associated with a higher risk of acute rejection after kidney transplantation.