Pretransplant Numbers of CD16+ Monocytes as a Novel Biomarker to Predict Acute Rejection After Kidney Transplantation: A Pilot Study

Am J Transplant. 2017 Oct;17(10):2659-2667. doi: 10.1111/ajt.14280. Epub 2017 Apr 22.

Abstract

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 pretransplant numbers of proinflammatory CD16+ monocytes can predict rejection. The study cohort consisted of 104 kidney transplant recipients (58 with no rejection and 46 with biopsy-proven rejection) and 33 healthy persons. Posttransplant median follow-up time was 14.7 mo (interquartile range 0.3-34 mo). 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 with those with no rejection (hazard ratio [HR] 1.60, 95% CI 1.28-2.00, p < 0.001) and healthy persons (HR 1.47, 95% CI 1.18-1.82, p < 0.001). In parallel, significantly fewer absolute numbers of CD16- monocytes were observed at pretransplant time points in rejectors versus nonrejectors (HR 0.74, 95% CI 0.58-0.94, p < 0,014). A higher pretransplant number of CD16+ monocytes is significantly associated with a higher risk of acute rejection after kidney transplantation.

Keywords: basic (laboratory) research/science; flow cytometry; immunobiology; kidney (allograft) function/dysfunction; kidney transplantation/nephrology; macrophage/monocyte biology: activation; macrophage/monocyte biology: trafficking; pathology/histopathology; rejection; translational research/science.

MeSH terms

  • Adult
  • Biomarkers / blood*
  • Case-Control Studies
  • Cohort Studies
  • Female
  • GPI-Linked Proteins / immunology
  • Graft Rejection*
  • Humans
  • Immunophenotyping
  • Kidney Transplantation*
  • Male
  • Middle Aged
  • Monocytes / immunology*
  • Pilot Projects
  • Receptors, IgG / immunology*

Substances

  • Biomarkers
  • FCGR3B protein, human
  • GPI-Linked Proteins
  • Receptors, IgG