# Renal graft function in transplanted patients correlates with CD45RC T cell phenotypic signature

## TL;DR

This study identifies a T cell marker signature involving CD45RC that correlates with kidney transplant success and could help predict and monitor transplant outcomes.

## Contribution

The study introduces a novel CD45RC-based T cell phenotypic signature linked to stable graft function in kidney transplant patients.

## Key findings

- CD45RC expression combined with other markers like HLA-DR, PD-1, IFNγ, and CD28 correlates with transplant outcomes.
- High CD45RC levels in CD8+ T cells before transplantation are associated with increased acute rejection risk.
- The CD45RC-based signature helps identify stable graft function and could guide immunosuppression adjustments.

## Abstract

Biomarkers that could predict the evolution of the graft in transplanted patients and that could allow to adapt the care of the patients would be an invaluable tool. Additionally, certain biomarkers can be target of treatments and help to stratify patients. Potential effective biomarkers have been identified but still need to be confirmed. CD45RC, one of the splicing variants of the CD45 molecule, a tyrosine phosphatase that is critical in negatively or positively regulating the TCR and the BCR signaling, is one marker already described. The frequency of CD8+ T cells expressing high levels of CD45RC before transplantation is increased in patients with an increased risk of acute rejection. However, single biomarkers have limited predictive reliability and the correlation of the expression levels of CD45RC with other cell markers was not reported. In this study, we performed a fluorescent-based high dimensional immunophenotyping of T cells on a cohort of 69 kidney transplant patients either with stable graft function or having experienced acute transplant rejection during the first year after transplantation or at the time of rejection. We identified combinations of markers and cell subsets associated with activation/inflammation or Tregs/tolerance (HLA-DR, PD-1, IFNγ, CD28) as significant biomarkers associated to transplant outcome, and showed the importance of cell segregation based on the CD45RC marker to identify the signature of a stable graft function. Our study highlights potential reliable biomarkers in transplantation to predict and/or monitor easily graft-directed immune responses and adapt immunosuppression treatments to mitigate adverse effects.