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Kidney Week

Abstract: FR-PO991

Deep Phenotyping of Urinary Cells with Cytometry by Time of Flight Reveals CD8+CD38+ T Cells as a Biomarker to Detect T Cell-Mediated Rejection

Session Information

  • Transplantation: Basic
    October 25, 2024 | Location: Exhibit Hall, Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

  • 2101 Transplantation: Basic

Authors

  • Goerlich, Nina, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Metzke, Diana, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Grothgar, Emil, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Wagner, Leonie Felicitas, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Choi, Mira, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Ostendorf, Lennard, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Mirkheshti, Pouneh, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Klocke, Jan, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Halleck, Fabian, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Budde, Klemens, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
  • Cravedi, Paolo, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Fribourg, Miguel, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Amann, Kerstin U., Universitatsklinikum Erlangen, Erlangen, Bayern, Germany
  • Baumgart, Sabine, Universitatsklinikum Jena, Jena, Thüringen, Germany
  • Enghard, Philipp, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany

Group or Team Name

  • Translational Transplant Research Center.
Background

Non-invasive monitoring and early detection of rejection are of high priority in kidney transplantation. Previously, we established urine flow cytometry (FC) as tool for non-invasive rejection detection. We hypothesized that an even deeper phenotyping of urinary cells improves the diagnostic yield of urinary T cells. Therefore, we established Cytometry by time of flight (CyTOF) analysis of urine cells to derive an improved biomarker for the detection of rejection in kidney transplant recipients (KTR). Our findings were subsequently validated in a FC-based validation cohort.

Methods

A total of 140 urine samples from KTR were analyzed from patients undergoing indication transplant biopsy. We developed a method for preserving urinary cells, enabling analysis using FC and CyTOF. Our antibody panel comprised 41 targets on kidney infiltrating immune cells and graft parenchymal cells. During data analysis, cells were clustered according to differential protein expression patterns and cluster identities were manually curated. Proportional patterns of different cell types per sample were correlated with pathological diagnoses indicated by reports of biopsies. CD8+CD38+HLA-DR+ T cells were identified as a potential biomarker for T cell-mediated rejection (TCMR) with CyTOF, which was confirmed in a validation cohort using FC.

Results

By utilizing CyTOF combined with a clustering approach, we identified CD8+CD38+HLA-DR+ T cells as a potential biomarker for TCMR. We translated our finding to FC and validated urinary CD8+CD38+, CD8+HLA-DR+, and CD8+CD38+HLA-DR+ T cells as a biomarker for TCMR in a validation cohort of 83 KTR. CD8+CD38+ T cells showed the best performance in identifying TCMR, showing an even higher AUC in this validation cohort (AUC 0.898) than our prior published urinary biomarkers to detect TCMR.

Conclusion

Urinary cell signature analysis by CyTOF is feasible and enables identifying potential new biomarkers in kidney transplantation. KTR with TCMR showed increased urinary CD8+ CD38+ T cells, which could be validated in a separate cohort by FC. We plan to test the capability of urinary CD8+CD38+ T cells to detect TCMR in a prospective trial.

Funding

  • Government Support – Non-U.S.