Abstract: PO2041
Urinary T Cell Subsets and Tubular Epithelial Cells as Biomarkers for Kidney Transplant Rejection
Session Information
- Transplantation: Evaluating Kidney Graft Injury - Pathways and Biomarkers
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 1902 Transplantation: Clinical
Authors
- Grothgar, Emil, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
- Goerlich, Nina, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
- Samans, Bjoern, Precision for Medicine GmbH, Berlin, Berlin, Germany
- Klocke, Jan, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
- Skopnik, Christopher, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
- Duerr, Michael, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
- Matz, Mareen, Berlin Institute of Health, Berlin, Berlin, Germany
- Olek, Sven S., Precision for Medicine GmbH, Berlin, Berlin, Germany
- Paliege, Alexander, Universitatsklinikum Carl Gustav Carus, Dresden, Sachsen, Germany
- Enghard, Philipp, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
Background
Early detection of kidney transplant (KT) rejection remains a challenge in patient care. Previously we developed a biomarker combination to detect rejection by analyzing urine cells using Flow cytometry (FC). The aim of this study was to confirm our previous findings and develop further markers to detect KT rejection.
Methods
Urine samples of 275 KT patients were analyzed. Cell population were quantified in 150 and 125 cases by epigenetic analyses and FC, respectively. Professional diagnoses from renal biopsies served to uniquely group graft deterioration into borderline rejection (BR), T cell mediated rejection (TCMR), and antibody mediated rejection (ABMR), other specific pathohistological diagnosis (other) or no rejection (No RX). For FC analyses urine sediments were stained for T cells (anti-CD3, -CD4, -CD8, -CD45RO, -CD45, -CCR7, -HLA-DR, -CD28) and tubular epithelial cells (TECs) (anti-Cytokeratin, -Vimentin, -CD10, -CD13, -CD227, -CD326). Epigenetic qPCR approach was used to determine T cells und TECs based on specific DNA methylation patterns identified by bisulfite sequencing.
Results
Absolute numbers of urinary T cells and TECs discriminated patients with and without TCMR. Most strikingly in this regard were increased numbers of various T cell subsets observed by FC in patients with TCMR compared to patients without TCMR (p<0.001 for HLA-DR+ T cells and effector memory T cells) whereby CD8+ HLA-DR+ T cells were most distinctive (p = 5.1e-07, AUC = 0.866-0.967). Epigenetic analyses qualitatively confirmed T cell and TEC quantities as determined by FC. Furthermore, the ratio of absolute numbers of T cells and TECs determined by epigenetic analyses discriminated patients with TCMR from those with other specific biopsy proven diagnoses than rejection, but individual T cell populations showed a higher sensitivity and specificity in segregating both groups (TCMR vs other: CD8+ T cells p=5.1e-05, AUC 0.87 (CI 95% 0.77-0.98), CD3+ T cells/TEC p=0.004, AUC 0.78 (CI 95% 0.65-0.92); ABMR vs other: CD8+ T cells p=0.0041, CD3+ T cells/TEC p=0.04).
Conclusion
Urinary T cell subsets reflect intrarenal inflammation in TCMR. TECs mirror intrarenal damage accompanied by rejection. Jointly, they yield high potential to monitor KT patients and detect rejection.
Funding
- Government Support – Non-U.S.