SP 8.03 Kidney Perfusate as a Non-invasive Source for Tissue-Resident T Cell Profiling
Prashanth Chowdary, Harry Persaud, Matthew Reeves, Dimitra Peppa, Reza MotallebzadehAbstract
Introduction
The kidney contains diverse tissue-resident lymphocyte populations that are central to local immune surveillance, antiviral defence, and transplant outcomes. However, their study is limited by the invasiveness of tissue biopsy. Kidney perfusate collected during live-donor nephrectomy may provide a minimally invasive “liquid biopsy” capable of capturing these resident immune cells.
Aim
This study evaluated whether perfusate-derived lymphocytes reflect tissue-resident T-cell phenotypes when compared with paired peripheral blood.
Methods
Lymphocytes isolated from kidney perfusates and paired peripheral blood mononuclear cells (PBMCs) from live donors (n=24) were analysed using multiparametric spectral flow cytometry. We compared the distribution of major lymphocyte subsets and assessed expression of residency (CD69, CXCR6), activation, inhibitory, and exhaustion associated markers across CD8⁺ and CD4⁺T-cell populations.
Results
Perfusate-derived lymphocytes exhibited phenotypic features consistent with tissue residency, including marked enrichment of CD69⁺ and CXCR6⁺ CD4⁺ and CD8⁺ T cells. These patterns were not present in matched PBMCs. Perfusate immune profiles were therefore clearly distinguishable from peripheral blood and revealed resident-enriched T-cell populations otherwise inaccessible without biopsy.
Conclusions
Kidney perfusate serves as a tractable, minimally invasive source for profiling tissue-resident T cells in healthy donor kidneys at the time of transplantation. This liquid biopsy approach provides direct access to the organ’s immune microenvironment and may enable scalable immunophenotyping for biomarker discovery, risk stratification for CMV reactivation and rejection, and improved understanding of transplant immunobiology.