Abstract: SA-PO1132
High Expression of KIR+CD8+ T Cells in Peripheral Blood Mononuclear Cells Indicate T-Cell Exhaustion in BK Virus (BKV) Nephropathy After Kidney Transplantation
Session Information
- Transplantation: Clinical - Infectious Diseases
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Author
- Lin, Ching-Yuang, China Medical University Hospital, Taichung, Taichung City, Taiwan
Background
There was a significant differences in clearance time of BKV viremia. KIR+CD8+ T cell was an important regulatory T cell. KIR+ receptors appeared to suppression of cytotoxic function of T cell during chronic infection. Previously, we found high level of KIR+CD8+ T cells in peripheral blood mononuclear cells (PBMCs) of BKVN patients. Clinically, there was significant difference in clearance time of BKVN between transient and persistent BKV viremia. We hypothesize that expression of KIR exhaustion marker on CD8+ T cells may contribute to the loss of the potential to suppress viral replication. The study aim was to determine the difference level of KIR+CD8+ T cells of those who had transient BKV viremia versus those persistent BKV viremia on BKVN.
Methods
Study cohort: 6 transient viremia and 9 persistent viremia on BKVN post transplantation from 2020-2025. BKV viremia: BKV virus DNA in plasma of the patients was tested by polymerase chain reaction to detect large T antigen of BKV. BKV viral load > 100 copies/mL was considered as BKV viremia. Post-transplant surveillance for BKV PCR was routinely in the first 6 months, every 2 months for 6 – 12 months, every 3 months from 1 – 3 years and every 6 months thereafter. BKV Stimulation: PBMC were isolated and stimulated with overlapping BKV viral peptides. KIR+ CD8+ T cells were measured by flow cytometry.
Results
BKV viremia clearance was different between KIR+ expression on specific CD8+ T cells, steady KIR+ expression was accumulated steady over time during persistent BKV viremia on BKVN. Persistent KIR expression was associated with persistent viremia on BKVN.
Conclusion
Expression of exhaustion marker KIR+ on CD8+ T cells contribute to impair BKV clearance on BKVN after kidney transplantation. The results might be provide a potential therapeutic value on precision medicine of BKVN patients.