Investigation of the level of CXCR5+PD-1+CD8+ follicular cytotoxic T cells and PD-1, PDL-1 mRNA expression in recipients WHO develop door-specific antibodies after renal transplantation

Objective: The development of donor-specific antibody (DSA) is one of the biggest obstacles to the success of kidney transplantation, and the biological events associated with the emergence of DSAs have not yet been fully elucidated. The relationship between the Follicular Cytotoxic T cell subgroup, which has been identified in recent years, and the development of DSA, is unknown. The aims of this thesis are; To examine CD8+CXCR5+PD-1+ follicular cytotoxic T cell levels and expression levels of PD1/PD-L1 genes in peripheral blood lymphocytes of healthy individuals and recipients who did not develop DSA 12 months after kidney transplantation to evaluate its correlation with observed mRNA expression and protein levels. Methods: In this study, the expression levels of PD-1, PD-L1 genes were determined using the Real-Time Quantitative PCR method from peripheral blood samples of 22 patients with DSA developed, 20 patients with DSA underdeveloped transplant and 21 healthy control groups of the same age and sex. Expression (%) levels of target cells were evaluated by flow cytometry method. IBM SPSS Statistics for Windows Version 22 and R.3.3.2 software were used to evaluate the data. Results: PD-1 and PD-L1 expression levels were higher in the patients compared to the transplant control group. According to the results of flow cytometry, CD8+CXCR5+PD-1+ cell expression (%) levels were found to be significantly higher in patients compared to the transplant control group. Conclusion: It shows that there may be a direct correlation between DSA and PD-1 / PDL-1 mRNA level and CXCR5+PD1+CD8+ follicular cytotoxic T cell in transplant patients after kidney transplantation. Keywords: Kidney Transplantation, DSA, PD-1, PD-L1, CD8+CXCR5+PD-1+T cell