#2938 DE NOVO DSA IS ASSOCIATED WITH HUMAN PERIPHERAL BLOOD CXCR5+PD-1+CD8+ T CELLS AND PD-1 PD-L1 MRNA EXPRESSION IN KIDNEY TRANSPLANT PATIENTS

Abstract

Abstract Background and Aims Donor-specific antibody (DSA) development is mainly responsible for chronic antibody-mediated rejection. The immunological events that cause the development of DSA is not fully elucidated. The relationship between the Follicular Cytotoxic T cell subgroup and the development of DSA is unknown. In this study we aimed to examine CD8+CXCR5+PD-1+ follicular cytotoxic T cell levels and expression levels of PD1/PD-L1 genes in peripheral blood lymphocytes in recipients who de-novo DSA positive or negative after kidney transplantation (KTX). Method 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 KTX patients with de-novo DSA positive, 20 KTX patients with DSA negative and 21 healthy control (Table 1). Our patient groups were PRA negative before transplantation. 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 expression level was higher in the KTX patients with de-novo DSA positive compared to the KTX patients with DSA negative group (p:0.006 CT: 0,84±0,23). According to the results of flow cytometry, CD8+CXCR5+PD-1+ cell expression (%) levels were found to be significantly higher in patients (3,06±1,98) compared to the transplant control group (0,52±0,40) (p: 0.001) (Figure 1). 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.