CTLA-4 (Cytotoxic T Lymphocyte Antigen-4) is an immune regulator molecule that is expressed on a variety of immune cells, including CD4+ and CD8+ T cells. After realizing the significance of this regulator molecule, researchers began to concentrate on its activation or inhibition in cancer. Even though there have been some studies on organ transplantation and autoimmunity, the role of the CTLA-4 molecule in renal transplantation has not been demonstrated. The goal of this study was to see how CTLA-4 gene expression and serum sCTLA-4 levels affected renal transplant patients. Peripheral blood samples were collected before and 1–3 months after renal transplantation from 29 recipients. CD8+ T lymphocytes were separated using magnetic beads and purity of the cells controlled by Flow cytometry. CTLA-4 mRNA levels were determined by Real-Time PCR while serum sCTLA-4 levels were assessed by ELISA. 55% of the patient had decreased level of CTLA-4 mRNA after transplantation when compared to pre-transplantation levels. Moreover 61% of the patient had lower serum sCTLA-4 levels after transplantation. sCTLA-4 levels were decreased 11% of the patients with rejection episode after transplantation when compared to stabile patients (5%). Kidney rejection is a complicated process influenced by numerous unknown factors. Several parameters should be evaluated together to precise rejection episodes or graft dysfunctions. Further research focused on the other immune checkpoint regulator molecules could give an opportunity to have an idea about the effect of these molecules on renal transplantation.

CTLA-4（细胞毒性 T 淋巴细胞抗原 4）是一种免疫调节分子，在多种免疫细胞上表达，包括 CD4+ 和 CD8+ T 细胞。在意识到这种调节分子的重要性后，研究人员开始集中精力研究它在癌症中的激活或抑制。尽管已有一些关于器官移植和自身免疫的研究，但CTLA-4分子在肾移植中的作用尚未得到证实。本研究的目的是了解 CTLA-4 基因表达和血清 sCTLA-4 水平如何影响肾移植患者。收集 29 名受者的肾移植前和肾移植后 1-3 个月的外周血样本。使用磁珠分离 CD8+ T 淋巴细胞，并通过流式细胞术控制细胞纯度。CTLA-4 mRNA 水平通过实时 PCR 测定，而血清 sCTLA-4 水平通过 ELISA 评估。与移植前水平相比，移植后 55% 的患者 CTLA-4 mRNA 水平下降。此外，61%的患者在移植后血清sCTLA-4水平降低。与稳定患者 (5%) 相比，移植后出现排斥反应的患者 sCTLA-4 水平降低了 11%。肾脏排斥是一个复杂的过程，受到许多未知因素的影响。应同时评估几个参数，以精确确定排斥反应或移植物功能障碍。针对其他免疫检查点调节分子的进一步研究可以为了解这些分子对肾移植的影响提供机会。