放射损伤对鼻咽癌外周血CD4+CD25high调节性T细胞的影响

目的通过分析放疗前后鼻咽癌(NPC)患者外周血CD4+CD25high调节T(Tr)细胞比例及其变化规律.初步探讨NPC患者免疫抑制机制和放疗对免疫抑制的影响,为有效提高NPC的治疗疗效提供参考.方法采用流式细胞术检测36例初治的鼻咽癌患者放疗前、放疗后和30例正常健康者(对照组)外周血中T细胞亚群及CD4+CD25high T细胞比例.结果放疗前鼻咽癌患者CD3+、CD4+、CD8+T细胞比例及CD4/CD8比值接近正常对照组(P＞0.05);而CD4+CD25high Tr细胞比例明显高于正常对照组[分别为(2.76±1.06)%,(2.06±0.98)%,P＜0.05];放疗结束时,与放疗前比较,外周血CD4+T细胞比例减低、但差异无统计学意义(P＞0.05);CD4+/CD8+比值减低(P＜0.05),而CD4+CD25high Tr细胞比例明显升高,差异有统计学意义[(4.88±1.02)%,P＜0.05].结论CD4+CD25high Tr细胞可能是鼻咽癌患者免疫抑制的重要原因之一,与鼻咽癌免疫逃逸有关.放疗后外周血CD4+CD25high Tr细胞比例比CD4+/CD8+比值更能敏感反映免疫功能状态,有可能成为鼻咽癌的更有效的免疫监测指标.

Influence of radiotherapy on CD4+CD25high regulatory cells in peripheral blood of NPC patients

Objective The current study was designed to investigate the changes in peripheralCD4⁺CD25^high regulatory T(CD4⁺CD25^high Tr) cells in patients with nasopharyngeal carcinoma(NPC) and the influence of radiotherapy on immunity function.Methods The peripheral blood was collected from 36 patients with NPC and 30 healthy controls.By using monoclonal antibodies,the blood samples were evaluated with flow cytometry for lymphocyte subsets and Tr cells. Results The ratio of CD4⁺/CD8⁺ in the NPC group was not significantly less than that in the healthy controls(P>0.05),but the prevalence of the CD4⁺CD25^high Tr cells was significantly higher than that of the healthy group [(2.76±1.06)% versus(2.06±0.98)%,P<0.05].At the end of radiotherapy,the proportion of CD4⁺CD25^high Tr cells was higher than before it [(4.88±1.02)%,P<0.05]. Conclusion The relative increase in CD4⁺CD25^high Tr cells in peripheral blood of NPC patients with or without radiotherapy was significantly higher than those in healthy controls,which may be related to immunosupression and tumor progression in such patients.This finding suggests that CD4⁺CD25^high Tr cells in peripheral blood of NPC patients can be a useful index for monitoring the immunity function.