DataSheet_2_Changes in T Lymphocyte Subsets in Different Tumors Before and After Radiotherapy: A Meta-analysis.docx

PurposeRadiation therapy (RT) induces an immune response, but the relationship of this response with tumor type is not fully understood. This meta-analysis further elucidated this relationship by analyzing the changes in T lymphocyte subsets in different tumors before and after radiotherapy.
MethodsWe searched English-language electronic databases including PubMed, EMBASE, and the Cochrane Library to collect studies on the changes in peripheral blood CD3+ T lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes before and after radiotherapy in tumor patients from January 2015 to April 2021. The quality of the included literature was evaluated using the NOS scale provided by the Cochrane Collaboration, and statistical software RevMan 5.4 was used to analyze the included literature. P<0.05 was considered to indicate statistical significance.
ResultsA total of 19 studies in 16 articles involving 877 tumor patients were included. All data were collected within 1 month before or after radiotherapy. Meta-analysis showed that numbers of CD3+ T lymphocytes (SMD: -0.40; 95% CI [-0.75, -0.04]; p = 0.03) and CD4+ T lymphocytes (SMD: -0.43; 95% CI: [-0.85, -0.02]; p = 0.04) were significantly reduced after radiotherapy compared with before treatment, but there was no statistically significant difference for CD8+ T lymphocytes (SMD: 0.33; 95% CI: [-0.88, 0.74]; p = 0.12). Subgroup analysis showed that peripheral blood T lymphocytes decreased in head and neck cancer. However, in prostate cancer and breast cancer, there was no significant change in peripheral blood. 1 month after radiotherapy, it has a potential proliferation and activation effect on lymphocytes in esophageal cancer and lung cancer. The results showed that CD8+T lymphocytes increased in peripheral blood after SBRT. Radiotherapy alone reduced CD3+ T lymphocyte numbers.
ConclusionsWithin 1 month of radiotherapy, patients have obvious immunological changes, which can cause apoptosis and reduction of T lymphocytes, and affect the balance of peripheral blood immune cells. The degree of immune response induced by radiotherapy differed between tumor types.

**目的**
放射治疗（Radiation Therapy, RT）可诱导机体产生免疫应答，但该免疫应答与肿瘤类型的关联尚未完全阐明。本荟萃分析通过分析不同肿瘤患者放疗前后外周血T淋巴细胞亚群的变化，进一步明确二者之间的关联。

**方法**
检索PubMed、EMBASE、考克兰图书馆（Cochrane Library）等英文电子数据库，收集2015年1月至2021年4月期间发表的、关于肿瘤患者放疗前后外周血CD3+ T淋巴细胞、CD4+ T淋巴细胞及CD8+ T淋巴细胞变化的相关研究。采用考克兰协作网（Cochrane Collaboration）提供的纽卡斯尔-渥太华量表（NOS scale）对纳入文献进行质量评价，并使用统计软件RevMan 5.4对纳入文献进行数据分析。以P<0.05作为判定统计学显著性的标准。

**结果**
最终纳入16篇文献中的19项研究，共涉及877例肿瘤患者，所有数据均采集于放疗前后1个月范围内。荟萃分析结果显示：与放疗前相比，放疗后患者外周血CD3+ T淋巴细胞（标准化均数差（Standardized Mean Difference, SMD）=-0.40；95%置信区间（95% Confidence Interval, 95%CI）[-0.75, -0.04]；P=0.03）与CD4+ T淋巴细胞（SMD=-0.43；95%CI [-0.85, -0.02]；P=0.04）的数量均显著降低，但CD8+ T淋巴细胞数量未表现出统计学显著性差异（SMD=0.33；95%CI [-0.88, 0.74]；P=0.12）。亚组分析结果显示：头颈部肿瘤患者外周血T淋巴细胞水平下降；而前列腺癌与乳腺癌患者的外周血T淋巴细胞水平无显著变化。放疗后1个月时，放疗对食管癌及肺癌患者的淋巴细胞具有潜在的增殖与活化效应。另有结果表明，接受立体定向体部放射治疗（Stereotactic Body Radiation Therapy, SBRT）后，患者外周血CD8+ T淋巴细胞数量升高；单纯放疗则会降低CD3+ T淋巴细胞的数量。

**结论**
放疗后1个月内，患者可出现显著的免疫学改变，可诱导T淋巴细胞凋亡并减少其数量，进而影响外周血免疫细胞的平衡状态。不同肿瘤类型诱导的放疗相关免疫应答程度存在差异。