代谢相关脂肪性肝病患儿外周血黏膜相关恒定T淋巴细胞的频率、表型及功能改变

Changes in the frequency,phenotype,and function of mucosal-associated invariant T lymphocytes in peripheral blood of children with metabolic associated fatty liver disease

目的探讨代谢相关脂肪性肝病(MAFLD)患儿外周血黏膜相关恒定T(MAIT)淋巴细胞的变化及其临床意义。方法选取2022年3月—2022年5月在湖南省儿童医院就诊的18例MAFLD患儿(MAFLD组)及同期20例正常对照儿童(对照组),采集外周血,流式细胞仪检测MAIT淋巴细胞(CD3^(+)CD161^(+)TCRVα7.2^(+)细胞)及其不同MAIT淋巴细胞亚型(CD4^(+)CD8-MAIT淋巴细胞、CD4-CD8-MAIT淋巴细胞、CD4-CD8^(+)MAIT淋巴细胞和CD4^(+)CD8^(+)MAIT淋巴细胞)比例,表达PD-1、CD69、穿孔素、CD107α、CXCR3、CXCR6和CCR6的MAIT淋巴细胞比例,分析MAIT淋巴细胞频率与肝脏炎症、脂肪含量和纤维化程度的相关性。符合正态分布的计量资料两组间比较采用t检验;非正态分布计量资料两组间比较采用Mann-Whitney U检验;相关性分析采用Spearman相关分析法。结果与对照组相比,MAFLD组中外周血MAIT淋巴细胞比例及表达PD-1、CD69、CD107α、CXCR3、CXCR6和CCR6的MAIT淋巴细胞比例均明显升高(P值均<0.05);MAIT淋巴细胞亚型中CD4^(+)CD8-MAIT淋巴细胞、CD4^(+)CD8^(+)MAIT淋巴细胞所占MAIT淋巴细胞比例明显升高(P值均<0.001),CD4-CD8^(+)MAIT淋巴细胞所占MAIT淋巴细胞比例降低(P<0.001);CD4^(+)CD8^(+)MAIT淋巴细胞(r=-0.474,P=0.047)和CD107α阳性MAIT淋巴细胞比例(r=-0.550,P=0.018)与ALT呈负相关。结论外周血MAIT淋巴细胞向肝脏趋化聚集,在儿童MAFLD肝脏炎症中发挥保护作用。

Objective To investigate the change in mucosal-associated invariant T(MAIT)lymphocytes in peripheral blood of children with metabolic associated fatty liver disease(MAFLD)and its clinical significance.Methods A total of 18 children with MAFLD who attended Hunan Children’s Hospital from March to May,2022,were enrolled as MAFLD group,and 20 normal children who attended the hospital during the same period of time were enrolled as control group.Peripheral blood samples were collected,and flow cytometry was used to measure the percentages of MAIT lymphocytes(CD3^(+)CDl61^(+)TCRVα7.2^(+)cells),different MAIT lymphocyte subsets(CD4^(+)CD8-MAIT cells,CD4-CD8-MAIT lymphocytes,CD4-CD8^(+)MAIT lymphocytes,and CD4^(+)CD8^(+)MAIT lymphocytes),and MAIT lymphocytes expressing PD-1,CD69,perforin,CD107α,CXCR3,CXCR6,and CCR6.The correlation of MAIT lymphocyte frequency with liver inflammation,fat content,and fibrosis degree was analyzed.The t-test was used for comparison of normally distributed continuous data between two groups,and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups.The Spearman correlation analysis was used for correlation analysis.Results Compared with the control group,the MAFLD group had significant increases in the percentage of MAIT lymphocytes in peripheral blood,the percentages of MAIT cells expressing PD-1,CD69,CD107α,CXCR3,CXCR6 and CCR6,and the percentages of CD4^(+)CD8-MAIT cells and CD4^(+)CD8^(+)MAIT lymphocytes among MAIT cell subsets(all P<0.05),as well as a significant reduction in the percentage of CD4-CD8^(+)MAIT cells among MAIT cell subsets(P<0.001).The percentages of CD4^(+)CD8^(+)MAIT lymphocytes and CD107α-positive MAIT lymphocytes were negatively correlated with alanine aminotransferase(r=-0.474 and-0.550,P=0.047 and 0.018).Conclusion The migration of peripheral blood MAIT lymphocytes to the liver plays a protective role against liver inflammation in children with MAFLD.