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.

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. [ABSTRACT FROM AUTHOR]