目的 探讨慢性乙型肝炎患儿外周血黏膜相关恒定T（MAIT）细胞的变化及其临床意义。方法 慢性乙型肝炎 (CHB) 组20例，健康对照（HC）组20例，收集患儿外周血，流式细胞技术检测MAIT细胞（CD3⁺CD161⁺TCRVα7.2⁺细胞）及其不同亚型（CD4⁺CD8^－MAIT细胞、CD4^－CD8^－MAIT细胞、CD4^－CD8⁺MAIT细胞和CD4⁺CD8⁺MAIT细胞）比例，表达PD-1、CD69、穿孔素、CD107α、CXCR3、CXCR6和CCR6的MAIT细胞比例，计量资料行Mann-Whitney U检验和Spearman相关性分析。结果 与HC相比，CHB组患儿外周血MAIT细胞及其不同亚型比例无变化（P>0.05），外周血表达PD-1、CD69、CD107α、CXCR3、CXCR6、CCR6和穿孔素的MAIT细胞比例均有升高（P<0.05）。表达CD69、PD-1、CD107α、穿孔素、CXCR6、CCR6和CXCR3的MAIT细胞比例与丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）及HBV-DNA荧光定量间无相关性（P>0.5）。结论 外周血MAIT细胞的不同免疫功能在儿童慢性乙型肝炎发病中起着一定作用。

Objective This study aimed to investigate the changes and the clinical implications of peripheral blood mucosal associated invariant T (MAIT) cells in children with chronic hepatitis B (CHB). Methods The investigation encompassed 20 patients with CHB and an equal number of age-matched healthy controls (HC). Peripheral blood specimens were obtained and analyzed using flow cytometry to quantify the presence of MAIT cells (defined as CD3⁺CD161⁺TCRVα7.2⁺), their subtypes, and the expression of various markers including PD-1, CD69, perforin, CD107α, CXCR3, CXCR6, and CCR6. Statistical comparisons between the groups were made using the Mann-Whitney U test and Spearman's correlation analysis. Results No significant differences were observed in the proportion of MAIT cells and their subtypes between the CHB and HC groups (P>0.05). However, the CHB group exhibited a significant increase in the proportion of MAIT cells expressing PD-1, CD69, CD107α, CXCR3, CXCR6, CCR6, and perforin (P<0.05). There was no significant correlation between the proportion of MAIT cells expressing CD69, PD-1, CD107α, perforin, CXCR6, CCR6 and CXCR3 and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatitis B virus (HBV) DNA fluorescent quantitation (P>0.05). Conclusion The distinct immunological functions of peripheral blood MAIT cells may contribute to the pathogenesis of CHB in pediatric patients.