慢性乙型肝炎患者特异性细胞毒性T淋巴细胞的变化

Changes of antigen-specific cytotoxic T lymphocytes during acute flare-ups in chronic hepatitis B patients

目的探讨慢性乙型肝炎急性发作及病情严重程度与特异性细胞毒性T淋巴细胞(CTL)水平的关系。方法从29例人白细胞抗原(HLA)-A2阳性慢性乙型肝炎急性发作及免疫耐受慢性乙型肝炎患者外周血中分离外周血单个核细胞,用HLA-A2*HBcAg抗原表位肽-五聚体复合体及CD8单克隆抗体染色后,用流式细胞仪检测乙型肝炎病毒(HBV)特异性的CTL细胞。并对6例急性发作患者进行动态检测HBV特异性的CTL、肝功能和病毒载量。结果19例急性发作慢性乙型肝炎患者五聚体阳性细胞占CD8阳性细胞的比例平均为1．4%±0．8%,而10例免疫耐受患者为0．6%±0．4%,两组间比较,t=2．180,P＜0．05,差异有统计学意义。急性发作导致重型肝炎的患者中,乙型肝炎核心抗原特异性CTL细胞阳性率平均为1．3%±1．0%,而非重型肝炎患者为1．4%±0．8%,两组间比较,差异无统计学意义。在12周的随访期内,患者丙氨酸氨基转移酶和病毒载量逐渐下降,但乙型肝炎核心抗原特异性CTL维持在较高的水平(＞0．7%)。结论慢性乙型肝炎患者急性发作与HBV特异性CTL有关,但主要的肝细胞损害可能并非直接由HBV特异性CTL引起的。

Objectives To detect HBV antigen specific cytotoxic T lymphocyte （CTL） changes in patients during acute flarc-ups and to study their association with flare-ups and aggravations into grave hepatitis by quantitative analysis of HLA- A2＊ restricted HBcAg-specific CTL cells. Methods The frequency of HBcAg-specific CTL cells in the peripheral blood mononuclear cells （PBMC） from 29 patients with persistent infection with HBV were quantified by flow cytometry using one HLA-A2＊HBV peptide pentamers complex （ProSTM MHC Pentamers）. Results There was a statistical difference of HBcAg specific CTLs between the patients with acute exacerbations （1.4% ± 0.8%） and the patients with immune tolerance （0.6% ± 0.4%） （t = 2.180, P = 0.01〈0.05）; There was no significant difference between the grave hepatitis group （1.3%± 1.0%） and the chronic hepatitis group （1.4% ± 0.8%） regarding frequencies of antigen specific CTL （t = 0.215, P = 0.833〉0.05）. The level of antigen specific CTLs in PBMC in the 6 cases of chronic hepatitis B with acute exacerbations maintained a relatively high level （〉0.7%） within the 12 week follow-up period. Conclusion HBcAg-specific CTLs may play an important role in hepatic flare-ups in patients with chronic HBV infection, but there was no direct relationship between antigen- specific CTLs and grave hepatitis.