慢性乙型肝炎病毒感染患者外周血特异性CD8^+T淋巴细胞检测的临床意义

Significance of circulating specific CD8^+ T cells detection in chronic hepatitis B patients

目的研究慢性乙型肝炎病毒(HBV)感染患者外周血特异性CD8+T淋巴细胞(CTL)频率的变化及临床价值。方法采用乙型肝炎病毒核心抗原(HBcAg)18-27表位肽-人类白细胞抗原(HLA)-A*0201五聚体及CD8单克隆抗体,设计流式细胞技术检测HLA-A2+6例、HLA-A2-12例非HBV感染者、HLA-A2+49例和HLAA2-42例HBV感染者外周血中针对该肽段的特异性CTL数量,占总计数CD8+细胞数百分比表示。结果 HLA-A2-HBV感染未抗病毒治疗者特异性CTL(0.30%～14.40%,中位数1.13%,n=20)与HLA-A2-非HBV感染者(0.33%～3.90%,中位数1.04%,n=12),差异无统计学意义(P>0.05),但显著低于HLA-A2-抗病毒治疗者(0.25%～20.30%,中位数2.11%,n=22,P<0.05);HLA-A2-抗病毒治疗者特异性CTL和HLA-A2+未抗病毒治疗者特异性CTL(0.20%～29.90%,中位数2.22%,n=20)均显著高于HLA-A2-非HBV感染者(P<0.01);HLA-A2+抗病毒治疗者特异性CTL(0.14%～39.22%,中位数1.33%,n=29)显著高于HLA-A2-非HBV感染者(P<0.05)。HLA-A2+未抗病毒组中血清HBV DNA<103 copy/mL、丙氨酸氨基转移酶小于40U/L者特异性CTL频率增高(P<0.05、0.01)。结论 HBV抗原肽-HLA-A*0201五聚体流式细胞技术能在体外直接检测外周血HBV特异性CTL频率的变化,其水平一定程度反映不同临床感染状态慢性HBV感染患者T淋巴细胞对特异性抗原表位免疫应答的差异。

Objective To investigate frequency change of peripheral blood specific CD8＋T lymphocytes（CTL）in patients with chronic HBV infection and to evaluate its clinical value.Methods Total of 109patients were enrolled,including 6cases of HLA-A2＋,12cases of HLA-A2-without HBV infection,49cases of HLA-A2 ＋and 42 cases of HLA-A2-with HBV infection.HBcAg 18-27epitope peptide-HLA-A＊0201pentamers and CD8monoclonal antibody were designed to detect the number of specific CTL in peripheral blood by using flow cytometry.Results The detected result of specific CTL in HLA-A2-HBV-infected patients with no antiviral treatment（0.30%14.40%,median 1.13%,n=20）was not statistically different with HLA-A2-non-HBV infected patients（0.33%3.90%,median 1.04%,n=12,P0.05）,but was significantly lower than HLA-A2-HBV-infected patients with antiviral treatment（0.25%-20.30%,median 2.11%,n=22,P0.05）.The specific CTL both in HLA-A2-HBV-infected patients with antiviral treatment and HLA-A2 ＋HBV-infected patients with no antiviral treatment（0.20%29.90%,median 2.22%,n=20）were significantly higher than control group（P0.01）.The detected result of specific CTL in HLA-A2 ＋HBV-infected patients with antiviral treatment（0.14%～39.22%,median 1.33%,n=29） was significantly higher than control group（P0.05）.The number of specific CTL was increased in HLA-A2 ＋ without antiviral therapy patients with serum HBV DNA less than 103 copy/mL and ALT less than 40IU/L（P 0.05,P0.01）.Conclusion HBV antigen peptide-HLA-A＊0201pentamers could directly detect the frequency change of peripheral blood specific CTL by using flow cytometry,and its level could reflect differences in epitope specificity of the immune response of T lymphocytes in patients with different clinical status of chronic HBV infection.