急慢性乙型肝炎患者外周血调节性T细胞鉴定与临床意义分析

目的观察不同类型HBV感染患者外周血CD4+CD25high调节性T细胞(Treg)的频率和临床指标的相关性。方法采集72例慢性乙型肝炎患者(CHB)、16例急性乙型肝炎患者(AHB)、32例健康人的外周血,流式细胞仪分析Treg频率及Treg细胞表面和细胞内分子表达。所有病例及对照均经酶联免疫吸附试验(ELISA)检测HBsAg、HBsAb、HBeAg、HBeAb、HBcAb,实时荧光定量RT-PCR检测血清HBVDNA载量,同时进行肝功能检测。结果CD4+CD25highTreg表面高表达CD45RO,低表达CD45RA,细胞内高表达CTLA-4。比较Treg占CD4+T细胞频率,慢性乙型肝炎组(3·9%±1·4%)与正常对照(3·5%±0·7%)比较差异无统计学意义(P>0·05),但是明显高于急性乙型肝炎组(3·1%±0·9%)(P<0·05),急性乙型肝炎组与正常对照比较差异无统计学意义(P>0·05)。慢性乙型肝炎组Treg频率在高病毒载量组(HBVDNA>107拷贝/ml,4·5%±1·9%)明显高于低病毒载量组(HBVDNA<107拷贝/ml,3·4%±0·6%)和正常对照组,并与病毒载量成正相关(r=0·32,P<0·01)。8例随访急性乙型肝炎患者Treg频率在恢复期(6·0%±1·7%)明显高于急性期(3·0%±0·6%),配对t检验P<0·001。结论CD4+CD25highTreg在慢性乙型肝炎患者高病毒载量组明显升高,这提示Treg可能通过抑制细胞免疫反应影响病毒清除;Treg在急性肝炎早期较低,随后增高,可能与Treg在急性肝炎的不同发病阶段中所起的作用有关。

The characterization of regulatory T cells in peripheral blood of HBV-infected patients

OBJECTIVE: CD4(+)CD25(high) regulatory T cells (Treg) have been shown to play an important role in maintaining peripheral tolerance against self and foreign antigens, and in suppressing T cell immune response. Our aim was to characterize circulating Treg in HBV-infected patients. METHODS: Treg in peripheral blood from 72 chronic hepatitis B (CHB) patients, 16 acute hepatitis B (AHB) patients and 32 healthy subjects were quantitatively analyzed using flow cytometry. Serum HBV markers were evaluated for each subject. HBV-DNA levels were measured using real-time RT-PCR. RESULTS: CHB patients presented a higher fraction of circulating Treg (3.9% +/- 1.4%) than those in AHB patients (3.1% +/- 0.9%) (P < 0.05), but were similar to healthy controls (3.5% +/- 0.7%). CHB patients with greater than 10(7) copies/ml of serum HBV DNA loads had a higher frequency (4.5% +/- 1.9%) of circulating Treg than health controls (P < 0.01) and the patients with less than 10(7) copies/ml of serum viral loads (3.4% +/- 0.7%). A correlation was found between circulating Treg and HBV DNA level (r = 0.32, P < 0.01). Furthermore, Treg was more frequent in convalescent phase (6.0% +/- 1.7%) than in early acute phase (3.0% +/- 0.6%). CONCLUSION: Increased peripheral Treg is found to be associated with HBV replication in chronic hepatitis B. In acute HBV infection, Treg is less frequent in early phase. The related mechanisms is under further investigation.