Ⅱ型树突状细胞在慢性乙型肝炎患者中的功能检测及其临床意义

Identification of circulating type Ⅱ pre-dendritic cells （pDC2） and its clinical significance in chronic hepatitis B virus infection

目的研究慢性乙型肝炎患者外周血中Ⅱ型树突状细胞（pDC2）的数量及其功能的变化与疾病的发生发展的关系。方法采用流式细胞分析技术对27例慢性乙型肝炎患者和15例健康人外周血中pDC2数量的变化以及其产生α干扰素的能力进行了检测，同时与T淋巴细胞亚群CD4^＋，CD8^＋的比值进行了比较分析。结果肝炎患者外周血pDC2的百分数（O．096±0．086）较正常人（0．304±0．093）明显降低，两者差异有统计学意义（P〈0．001），特别是慢性肝炎患者pDC2产生IL-12及IFNα的能力明显低于正常人群（P〈0．001）；而CD4^＋／CD8^＋的比值则明显高于正常人（P〈0．01）。同时发现在HBVDNA（＋）的患者中其pDC2的百分数和CD4^＋／CD8^＋的比值分别为0．087±0．054和1．95±0．562，均明显高于HBVDNA（-）患者（分别为0．043±0．031和1．44±0．476），差异有统计学意义（P〈0．01）。结论与正常人相比，慢性乙型肝炎患者外周血中pDC2的数量和其产生细胞因子的能力降低，后者可能与慢性乙型肝炎患者病程的进展以及血清中HBVDNA阳性有关。

Objective To investigate the characteristics of ciculating type Ⅱ pre-dendritic cells （pDC2） and evaluate its role in patients with chronic hepatitis B virus infection. Methods The quantitative alterations of pDC2 in 27 chronic HBV-infected patients as treated group and 15 healthy individuals as a control group were analyzed by using flow cytometry based on the comparison of CD4^＋/CD8^＋ ratios of T lymphocyte subsets between the two groups. The IFN-alpha-producing ability of pDC2 after incubation was determined by ELISA. Results The percentage of pDC2 （0.096 ± 0.086） from the peripheral blood in chronic HBV-infected patients were significantly lower than that （0.304 ± 0.093） inform the normal controls （ P 〈 0.001） while the CD4^＋/CD8^＋ ratios were higher than those in normal controls （P 〈 0.01 ）. The values of IFN-alpha-producing function and IL- 12 of circulating pDC2 in chronic HBV-infected patients group were significantly lower than those in healthy subjects （P 〈 0.001 ）. The percentage of pDC2 and CD4^＋/CD8^＋ ratios were higher in the patients positive for HBV DNA in sera than those in patients negative for HBV DNA in sera （ P 〈 0.01 ）. Conclusion The decreased number of ciculating pDC2 and IFN-alpha-producing function from peripheral blood in patients with chronic hepatitis B virus infection may result in the decline of host immune response, which may partially contribute to the disease progress of HBV infection and existence of viral genomic DNA in patient＇s sera.