不同肝纤维化程度慢性乙型肝炎患者的血浆蛋白质组学分析

Plasma proteome analysis of chronic hepatitis B patients with different stages of liver fibrosis

目的探索与肝纤维化程度相关的新血浆标志物，为开发有临床应用价值的肝纤维化无创诊断提供新型检测分子。方法收集慢性乙型肝炎患者血浆，并根据肝活组织病理学诊断肝纤维化的分期进行分组，包括S0～1组40例，S2～3组20例和S4组20例。血浆样品去除血浆中的白蛋白和免疫球蛋白G后，通过二维凝胶电泳进行分离，采用ImageMaster软件分析获得的电泳图谱，找到与疗效相关的差异蛋白质。差异蛋白质点经过胰酶酶切后，通过在线纳升级反向液相色谱串联电喷雾离子阱质谱分析进行鉴定。结果通过比较不同组血浆蛋白质的二维凝胶电泳图谱，共发现了14个在S0～1组、S2～3组和S4组血浆样品中表达差异的蛋白质点。液相色谱串联质谱分析鉴定差异蛋白质点，包括人纤维蛋白原γ链、接联球蛋白、补体蛋白C3、免疫球蛋白κ链C区和载脂蛋白A—I。结论通过对不同肝纤维化程度的慢性乙型肝炎患者血浆进行蛋白质组学分析，发现和鉴定了5种在乙型肝炎患者血浆中表达水平与肝纤维化进程相关的差异蛋白质，这些蛋白质可能是评价患者肝纤维化程度的潜在生物标志物。

Objective To identify plasma biomarkers with specific relation to the various liver fibrosis stages that can be used to assess hepatitis B virus （HBV）-infected patients for non-invasive liver fibrosis and to evaluate the prognosis of the liver fibrosis. Methods Plasma samples were collected from 80 HBV- positive patients at the Hepatitis Department of Shanghai Public Health Clinical Center between September 2008 and January 2011. The samples were grouped according to the patient＇s stage of hepatic fibrosis determined by liver biopsy： S0-1 （n = 40）, S2-3 （a = 20）, and S4 （n = 20）. Each plasma sample was processed to remove the two most abundant proteins, albumin and immunoglobulin G （IgG）, and then resolved by two- dimensional （2D） electrophoresis. ImageMaster 2D analysis software was used to identify differentially expressed proteins related to the liver fibrosis stages. After trypsin digestion, the differential proteins were identified by online reversed-phase nano-flow liquid chromatography coupled with electrospray ionization ion trap mass spectrometry （MS）. Results The patients in the three groups were not significantly different in age （range： 30-50 years; P = 0.053） or sex （x2 = 0.155, P = 0.926）. Low-abundance proteins were efficiently enriched by the albumin/IgG depletion method. Fourteen differentially expressed proteins were detected among the S0-1, S2-3 and S4 groups, all of which were identified by tandem MS and included fibrinogen gamma chain, haptoglobin, complement C3, Ig kappa chain C region, and apolipoprotein A-I. Conclusion Plasma proteomic analysis of chronic hepatitis B patients identified a panel of differentially expressed proteins related to different stages of liver fibrosis. These proteins may represent diagnostic and prognostic biomarkers of HBV-related hepatic fibrosis.