不同方法诊断低水平HCV的比较

An evaluation on different methods for detecting low-level hepatitis C virus

目的评价各种检测方法对HCV的诊断价值。方法运用微粒子免疫分析法(CMIA),免疫印迹法(RIBA),电化学发光免疫分析法(ECLIA),酶法(ELISA)和荧光定量PCR法检测84份HCV样本。结果31份CMIA法检测HCV抗体为0.40~10.0的样本,RIBA再测有14(45.16%)是不确定,8(25.81%)是有反应性,9(29.03%)是无反应性。不确定样本中的2份可能与RF,IgG和IgA有关。根据ROC曲线分析,抗-HCV(ECLIA)、HCV-Ab(CMIA)、HCV-Ag(CMIA)和HCV RNA曲线下面积分别为1.000、0.997、0.753和0.679,此时cut-offs分别为15.85 COI、3.31 S/CO、3.32 fmol/L和3.94E+03拷贝/mL。HCV RNA的对数值与HCV-Ag呈正相关(R=0.91,P<0.01)。RIBA实验有反应性的标本中,97.5%Core抗原和NS3抗原都有条带,其次37.5%NS4-1或NS5抗原有条带,仅有2.5%NS4-2抗原有条带。结论低水平HCV抗体需要有两种以上的方法来提高诊断准确性,电化学推荐的参考值分别为15.85 COI(ECLIA)和3.31 S/CO(CMIA)。一定程度上HCV Ag检测可以替代HCV RNA检测。

Objective Contradictory results in testing anti-hepatitis C virus antibody by chemiluminescence immunoassays(CLIAS)are very common,especially in the cases of low-level anti-HCV.The aim of this study was to explore the diagnostic values of various methods of single detection for low-level anti-HCV and to analyze their effectiveness.Methods A total of 84 serum samples were assessed for HCV via chemiluminescence microparticle immunoassay(CMIA),Enzyme-linked immunosorbent assay(ELISA),electro chemiluminescence immunoassay(ECLIA),recombinant immunoblot assay(RIBA)and Polymerase Chain Reaction(PCR)assay.Results Of the 31 samples with an anti-HCV S/CO ratio between 0.40-10.0 as tested by Architect,45.16%were indeterminate,25.81%were positive,and 29.03%were negative according to RIBA.Furthermore,2 out of 19 samples were related with RF,IgG or IgA.Areas under the ROC in ECLIA,CMIA,HCV-Ag and HCV-RNA were 1.000,0.997,0.753 and 0.679,respectively,and their cut-offs were 15.85 COI,3.31 S/CO,3.32 fmol/l and 3.94E+03 copies/ml,respectively.The HCV Ag test showed a strong correlation between the logarithmic values of HCV-RNA and HCV-Ag(R=0.91,P<0.001).Of the positive RIBA samples,97.5%presented reactivity for Core or NS3 antigens on nitrocellulose immunoblot test strips,while only 37.5%presented reactivity for NS4-1 or NS5 antigens and only 2.5%for NS4-2.Conclusion Two methods are required for testing Low-level anti-HCV to improve the diagnostic accuracy,and reference values of 15.85 COI(ECLIA)and 3.31 S/CO(CMIA)are recommended.To some extent,HCV-Ag may be assayed instead of HCV RNA.