丙型肝炎抗体S／CO值与RNA定量检测结果相关关系的初步探讨

Study on the Relationship between S/CO （signal to cutoff） Value of the Anti-HCV Assay and the Result of Quantitative HCV RNA Detection

目的探讨免疫发光法检测丙肝抗体S／CO（signaltocutoff）值与HCVRNA检测阳性率之间的关系。方法对1111例丙肝患者行HCV抗体和HCVRNA的实验室检测，以抗体水平进行分段统计，并以HCVRNA检测结果为参考采用ROC曲线评价S／CO值对丙肝患者的诊断效能。结果HCVRNA阳性率随s／co值的增大而升高，S／CO值在0～1时．HCVRNA阳性率为1．09％；在1～5时，阳性率为5．06％；在5～8时，阳性率为24．5％；8～10时，为50％；〉10，阳性率为100％。同时发现，S／CO值较低时HCVRNA阳性病例多为HIV／HCV共感染患者。根据ROC曲线可知，S／CO最佳诊断界值为6．94．此时诊断灵敏度和特异度均为93％。结论丙肝抗体S／CO值与HCVRNA检测结果较一致，临床实践中可参考S／CO值，并充分考虑患者实际情况，以合理选择检验项目，提高诊断效能。

Objective To investigate the statistical relationship between S/CO （signal to cutoff） value of the anti-HCV assay and the positive rate of quantitative HCV RNA detection. Methods Anti HCV assay and quantitative HCV RNA detection were performed for 1 lll patients with HCV infection. The detection results were divided into several groups for further a- nalysis according to the value of S/CO. Based on quantitative HCV RNA detection,ROC curve was employed to evaluate the detection efficacy of anti-HCV assay. Results The positive detection rate of the quantitative HCV RNA increased along with the rising value of S/CO. When the value of the S/CO was between 0 ~ 1,1 ~ 5,5 ~ 8,8 ~ 10 and 〉 10, the positive de- tection rate of quantitative HCV RNA turned out to be 1.09% ,5. 06%,24.5% ,50 % and 100% ,respectively. Moreover,the majority of patients with low values of S/CO and positive HCV RNA were proved to he HIV/HCV coinfected. The ROC curve revealed that the cut-off value of the S/CO was 6.94 based on quantitative HCV RNA detection,and both the sensitiv ity and specificity were 93% at this point. Conclusion The value of S/CO correlates well with quantitative HCV RNA de- tection. In order to increase the detection efficacy,the clinical state of the individuals should be taken into consideration for orooerly selection of laboratory items.