传染性非典型肺炎的血清学诊断研究

目的 评估传染性非典型肺炎(世界卫生组织又称严重急性呼吸综合征，SARS)血清病毒特异性抗体检测在SARS诊断中的实用价值，了解免疫荧光抗体法(IFA)和酶联免疫吸附法(ELISA)对SARS病毒特异性抗体检测结果的一致性程度。方法 用IFA和ELISA检测267例不同病程SARS患和132例对照组血清SARS病毒特异性抗体，以敏感度、特异度、阳性预测值(17PV)、阴性预测值(NPV)和准确度评价其诊断价值，并以Kappa值评价两种检测方法结果的一致性。结果 以IFA检测的血清特异性IgM类和IgG类抗体阳性率在病程第11天明显增高，病程≥11天，IgM类抗体诊断SARS的敏感度为65．6％，特异度100．0％，PPV 100．0％，NPV 71．0％，准确度81．3％；IgG类抗体则分别为敏感度91．1％，特异度97．0％，PPV 97．3％，NPV 90．1％，准确度93．8％。以ELISA方法所测结果与IFA结果相仿。对IFA和ELISA法检测的一致性检验示Kappa值分别为0．640和0．779。结论 血清病毒特异性抗体在SARS发病10天以上阳性率高，抗体检测有助于确立发病10天以上SARS的血清学诊断。IFA和ELISA检测SARS病毒抗体的一致性较好。

Serum antibodies detection for serological diagnosis of severe acute respiratory syndrome

Objective To evaluate the significance of serum specific antibodies against severe acute respiratory syndrome (SARS) virus in the diagnosis of SARS and the concordance of IFA and ELISA in the antibodies measurements. Methods Specific antibodies of IgM and IgG against SARS virus in 267 serum specimens from patients with SARS and 132 from non-SARS patients or healthy persons were assayed with IFA or ELISA. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were used to evaluate the significance of the antibodies in diagnosis of SARS. The concordance of different measurements was tested with Kappa. Results The positive rate of specific IgM and IgG detected by IFA increased sharply on the eleventh day of the disease. The sensitivity, specificity, PPV, NPV, and accuracy of IgM in diagnosis of SARS on eleventh day or later were 65.6%, 100.0%, 100.0%, 71.0%, and 81.3%, respectively, and IgG were 91.1%, 97.0% 97.3%, 90.1%, and 93.8%, respectively. Similar results could be seen when IgM and IgG were detected by ELISA. The Kappa of IFA and ELISA for IgM and IgG were 0.640 and 0.779 respectively. Conclusions The antibodies against SARS virus can be detected in the mid- and late stage of SARS. The antibodies can be used in the serological diagnosis of SARS. There is high concordance of IFA and ELISA results in measurement of SARS antibodies.