Alifano M, De Pascalis R, Sofia M, Faraone S, Del Pezzo M, Covelli I
Institute of Respiratory Disease, University of Naples Federico II, Italy.
Thorax. 1998 May;53(5):377-80. doi: 10.1136/thx.53.5.377.
Diagnosis of extrapulmonary tuberculosis is often difficult to establish using standard methods. Serological techniques based on detection of antibodies against mycobacterial antigen A60 have shown good sensitivity and specificity in pulmonary tuberculosis. The present study was undertaken to define the diagnostic accuracy of testing for IgG and IgA against A60 in extrapulmonary tuberculosis.
One hundred and ninety eight subjects were studied: 42 patients with extrapulmonary tuberculosis confirmed by microbiology and/or histology, 24 subjects with healed pulmonary or extrapulmonary tuberculosis, 44 patients with a defined non-tuberculous disease, and 88 healthy volunteers (44 PPD negative and 44 PPD positive). Detection of IgG and IgA against A60 antigen was carried out by enzyme-linked immunosorbent assay. Cut off values were determined by receiver operating characteristic curves.
Sensitivity of the IgG test was 73.8% in extrapulmonary tuberculosis, while the specificity was 96.1%. The IgA test showed a sensitivity of 69.0% with a specificity of 93.6%. Combination of the IgG and IgA tests showed a sensitivity of 80.9% and a specificity of 92.3%. Patients with extrapulmonary tuberculosis showed significantly higher titres of both IgG and IgA against A60 than other groups.
Anti-A60 IgG or IgA tests are characterised by good sensitivity and specificity. The combined use of both tests allows an increase in diagnostic accuracy of extrapulmonary tuberculosis.
使用标准方法往往难以确诊肺外结核病。基于检测抗分枝杆菌抗原A60抗体的血清学技术在肺结核中显示出良好的敏感性和特异性。本研究旨在确定检测抗A60 IgG和IgA在肺外结核病中的诊断准确性。
对198名受试者进行了研究：42例经微生物学和/或组织学确诊的肺外结核病患者，24例已治愈的肺结核或肺外结核病患者，44例明确的非结核性疾病患者，以及88名健康志愿者（44名PPD阴性和44名PPD阳性）。采用酶联免疫吸附测定法检测抗A60抗原的IgG和IgA。通过受试者工作特征曲线确定临界值。
在肺外结核病中，IgG检测的敏感性为73.8%，而特异性为96.1%。IgA检测的敏感性为69.0%，特异性为93.6%。IgG和IgA检测联合使用时，敏感性为80.9%，特异性为92.3%。肺外结核病患者的抗A60 IgG和IgA滴度均显著高于其他组。
抗A60 IgG或IgA检测具有良好的敏感性和特异性。两种检测联合使用可提高肺外结核病的诊断准确性。
