Department of Immunology, Tuberculosis Research Centre (ICMR), Chennai, Tamil Nadu, India.
PLoS One. 2010 Feb 4;5(2):e9051. doi: 10.1371/journal.pone.0009051.
The measurement of Interferon gamma or Interferon gamma inducible protein (IP)-10 in antigen stimulated blood samples is suggested as an alternative method for latent tuberculosis (TB) diagnosis. Nonetheless, their role in active TB diagnosis, particularly in TB endemic settings is yet to be defined. In this study, the sensitivities and specificities of Interferon gamma release assay (IGRA), IP-10 assay and tuberculin skin test (TST) in detecting active TB cases were assessed in human immunodeficiency virus (HIV) sero-negative TB patients and healthy controls respectively.
METHODS/PRINCIPAL FINDINGS: A total of 177 adult TB patients and 100 healthy controls were included for this study. QuantiFERON-TB Gold In-tube (QFT-IT) method was used to analyze the sensitivity and specificity of IGRA. QFT-IT, IP-10 and TST yielded the diagnostic sensitivities of 90.6% (95%CI: 86.3%-94.9%), 92.5% (95%CI: 88.6%-96.4%) and 68.9% (95%CI: 60.6%-77.2%) and specificities of 55% (95% CI: 35.2%-54.8%), 48% (95% CI: 38.2%-57.8%) and 75.5% (95% CI: 66.8%-84.2%), respectively. The extent of pulmonary involvement or presence of diabetes mellitus did not appear to influence the sensitivities of any of these tests. The combination of any of the two tests among QFT-IT, IP-10 and TST showed >98% sensitivity among smear negative cases and particularly the combination of IP-10, TST and smear microscopy showed 100% sensitivity, however, the specificity was decreased to 44.8%.
CONCLUSIONS/SIGNIFICANCE: QFT-IT and IP-10 were highly sensitive in detecting active TB cases. The combination with TST improved the sensitivity of QFT-IT and IP-10 significantly. Although the higher sensitivity of combination of QFT-IT/IP-10 and TST may be useful in active TB diagnosis, they are limited by their poor specificity due to the high prevalence of latent TB in our settings.
在抗原刺激的血液样本中测量干扰素γ或干扰素γ诱导蛋白(IP)-10 被建议作为潜伏性结核(TB)诊断的替代方法。尽管如此,它们在活动性 TB 诊断中的作用,特别是在 TB 流行地区的作用仍未确定。在这项研究中,分别在 HIV 血清阴性的 TB 患者和健康对照者中评估了干扰素释放试验(IGRA)、IP-10 检测和结核菌素皮肤试验(TST)在检测活动性 TB 病例中的敏感性和特异性。
方法/主要发现:本研究共纳入 177 例成人 TB 患者和 100 例健康对照者。使用 QuantiFERON-TB Gold In-tube(QFT-IT)方法分析了 IGRA 的敏感性和特异性。QFT-IT、IP-10 和 TST 的诊断敏感性分别为 90.6%(95%CI:86.3%-94.9%)、92.5%(95%CI:88.6%-96.4%)和 68.9%(95%CI:60.6%-77.2%),特异性分别为 55%(95%CI:35.2%-54.8%)、48%(95%CI:38.2%-57.8%)和 75.5%(95%CI:66.8%-84.2%)。肺受累程度或糖尿病的存在似乎并未影响这些检测的敏感性。在 QFT-IT、IP-10 和 TST 中任意两种检测的组合在涂片阴性病例中显示出超过 98%的敏感性,特别是 IP-10、TST 和涂片显微镜检查的组合显示出 100%的敏感性,然而特异性降低至 44.8%。
结论/意义:QFT-IT 和 IP-10 对检测活动性 TB 病例具有高度敏感性。与 TST 联合使用可显著提高 QFT-IT 和 IP-10 的敏感性。尽管 QFT-IT/IP-10 和 TST 联合使用的更高敏感性可能有助于活动性 TB 诊断,但由于我们的环境中潜伏性 TB 的高患病率,它们的特异性较差。