Clark S A, Martin S L, Pozniak A, Steel A, Ward B, Dunning J, Henderson D C, Nelson M, Gazzard B, Kelleher P
Department of Immunology, Imperial College, Chelsea & Westminster Hospital, London, UK.
Clin Exp Immunol. 2007 Nov;150(2):238-44. doi: 10.1111/j.1365-2249.2007.03477.x. Epub 2007 Aug 2.
There are limited data on the efficacy of T cell-based assays to detect tuberculosis (TB) antigen-specific responses in immune-deficient human immunodeficiency virus (HIV) patients. The aim of this study is to determine whether TB antigen-specific immune responses can be detected in patients with HIV-1 infection, especially in those with advanced disease (CD4 T cell count < 300 cells/microl). An enzyme-linked immunospot (ELISPOT) assay, which detects interferon (IFN)-gamma secreted by T cells exposed to TB antigens, was used to assess specific immune responses in a prospective study of 201 HIV-1-infected patients with risk factors for TB infection, attending a single HIV unit. The performance of the ELISPOT assay to detect TB antigen-specific immune responses is independent of CD4 T cell counts in HIV-1 patients. The sensitivity and specificity of this assay for the diagnosis of active tuberculosis does not differ significantly from values obtained in immunocompetent subjects. The negative predictive value of the TB ELISPOT test is 98.2%. A positive predictive value of 86% for the diagnosis of active tuberculosis was found when the combined number of early secretory antigen target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) IFN-gamma spots to CD4 T cell count ratio was > 1.5. TB antigen-specific immune responses can be detected in HIV patients with low CD4 T cell counts using ELISPOT technology in a routine diagnostic laboratory and is a useful test to exclude TB infection in immune-deficient HIV-1 patients. A combination of TB antigen-specific IFN-gamma responses and CD4 T cell counts has the potential to distinguish active tuberculosis from latent infection.
关于基于T细胞的检测方法在免疫缺陷的人类免疫缺陷病毒（HIV）患者中检测结核（TB）抗原特异性反应的疗效数据有限。本研究的目的是确定在HIV-1感染患者中，尤其是在那些疾病进展期（CD4 T细胞计数<300个/微升）的患者中，是否能检测到TB抗原特异性免疫反应。在一项对201名有TB感染风险因素、就诊于单一HIV治疗单位的HIV-1感染患者的前瞻性研究中，采用酶联免疫斑点（ELISPOT）检测法，该方法可检测暴露于TB抗原的T细胞分泌的干扰素（IFN）-γ，以评估特异性免疫反应。ELISPOT检测法检测TB抗原特异性免疫反应的性能与HIV-1患者的CD4 T细胞计数无关。该检测法诊断活动性结核病的敏感性和特异性与免疫功能正常受试者所获得的值相比，差异无统计学意义。TB ELISPOT检测的阴性预测值为98.2%。当早期分泌抗原靶标6（ESAT-6）和培养滤液蛋白10（CFP-10）的IFN-γ斑点数与CD4 T细胞计数的比值>1.5时，诊断活动性结核病的阳性预测值为86%。在常规诊断实验室中，使用ELISPOT技术可在CD4 T细胞计数低的HIV患者中检测到TB抗原特异性免疫反应，这是排除免疫缺陷的HIV-1患者TB感染的一项有用检测。TB抗原特异性IFN-γ反应和CD4 T细胞计数的联合应用有可能区分活动性结核病和潜伏感染。
