Kalantri Yatiraj, Hemvani Nanda, Chitnis D S
Department of Microbiology and Immunology, Choithram Hospital and Research Centre, Indore 452 014, India.
Indian J Exp Biol. 2009 Jun;47(6):463-8.
Quantiferon TB gold (QFT-G) with recombinant antigen cocktail is well evaluated for diagnosis of pulmonary tuberculosis (PTB). However, diagnosis of extra-pulmonary tuberculosis (EPTB) is more difficult due to limitations of conventional techniques. This study compares recombinant antigens based QFT-G and low cost PPD based interferon test for the diagnosis of PTB and EPTB. IFNgamma release, with recombinant antigens and PPD, was assayed by ELISA from 140 cases of EPTB, 100 cases of PTB along with acid fast bacillus (AFB) detection, AFB culture on LJ and MGIT BACTEC. Sensitivity and specificity for QFT-G recombinant antigens was 84.29% and 96%, while for PPD based interferon was 70% and 84% for EPTB group. The sensitivity was far superior to AFB smear and culture for both the antigens. Nine samples were identified as non-tubercular mycobacteria (NTM) in the EPTB group and all were negative for QFT-G, but six of them were positive for PPD based test. Results of the study show that QFT-G using recombinant antigen is sensitive and specific for both PTB and EPTB diagnosis. The PPD based test is economic and offers comparable performance for PTB and EPTB diagnosis and also useful for diagnosis of NTM.
采用重组抗原组合的结核菌素释放试验（QFT-G）在肺结核（PTB）诊断方面已得到充分评估。然而，由于传统技术的局限性，肺外结核（EPTB）的诊断更为困难。本研究比较了基于重组抗原的QFT-G和基于低成本结核菌素纯蛋白衍生物（PPD）的干扰素检测对PTB和EPTB的诊断效果。通过酶联免疫吸附测定法（ELISA）检测了140例EPTB患者、100例PTB患者的γ干扰素释放情况，同时进行了抗酸杆菌（AFB）检测、在罗琴培养基（LJ）和分枝杆菌生长指示管（MGIT）BACTEC上的AFB培养。EPTB组中，QFT-G重组抗原的敏感性和特异性分别为84.29%和96%，而基于PPD的干扰素检测的敏感性和特异性分别为70%和84%。两种抗原的敏感性均远高于AFB涂片和培养。EPTB组中有9个样本被鉴定为非结核分枝杆菌（NTM），所有样本QFT-G检测均为阴性，但其中6个样本基于PPD的检测为阳性。研究结果表明，使用重组抗原的QFT-G对PTB和EPTB诊断均敏感且特异。基于PPD的检测经济实惠，在PTB和EPTB诊断方面表现相当，对NTM诊断也有帮助。
