Comparison Of Detection Performances Between Two Kits For Mycobacterium Tuberculosis Infection

Objective:As a new kind of enzyme immune technology-the assay of interferon-gamma release assay (IGRA) based on Mycobacterium tuberculosis(MTB) specific antigen, owns high sensitivity and specificity. This study is based on the assay, and uses the method of contrasting two kits, verifying the clinical detection performances of the reference kit, furthermore, to evaluate the clinical detection performances of the test kits.Methods:108clinical blood samples were detected (61in tuberculosis group,31in other nontuberculous pulmonary disease group,13in healthy control group),82of which were detected with two kits contrastively (43in tuberculosis group,26in other nontuberculous pulmonary disease group,13in healthy control group). It ts QuantiFERON-TB Gold (Cellestis, Melbourne, Australia) that regarded as reference kit and a related kit developed by a domestic company regarded as test kit, based on the results of clinical diagnosis to calculate the accuracy of the test kits and to explorer the basic immune status by counting the quantity of IFN-γ in tuberculosis group and healthy control group.Results:The sensitivity, specificity, positive predictive value, negative predictive value, and the diagnostic validity of the reference kit were81.39%(35/43),76.92%(30/39),79.55%(35/44),78.95%(30/38), and79.27%(65/82) respectively; the same values mentioned above of test kit were73.77%(45/61),84.09%(37/44),86.54%(45/52),69.81%(37/53), and78.09%(82/105) respectively. The coincidence rate of the two kits is86.56%,(Kappa=0.734). The quantity of IFN-y after stimulation showed significantly higher in tuberculosis group than that in healthy control group,(t=2.529, p=0.014).Conclusions:The detection performances of the two kits were nearly the same, and the two kits can be used for the auxiliary diagnosis of MTB infection. T cell activity may be increased reactively in tuberculosis patients to some extent.