Clinical application of enzyme-linked immunospot assay for rapid detection of active pulmonary tuberculosis infection

Objective To evaluate the clinical application of enzyme-linked immunospot(ELISPOT) assay for rapid detection of active pulmonary tuberculosis.Methods Rapid T-SPOT.TB assay was employed to detect Mycobacterium tuberculosis antigen specific T cells in blood samples from 36 patients with active pulmonary tuberculosis receiving initial anti-tuberculosis treatment shorter than 1 month and 30 healthy individuals.The conventional PPD skin test was performed on 26 patients with active tuberculosis at the same time.Results By the T-SPOT.TB assay,positive rates for the 36 patients with active tuberculosis and 30 healthy controls were 80.6% and 6.7%,respectively.For diagnosing active pulmonary tuberculosis,this assay had a sensitivity of 80.6%,specificity of 93.3%,positive predictive value of 93.5% and negative predictive value of 80.0%.The positive rate of T-SPOT.TB assay was higher than that of PPD skin test in 26 patients(80.6% vs 61.5%),but no significant difference was found(P0.05).Conclusions T-SPOT.TB assay is a rapid,more sensitive and specific method for detecting Mycobacterium tuberculosis infection.It will be a useful tool to early and rapidly diagnose active pulmonary tuberculosis infection in China.