Diagnostic Value of T-cell Enzyme-linked Immunospot Assay for Pulmonary Tuberculosis and Extrapulmonary Tuberculosis

Objective To investigate the diagnostic value of T-cell Enzyme-linked immunospot assay(T-SPOT.TB) in patients with pulmonary tuberculosis and extrapulmonary tuberculosis.Methods T-SPOT.TB was used to detect T-cell frequency in 55 patients with active tuberculosis,14 case-controls with non-tuberculosis lung diseases,9 case-controls with non-tuberculosis extrapulmonary diseases and 12 healthy controls.Results The positive rate of T-SPOT.TB was significantly higher in the patients with pulmonary tuberculosis and extrapulmonary tuberculosis than controls(P0.01).The sensitivity of T-SPOT.TB assay was 88.57%,80.00% and 93.33%,the specificity was 85.71%,85.71% and 88.89%,the positive predictive value was 93.94%,88.89% and 96.55%,and the negative predictive value was 75.00%,75.00% and 80.00% in sputum smear-positive tuberculosis,sputum smear-negative tuberculosis and extrapulmonary tuberculosis,respectively.There was no statistical difference between extrapulmonary tuberculosis and sputum smear-positive tuberculosis and smear-negative tuberculosis(P0.05).Conclusion T-SPOT.TB assay possesse satisfactory sensitivity and specificity to diagnose tuberculosis infection and has an important clinical value in the diagnosis of extrapulmonary tuberculosis and sputum-negative pulmonary tuberculosis.