Value of T-SPOT in the diagnosis of pulmonary tuberculosis

Abstract

Objective To investigate the value of T cell enzyme-linked immunospot tuberculous test (T-SPOT) in the clinical diagnosis of pulmonary tuberculosis. Methods The clinical data of 286 suspected pulmonary tuberculosis patients, who experienced T-SPOT test and sputum bacteria test (including sputum acid fast stain and mycobacterium culture) in Plumonary Hospital of Changsha Central Hospital from June 2016 to March 2017 were retrospectively analyzed. Of them, 187 cases of pulmonary tuberculosis were clinically confirmed. The specificity, sensitivity, negative predictive value and positive predictive value of two detection methods in clinical diagnosis of pulmonary tuberculosis were evaluated. And the clinical characteristics of T-SPOT of false negative cases were analyzed in order to speculate on the possible risk factors leading to the false negative. Results The sensitivity (85.03%) and negative predictive value (75.65%) of T-SPOT were higher than those of sputum bacteria test (54.55%, 51.98%) in clinical diagnosis of pulmonary tuberculosis, but the specificity (87.88%) and positive predictive value (92.98%) of T-SPOT were lower than those of sputum bacteria test (92.93%, 93.58%), and sensitivity, specificity and negative predictive value were statistically different between the two methods (P<0.05). The underlying disease status (such as malignancy, human immunodeficiency virus infection, diabetes, connective tissue disease and organ transplantation) may be correlated with false negative results of T-SPOT. Conclusions T-SPOT has good application values in the clinical diagnosis of pulmonary tuberculosis, of which results may be affected by some clinical factors and need to be analyzed synthetically. Key words: Pulmonary tuberculosis; Diagnosis; T cell enzyme-linked immunospot tuberculous test