Diagnostic Value of T-Cell Enzyme Linked Immunospot Assay for Tuberculosis Infection in Pulmonary Tuberculosis and Extrapulmonary Tuberculosis

Abstract

This study aims to observe and analyze the diagnostic value of T-cell enzyme linked immunospot assay for tuberculosis infection during the diagnosis of pulmonary tuberculosis and extrapulmonary tuberculosis. The study objects were 200 cases of tuberculosis patients in the outpatient department or inpatient department of our hospital, including 100 patients with active pulmonary tuberculosis, 100 patients with extrapulmonary tuberculosis. Meanwhile, we selected 90 non pulmonary tuberculosis patients with pulmonary disease, 90 cases of extrapulmonary nontuberculous disease and 90 cases with health examination. T-cell enzyme linked immunospot test for tuberculosis infection was used to detect tuberculosis antigen specificity and the frequency of T cells secreting Interferon gamma and the results were analyzed in detail. The positive rate of T-cell enzyme-linked immunospot assay for tuberculosis infection in pulmonary tuberculosis group was higher than that in non-pulmonary tuberculosis group and healthy control group (p<0.05). The positive rate of pulmonary tuberculosis group was significantly higher than that of non-pulmonary tuberculosis group and healthy control group (p<0.05). The diagnostic sensitivity of T-cell enzyme linked immunospot assay for tuberculosis infection was 88.56 % to bacteriological positive tuberculosis, 80.25 % to bacteriological negative tuberculosis and 93.36 % to extrapulmonary tuberculosis. The diagnosis specificity was respectively 85.67 %, 84.36 %, 89.73 %, the positive predictive values were respectively 93.95 %, 88.79 % and 96.56 %, while the negative predictive values were 74.00 %, 74.00 % and 80.00 %, respectively. By comparing the bacteriological positive tuberculosis and bacteriological negative tuberculosis, there is no significant difference in diagnostic efficiency of T-cell enzyme linked immunospot assay for tuberculosis infection (p>0.05). In comparison of extrapulmonary tuberculosis group, bacteriological negative pulmonary tuberculosis and bacteriological positive pulmonary tuberculosis group, result showed that T-cell enzyme linked immunospot assay for tuberculosis infection diagnostic efficacy was not statistically significant (p>0.05). T-cell enzyme linked immunosorbent assay has ideal sensibility, specificity in diagnosis of tuberculosis infection, which can be widely used in diagnosis of extrapulmonary tuberculosis and bacteriological negative pulmonary tuberculosis.