ABSTRACT
Objective To evaluate the diagnostic value of ESAT6 and CFP10 in smear-negative pulmonary tuberculosis.Methods 32 patients of smear-negative pulmonary tuberculosis were selected as the observation group.80 cases of other non-tuberculous respiratory diseases were selected as the control group.ESAT6 and CFP10 polypeptides were used as a stimulating source,the amount of IFN-γsecreted by peripheral blood T lymphocytes was measured by ELISPOT technique.The result was compared with serum anti-tuberculosis antibody (TB-Ab).Results The positive rates of ESAT-6,CFP-10 and combination detection in the observation group were 84.4％,78.1％ and 90.6％ respectively,which were significantly higher than those in the control group,the differences were statistically significant (x2 =71.94,67.43,73.51,all P ＜ 0.01).The sensitivity (90.6％) and negative predictive value (96.1％) of ESAT6,CFP10 combined detection had no statistically significant differences compared with TB-Ab method (x2 =2.20,1.78,all P ＞ 0.05).The specificity (92.5％),positive expected value (82.9％) and the diagnostic accuracy (92.0％) of ESAT6,CFP10 combined detection were significantly higher than those of TB-Ab (60.0％,40.7 ％,62.5 ％),the differences were statistically significant (x2 =11.24,12.07,7.92,all P ＜ 0.01).The positive likelihood ratio of ESAT6,CFP10 combined detection was greater than 10 and negative likelihood ratio was less than 0.1.The possibility of diagnosis was significantly increased.Youden index co-detected by ESAT6 and CFP10 was 0.8,and that detected by TB-Ab was 0.3,indicated that the combined accuracy of ESAT6 and CFP10 was higher than TB-Ab.Conclusion Mycobacterium tuberculosis specific antigen ESAT6,CFP10 can be used as a stimulating source to stimulate effect T lymphocyte to secrete interferon-γ (IFN-γ).IFN-γ can be detected using ELISPOT.Mycobacterium tuberculosis specific antigen ESAT6,CFP10 can be used to quickly assistant the diagnosis of tuberculosis.They have higher sensitivity,specificity and good application value in the auxiliary diagnosis of smear-negative pulmonary tuberculosis.