RESUMEN
Objective To investigate the diagnostic value of 16 ku-38 ku-ESAT-6 protein in tuberculosis (TB). Methods ELISA was used for measuring the level of recombinant 16 ku-38 ku-ESAT-6 protein in 105 TB patients (TB group,26 patients with smear-positive, 79 patients with smear-negative) and 45 controls (control group, 20 healthy volunteers and 25 subjects with pulmonary diseases other than TB). The value of the antigen for diagnosis of TB in serodiagnosis was assessed, and ROC curve evaluation system was established. Results In control group, the positive rate of anti-recombinant 16 ku-38 ku-ESAT-6 protein and commercialization of TB antibody test kit had significant difference [6.67% (3/45) vs. 51.11% (23/45)](P＜0.01);but in TB group, there was no significant difference [59.05%(62/105) vs. 64.76% (68/105)](P＞0.05). The optical density value in TB group and control group was 2.22 ± 0.58 and 1.35 ± 0.24,and there was significant difference(t = 6.06,P＜ 0.01). The sensitivity, specificity, positive predictive value and negative predictive value of the test was 59.05%,93.33%,95.38%,49.41% respectively. Analyzed by ROC curve, the area under the curve was 0.751, the- value of cutoff was 2.52, and sensitivity and specificity was 65.4% and 84.8%. Conclusions Recombinant 16 ku -38 ku -ESAT-6 protein of mycobacterium tuberculosis has higher specificity, and it can significantly distinguish TB and non-TB. So it might be selected as one of diagnosis antigens of TB.