[The serodiagnostic value of antigens secreted from Mycobacterium tuberculosis]

To study the serodiagnostic value of 3 antigens secreted from Mycobacterium tuberculosis: the 81,000 antigen, the 38,000 antigen and the CF-10 antigen.

The 38,000 antigen was purified from supernatant of exponential growth of Mycobacterium tuberculosis. The 81,000 antigen and CF-10 antigen were expressed by fusion with 6 histidine and purified by nickel chelate chromatographic column. Sera were obtained from 149 patients with tuberculosis (108 smear positive and 41 smear negative), 24 patients with non-tuberculosis lung diseases and 170 healthy human controls in Anhui province from March 2002 to April 2005. Antigenicity and specificity of the 3 antigens were detected by enzyme-linked immunosorbent assay.

Purified antigens had a high purity (> 95%) and a high specificity (> 98%). The positive rates of the 81,000 antigen, the 38,000 antigen and the CF-10 antigen in tuberculosis patients were 64.4% (96/149), 57.0% (85/149) and 37.6% (56/149) respectively. The negative rates in nontuberculosis patient were all above 98%. The positive rate of the 3 antigens combined was 81.2% (121/149) and the negative rate was 98%.

The specificity of the 3 antigens was high. Sensitivity and specificity of the 3 antigens combined was better than each antigen alone. It is clinically practical that detection of multiple antigens may be used to improve the serodiagnosis of Mycobacterium tuberculosis.