Enzyme-linked immunosorbent assay using Mycobacterium tuberculosis antigen 5 for the diagnosis of pulmonary tuberculosis in China.

Measurement of serum IgG antibody to Mycobacterium tuberculosis antigen 5 by enzyme-linked immunosorbent assay was evaluated as a serodiagnostic test for pulmonary tuberculosis in China. The test was 89% sensitive and 94 to 100% specific with high accuracies of prediction. Among 82 tuberculous patients, antibody titer was related to the extent of pulmonary disease. Among control subjects, false positive tests were encountered among 5 of 52 persons with other pulmonary disease and not among 30 healthy subjects. The characteristics of this test compare favorably with those reported for sputum smear examination.