Serodiagnosis and follow up of patients with pulmonary tuberculosis by enzyme-linked immunosorbent assay.

A new ELISA assay based on antigen A60 from M. bovis BCG was used to quantitate specific anti-mycobacterial antibodies in 250 sera from 133 subjects: 90 tuberculosis cases and 43 controls. Controls were all negative, suggesting the specificity of this assay. In subjects with secondary pulmonary tuberculosis, a correlation was observed between the anti-mycobacterial antibody titer and culture positivity. In fact, positive ELISA assays were found in 88.8% of patients with positive cultures for M. tuberculosis and in 45% of culture-negative tuberculosis patients under therapy. According to our results the A60 ELISA assay is useful in monitoring the efficacy of anti-mycobacterial drugs. In pulmonary tuberculosis cases with positive cultures for M. tuberculosis higher levels of specific anti-mycobacterial IgGs were found after therapy.