Diagnostic potentialities of enzyme-linked immunosorbent assay in tuberculosis using purified tuberculin antigen

Delayed hypersensitivity tests with tuberculin or purified tuberculin (PPD) have been used for detection of tuberculous infection. The present paper describes an enzyme-linked immunosorbent assay (ELISA) for detection of PPD-antibodies in tuberculosis patients. The ELISA test was positive in nearly 80% of cases having bacteriological evidence of tuberculosis. The test could also detect PPD-antibodies in 66% of the cases not showing bacteriological evidence of tuberculosis. The potentiality of the test in the immunodiagnosis of tuberculosis is discussed.