Diagnosis of tuberculosis by detection of mycobacterial antigen in pleural effusions and ascites.

We describe a method for the diagnosis of pleural and peritoneal tuberculosis by the detection of tuberculous antigens using an enzyme-linked immunosorbent assay. Eleven tuberculous pleural fluid and 10 tuberculous ascitic fluid samples were studied by this technique, using 10 non-tuberculous pleural fluid and 14 non-tuberculous ascitic fluid samples as controls. An absorbance value of 0.3 was found to separate the tuberculous groups from their controls to a statistically significant extent (ascitic fluid P less than 0.05; pleural fluid P less than 0.01).