The use of adenosine deaminase assays in the diagnosis of tuberculosis.

We describe a rapid method for the estimation of adenosine deaminase (ADA) activity in cerebrospinal, pleural, peritoneal, and pericardial fluids. Tuberculous effusions show significantly higher levels of ADA activity compared with effusions due to other underlying lesions such as neoplasms, bacterial and viral infections and simple transudates. Similarly, tuberculous meningitis results in raised ADA activity in the cerebrospinal fluid (CSF) when compared with the CSF from patients with other neurological disorders and from normal subjects. The results in 359 cases studied indicated the value of ADA assays in the diagnosis of tuberculous diseases. Levels above 30 IU/I in effusions and above 6 IU/I in the CSF indicate probable tuberculosis.