Pleural fluid adenosine deaminase in rheumatoid arthritis and systemic lupus erythematosus

Abstract

The observation that the activity if adenosine deaminase (ADA) is higher in tuberculous pleural effusions than in malignant, parapneumonic and transudative effusions was recently confirmed by Ocana et al. These authors also reported high pleural fluid ADA activity in one patient with rheumatoid pleural effusion and asked for studies on more patients with connective tissue diseases. We have measured the activity of ADA in pleural fluid and serum in a series of patients, comprising 14 with tuberculosis, six with rheumatoid arthritis (RA), and three with systemic lupus erythematosus (SLE). Our study confirms earlier reports that the determination of ADA in pleural fluid is a valuable tool in the diagnosis of tuberculous pleurisy, but shows that it does not differentiate between tuberculous and rheumatoid pleurisy.