NEURON-SPECIFIC ENOLASE LEVELS IN PLEURAL EFFUSIONS IN PATIENTS WITH RHEUMATOID-ARTHRITIS

Background - High pleural fluid levels of neurone-specific enolase (NS E) have been reported, not only in patients with small cell lung cance r but also in those with chronic inflammatory diseases. Methods - NSE concentrations were determined in pleural fluid and serum from 342 pat ients with pleural effusions including 17 with rheumatoid arthritis. R esults - The median NSE concentration in pleural fluid was higher in r heumatoid effusions than in any other condition studied. The median pl eural fluid:serum NSE ratio was highest in patients with rheumatoid ar thritis (11.6) and about unity in all other diseases including small c ell lung cancer (0.9). In patients with rheumatoid arthritis pleural f luid concentrations of NSE correlated inversely with pleural fluid glu cose concentrations and the pH of the pleural fluid. Conclusions - A h igh pleural fluid:serum NSE ratio was found consistently in pleural ef fusions from patients with rheumatoid disease.