TUMOR-NECROSIS-FACTOR, INTERLEUKIN-1 AND ADENOSINE-DEAMINASE IN TUBERCULOUS PLEURAL EFFUSION

Tumour necrosis factor (TNF) and interleukin-1 (IL-1) are powerful med iators with a key role in inflammation. This study was undertaken to s tudy the presence of TNF and IL-1 in tuberculous effusion where there is marked inflammation and where examination of the pleural fluid may give information about the local inflammatory reaction. Adenosine deam inase activity (ADA, a marker of TB pleurisy) was also tested. Tumour necrosis factor, IL-I and ADA levels were measured in the pleural flui d and serum of 97 patients; 33 with tuberculous effusion, 33 with mali gnant effusion, and 31 patients with benign nontuberculous effusion. P leural fluid TNF and ADA levels were higher in tuberculous (TB) patien ts than in patients with benign disorders or cancer (P<0.01). Serum TN F levels were also higher in TB patients than other benign (P<0.01) or malignant (P<0.05) effusions. There was a positive correlation betwee n serum and pleural fluid values (r=0.998-0.999, P<0.001) although ple ural fluid concentration was higher (P<0.001), possibly suggesting loc al production in the pleural cavity. Pleural fluid IL-1 levels were no t raised in any patient group but there was a positive correlation bet ween TNF and IL-1. In addition, a positive correlation was found betwe en TNF and ADA levels, probably indicating some common production mech anism. Furthermore, ADA sensitivity in the diagnosis of tuberculous ef fusion was augmented by the combined use of TNF and ADA. The use of bo th these markers may prove useful in the differential diagnosis of TBC pleurisy.