Concentration of Hyaluronic Acid in Pleural Fluid as a Diagnostic Aid for Malignant Mesothelioma

Hyaluronic acid (HA) was determined with a radiometric assay in the serum and pleural fluid of 85 patients with pleural effusions, including 15 with malignant mesothelioma, 32 with other cancer, 31 with nonmalignant inflammatory diseases, and seven with congestive heart failure. With a cutoff level at 100 mg/L, the pleural fluid concentration of HA was raised in 73 percent of patients (11 of 15) with malignant mesothelioma and in 23 percent with nonmalignant inflammatory diseases, but in none with other cancer and in none with congestive heart failure. The median concentration of pleural fluid HA was significantly higher in patients with mesothelioma than in those with other cancer (p