Hyaluronic acid content of effusions as a diagnostic aid for malignant mesothelioma

A high-performance liquid chromatographic technique, using a size exclusion column (TSK-5000PW), has been developed for the quantification of hyaluronic acid (HA) in pleural and peritoneal effusions. Sample preparation requires only a 100-fold dilution of the exudate with phosphate buffer prior to analysis. Chromatographic conditions are: 0.05 M phosphate buffer (pH, 5.0) mobile phase at a flow rate of 1.0 ml/min, ultraviolet absorbance detection at 200 nm. The method resolves HA from all other glycosaminoglycans. The presence of HA is confirmed by the removal of the HA peak (retention time, approx. 5.3 min) by incubation of a second sample aliquot with hyaluronidase. Effusions of 13 of 14 patients with confirmed malignant mesothelioma contained HA in the 0.3 to 11.1 mg/ml range. In only one case was no HA detected. None of the effusions from 56 control patients with various other primary tumors contained detectable HA, i.e., there were no false positives. An unidentified peak, not susceptible to hyaluronidase appeared in 11% (6 of 56) of the controls. A single mesothelioma case was correctly identified in a group of 10 coded samples. It is suggested that an effusion with an HA concentration greater than 0.25 mg/ml, confirmed by hyaluronidase susceptibility, is an indication of the presence of malignant mesothelioma. The test is simple and rapid, and it is recommended that any effusion of uncertain etiology be screened for the presence of HA.