Fibronectin in neoplastic peritoneal effusions in dogs.

Fibronectin is a glycoprotein found in soluble form in plasma and in an insoluble form in connective tissue matrices. Fibronectin isolated from canine peritoneal effusions by affinity chromatography on gelatin-Sepharose was found to be immunologically indistinguishable from the plasma form, as shown by double immunodiffusion techniques. Utilizing an enzyme immunoassay technique, 7 patients with disseminated splenic hemangiosarcoma were found to have peritoneal fibronectin concentrations of 309 ± 133 (mean ± SD) μg/ml. In 8 patients with widespread lymphoma the peritoneal fibronectin concentrations were 323 ± 147 μg/ml. In 5 patients with hepatoma the peritoneal fibronectin concentrations were 361 ± 121 μg/ml. In 6 patients, 2 with mesothelioma, 2 with pancreatic adenocarcinomas, and 2 with prostatic adenocarcinoma, the peritoneal fibronectin concentrations were 315 ± 115 μg/ml. The lowest concentrations 117 ± 46 μg/ml, were found in patients with malignant disease and concurrent peritoneal thrombus formation. These data suggest that decreased fibronectin concentrations in peritoneal effusions are associated with, at least, a locally hypercoagulable state.