Gelatin-reactive protein in human serum--bioassay, characterization and clinical significance

We investigated the adherence of gelatinized lipid emulsion (GLE) to tissues and cells, the reaction system of this phenomenon and the clinical significance of the adherence-promoting factor (APF) in human serum. In the presence of fresh human serum, GLE adhered to all tested tissues and blood cells. APF was shown to be macromolecular alpha 2-globulin; it formed flocculent precipitate with gelatin, and adsorbed to gelatin-Sepharose. Therefore, we termed APF gelatin-reactive protein (GRP) although it may be identical or closely related to plasma fibronectin. We also noted a significant decrease in GRP activity in patients with systemic disorders including cancer, liver cirrhosis, and systemic lupus erythematosus when their sera were assayed by the GLE-rat liver system.