title: Determination of plasma protein S--the protein cofactor of activated protein C.
abstract: Protein S, an important cofactor of activated protein C, and C4b-binding protein were purified from human plasma. Specific antibodies against the purified proteins were raised in rabbits and used for the development of immunologic assays for these proteins in plasma: an immunoradiometric assay for protein S (which measures both free protein S and protein S complexed with C4b-binding protein) and an electroimmunoassay for C4b-binding protein. Ranges for the concentrations of these proteins were established in healthy volunteers and patients using oral anticoagulant therapy. A slight decrease in protein S antigen was observed in patients with liver disease (0.78 +/- 0.25 U/ml); no significant decrease in protein S was observed in patients with DIC (0.95 +/- 0.25 U/ml). Criteria were developed for the laboratory diagnosis of an isolated protein S deficiency.
authors.forename: R M
authors.initials: RM
authors.lastname: Bertina
authors.forename: A
authors.initials: A
authors.lastname: van Wijngaarden
authors.forename: J
authors.initials: J
authors.lastname: Reinalda-Poot
authors.forename: S R
authors.initials: SR
authors.lastname: Poort
authors.forename: V J
authors.initials: VJ
authors.lastname: Bom
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D002352:Carrier Proteins / Q000097:blood*; D003169:Complement Inactivator Proteins; D005260:Female; D006023:Glycoproteins / Q000097:blood* / Q000172:deficiency; D006801:Humans; D007118:Immunoassay; D008107:Liver Diseases / Q000150:complications; D008297:Male; D010314:Partial Thromboplastin Time; D011486:Protein C; D017293:Protein S; D011863:Radioimmunoassay; D012016:Reference Values
chemical_list: D000925:Anticoagulants; D002352:Carrier Proteins; D003169:Complement Inactivator Proteins; D006023:Glycoproteins; D011486:Protein C; D017293:Protein S