Electroimmunoassay of factor VII antigen by Laurell's method Fundamental and clinical studies

• Published in: Blood & Vessel Vol. 17; no. 4; pp. 327 - 334
• Main Authors: TAKAMIYA, Osamu, KINOSHITA, Seiji, YOSHIOKA, Keiichiro
• Format: Journal Article
• Language: English
• Published: The Japanese Society on Thrombosis and Hemostasis 01.08.1986
• Subjects: 125I-labelled anti-factor VII antibody; autoradiography; Factor VII antigen; Immunoelectrophoresis
• ISSN: 0386-9717; 1884-2372
• DOI: 10.2491/jjsth1970.17.327

Factor VII antigen has been measured with the antibody neutralization assay according to Goodnight, until recent report of Fair in which a double-antibody equilibrium radio-immunoassay for factor VII antigen is employed. No quantitative precipitation arc of factor VII antigen in plasma has been reported because of its very low concentraiton. In the present method developed by the authers, a clear precipitation arc of factor VII antigen appeared by immuno-electrophoresis using 125I-labelled anti-factor VII antibody incorporated in the Laurell plate to enhance the sensitivity. A plasma sample was electrophoresed directly on 1% agarose containing 1% anti-human factor VII rabbit serum, 0.1% 125I-labelled anti-human factor VII specific IgG and 0.5% polyethyleneglycol 6000, and after washing, autoradiographed at -70°C for 48hr. A distinct rocket was seen from 45μl of undiluted plasma to 16-fold diluted plasma. Of 5 cases with congential factor VII deficiency, 4 cases had no detectable factor VII antigen, one case had factor VII antigen. Factor VII antigen levels in 19 patients of liver disease varied from 9 to 125%, and the assayed values of factor VII antigen and activity correlated relatively well (r=0.96). In contrast, factor VII antigen levels in 20 patients treated with Warfarin varied from 16 to 100%, and the antigen levels were slightly higher than the activity.