Immunoassay means and methods useful in human native prothrombin and

Abstract

Antibodies which form immune complexes with human native prothrombin only, in the presence of mixtures of human native prothrombin and human abnormal prothrombin as well as antibodies which form antibody antigen complexes with human abnormal prothrombin in the presence of such mixtures have been obtained. Immunoassay techniques are used for qualitative and quantitative determinations of these antigens in human plasma or serum. Unique methods of obtaining the antibodies are described including obtaining antibodies to native prothrombin by dissociation of antigen antibody complexes formed in the presence of calcium ions with a material having a greater affinity constant for binding with calcium ions than does prothrombin. Dissociation of the complex in this manner yields human native prothrombin antibodies which are specific and non-reactive with human abnormal prothrombin. A process is described in which assays are applied to the sensitive detection of vitamin K deficiency and various forms of liver disease including hepatocellular carcinoma, and to monitoring of anticoagulant therapy with sodium warfarin. The invention described herein was made in the course of working under a grant from the Department of Health and Human Services.