Immunodetection of human fibrin using monoclonal antibody-64C5 in an extracorporeal chicken model

The potential use of a fibrin-specific monoclonal antibody-64C5 as a thrombus detecting agent was examined in a quantifiable extracorporeal circulatory model using the chicken. This species was selected because antibody-64C5 did not cross-react with chicken fibrin. Human fibrinogen was clotted with human thrombin and factor XIII on filter paper disks, which were then inserted into an ex-vivo chamber that interrupted an extracorporeal loop between a carotid artery and a jugular vein. Antibody-64C5 was injected intravenously and after an equilibration period, disks bearing human fibrin were placed in the extracorporeal chamber and exposed to circulating antibody. Uptake which was quantified by treating the disks with 125I-goat antimouse-(Fab')2 was rapid, with 70 percent of maximal uptake occurring within 10 min. Fibrinolysis, although measurable, had no adverse effect upon uptake of the monoclonal antifibrin-64C5.