Monoclonal antibodies to a synthetic fibrin-like peptide bind to human fibrin but not fibrinogen.

A synthetic heptapeptide from the amino terminus of the beta chain in human fibrin was used as an antigen to produce monoclonal antibodies that bind to fibrin even in the presence of human fibrinogen at the concentration found in plasma. As expected, the antifibrin activity was inhibited by the peptide antigen but not by a control heptapeptide. In a chicken ex vivo circulatory model for fibrin detection, intravenously administered monoclonal antibodies bound to human fibrin-coated disks placed in an extracorporeal chamber. These findings may lead to better methods for identifying deep vein and coronary artery thrombi.