The rate of fibrinopeptide B release modulates the rate of clot formation: a study with an acquired inhibitor to fibrinopeptide B release

An asymptomatic 50-year-old male with a gamma globulin paraprotein was found to have prolonged prothrombin time, activated partial thromboplastin time, and thrombin time but a normal reptilase time. The prolonged clotting times were not the result of a factor deficiency because they were not corrected by the addition of normal plasma. Instead, this patient had an antibody that delayed thrombin-mediated fibrinopeptide B release thereby producing …