Relation of plasma fibrinogen concentration changes to human arteriosclerosis

Abstract

A 35% increase (P < 0.001) in plasma fibrinogen levels was found in patients who recovered from the trauma of myocardial infarction and had not received anticoagulant therapy for 5 months preceding donation of plasma. The elevated fibrinogen levels are not a consequence of inflammatory conditions or traumatized tissue resulting from clinically overt vascular incidents. The fibrinogen level does not return to normal following a myocardial infarction. Occlusion of beta lipoproteins in the fibrin coagulum did not account for elevated levels of fibrinogen as shown by experiments where a) known quantities of alpha and beta lipoproteins were added to the test system, b) correction was made for the occlusion factor, and c) the increased yield due to this occlusion factor represented only a 3.5% increase in fibrinogen yield for as much as 300% increase in the level of beta lipoproteins. The fibrinogen level not only increases with age but also superimposes upon the arteriosclerotic an increase in addition to that occurring with increasing chronologic age. The role of fibrin in vascular hypertrophy and atheromatous development is emphasized. Possible causes for abnormal levels of fibrinogen are discussed. Note: (With the Technical Assistance of A. C. Schram and D. Mills) Submitted on December 5, 1960