γ' Fibrinogen as a novel marker of thrombotic disease.

γ' Fibrinogen is an isoform of fibrinogen that normally constitutes about 7% of total plasma fibrinogen, and arises from an alternative processing event in the γ chain mRNA. γ' Fibrinogen is a newly-emerging cardiovascular disease (CVD) risk factor that appears to have an independent association with CVD from that of total fibrinogen, which is itself a well-established CVD risk factor. γ' Fibrinogen shows a significant association with coronary artery disease and myocardial infarction in at least four case-control studies, including the Stockholm Coronary Artery Risk Factor study and the Framingham Heart Study. γ' Fibrinogen is also significantly associated with stroke, as shown in the Erasmus Stroke Study and others. The role of genetic polymorphisms in the association between γ' fibrinogen and CVD is under active investigation. γ' Fibrinogen increases during inflammation, and is differentially regulated from total fibrinogen under pathologic conditions, as demonstrated in the Periodontitis and Vascular Events study. The association between γ' fibrinogen and venous thromboembolism remains unclear, however, with some studies showing an inverse association with γ' fibrinogen levels and other studies showing the opposite.