The Relationship of Plasma Fibrinogen (Factor I) Level to Fibrin Stabilizing Factor (Factor XIII) Activity

Abstract

Abstract The relationship of fibrinogen concentration to Factor XIII activity in the plasmas of 110 subjects (90 patients and 20 healthy volunteers) was studied. No definite, consistent, predictable relationship could be established. However, in certain pathological conditions, with hyper- or hypofibrinogenemia, a moderate reduction in Factor XIII activity may be present, and usually occurs without hemorrhagic manifestations. On the other hand, examination of normal plasmas artificially enriched with large amounts of bovine fibrinogen revealed no changes in Factor XIII activity. In the light of these observations, the suggestion is made that reduced Factor XIII activity may be encountered in certain disease conditions without simultaneous changes in fibrinogen concentration. The site of synthesis of these two proteins, although most likely the liver, would appear to not influence their plasma concentrations simultaneously.