Fibrinogen Caracas I: a dysfibrinogenemia with a hemorrhagic diathesis associated with diminished fibrin fiber diameter and reduced fibrin gel porosity

Fibrinogen Caracas I is a dysfibrinogenemia with a mild bleeding diathesis and a defective wound healing. We have characterized this abnormal fibrinog en using transmission electron microscopy (TEM) in combination with turbidi ty and permeation studies. Turbidometric and permeability analysis showed t hat the abnormal fibrin had a significantly decreased mass:length ratio and fiber diameter. In addition, the permeability studies of plasma fibrin clo ts showed that the gel porosity of the abnormal fibrinogen was reduced. Ima ges of the abnormal fibrin structure obtained using TEM showed that the fib ers were thinner, much less branched and less ordered than normal fibers. D iminished fibrin fiber diameter and reduced fibrin gel porosity have been t aken as hallmarks of thrombophilic dysfibrinogenemias. The results of the p resent study show that these features are not necessarily predictive of thr ombophilia. Further studies performed on a larger number of dysfibrinogenem ias need to be conducted in order to establish the implications of these pa rameters on the clinical outcome. (C) 1998 Lippincott Williams & Wilkins.