Studies on Fibrin Monomer Aggregation in Congenital Dysfibrinogenaemia (Fibrinogen ‘Zürich’): Separation of a Pathological from a Normal Fibrin Fraction

Summary: Further characterization of the delay in aggregation of fibrinogen ‘Zürich’ showed a potentiation of the defect by increasing ionic strength and an acceleration by calcium ions or protamine. A new type of paracoagulation due to soluble abnormal fibrin monomers in fresh serum is described. Using Reptilase, it was possible to separate a fibrin fraction with normal aggregation from a pathological fraction with virtually no clot formation. Mixtures of equal parts of the abnormally aggregating fraction with normal monomers of either patient or control demonstrated a pattern of aggregation analogous to monomers of the patient's whole fibrinogen. It appears possible that certain differences between some published cases of dysfibrinogenaemia might be due to the association of variable amounts of pathological fibrinogen with normal fibrinogen.