Dysfibrinogenemia and Nephrotic Syndrome: A Case Report

Abstract

Dysfibrinogenemia was found in a 70-year-old female with nephrotic syndrome (urinary protein, 6.6 g/day; serum total protein, 3.5 g/dl). Plasma fibrinogen concentration showed different values by several assay methods used; it was decreased to 105 mg/dl by thrombin time method, but increased to 578 mg/dl, 627 mg/dl and 581 mg/dl by micro-Kjeldahl method, tyrosine method and Laurell method, respectively. Plasma fibrinogen levels in 7 family members were almost normal by the four different assay methods.
Purified fibrinogen (200 mg/dl) of the patient gave thrombin time of 188.2 sec (control, 30.8) and reptilase time of over 1800 sec (control, 78.6), both of which were greatly prolonged. Patient's fibrinogen showed normal release of fibrinopeptide and cross-linking by factor XIII, but polymerization of fibrin monomers was impaired. Molecular weight, antigenicity, electrophoretic mobility and carbohydrate content of the patient's fibrinogen did not differ from those of normal fibrinogen. Thus the cause of impaired polymerization in the present fibrinogen requires further study at a molecular level.