Fibrinogen replacement therapy for congenital fibrinogen deficiency

This review of published studies was conducted to derive data on patients with congenital fibrinogen deficiency (CFD), including dosing of fibrinogen replacement therapy, outcome, and adverse events, either temporally related or distant to fibrinogen replacement, in order to assist clinicians in developing treatment plans for patients with CFD. A systematic review was performed of case reports identified by a MEDLINE search between 1961 and 2010. Eligible studies included subjects with a diagnosis of CFD who received fibrinogen replacement. An attempt was made to extract dose, frequency, duration, hemostatic efficacy and adverse events such as thrombosis or allergic reactions. Reported thrombotic events distant from fibrinogen replacement were also recorded. From 104 papers reviewed, a total of 50 cases were identified: afibrinogenemia (35), hypofibrinogenemia (6), and dysfibrinogenemia (9). Fibrinogen replacement therapy was generally effective in preventing or treating bleeding in doses adequate to achieve and maintain fibrinogen activity above 50-100 mg dL(-1) (non-surgical and obstetric use) or 100-200 mg dL(-1) (surgical prophylaxis). Increased fibrinogen clearance was observed with massive hemorrhage, major surgery, and advanced pregnancy. Obstetric outcomes were optimized when fibrinogen replacement was initiated prior to conception. Uncontrolled hemorrhage, allergic reactions and antibody formation were rare events. However, thromboses, both related and unrelated to fibrinogen replacement, occurred in 15 of 50 (30%) patients overall, and in eight of 12 (67%) adult non-obstetric patients with afibrinogenemia. Published fibrinogen replacement regimens are presented for 50 CFD patients. Fibrinogen replacement therapy requires careful monitoring of fibrinogen levels. Afibrinogenemia is associated with thromboembolic complications with or without treatment.