Hereditary fibrinogen disorders (HFD) are rare coagulation disorders resulting from mono-or bi-allelic mutations in fibrinogen genes. 1According to the levels of fibrinogen activity and antigen, HFD are classified into quantitative (afibrinogenemia and hypofibrinogenemia) or qualitative (dysfibrinogenemia and hypodysfibrinogenemia) disorders. 2 The spectrum of symptoms is broad and heterogeneous among patients with HFD, even if bleeding is the most common complication of all HFD sub-types. 3 The bleeding phenotype is mostly correlated to the fibrinogen level, 4 ranging from life-threatening haemorrhage to postsurgical bleeding. In afibrinogenemia, the majority of patients suffer from severe bleeding such as umbilical cord bleeds, muscle haematomas, haemarthroses and bleeding in the central nervous system. 5 Paradoxically, thrombotic events can occur in patients with afibrinogenemia, even in the absence of fibrinogen administration. 6 In hypofibrinogenemia, spontaneous bleeding is less frequent and complications are mainly associated with trauma or surgery. 7 In dysfibrinogenemia, the cumulative incidence of major bleeding has been estimated to be about 19% at 50 years of age. 8 However, some dysfibrinogen variants are strongly associated with an increased risk of thrombosis. 9 In all types of HFD, surgery and pregnancy are high-risk bleeding situations.As for most coagulation factor deficiencies, in HFD, the bleeding prevention and management is based on replacement of the lacking protein. Three sources of fibrinogen are currently available: fresh frozen plasma, cryoprecipitate and lyophilized fibrinogen concentrate. 10 The latter is the best option, although still not widely available. It confers several advantages compared to fresh frozen plasma and cryoprecipitate: (a) it represents a safer therapeutic option due
AbstractHereditary fibrinogen disorders (HFD) are rare coagulation disorders. Even if the spectrum of symptoms is broad depending on the sub-type, bleeding is the most common complication. Of the available sources of fibrinogen replacement, fibrinogen concentrate provides a safer and more effective option to treat and prevent bleeding.Recent clinical trials on established and new fibrinogen concentrates have increased our knowledge on the clinical pharmacology of these products, pointing out possible age and weight differences for dose adjustment. The efficacy of fibrinogen infusions has been demonstrated, especially for the management of acute bleeding with an excellent response based on investigator rating. The target fibrinogen levels in the setting of both minor and major surgeries have been better specified. The safety has been confirmed with a low number of adverse events but there still remains concern over possible thrombotic risks. Pharmacological, clinical aspects and future perspectives on the utilization of fibrinogen concentrates in the treatment and prevention of bleeding in patients with HFD are reviewed.