Abstract:

Coagulation factor Ⅷ (FⅧ) deficiency is a rare bleeding disorder that can manifest as spontaneous or delayed life-threatening hemorrhage. FⅧ is composed of two catalytic subunits (FⅧ-A₂) and two carrier (FⅧ-B₂) subunits that have several functions in addition to its important role in hemostasis, including angiogenesis, maintenance of pregnancy, wound healing, and bone metabolism. FⅧ deficiencies can be classified as congenital or acquired according to etio-logy. The global incidence of congenital FⅧ deficiency is 0.05 per 100 000. Most patients with congenital FⅧ deficiency typically present with FⅧ-A deficiency. Acquired FⅧ deficiency, which typically arises from factors such as hyperconsumption and decreased synthesis, is more common than the congenital form. In rare instances, patients with acquired FⅧ deficiency may develop inhibitors targeting FⅧ subunits. The occurrence can be idiopathic or associated with comorbidities, such as malignancies or autoimmune disorders. A quantitative functional FⅧ activity assay is the first-line screening test for diagnosing FⅧ deficiency. For congenital FⅧ deficiency, enzyme-linked immunosorbent assays (ELISA) are required to determine the type of deficiency and to detect associated molecular genetic mutations. If acquired FⅧ deficiency is suspected, immunological tests are also required to detect inhibitors. Treatment primarily includes FⅧ replacement therapy and/or immunosuppressive therapy. Therapeutic options for FⅧ replacement have evolved from traditional fresh frozen plasma (FFP), old plasma, whole blood, and cryoprecipitate to plasma-derived and recombinant FⅧ concentrates. Although treatment targets and thresholds for FⅧ deficiency have not been clearly established, timely diagnosis and appropriate management of patients with severe FⅧ deficiency can significantly reduce the morbidity and mortality rates.

Key words: Coagulation factor Ⅷ deficiency, Acquired coagulation factor Ⅷ deficiency, Coagulation factor Ⅷ inhibitor, Coagulation disorder