Hemophilia A is treated with which clotting factor?

• A. Factor VIII
• B. Factor IX
• C. Factor VII
• D. Von Willebrand factor

Answer: (A)

Factor VIII replacement is used to treat Hemophilia A because this condition stems from a deficiency of Factor VIII, a crucial cofactor in the intrinsic pathway that drives thrombin generation and proper clot formation. Replacing the missing Factor VIII restores the cascade’s function and allows fibrin to form normally, reducing bleeding. The other options address different conditions: Factor IX deficiency causes Hemophilia B, not A; Factor VII is part of the extrinsic pathway and isn’t the standard therapy for Hemophilia A; Von Willebrand factor is involved in von Willebrand disease and is not used to treat Hemophilia A (though some products may include it, the primary treatment for A is Factor VIII).