Which agent is used to bypass inhibitors in the management of low-titre FVIII inhibitors (<5 BU)?

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Multiple Choice

Which agent is used to bypass inhibitors in the management of low-titre FVIII inhibitors (<5 BU)?

Porcine FVIII is used to bypass inhibitors because it behaves like FVIII but is not as readily recognized by antibodies directed against human FVIII. With low-titre inhibitors (less than about 5 BU), porcine FVIII can provide sufficient FVIII activity to promote clot formation without being fully neutralized, allowing hemostasis to improve while you manage the bleed. Desmopressin works by releasing stored endogenous FVIII, but when inhibitors are present, that FVIII is rapidly inactivated, making this approach ineffective. Human recombinant FVIII would be targeted and neutralized by the inhibitors. Factor IX concentrates don’t bypass FVIII inhibitors because they don’t restore the FVIII-dependent step of the coagulation cascade.

Porcine FVIII is used to bypass inhibitors because it behaves like FVIII but is not as readily recognized by antibodies directed against human FVIII. With low-titre inhibitors (less than about 5 BU), porcine FVIII can provide sufficient FVIII activity to promote clot formation without being fully neutralized, allowing hemostasis to improve while you manage the bleed.

Desmopressin works by releasing stored endogenous FVIII, but when inhibitors are present, that FVIII is rapidly inactivated, making this approach ineffective. Human recombinant FVIII would be targeted and neutralized by the inhibitors. Factor IX concentrates don’t bypass FVIII inhibitors because they don’t restore the FVIII-dependent step of the coagulation cascade.

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