Spontaneous appearance of human and porcine factor VIII inhibitors: which therapeutic approach?

An 82-year-old woman presented with severe bleeding due to antibodies inactivating both human and porcine factor VIII. Treatment with porcine factor VIII was successful in correcting the hemorrhagic manifestations, despite the fact that subsequent studies showed that the baseline porcine inhibitor titer was greater than the human inhibitor titer. Anamnestic response to porcine factor VIII did not allow us to use it longer; immunosuppressive therapy, however, was successful in long-term control of the anti-factor VIII antibody titer and in preventing further bleeding.