Antibodies to the clotting factor
Antibodies destroy the clotting factor before it has a chance to work. This is a very serious problem, because the main treatment for Hemophilia - replacing clotting factors - is no longer effective.
The inhibitor formation that neutralizes or inhibits the therapeutic effects of factor treatment used to treat and prevent Hemophilia bleeding poses one of the most difficult challenges of Hemophilia care. The immune system of protein recognizes the infused factor as foreign protein. Hence, inhibitors may result that neutralize infused factor. The mechanism of inhibitor development remains unknown.
The development of factor VIII inhibitors remains the most serious, life threatening and most expensive complication of FVIII therapy. Developing an inhibitor is one of the worst things that can happen to a PWH. These patients suffer more serous bleeding complications and they have greater disability, and incredible expenses.