An inhibitor happens when the body s own immune system sees the factor concentrate as a foreign agent, and then destroys it.
Inhibitors are the body s way of fighting off what it sees as a foreign agent.
This means that as soon as the factor concentrate is infused, it is eliminated. This is similar to what happens when a person receives a transplanted organ. The body s immune system sees the organ as foreign and tries to reject it. People who receive transplanted organs need to take drugs to stop this from happening. In hemophiliacs with inhibitors to factor concentrates, the rejection starts to happen as soon as the blood product is infused.