Immune Tolerance to Treat an Inhibitor

Immune tolerance induction (ITI) is a treatment protocol that can be offered to people with an inhibitor to try to eliminate the inhibitor. During ITI, a person with an inhibitor is given factor VIII or IX regularly. How often factor will be given and at what dose is determined by your doctor. The goal is for the immune system to learn to tolerate having factor in the blood and stop making the antibodies against factor (the inhibitor). That is why it is called “immune tolerance” induction. Sometimes the treatment also includes drugs to suppress the immune system to reduce the antibody production. ITI is not something you do on your own. It takes the direction and support of the staff at your HTC. Treatment with ITI can take several months to over a year. It is not an easy treatment in terms of the time commitment, cost, and side effects of the immune suppressing medications. ITI does work about 60% to 80% of the time. However, in some cases the inhibitor may return after it has been eliminated. Researchers continue to work on figuring out the best protocols for successful ITI.