HoG Handbook

Immune Tolerance to Treat an Inhibitor


There is a treatment to try to get rid of an inhibitor.  It is called immune tolerance.  With immune tolerance, a person with an inhibitor is given factor VIII or IX every day.  Sometimes they are also given drugs to weaken the immune system.  Treatment with immune tolerance can take several months to over a year.

With immune tolerance, you are trying to give more factor to the body than the immune system can handle.  You hope that the immune system will not be able to make enough antibodies to stop the factor.  You want the immune system to tolerate having factor in the blood and stop making antibodies.  That is why it is called "immune tolerance".  Immune tolerance works about 60% to 80% of the time.

Being on immune tolerance is not easy.  It costs a lot of money to pay for factor every day.  It takes a lot of time to mix up factor and give it every day.  Getting stuck with a needle so often is rough on your veins.  Even after the inhibitor is gone, it may come back.

Immune tolerance is done most often with children.  Some parents decide to stick their children each time to give the factor.  Others decide to have a "line" or a "port" put in to give factor.  A line, also called a "Hickman line" or "Hickman catheter", is a plastic tube that runs from outside the body to a vein in the chest.  The tube is always hanging from outside the skin of the chest.  To give factor, it is injected through the outside end of the tube.

A port (also called a port-a-cath) is a round disk that has been put under the skin.  It has a tube that runs inside the body from the disk to a vein.  Factor can be injected through the disk.  It takes surgery to put a line or a port in place.  Both ports and lines can get infected.  Your doctor can talk to you about the good and bad points of each.

Immune tolerance is not something you do on your own.  It takes the direction and support of the staff at your HTC.  Researchers are working to figure out the best way to do immune tolerance.