Haemophilia is managed by injecting clotting factor. This can vary dependant on your condition and severity. The below are the most common factors used at Bristol Royal Hospital for Children, talk to your team if you have any questions about any of them. They are available in different doses dependant on your need.

If you have haemophilia A you may receive factor VIII, the brand names for this include Advate, Elocta, Refacto Af and NovoEight.

If you have haemophilia B you may received factor IX, the brand names for this include Alprolix and BeneFIX.

If you have Von Willibrand disease you may received factor VIII or VWF, the brand names for this include Wilate. You may also require a DDAVP Desmopressin injection if you have Von Willibrand disease of mild haemophilia A.

What is an inhibitor?

You might have heard your team talk about inhibitors. An inhibitor is a type of antibody that prevents factor replacement treatment from working. When an inhibitor develops, it binds to factor concentrates such as factor VIII or factor IX, stopping them from working and making bleeding more difficult to treat. Of people with severe haemophilia A, about 30% will develop inhibitors; among those with mild and moderate haemophilia A the figure is about 9%. However, only 3% of people with haemophilia B will develop an inhibitor.

Known risk factors in the development of inhibitors include:

• severity of the bleeding disorder
• ethnicity
• family history of inhibitors
• number of days treated with clotting factor concentrate

Inhibitors typically develop in the first 50 treatment days, with most developing in the first 20 days. This is why when people with severe haemophilia develop inhibitors it is usually during childhood, whilst people with mild or moderate conditions tend to develop them later in life.

Inhibitors are treated with immune tolerance therapy (ITT). ITT involves regular exposure to factor treatment with the aim of the body becoming accustomed to the clotting factor. Studies show that by flooding the system with factor VIII or factor IX the body often stops rejecting it.

Talk to your team if you have any questions about inhibitors.