Caring for patients around the world
Spotlight on a rare form of haemophilia
As we have seen, haemophilia is a rare hereditary disease where the blood does not clot following a wound or trauma.
There are two types of haemophilia: haemophilia A, which is characterised by a deficiency of clotting factor VIII, and haemophilia B, which is characterised by a deficiency of clotting factor IX.
Complications can occur in some patients with haemophilia: one of the most common is permanent damage to the joints.
Another major and serious complication is the development of inhibitors.
As a reminder, haemophilia is treated through chronic administration of the missing or deficient factor VIII or IX. In some cases, the clotting factor injected is considered by the human body as a foreign substance, and the body then defends itself by producing antibodies. They are called inhibitors in this case because they neutralise the clotting function of the factor administered.
Worldwide, 7,571 patients with haemophilia A and B* are known to have developed inhibitors, which means only 3% of haemophiliacs A and B patients worldwide are affected.
Haemophilia patients who develop inhibitors have a 70% higher risk of mortality than patients without inhibitors**.
There are few treatments available to manage this serious complication. One available treatment is Immune Tolerance Induction (ITI), for example, which eliminates the inhibitors by injecting large quantities of factors VIII or IX. The administration of so-called “bypassing” agents goes around the inhibitor, for example, by injecting recombinant activated coagulation factor VII.
*Source: https://www1.wfh.org/publications/files/pdf-2399.pdf
**Source: Walsh CE, Soucie JM, Miller CH, United States Hemophilia Treatment Center N. Impact of inhibitors on hemophilia A mortality in the United States. Am J Hematol. 2015;90(5):400-5.
