Acquired haemophilia A is a very rare condition where a person’s immune system (a system that protects your body from diseases) develops antibodies, also known as inhibitors, that mistakenly target the body’s own clotting factors, most commonly factor VIII. It is not hereditary.
People with acquired haemophilia A would previously have been well with no history of bleeding and would have had normal blood clotting tests. In some cases, there is an underlying medical condition that can trigger acquired haemophilia A, for example, autoimmune conditions and certain cancers. In other cases, no cause of acquired haemophilia A is found.
There are several differences between acquired and hereditary forms of haemophilia. These include:
- How severe the bleeding is can be variable. Some people with acquired haemophilia A may have very little bleeding while others have significant life-threatening bleeding.
- The pattern of bleeding is different. In acquired haemophilia A it often includes skin, gastrointestinal and muscle bleeds rather than joint bleeds. However, bleeding can occur at any site in the body.
- The age when people with acquired haemophilia A first seek medical care for their condition is different to hereditary forms of haemophilia. Although acquired haemophilia A can occur at any age, it most often occurs in older people and in some women in late pregnancy or who have recently given birth.
- In acquired haemophilia A both males and females are affected equally.
Treatment for acquired haemophilia A is firstly to control the bleeding and then to remove the inhibitor and treat the underlying medical condition (if there is one). A small number of people do not respond to treatment or the inhibitor comes back. Getting rid of the inhibitor involves medications to suppress the immune system.
People with acquired haemophilia should be monitored by a Haemophilia Treatment Centre for specialist care.
LINKS TO SELECTED RESOURCES:
Acquired hemophilia
(National Organization for Rare Disorders (NORD))
If you have acquired haemophilia, ask your Haemophilia Treatment Centre for more information about your disorder.
Sources:
Australian Bleeding Disorders Registry Annual Report 2020-21. Canberra: National Blood Authority, 2021. Accessed 29 March 2023
World Federation of Hemophilia. Acquired hemophilia. Montreal: WFH, 2012. Accessed 2 February 2023
Reviewers: Bleeding disorder community representatives from HFA Haemophilia Consumer Review Group (individuals not named for privacy reasons); Australian Haemophilia Centre Directors’ Organisation: Dr Janice Chamberlain, Dr Liane Khoo; Australia and New Zealand Haemophilia Psychosocial Group: Kathryn Body, Jane Portnoy; Australia and New Zealand Physiotherapy Haemophilia Group: Cameron Cramey, Alison Morris; Australian Haemophilia Nurses’ Group: Jaime Chase, Alex Klever, Stephen Matthews, Robyn Shoemark; Haemophilia Foundation Australia: Sharon Caris, Suzanne O’Callaghan.