Acquired Hemophilia

Acquired hemophilia is an autoimmune disorder in which the immune system mistakes proteins that are part of the body as foreign and starts producing antibodies against them.

The disease shares few similarities with inherited hemophilia, a bleeding disorder that affects mostly males from birth. Acquired hemophilia, a very rare condition found in about 1 in every 1 million people, can affect males and females equally.

The disease may develop at any age, but usually affects much older people.


People with acquired hemophilia develop antibodies against blood-clotting factors, often against factor VIII (FVIII). Clotting factors are proteins that are crucial for blood to clot correctly. Once bound to these antibodies, clotting factors are no longer able to work as they should, impairing the blood’s ability to clot and bleeding to stop.

In about half of all cases, the cause for the immune overactivity against FVIII is never established, and the condition is called idiopathic [unknown cause] acquired hemophilia.

In the remaining 50% of cases, acquired hemophilia may be associated with other illnesses, such as rheumatoid arthritis, ulcerative colitis, asthma, psoriasis, and cancer. In very rare cases, it may be triggered in response to certain therapies or by pregnancy. A case report found that acquired hemophilia A also may be related to SARS-CoV-2 infection, the virus that causes COVID-19.


The most common sign of the disorder is extensive bruising on the body, particularly on the arms, legs, or trunk, caused by under-the-skin bleeding.

Spontaneous bleeding can occur in the muscles, causing pain and a temporary loss of movement.

Acquired hemophilia is often characterized by prolonged bleeding after a surgical procedure, as well as by the presence of blood in the urine or stool. Specific symptoms may include nosebleeds (epistaxis) and bleeding under the skin, which is followed by solid swellings of congealed blood (hematomas). A risk of bleeding in the stomach, intestines, and urinary organs is also known.

Women may experience genital heavy bleeding during pregnancy and especially after childbirth.


Once diagnosed, acquired hemophilia can be successfully treated. The first step in treating it includes controlling immediate bleeding, followed by eliminating FVIII antibodies from the body.

Bleeding is often controlled by injecting a combination of clotting factors directly into a patient’s bloodstream that bypass the need for FVIII. These are called bypassing agents and include recombinant activated factor VII (NovoSevenRT) or activated prothrombin complex concentrates (aPCC; FEIBA).

Obizur, a man-made version of FVIII of pig origin, is approved in the U.S. and Europe to treat bleeding episodes in adults with acquired hemophilia A.

Immunosuppressive therapies may also be given to stop the production of FVIII antibodies. These include corticosteroids and chemotherapy agents. Antibodies or inhibitors against FVIII could disappear without treatment, but patients require regular check-ups and hospital care until then.


Last updated: Nov. 30, 2021


Hemophilia News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.