Acquired hemophilia is an autoimmune condition that causes problems with your blood’s ability to clot. It’s extremely rare but can cause life threatening bleeding.

Hemophilia is a group of conditions that cause problems with blood clotting. They can cause severe bleeding, even from minor injuries.

Acquired hemophilia is a rare form of hemophilia. It’s an autoimmune condition that occurs when your immune system attacks proteins in your blood that help your blood stick together.

Acquired hemophilia happens about as often in males as in females. It’s estimated to affect about 0.2–1 person per million per year. It most commonly affects older adults and is extremely rare in children.

In this article, we break down everything you need to know about acquired hemophilia, including how it’s diagnosed, treatment options, and what the outlook is for people with this condition.

Language matters

You’ll notice that the language used to share stats and other data points in this article is pretty binary, fluctuating between the use of “male” and “female” or “men” and “women.” Although we typically avoid language like this, specificity is key when reporting on research participants and findings.

Unfortunately, the studies and surveys referenced in this article didn’t report data on, or include, participants who were transgender, nonbinary, gender nonconforming, genderqueer, agender, or genderless.

Acquired hemophilia is a rare autoimmune condition that causes excessive bleeding that can range from minor to life threatening. It develops when your immune system attacks proteins that help your blood stick together. In most people with acquired hemophilia, this protein is blood clotting factor VIII.

Most types of hemophilia are congenital, meaning they are caused by gene mutations present from birth. The most common type of hemophilia is called hemophilia A, or classic hemophilia. This condition is linked to a mutation on your X chromosome.

The initial symptom of acquired hemophilia is often severe bleeding that develops without a history of a bleeding disorder. You may bruise easier than usual and notice large bruises on your body not caused by a significant injury.

Bleeding or bruising might occur spontaneously, meaning it occurs for no apparent reason.

Other symptoms of acquired hemophilia can include:

Acquired hemophilia is an autoimmune disorder, which means it occurs when your immune system mistakenly attacks healthy cells.

A type of white blood cell in your body called B cells creates proteins called antibodies. These proteins bind to substances that your immune system perceives as harmful so that other immune cells can destroy them.

In the case of acquired hemophilia, your body creates autoantibodies against proteins called clotting factors. Autoantibodies are antibodies that bind to your own healthy cells that aren’t harmful to your body.

Researchers aren’t entirely sure why some people develop acquired hemophilia, but it seems to affect males and females about equally.

Infections and some underlying health conditions appear to trigger the development of acquired hemophilia. In about 50% of cases, it has a link with one of the following conditions:

Acquired hemophilia has also been associated with reactions to some medications, such as:

  • penicillin
  • interferon
  • sulphonamides
  • phenytoin
  • fludarabine

Can you develop hemophilia later in life?

Classic hemophilia is congenital, meaning that it’s present from birth. In contrast, acquired hemophilia usually develops in people between the ages of 60–80. About 80% of cases occur in people over the age of 80. Women who have recently given birth also seem to have a higher chance of the condition.

Your doctor will likely suspect some form of hemophilia based on your signs and symptoms. More than 80% of people have bruises, and 20% have signs of gastrointestinal bleeding.

Your doctor can confirm the diagnosis with a coagulation test. A coagulation test involves taking a small sample of your blood for lab testing to see how well it sticks together.

Doctors routinely perform the following tests to diagnose acquired hemophilia:

People with acquired hemophilia have a prolonged aPTT result and a normal PT result.

Acquired hemophilia has no known cure. Treatment is broken into four pillars:

  1. Avoiding activities that may cause bleeding
  2. Controlling bleeding
  3. Getting rid of autoantibodies
  4. Treating underlying conditions linked with acquired hemophilia.

People with minor bleeding may only need observation. Spontaneous remission has been reported in about 25% of cases. In postpartum women, it usually resolves within a few months of giving birth.

People with major bleeding will likely need to take medications to manage their symptoms.

Medications that control bleeding

Two types of medication are used to manage bleeding. Bypassing agents are often the recommended first-line therapy due to their rapid action and high level of effectiveness. They bypass the need for the blood clotting factor your immune system is attacking.

If these drugs don’t work, your doctor might recommend medications that increase blood clotting factor VIII levels, such as the medication desmopressin (DDAVP, Stimate). These medications are often combined with drugs that decrease autoantibodies.

Usually, the first-line therapy for decreasing autoantibodies is corticosteroids, possibly with cyclophosphamide. Researchers are examining the drug rituximab (Rituxan) in clinical trials. It may be considered in people who don’t respond to their first treatment.

Acquired hemophilia can cause bleeding that ranges from mild to life threatening. Improvements in treatment have led to lower death rates. Current research suggests that death rates are between 8–22%, although some studies show lower rates.

Acquired hemophilia has an excellent outlook in about 97% of women who have recently given birth. Spontaneous remission occurs at an average of about 30 months.

With medication, about half of people can achieve autoantibody remission within 5 weeks.

Acquired hemophilia is a rare autoimmune disease where your immune system attacks proteins in your blood that help it stick together. It occurs most often in people over age 60.

Acquired hemophilia doesn’t have a cure, but it can often be well-managed with medications. It often resolves spontaneously in women who have recently given birth.