Autoimmune hemolytic anemia (AIHA) is a condition in which the immune system attacks red blood cells. People with AIHA often develop additional diseases — known as comorbidities — including other inflammatory diseases. For example, certain types of inflammatory bowel disease (IBD), including ulcerative colitis, are associated with AIHA.

Studies show that AIHA and ulcerative colitis are connected through similar autoimmune mechanisms and treatments. If you have AIHA and ulcerative colitis, understanding how they are related can help you and your doctor determine a treatment plan along with ways to manage symptoms.

What Are AIHA and Ulcerative Colitis, and How Are They Related?

Both AIHA and ulcerative colitis are autoimmune diseases, which occur when the immune system mistakes patterns on the body’s healthy cells as foreign (known as antigens) and tries to destroy what it sees as invaders. In AIHA, the red blood cells are covered with autoantibodies that tell the immune system to launch an attack, a process known as hemolysis. With ulcerative colitis, a chronic type of IBD, the lining of the intestines and digestive tract become inflamed, resulting in ulcers. Ulcerative colitis also involves autoantibodies, most commonly antineutrophil cytoplasmic antibodies.

Both conditions can also lead to anemia, or a low red blood cell count. With ulcerative colitis, anemia may occur from intestinal bleeding. People with anemia may also have an iron deficiency and difficulty absorbing key nutrients from food in the intestines, which also contributes to a low red blood cell count. Around 33 percent of people with IBD develop anemia.

People with active ulcerative colitis flares may develop AIHA, which is known as secondary AIHA because it results from another disease, not on its own. Other diseases that may cause secondary AIHA include lymphoma and other cancers, other autoimmune diseases, and viral infections. Secondary AIHA is associated with more severe ulcerative colitis symptoms and sometimes develops in response to ulcerative colitis treatments.

Diagnosing AIHA and Ulcerative Colitis

Diagnosing AIHA and ulcerative colitis correctly is the first step toward getting the treatment you need. Doctors diagnose AIHA using various blood tests, including:

• Complete blood count — Measures concentrations of red blood cells, white blood cells, platelets, and hemoglobin
• Reticulocyte count — Measures levels of reticulocytes (slightly underdeveloped red blood cells)
• Coombs test — Looks for antibodies that fight red blood cells
• Haptoglobin test — Measures levels of haptoglobin, a protein made by the liver that binds to hemoglobin

Ulcerative colitis is diagnosed using a combination of imaging procedures such as CT scans, a colonoscopy (a procedure to look inside the colon), and blood and stool samples. Doctors often also test for anemia because it commonly occurs with ulcerative colitis.

Treatments for AIHA and Ulcerative Colitis

Treatments for AIHA depend on what subtype you have. The two main types of AIHA are cold and warm AIHA. Warm AIHA is caused by a type of antibody known as immunoglobulin (Ig) G. IgG is made at your body’s normal temperature. Cold AIHA occurs when the body produces immunoglobulin antibodies at colder temperatures. One subtype of cold AIHA is cold agglutinin disease, which involves IgM antibodies. Taking certain medications may also trigger the immune system to destroy red blood cells in a condition known as drug-induced AIHA.

The main goal of treatments for both ulcerative colitis and AIHA is to fight the effects of autoantibodies and dampen the inflammation that damages healthy tissues.

Treatments for AIHA

Treatments specific to AIHA include corticosteroids, chemotherapy, and targeted therapies. Surgery, such as splenectomy (removing the spleen), can help those with warm AIHA. Procedures such as IV immunoglobulin, blood transfusions, and plasmapheresis can also help alleviate symptoms.

Treatments for Ulcerative Colitis

Treatments specific to ulcerative colitis include 5-aminosalicylates, along with over-the-counter drugs such as pain relievers and antidiarrheal medications. Surgery to remove the colon and rectum may also be performed to treat ulcerative colitis.

Shared Treatments

AIHA and ulcerative colitis also share some treatments, including immunosuppressive drugs such as azathioprine (sold as Azasan and Imuran) and cyclosporine (sold as Gengraf, Neoral, and Sandimmune). Corticosteroids are also used to manage both conditions by regulating the immune system to reduce inflammation.

Biologics offer another treatment option for AIHA and ulcerative colitis. Biologic drugs target the cause of inflammation at its source and change the immune response.

Treating AIHA Caused by Ulcerative Colitis

The first-line treatment commonly used for ulcerative colitis-associated AIHA, and AIHA generally, is corticosteroids. These anti-inflammatory medications help tone down inflammation. Corticosteroids for AIHA include:

• Prednisone
• Dexamethasone
• Methylprednisolone
• Prednisolone

These medications are often used for a few months to help treat AIHA, and around 70 percent to 85 percent of people respond well to this therapy. Studies also show that surgical resection (removing portions of the intestines) to treat IBD can also help people achieve remission (disappearance of symptoms) from AIHA.

AIHA Caused by Ulcerative Colitis Medications

Isolated cases of drug-induced AIHA have been reported in response to ulcerative colitis treatments, including immunotherapies and sulfasalazine. Researchers believe that the AIHA autoantibodies react to drugs that are attached to red blood cells. As a result, more red blood cells are destroyed, creating AIHA symptoms.

The only way to diagnose drug-induced AIHA is to stop using the ulcerative colitis medications and see if symptoms improve. Although individual health care providers have noted these drug-induced cases, no long-term studies officially connect immunotherapies and immunomodulatory drugs for treating ulcerative colitis to AIHA.

Connecting With Others

AIHA is a rare disease, but you’re not alone. On myAIHAteam, people with AIHA and their loved ones come together to ask questions, give advice, and share their stories with others who understand life with this condition.

Are you living with AIHA and ulcerative colitis? How have your treatments affected your health? Share your experience in the comments below, or start a conversation by posting on myAIHAteam.