Autoimmune hemolytic anemia (AIHA) is a condition in which the immune system attacks red blood cells, and it often occurs with other health conditions. In some people, AIHA develops as a result of other diseases. In others, AIHA may lead to changes in the body that cause additional conditions to develop.

When someone has more than one disease at the same time, the conditions are known as comorbidities. When another medical condition develops during an existing disease or after treatment, it is known as a complication. Having a comorbidity or complication may make it harder for your health care team to diagnose or treat your AIHA, and it may even influence your prognosis (the likely course of a disease).

Understanding how other health conditions are related to AIHA can help you talk to your doctor about treatment options. Addressing these related conditions may help you feel better, prolong survival, and improve your overall health.

AIHA Comorbidities

Many people with AIHA had other health conditions first. In many cases, it’s not clear how AIHA may be linked to these disorders or whether these conditions directly cause AIHA.

When AIHA occurs as a complication of another underlying condition, it is called secondary AIHA. When AIHA occurs on its own in the absence of other conditions, doctors refer to it as primary AIHA.

Blood Cancers

Having certain types of blood cancer can raise the risk of AIHA. According to a study in Frontiers in Immunology, about 5 percent to 10 percent of people with chronic lymphocytic leukemia (cancer that affects the immune cells) develop AIHA. In some cases, people may have AIHA before being diagnosed with chronic lymphocytic leukemia.

AIHA is also seen in about 2 percent to 3 percent of people with non-Hodgkin lymphoma, a different form of immune cell cancer. However, people with certain types of non-Hodgkin lymphoma have a much higher risk. AIHA occurs in:

• About 13 percent to 19 percent of those with angioimmunoblastic T-cell lymphoma
• Around half of people with marginal zone lymphoma
• Between 15 percent and 20 percent of those with Waldenstrӧm’s macroglobulinemia

In a small study from the Asia-Pacific Journal of Clinical Oncology, 10 percent of people with multiple myeloma had AIHA. Multiple myeloma is a type of cancer that affects the plasma cells (immune cells that make antibodies).

A related disorder, monoclonal gammopathy of undetermined significance (MGUS), is not a cancerous condition but sometimes develops before myeloma. People with AIHA are six times more likely to have MGUS compared to people without AIHA. However, many people with MGUS don’t know they have the condition, so researchers aren’t yet sure whether MGUS or AIHA typically develops first.

Usually, the treatments used to manage these blood cancers help treat AIHA as well. However, some cancer treatments like ibrutinib (Imbruvica), venetoclax (Venclexta), idelalisib (Zydelig), and lenalidomide (Revlimid) can also increase AIHA risk, although this is rare. AIHA also develops in 2 percent to 4 percent of people who undergo stem cell transplant, a procedure that may be used to treat blood cancers.

Other Cancers

AIHA can also develop as a result of other types of cancer. In particular, one study found that 9 percent of people with prostate cancer and 5.6 percent of those with ovarian cancer developed autoimmune disorders. AIHA was one of the most commonly diagnosed immune conditions in these types of cancer.

AIHA can also occur with other cancer types, especially thymoma (cancer of the thymus), renal cell carcinoma (kidney cancer), and Kaposi sarcoma. Once these cancers are treated, AIHA often disappears.

Some newly developed cancer medications called immune checkpoint inhibitors can also lead to AIHA, although this is rare. These drugs are often used to treat lung cancer and melanoma and include nivolumab (Opdivo) and pembrolizumab (Keytruda).

Autoimmune Disorders

Several types of immune system problems have been linked with AIHA. In particular, AIHA can be comorbid with autoimmune disorders — conditions in which the immune system becomes overactivated and begins attacking the body’s tissues.

AIHA occurs when the immune system attacks red blood cells. During some related autoimmune diseases, the immune system can also attack other types of blood cells:

• Idiopathic thrombocytopenic purpura — This is a condition in which the immune system attacks platelets (the cells that help blood clot properly), leading to bleeding and bruising problems.
• Autoimmune neutropenia — This is a disorder in which the immune system attacks neutrophils, a type of white blood cell that helps the immune system fight infections.
• Evans syndrome — This is a condition in which AIHA and idiopathic thrombocytopenic purpura occur together. Autoimmune neutropenia also occurs in about 15 percent of people with Evans syndrome.

AIHA is also linked to systemic lupus erythematosus (commonly called lupus), another autoimmune condition that often leads to joint pain, rashes, and organ damage. One study found that 3 percent of adults and 14 percent of children with lupus had AIHA. In these cases, AIHA is often treated with corticosteroids, splenectomy (removal of the spleen), or immunosuppressive medications (drugs that calm the immune system).

People with inflammatory bowel disease (IBD) are more likely to be diagnosed with AIHA. IBD is a group of conditions in which there is a lot of inflammation in the digestive system. In particular, AIHA occurs more often in people with ulcerative colitis — a type of IBD that affects the colon (large intestine). IBD treatments, including surgery and medications like infliximab (Remicade), may help heal AIHA.

Other autoimmune disorders have also been linked to AIHA in rare cases. These include scleroderma, rheumatoid arthritis, Hashimoto thyroiditis, Graves’ disease, and Sjögren’s syndrome.

Immunodeficiency Disorders

Immunodeficiency disorders are conditions in which the immune system doesn’t work as well as it should. Rarely, AIHA can occur at the same time as immunodeficiency disorders like common variable immunodeficiency, IgA deficiency, and autoimmune lymphoproliferative syndromes.

Other Blood Disorders

AIHA is linked to a red blood cell disorder called beta-thalassemia. In this condition, red cells don’t have enough hemoglobin (a protein that helps carry oxygen). About 6 percent of people with beta-thalassemia are also diagnosed with AIHA.

In a couple of cases, people with sickle cell disease have also been found to develop AIHA, although this is very rare.

Infections

In rare cases, certain viral infections may lead to a higher risk of AIHA. Those infected with the hepatitis C virus, which attacks the liver, are 2.8 times more likely to have AIHA. Furthermore, people with hepatitis C who receive interferon treatments develop AIHA 11.6 times more often. AIHA is also 20 times more common in people with HIV infections, as noted in a study in Immunity & Ageing.

Some bacterial infections also raise the risk of AIHA. Mycoplasma pneumoniae (a bacteria that causes lung infections), tuberculosis (a lung infection), and brucellosis or undulant fever (an infection that affects the whole body) may all lead to AIHA.

Paroxysmal cold hemoglobinuria, a rare type of AIHA, usually develops after an infection, especially in children.

Certain types of antibiotics used to treat infections can also lead to a type of AIHA called drug-induced immune hemolytic anemia, although this is rare. Some of the most common drugs linked to drug-induced immune hemolytic anemia include penicillin, piperacillin, ceftriaxone, and cefotetan.

Genetic Disorders

People with a rare genetic disorder called Kabuki syndrome may also be at risk for developing AIHA. Those with Kabuki syndrome have distinctive facial features, intellectual disability, delays in growth, and immune system abnormalities. Researchers estimate that 13.6 percent of people living with Kabuki syndrome have autoimmune conditions, and one of the most common is AIHA.

Complications

In some cases, other health conditions develop after an AIHA diagnosis. Work with your doctor to determine which of these conditions you may be at risk for, and ask about treatments that may help prevent these conditions.

Blood Clotting Problems

Normally, the blood forms clots when a blood vessel is damaged. Blood clots help prevent too much blood from being lost. However, some health problems develop when the blood forms clots inside of undamaged blood vessels.

Up to 1 out of 5 people with AIHA have conditions caused by blood clots. This number jumps as high as 1 out of 3 for people with warm AIHA. Blood clotting problems include:

• Deep vein thrombosis — A blood clot within a vein, often in the legs
• Pulmonary embolism — A blood clot that blocks blood flow to the lungs
• Stroke — A blood clot blocking blood from reaching the brain
• Heart attack — A blood clot that prevents blood from reaching the heart

It’s thought that blood clotting problems and AIHA are linked because when red blood cells break apart, they release chemicals that can prevent blood clotting factors from working properly.

People with AIHA are more likely to experience blood clotting problems if they have high hemoglobin levels, high levels of LDL (“bad” cholesterol), or have previously undergone a splenectomy (surgical removal of the spleen). People with AIHA may be able to prevent blood clotting problems by taking medications called anticoagulants.

Talk to Your Doctor About Related Conditions

Having other health problems in addition to AIHA may complicate treatment and lead to less favorable outcomes. However, managing comorbid conditions can improve your quality of life.

Make sure to have regular follow-up appointments with your health care team and bring up any new or changing symptoms. Speak openly with your team about your health concerns, and consider seeking care from a specialist if you are facing challenges while managing your health conditions.

Condition Guide

• What Are the Common Symptoms in People With AIHA?
• Exploring Autoimmune Hemolytic Anemia Treatment Options
• What Causes AIHA?
• What Are the Different Types of AIHA?
• How Is AIHA Diagnosed?
• What Is AIHA? An Overview of Autoimmune Hemolytic Anemia