Evans syndrome is a rare disorder that causes the immune system to destroy certain blood cells.
It can cause low blood cell levels and anemia, which may lead to a variety of symptoms.
Treatments are available that can increase blood cell counts and relieve a person’s symptoms.
Keep reading to learn more about Evans syndrome, including the causes, symptoms, and treatment options.
Evans syndrome is a rare combination of two or more of the following autoimmune blood disorders:
- Autoimmune hemolytic anemia (AIHA), in which the immune system destroys red blood cells. Red blood cells are responsible for carrying oxygen to the body’s organs and tissues.
- Immune thrombocytopenia (ITP), in which the immune system attacks platelets. Platelets help stop bleeding by forming blood clots.
- Autoimmune neutropenia (AIN), which causes the immune system to attack neutrophils. Neutrophils are white blood cells that help with healing tissues and fighting infections.
A person with Evans syndrome will have AIHA along with ITP or AIN. A combination of AIHA with ITP is more common, according to the National Organization for Rare Disorders (NORD).
Usually, a person will develop one blood disorder first and then another one later. Sometimes, a person will develop both disorders at the same time, but this is less common.
A person must have two of these conditions for a doctor to diagnose Evans syndrome.
Experts do not know how many people get Evans syndrome. A Danish study of adults with Evans syndrome found that it may affect up to 21.3 of every million people.
According to the NORD, the incidence and prevalence of Evans syndrome are unknown. The organization describe this condition as rare.
Due to the immune system attack that Evans syndrome causes, people with this condition have abnormally low levels of blood cells. Doctors may refer to this as cytopenia.
Cytopenia causes a variety of symptoms that vary from person to person. The severity of the disease and the specific blood cells that the disease involves will determine what symptoms a person develops.
Some people have periods of remission during which symptoms of the disease go away. Remission may happen after successful treatment. However, people may also have periods when symptoms get worse.
Low levels of red blood cells due to Evans disease may cause anemia. Anemia means that the body does not have enough red blood cells to get oxygen to the organs and tissues.
Anemia may cause the following symptoms:
- pale skin
- dizziness or lightheadedness
- shortness of breath
- rapid heartbeat
- yellowing of the skin and eyes (jaundice)
Low levels of platelets may cause bleeding under the skin because the blood cannot clot properly.
If this occurs, a person may notice:
- tiny purple or red spots on the skin (petechiae)
- purple spots on the skin, which may appear raised (purpura)
- larger purple blotches on the skin (ecchymosis)
- skin that bruises easily
People who have low levels of neutrophils are more likely to get infections. Their symptoms may include:
- a fever
- feeling unwell
- sores or ulcers inside the mouth
- frequent illnesses
People with Evans syndrome may also have an enlarged spleen, liver, or lymph nodes.
A person may not notice these signs, but a doctor can identify them during an exam or on an imaging test.
Experts do not know why some people get Evans syndrome. The Genetic and Rare Diseases Information Center state that Evans syndrome does not usually appear to run in families.
A healthy immune system consists of cells, tissues, and organs that defend the body against germs, diseases, and invaders.
When the immune system senses an invader, it makes proteins called antibodies that destroy the foreign substance.
In Evans syndrome, the immune system treats blood cells as invaders, making antibodies that harm them.
According to the NORD, certain triggers may lead to Evans syndrome. Possible triggers include illnesses, infections, and other health conditions.
There is no specific test that will diagnose Evans syndrome. Instead, a doctor will run a variety of tests to rule out other health issues.
Some of the tests that doctors may use to confirm a diagnosis include:
- a complete blood count (CBC), which measures a person’s number of blood cells
- a direct or indirect Coombs test, which looks for antibodies against red blood cells (positive in AIHA)
- a bone marrow biopsy
- CT scans of the chest, abdomen, and pelvis
A doctor usually diagnoses Evans syndrome if the person has both AIHA and ITP, even if they do not develop these disorders at the same time.
There is no cure for Evans syndrome, so treatment focuses on relieving symptoms and increasing blood cell counts.
Treatment for Evans syndrome varies from person to person. The most suitable treatment will depend on the person’s:
- health status
- blood cell count
Treatment options can include:
One of the most common treatments for Evans syndrome is corticosteroids. These medications can help lower the activity of the immune system.
However, corticosteroids can have many side effects, including:
- high blood pressure
- weight gain
- mood swings
- high blood sugar
Intravenous immunoglobulin (IVIg) is a solution that contains antibodies from healthy donors.
A person receives this treatment intravenously, which means through an injection into the veins. IVIg can help prevent the immune system from attacking the body.
These medications work by lowering the level of activity of the immune system. Possible side effects include a higher risk of getting illnesses and infections.
Rituximab is a newer medication that avoids some of the side effects of immunosuppressive drugs.
The NORD state that rituximab “appears to be a highly effective treatment” for Evans syndrome.
In some cases, treatment may involve surgically removing the spleen in a procedure called a splenectomy.
However, people with Evans syndrome have mixed responses to this procedure, so it is hard to determine whether it helps with symptoms. The surgery also carries risks.
Some researchers say that the risks of splenectomy outweigh its benefits, especially because newer treatments, such as rituximab, are now available.
Hematopoietic stem cell transplantation
A stem cell transplant could help reset the immune system and provide a potential cure for Evans syndrome, according to one article.
The treatment requires a donor to provide stem cells. The donor will usually be a close family member who is a proper match.
However, stem cell treatment may not work for everyone, and no large studies have yet proved that it is effective.
When a person has a rare and chronic disease, such as Evans syndrome, they may benefit from social and emotional support.
It can be difficult for a person to deal with the symptoms of a rare disease, as they may not know anyone who has faced the same challenges.
Online and in-person support groups are available for people with Evans syndrome and autoimmune conditions. These include RareConnect, an online community for people with rare diseases, and the Evans Syndrome Foundation.
A person should ask their doctor about support groups or community resources that can help.
Family members and other loved ones can take steps to educate themselves about Evans syndrome so that they better understand the illness and how they can provide support.
Evans syndrome is a rare immune system disorder that reduces a person’s blood cell count and can lead to anemia and other complications.
Although there is no cure, newer treatments and advanced medical care can help relieve symptoms and improve quality of life.