Evans syndrome

Evans syndrome is a rare autoimmune disorder. The immune system, which normally fights germs, makes antibodies that destroy the body’s own blood cells. It most often destroys red blood cells, which carry oxygen, and platelets, which help blood clot. Sometimes it also destroys neutrophils, a type of white blood cell that fights infection.

Doctors describe it as a combination of autoimmune cytopenias, meaning low blood counts caused by the immune system. Low red cells from this attack are called autoimmune hemolytic anemia (AIHA). Low platelets are called immune thrombocytopenia (ITP). The two problems can start at the same time, but more often one follows the other. Traditionally, Evans syndrome meant having both AIHA and ITP. Some experts now use the name for any two of the three kinds of low counts.

Evans syndrome can be primary, when no other cause is found, or secondary, when it comes with another condition. Telling the two apart matters, because it can change treatment.

Evans syndrome happens when the immune system loses its normal balance and turns against the body’s own blood cells. Doctors call this immune dysregulation. In many people, the reason is not known.

In children, a genetic cause is common. In a French national study, 80 children with Evans syndrome had genetic testing, and 52 of them (65%) had a gene change that could explain it. Many of these changes were in genes already known to cause inherited immune disorders, such as FAS, CTLA4, LRBA, STAT3 and PIK3CD. FAS changes cause autoimmune lymphoproliferative syndrome (ALPS), and PIK3CD changes cause activated PI3K-delta syndrome (APDS). Children’s Hospital of Philadelphia says most cases of Evans syndrome are caused by inherited disorders that affect how the immune system is tuned.

In adults, doctors look closely for another illness behind it. In a study of 116 adults at 13 European centers, about 1 in 5 had an underlying or linked condition, mainly another autoimmune disease or a blood cancer. NORD lists other links, including lupus, antiphospholipid syndrome, lymphoma, chronic lymphocytic leukemia and common variable immunodeficiency.

Symptoms depend on which blood cells are low. Low red blood cells can cause pale skin, tiredness, weakness, dizziness, shortness of breath, dark urine and yellow skin or eyes (jaundice). Low platelets can cause easy bruising, tiny red dots under the skin (petechiae), nosebleeds, bleeding gums or heavy periods. Low neutrophils can cause fevers, mouth sores and more infections.

Evans syndrome often follows a long course, with relapses and calmer times. Serious problems can include severe anemia, bleeding, infections and blood clots. In the study of 116 European adults, 42 in 100 had bleeding, mostly mild. About 1 in 3 had infections and about 1 in 5 had blood clots, and these were often serious. Infections and clots were more common in people who needed more treatments.

Many children with Evans syndrome also develop other immune problems over time. In a French national study of 151 children followed for more than 5 years, 74 in 100 had at least one other immune-related problem by age 20. The most common were swollen lymph nodes or a large spleen, and skin, gut, liver or lung problems.

No single test proves Evans syndrome. Doctors diagnose it by finding two kinds of immune-caused low blood counts and ruling out other causes. A complete blood count (CBC) measures red cells, white cells and platelets. A reticulocyte count shows how fast the marrow is making new red cells. A test for red cell breakdown (LDH) and a direct antiglobulin test (DAT, or Coombs test) point to autoimmune hemolytic anemia. The DAT finds antibodies stuck to red cells.

Other conditions can look similar, including leukemia and lymphoma. Some disorders also cause both anemia and low platelets, such as paroxysmal nocturnal hemoglobinuria (PNH) or thrombotic thrombocytopenic purpura (TTP). So doctors may add a bone marrow test, flow cytometry and scans. The first expert recommendations for adults (2024) advise wide testing, including a bone marrow check and a CT scan, to look for an underlying disease.

In children, doctors also look for an inherited immune cause. This can include immune function tests, a blood test for a kind of T cell linked to ALPS (double-negative T cells) and genetic testing. There is no agreed checklist for children yet. In a 2026 survey of experts in North America, testing varied widely, and most got genetic testing from commercial labs, often meeting insurance barriers.

Treatment aims to bring blood counts up to safe levels and prevent bleeding and other problems. The first treatment is usually a steroid such as prednisone, sometimes with immunoglobulin (IVIG), which is made from antibodies in blood donated by healthy people. Most people respond at first, but relapses are common.

When the condition comes back or does not respond, care teams have several choices. The first expert recommendations for adults, published in 2024, include rituximab (an antibody medicine), medicines that help the body make platelets (thrombopoietin receptor agonists) and fostamatinib. They move broader immune-suppressing medicines to later lines. They discourage rituximab and spleen removal for people with an immune deficiency or severe infections. Sirolimus is another option. In a 2026 single-center study of adults with hard-to-treat disease, 12 of 15 people with Evans syndrome responded by 6 months.

Finding a genetic cause can change the plan. French experts who follow children with these conditions recommend genetic testing within 3 months of diagnosis when a child has more than one kind of immune-caused low count. Some inherited immune disorders have targeted medicines. European transplant experts note that abatacept for CTLA4 or LRBA problems and leniolisib for APDS have helped calm autoimmune problems when given before a transplant. In the U.S., the FDA approved leniolisib (Joenja) for APDS in 2023 for people 12 and older, and in 2026 for some children aged 4 to 11.

A stem cell transplant is rare. It may be considered when severe disease keeps coming back after many treatments. It can use the person’s own stem cells (autologous) or cells from a donor (allogeneic). In their 2025 recommendations, European transplant experts (EBMT) list both as clinical options, meaning they can be done after careful weighing of risks and benefits.

Evans syndrome is usually long-lasting, with flares and calmer times. Regular blood tests help the care team spot a relapse early. Many people need several treatments over the years. In the French study of children followed for a middle time of 11 years, the red cell problem was in lasting remission in about 3 in 4 children after 10 years, and the platelet problem in more than half.

Care often involves several specialists, such as a hematologist (blood doctor), an immunologist and sometimes a rheumatologist. Because many treatments weaken the immune system, preventing infections is a big part of care. Experts in adult care also give advice on preventing blood clots.

Teens and young adults need extra attention as they move from children’s to adult care. In a French study of 151 children with Evans syndrome, deaths happened at a middle age of 18, most often from infection. The researchers called teens and young adults a high-risk group. French experts recommend structured programs for this move so no one is lost to follow-up.

Most people with Evans syndrome never need a donor. When a stem cell transplant is used, it can use the person’s own cells or cells from a donor. For donor transplants, European transplant experts (EBMT, 2025) list a matched brother or sister and a well-matched unrelated donor as clinical options, and partly matched donors as an option with less evidence.

A donor matters most when testing finds an inherited immune disorder behind Evans syndrome. For inherited immune disorders that a transplant is known to cure, European transplant and immune deficiency experts (EBMT/ESID, 2026) class a donor transplant as a clinical option. The decision depends on the natural course of the disorder, how severe it is, other health problems, age, the family’s wishes and whether a donor is available.

The Jada Bascom Foundation helps people find the official donor registry where they live. For most people living with Evans syndrome, joining a registry is a way to help other patients rather than a need of their own.

Evans syndrome is usually long-lasting. Relapses are common, and many people need several treatments. Some people have long remissions. The outlook depends a lot on age and on whether another illness is behind it.

In children, the best long-term data come from France’s national registry. Most children with Evans syndrome were alive 20 years after diagnosis. But deaths were more common than in children with only one kind of immune-caused low count. In an earlier study from the same registry, infections were the most common cause of death. The researchers linked deaths to strong treatments, an underlying immune deficiency, or both.

In adults, the outlook is more serious. In Denmark, people with secondary Evans syndrome did worse than people with primary Evans syndrome. The most common causes of death were bleeding, infections and blood cancers.