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Evans syndrome (ES) is an uncommon autoimmune disease in which an individual's antibodies attack their own red blood cells, white blood cells, or platelets. It is also known as autoimmune hemolytic anemia and autoimmune thrombocytopenia. It is estimated that 1 out of 80,000 US residents has ES.

People typically also experience Coombs' positive hemolytic anemia and thrombocytopenia. Autoimmune hemolytic anemia is a condition in which the red blood cells are destroyed faster than they can be produced. Thrombocytopenia is a condition in which the affected person has too few platelets.

A person with Evans syndrome will usually have both affected red blood cells and platelets. One usually develops first, with the other following.

The syndrome was first described by Robert Evans in medical literature and associates. It was not thought to be its own distinctive condition until more recently, however.

Signs and symptoms
People affected by Evans syndrome typically experience paleness, dizziness, purpura, and fatigue. However, symptoms vary depending on which is affected: red blood cells, white blood cells, or platelets. These side affects can be life-threatening and severe.

For those with affected red blood cells, anemia is the most common symptom. With anemia brings light-headedness, fatigue, paleness, and shortness of breath.

For persons affected with low platelets, purpura, unexplained bruising, and prolonged bleeding will occur. Usually, people will have both affected red blood cells and platelets.

For those with affected white blood cells, they will be more susceptible to infections. When a person has affected white blood cells, it is called neutropenia. This is a more rare occurrence with Evans syndrome.

It is also common for people with Evans syndrome to go through periods of remission, in which symptoms are less severe or even disappear.

Causes
The direct cause of Evans syndrome is unknown. It is only known that it is a disease which affects the immune system. However, there are a few other conditions which are thought to occur in conjunction with Evans syndrome. They are Lupus, IgA deficiency, autoimmune lymphoproliferative syndrome (ALPS), and Sjogren syndrome. When Evans syndrome is diagnosed with another condition, it is known as Secondary Evans syndrome. When it is diagnosed on it's own, it is primary and known as idiopathic. This distinction can be very important in treatment.

It is not thought to be inherited, however there are a few medical journals which mention siblings having Evans syndrome (although very rare). It affects both children and adults. Incidence among certain populations is not yet known.

Mechanism
The bodies immune system will attack anything that has an antibody on it. The antibody, which is attached to something else like a virus, tells the immune system that it is not welcome and should be destroyed. In Evans Syndrome - more specifically autoimmune hemolytic anemia - the red blood cells which are produced in the bone marrow, have antibodies attached to them. This signals the immune system to destroy them.

Due to the destruction of the bodies own red blood cells by the immune system, paleness, fatigue, and light-headedness will occur. This is because the red blood cells carry oxygen throughout the body by way of hemoglobin. If oxygen is low, skin becomes pale, the body becomes tired, and light-headedness will occur.

In the case of thrombocytopenia, the bodies own platelets are destroyed. The mechanism of this happening is the same as in the destruction of red blood cells. When platelets are low, the body is unable to clot blood properly so bleeding becomes an issue.

When white blood cells are destroyed, the body is unable to fight off infections as easily. This is because white blood cells are responsible for signaling of the destruction of pathogens.

Diagnosis
A person must present with certain characteristics to be diagnosed with Evans syndrome. Bruising, bleeding, dizziness, and paleness are the most common symptoms associated. There is no specific test that is conclusive, however general blood tests can be done. A complete blood count (CBC) and DAT (direct antiglobulin test) are the most common blood tests performed. Other conditions can be ruled out by performing bone marrow biopsies, antibody assays, and a CT scan.

In children, autoimmune lymphoproliferative syndrome (ALPS) should be ruled out, due to the high prevalence of these two conditions appearing together. This involves a blood test that checks for double-negative T-cells by flow cytometry.

Treatment
There is no cure for Evans syndrome (ES). Treatment is usually based on the individual, because most have varying forms and severity of the condition. Treatment may come from a combination of doctors such as hematologists, rheumatologists, pediatricians (in children), immunologists, and surgeons. Age and general health also come into play when deciding how to treat the patient with ES.

Initial treatment is with glucocorticoid corticosteroids or intravenous immunoglobulin. In children, a positive response to a short steroid course is achieved in approximately 80% of cases. Many cases initially respond well, however, relapses are not uncommon. Immunosuppressive drugs are then used.

A splenectomy may be effective, but relapses are not uncommon.

A relatively new therapy is now available called Rituximab. This is a monoclonal antibody, or artificial antibodies. Good results have been produced using this drug, although relapse within a year is not uncommon.

Stem cell transplantation may be a prospect for a cure, however, it is a high-risk option.

Prognosis
Evans syndrome (ES) is serious and has a mortality rate of 7%.

The prognosis is extremely variable. With the right combination of treatments, patients may go into remission for long periods. However, others may have no periods of remission and instead face long, chronic problems.

People with ES tend to be at a higher risk for developing other autoimmune disorders. Recently, a study of 12 children showed that 58% had developed elevated double-negative T cells, showing that these children also had autoimmune lymphoproliferative syndrome (ALPS).

Recent Research
To better understand the outcome of Evans syndrome in adults, a study was done with 68 patients (60% women) who had the syndrome. Evans syndrome was primary for 50% of the patients, but did have another underlying condition, such as Lupus or lymphoproliferative disorders. The patients were given corticosteroids. After a follow-up time of 4.8 years, it had been found that 22 patients were in remission and 16 had died. The final conclusions of this study were that this syndrome has a high chance of being life-threatening.