What Is Evans Syndrome?

Introduction

Evans syndrome, also known as immune pancytopenia or autoimmune hemolytic anaemia and autoimmune thrombocytopenia, is a rare, life-threatening autoimmune disease where the immune system attacks the body’s own blood cells. Characterized by a shortage of platelets and the early destruction of red blood cells, it can manifest through symptoms such as paleness, fatigue, and weakness, which persist chronically but may spontaneously improve or worsen. Diagnosis relies on blood tests, and management strategies, including medications, surgery, and blood transfusions, are tailored to individual patient needs.^1,2

Causes of Evans syndrome 

Evans syndrome, being an autoimmune disease, results from the immune system’s attack on the body’s blood cells, as opposed to an attack by a foreign body.  This attack leads to a deficiency in platelets and the premature destruction of red blood cells. In some cases, particularly in children, underlying conditions may contribute to Evans syndrome, while in others, the cause remains unknown.¹ 

Several conditions have been identified as possible triggers for Evans syndrome, including autoimmune diseases, cancers, and infections.³ 

Risk factors for Evans syndrome

Several factors can increase the likelihood of someone having Evans syndrome:^1,3

• Family history or personal history of autoimmune diseases
• Cancers
• Infections
• Recent vaccinations
• Drugs
• Being assigned female at birth

Signs and symptoms of Evans syndrome

The signs and symptoms of Evans syndrome can occur in childhood or adulthood. They often persist chronically, and may spontaneously improve or worsen.²

Thrombocytopenia

Evans syndrome causes a deficiency of platelets,  also known as thrombocytopenia,  and can lead to several signs and symptoms:^2,4,5

• Bleeding
• Enlarged spleen
• Skin rashes or spots

Anaemia

Evans syndrome causes the early destruction of red blood cells, resulting in anaemia, which can physically affect patients in several ways:^2,6

• Paleness
• Fatigue 
• Weakness
• Shortness of breath
• Difficulty concentrating

Diagnosis of Evans syndrome

A range of techniques and tests can be employed to diagnose Evans syndrome and rule out other conditions. Several conditions are usually considered and ruled out during the diagnosis of Evans syndrome, including haemolytic uremic syndrome, Kasabach-Merritt syndrome, and vitamin deficiencies, among others.^1,3

Medical history

During your consultation with a doctor, a medical history is taken. Here, the doctor establishes an understanding of your current health status, as well as any past conditions or therapies you've undergone. This information helps the doctor determine a possible cause for the signs and symptoms you're currently experiencing. This is also an opportunity for you to share any details with your doctor that you feel are relevant.⁷

Blood tests

Blood tests typically take a few minutes and involve a small needle being inserted into the arm to take a sample of blood. Side effects after blood tests aren’t common, though they may leave a small bruise at the site where the needle was inserted, which can be slightly painful. Diagnosing Evans syndrome may involve several types of blood tests,  including a complete blood count, coagulation studies, and antibody testing.

A complete blood count, also known as a full blood count, determines the number of different types of cells in the blood. As Evans syndrome commonly causes a reduction in red blood cells and platelets, these abnormalities can be detected with a complete blood count.²

Coagulation studies can determine whether your blood clots normally. Since Evans syndrome can cause a deficiency of platelets, which are crucial for blood clotting, individuals with Evans syndrome may face problems forming blood clots and may experience abnormal bleeding. Coagulation studies can detect problems with blood clotting that are associated with Evans syndrome.^2,4,5 

Antibody testing detects antibodies that are present in the blood. As Evans syndrome is an autoimmune disease that involves abnormal antibodies in the body, antibody tests provide an opportunity to detect these abnormal antibodies.⁸

Bone marrow biopsy

Bone marrow is located within bones and is the site where blood cells are produced. A  bone marrow biopsy, lasting about 15 minutes, can detect abnormalities in blood cell production associated with Evans syndrome.  The biopsy site is typically at the hip bone, where an anaesthetic injection is administered to numb pain. A needle is then inserted into that site to retrieve a sample of bone marrow. Although a sharp pain may be experienced during needle insertion, this typically passes almost immediately. Complications of bone marrow biopsies aren't common, though some pain may be experienced the day following the procedure, which can be relieved with painkillers.²

Management and treatment of Evans syndrome 

Corticosteroids

Corticosteroids suppress the immune system, which, as the immune system attacks the body’s own blood cells in Evans syndrome, can treat the condition. Corticosteroids are typically a first-line option for treating Evans syndrome and are administered through a needle in the arm. Depending on the severity of your condition and the specific corticosteroid being administered, you may need corticosteroids for days or weeks.^3,9

Immunoglobulin therapy

Immunoglobulin therapy involves infusing antibodies from healthy donors into the patient’s bloodstream to suppress the abnormal immune response and prevent further damage to the blood cells. Immunoglobulin therapy may be given with corticosteroids. It can help prevent a deficiency of platelets, thereby preventing the signs and symptoms associated with thrombocytopenia.¹

Immunosuppressants

Immunosuppressants decrease the activity of the immune system, which, due to the inappropriate activity of the immune system in Evans syndrome, can be considered as an option in treating the condition. However, immunosuppressant therapy can make patients more vulnerable to infections.^1,10

Blood transfusions  

Where other therapies aren’t effective, blood transfusions may be considered in treating Evans syndrome. Blood transfusions can deliver red blood cells to a recipient, which is helpful for Evans syndrome, where patients are commonly deficient in red blood cells. Blood transfusions can take several hours, with blood being delivered through a needle inserted in the arm.¹

Splenectomy

A splenectomy is the surgical removal of the spleen. As the spleen plays a role in controlling the quantity of red blood cells, abnormal spleen function can result in a shortage of red blood cells. Sometimes, a splenectomy is considered when other therapies are not successful in treating Evans syndrome, and it can help ensure red blood cells stay at a normal level. Pain following a splenectomy can occur, but painkillers can relieve this.^5,11

FAQs

Can Evans syndrome be cured?

Outcomes for those with Evans syndrome vary depending on the patient. Sometimes, signs and symptoms can spontaneously resolve. Medications like corticosteroids, immunoglobulin therapy, and immunosuppressants can relieve signs and symptoms of Evans syndrome. However, more unconventional therapies, like blood transfusions or splenectomy, may sometimes be needed to improve the condition. Curing the condition cannot be guaranteed.²

What is the outlook for those with Evans syndrome?

Management and treatment can prolong survival with Evans syndrome. However, on average, the life expectancy following a diagnosis of Evans syndrome is around seven years.¹²

Summary

Evans syndrome is a rare life-threatening autoimmune disease resulting from the body’s immune system attacking blood cells. The attack on blood cells by the immune system typically leads to a deficiency in platelets and the early destruction of red blood cells. As a result, those with Evans syndrome can experience bleeding, skin rashes or spots, paleness, fatigue, and weakness, among other signs and symptoms. A medical history, blood tests, and bone marrow biopsy can aid in diagnosing the condition. Management and treatment of Evans syndrome can create a better outlook for patients and can involve corticosteroids, immunoglobulin therapy, immunosuppressants, blood transfusions, and splenectomy, with management and treatment varying depending on how severe a patient’s signs and symptoms are.