What is Evans syndrome?

Evans syndrome is a rare autoimmune disorder where your child’s immune system mistakenly attacks their body. Most commonly, it affects the numbers of red blood cells (affecting the amount of oxygen that travels through blood and to the tissues) and the platelets (the part of the blood that helps to stop bleeding and heal wounds). It can also affects the body’s first line of defense against illness by destroying white blood cells that help fight bacterial infection (the neutrophils).

Causes of Evans syndrome

Most cases of Evans syndrome are caused by inherited disorders of the immune system that cause problems in how the immune system tunes the response to infection (immune dysregulation). These immune problems can sometimes cause an increased risk of infection, but more often cause an increase in autoimmune disease. Over half of children with Evans syndrome have an identifiable, genetic cause of the disease. In those children, knowing the part of the immune system that is imbalanced can help guide treatment. 

Symptoms of Evans syndrome

Symptoms of Evans syndrome may appear differently in your child than others. This can depend on the type of disorder they have and the parts of their blood that are affected.

Three areas of the hematologic system may be affected:

• Your child may not have enough white blood cells (neutrophils) that help our bodies fight infection. This is called neutropenia. Children with neutropenia usually do not have any symptoms, but sometimes can get inflammation of the gums (gingivitis) and bleeding when they brush their teeth or mouth ulcers. Rarely, the neutropenia can lead to bacterial infection including bacteria in the blood (sepsis).
• Your child may not have enough healthy red blood cells to carry oxygen throughout their body. This is called autoimmune hemolytic anemia (AIHA). Children with AIHA will be pale, and may have dark urine, yellow eyes or skin (jaundice) and may be tired or dizzy.
• Your child may have lower-than-normal platelets that help blood clots and prevent excess bleeding. This is called thrombocytopenia. Children with low platelet counts may have nosebleeds, easy bruising, a rash of small red spots called “petechiae”, gum bleeding, heavy menstrual bleeding or blood in their urine or stool. Rarely, low platelet counts can lead to more severe bleeding including bleeding in the brain or GI track.

Your child may experience these symptoms one at a time or all together. You may notice varying symptoms depending on which part of their immune system is affected at any given time.

Additional symptoms of Evans syndrome

Children with low platelet count typically experience:

• Increased bruising
• Tiny red dots from small bleeds into the skin (petechia)
• Bleeding symptoms, like a bloody nose or heavy menstrual cycle

Youth with a low red blood cell count (AIHA) typically experience:

• A yellowish tint of the eyes and skin that begins on the face and can move further down the body (jaundice)
• low energy levels fatigue)
• Dark brown urine
• Pale skin
• Dizziness
• Shortness of breath

Children with a neutrophil count (neutropenia) typically experience:

• A body temperature of 100.4 degrees Fahrenheit or higher (fever)
• Mouth sores
• Increased bacterial infections

Diagnosing Evans syndrome

We know it can be confusing and scary when you cannot figure out why your child is sick. The Division of Allergy and Immunology at Children's Hospital of Philadelphia (CHOP) will provide sensitive, patient-centered care to your child. We will work closely with your family during testing to help you fully understand your child’s diagnosis and potential treatments and next steps.

Our team uses a variety of blood tests to help determine if your child has Evans syndrome, including:

• A complete blood count (CBC) to measure your child's platelet and neutrophil counts as well as the hemoglobin (a measure of the number of red blood cells).
• A blood test to find out if your child is breaking down red blood cells (LDH and/or haptoglobin).
• A blood test to measure how quickly new red blood cells are being created and released into your child’s blood (a reticulocyte count) and how quickly new platelets are being created and released (immature platelet fraction)
• A urine test to look for breakdown of red blood cells in the urine.
• A blood test to look for antibodies against red blood cells (Direct Coombs Test/Direct Antiglobulin Test)
• Your doctor may also recommend immunologic testing using blood tests to see how well your child is able to make antibodies, if they have normal numbers of other immune cells including T cells and B cells and if they have made normal responses to prior vaccines or even genetic testing to look for changes in genes that tell the immune system how to work.

If necessary, we may also use additional testing to assess your child’s unique situation. Additional testing may include a bone marrow biopsy or Chest Xray or CT scan.