
Is it Evans syndrome or could it be APDS?
Activated PI3K delta syndrome (APDS) and Evans syndrome are both rare chronic conditions. Evans syndrome is an autoimmune condition that causes a lower than normal level of blood cells known as cytopenia. People with Evans syndrome can have two forms of cytopenia at the same time, or they may occur sequentially. APDS is a rare primary immunodeficiency (PI) that causes immune deficiency and immune dysregulation. Immune dysregulation can cause autoimmune complications. In around 30% of cases, people with APDS have autoimmune conditions, with cytopenia being the most common manifestation.
APDS is complex and difficult to diagnose
APDS has a wide variety of symptoms which can make it difficult to recognize. It has been reported that the median delay to diagnosis of APDS is seven years. Sometimes people can be diagnosed with other conditions, like Evans syndrome, until APDS is confirmed through a genetic test.
In a study of children (n=80) with Evans syndrome who underwent genetic testing, 40% had
abnormalities in certain genes that are known to cause PI, including PIK3CD, which causes APDS.
How do Evans syndrome & APDS affect the body?
- In Evans syndrome the body’s immune system produces antibodies that mistakenly destroy the blood cells, platelets and sometimes certain white blood cells known as neutrophils, resulting in cytopenia.
- The two common forms of cytopenia in Evans syndrome are autoimmune hemolytic anemia (AIHA) and immune thrombocytopenic purpura (ITP).
- In Evans syndrome the body’s immune system produces antibodies that mistakenly destroy the blood cells, platelets and sometimes certain white blood cells known as neutrophils, resulting in cytopenia.
- In people with APDS, the process of making white blood cells is
disrupted; this can result in too many underdeveloped white blood
cells and not enough functioning white blood cells in the body.
When the white cells are not functioning as they should, this is
called immune dysregulation and can cause autoimmune
conditions. - The most common autoimmune manifestation in APDS is
cytopenia.
- In people with APDS, the process of making white blood cells is
- If you have experienced a lack of response to standard Evans
syndrome treatments, or have cytopenia plus some of the symptoms outlined below, discuss with your doctor if you are a candidate for genetic testing for APDS.

APDS can be diagnosed with a genetic test.
Most Common APDS Signs & Symptoms
The most common, and often earliest reported APDS symptoms include frequent and severe infections of the ears, sinuses, and upper and lower respiratory tracts which begin in infancy.
Common APDS signs & symptoms include:

96-100% of cases
Ear, Sinus, and Respiratory Tract Infections

71-89% of cases
Enlarged Tonsils, Lymph Nodes, or Spleen

51% of cases
Chronic Cough

51% of cases
Gastrointestinal (Digestive Tract) Issues

36-49% of cases
Herpes Infections

~30% of cases
Autoimmune and Autoinflammatory Disorders

~30% of cases
Low Numbers of Blood Cells

27-31% of cases
Developmental Delay

12-25% of cases
Lymphoma
People who suffer from any two or more of the above conditions, should consider APDS.
A genetic test may shorten the diagnostic journey.
- Before patients are correctly diagnosed with APDS, they often have a lengthy wait for a diagnosis involving multiple visits to various specialists. Symptoms are treated without identifying the underlying cause.
- The goal of a quick diagnosis and treatment is to interrupt disease progression to permanent damage or malignancy.
- As primary immunodeficiencies are inherited, family members of a confirmed patient should be genetically tested. While family members may not have the same symptoms or any symptoms, they may still carry the genetic condition and pass it onto their biological children.
- Stop the never-ending swirl of doctor visits and specialist appointments as you look for answers. Talk with your doctor about getting a no-charge genetic test from the navigateAPDS program*.
Every year new genetic variants are picked up by the latest genetic tests.
Five years ago we had only identified 200 genes, and by 2019 we had identified 407.
If you have had a genetic test in the past, speak to your doctor to see if retesting is appropriate for you.
Download this information sheet about our no-charge genetic testing program navigateAPDS* to share with your doctor.


*This program is currently available in the US and Canada only.
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