Chronic eosinophil diseases are types of blood disorders associated with abnormally high numbers of a rare white blood cell type called eosinophils. Eosinophils are a type of white blood cells in the body and are found in the blood stream of all people. They are believed to help the body fight against parasitic infections, cancer, or can cause allergic reactions.
Chronic eosinophil diseases are conditions where a higher-than-normal number of eosinophils exist but aren’t needed. Because of this, the eosinophils travel to various organs throughout the body and can cause damage. The heart is particularly susceptible to this damage and can lead to heart failure. Excess eosinophils may also travel to the lung, gut, and brain and cause symptoms and/or damage.
Chronic eosinophil leukemia (CEL) is a type of leukemia in which too many eosinophils are found in the bone marrow, blood, and other tissues. CEL is often associated with particular mutations in growth factor receptors such as PDGFRA, PDGFRB or FGFR1.
It is possible that CEL can be slow to progress, and it may stay the same for many years without changing. If the disease does change rapidly, CEL could progress to an acute leukemia.
Chronic eosinophilic leukemia symptoms often resemble infection or inflammation, making it more difficult to diagnose. It is considered a myeloproliferative neoplasm (MPN). People with CEL may present with hypersensitivity or severe allergic reactions, as well as other symptoms including fever, fatigue, cough, diarrhea, itching, or swelling.
CEL is rare and a full work-up including a physical exam, blood tests, biopsies, and molecular testing may be done if you present with symptoms in order to rule out other diseases.
CEL and other chronic eosinophil diseases are often treated with steroids, which require long term use to be effective. Other treatment options include chemotherapy drugs that destroy cancer cells or tyrosine kinas inhibitors (TKI) that can inhibit the proteins that cause the excess eosinophils. Many patients may need a combination of therapy options in order to best control their disease. There are also clinical trials trying to develop better therapies for eosinophilic neoplasms.