An eosinophil is a type of leukocyte. This white blood cell participates in your body’s immune system response by releasing a variety of granules containing enzymes and proteins that trap and kill cells, as well as promote inflammation.
Eosinophils are just one of 5 main types of white blood cells involved in protecting your body against foreign invaders. At any given time, a small number of these leukocytes can be found circulating in your blood.
Although the full extent of what an eosinophil does is yet to be determined, research has discovered they’re produced in the response to parasites, allergens and abnormal cells. As such, they actively protect against certain parasites and contribute to the inflammation associated with allergic disorders.
When the body wants to attack a substance, such as an allergy-triggering food or airborne allergen, eosinophils respond by moving into the area and release a variety of granules. There are a variety of health conditions associated with an eosinophil release, for instance:
- drug allergy
- scarlet fever
- allergies, hay fever
- Churg Strauss syndrome
- some bone marrow disorders
- autoimmune diseases ~ lupus
- cancer ~ leukemia, lymphoma, ovarian
- gastrointestinal disorders ~ Crohn’s disease, ulcerative colitis
- parasite infection ~ lymphatic filariasis, trichinosis, ascariasis
Should your body produce too many eosinophils, they can cause chronic inflammation and their granules can be toxic to tissue, resulting in tissue damage.
Sometimes, excessive eosinophils concentrate in a variety of organ tissue for no apparent reason and can cause damage. This health condition is known as an eosinophilic disorder and is further differentiated according to location, for instance:
- eosinophilic colitis
- eosinophilic fasciitis
- eosinophilic gastritis
- eosinophilic enteritis
- eosinophilic pneumonia
- eosinophilic esophagitis
Hypereosinophilic syndrome is a persistent elevation of eosinophils in the blood (eosinophilia) accompanied by multiple organ damage. If left untreated, the organ damage caused by this syndrome is typically fatal.
Eosinopenia means your eosinophil count is too low, which can occur with Cushing’s syndrome, stress and taking corticosteroids. Generally, this white blood cell deficiency is not considered a major health concern so long as other leukocytes can compensate.