Eosinophils are a type of blood defense cell that comes from the differentiation of a cell produced in the bone marrow, myeloblast, and aims to defend the body from the invasion of foreign microorganisms, being very important for the action of the immune system.
These defense cells are present in the blood at high concentrations mainly during allergic reactions or in cases of parasitic, bacterial and fungal infections.Eosinophils are generally found in lower blood concentrations than other body defense cells, such as lymphocytes, monocytes or neutrophils, which also act in the immune system.
- The amount of eosinophils in the blood is evaluated in the white blood cell.
- Which is part of the blood formula in which the body’s white blood cells are evaluated.
- Normal blood eosinophil values are:.
Values may change slightly depending on the laboratory in which the test was performed and, therefore, the reference value must also be verified in the test itself.
When the test value is outside the normal range, it is considered that the person may have increased or decreased eosinophils, having each change different causes.
When the number of eosinophils in the blood is greater than the normal reference value, eosinophilia is characterized, the main causes of eosinophilia are:
In some rare cases, it is still possible to discover the cause of the increase in eosinophils, a situation called idiopathic eosinophilia.There is also a situation called hypeosinophilia, which occurs when the number of eosinophils is very high and exceeds 10,000 cells /L, which is more common in autoimmune and genetic diseases, such as hypereosinophil syndrome.
A person with high eosinophilia does not always have symptoms, but they can result from the same illness that caused the eosinophilia, such as shortness of breath in asthma, sneezing, and stuffy nose in allergic rhinitis or abdominal pain in parasitic infections. , for example.
For people with inherited hypereosinophilia, it is possible that excess eosinophils can cause symptoms such as stomach pain, itchy skin, fever, body pain, abdominal cramps, diarrhea, and nausea.
The low number of eosinophils, called eosinopenia, occurs when eosinophils have less than 40 cells / L, reaching 0 cells / L.
Eosinopenia can occur in acute bacterial infections, such as pneumonia or meningitis, because these are serious bacterial infections that generally increase other types of defense cells, such as neutrophils, that can decrease the absolute or relative number of eosinophils.It may also be the result of decreased immunity due to illness or the use of medications that impair immune system function, such as corticosteroids.
In addition, it is possible to have low levels of eosinophils without any changes, which can also occur during pregnancy, during which time a physiological reduction in the number of eosinophils occurs.
Other rare causes of eosinopenia include autoimmune diseases, bone marrow disease, cancer or HTLV, for example.
The low number of eosinophils usually does not cause symptoms unless it is associated with a disease that may have some form of clinical manifestation.