Eosinophils, also called acidophils, are granulocytes that develop during hematopoiesis before joining as a blood component. They are white cells and are part of the body's immune system, being responsible for the control of parasites and specific infections in vertebrates. Eosinophils act alongside mast cells, which are cells that act against allergy and asthma.
In healthy people eosinophils account for approximately 1-6% of white blood cells, and their size ranges from 12 to 17 micrometers. These cells can live in the tissues for 8 or 12 days in the absence of stimulation.
Low values of eosinophils:
When patients have low levels of eosinophils in blood tests, they are said to have a condition known as eosinopenia, which represents a lower level of the normal amount of eosinophils present in the blood, thus leaving the organism with a low mechanism of immunity against parasites or viruses. Some causes for which the eosinophils present a decrease in their levels could be: When presenting an acute infection, especially during the typhoid fever, where these cells can have a quite low count. The causes for which leucopenia is diagnosed are generally the same causes that cause eosinopenia, such as plastic anemia, HIV, exposure to radiation, among others. Treatments with corticosteroid hyperadrenocorticism. Mental stress. Cushing's disease, where the formation of Eosinophils is reduced due to high levels of adrenocortical hormones such as cortisol and aldosterone. Autoimmune diseases such as disseminated erythomatous lupus. Plastic anemia.
High eosinophil values:
When a patient has higher than normal levels of eosinophils, he is said to have a condition known as eosinophilia. High levels of eosinophils can circulate throughout the bloodstream, but high levels of eosinophils can also occur in specific areas of the body where infection or inflammation occurs. This is called tissue eosinophilia. When levels exceed 500 eosinophils per microliter of blood in the analysis of blood of an adult person is diagnosed with eosinophilia. In this case the patient could present symptoms such as difficulty breathing, coughing and wheezing. Other rare manifestations would be diarrhea, abdominal pain, weight loss and rashes. Generally high eosinophil counts are due to the presence of other diseases such as:
Vasculitis such as Churg-Strauss syndrome.
Autoimmune diseases such as systemic lupus erythematosus.
Eosinophilia is a rare condition and is usually a secondary factor caused by other diseases, however, in the Western world the most frequent cause for high levels of eosinophils are allergic or atopic diseases, especially when located in the airways , parasitic infections worldwide are the most common causes for a patient to present high levels of eosinophils.