Blood count Strong evidence indicates that blood eosinophil counts can predict the effectiveness of specific anti-inflammatory drugs. Despite their increasing use in clinical practice, data on "normal" blood eosinophil counts remain insufficient. Due to the right-skewed distribution of these counts, median values are more informative than mean values for determining normal levels. Few large-scale studies have reported median blood eosinophil counts, with the median for healthy individuals being 100 cells/μL and the 95th percentile at 420 cells/μL. Thus, it is now evident that the normal median blood eosinophil count in healthy adults is around 100 cells/μL, with counts above 400 cells/μL considered outside the normal range. Current cutoffs such as 150 or 300 cells/μL used in asthma or COPD management fall within the normal range.
Eosinophilia An increase in eosinophils, i.e., the presence of more than 500 eosinophils/microliter of blood is called an
eosinophilia, and is typically seen in people with a parasitic infestation of the
intestines;
autoimmune and
collagen vascular disease (such as
rheumatoid arthritis) and
Systemic lupus erythematosus;
malignant diseases such as
eosinophilic leukemia,
clonal hypereosinophilia, and
Hodgkin lymphoma;
lymphocyte-variant hypereosinophilia; extensive
skin diseases (such as exfoliative
dermatitis);
Addison's disease and other causes of low
corticosteroid production (corticosteroids suppress blood eosinophil levels);
reflux esophagitis (in which eosinophils will be found in the squamous epithelium of the esophagus) and
eosinophilic esophagitis; and with the use of certain
drugs such as
penicillin. But, perhaps the most common cause for eosinophilia is an allergic condition such as asthma. In 1989, contaminated
L-tryptophan supplements caused a deadly form of eosinophilia known as
eosinophilia-myalgia syndrome, which was reminiscent of the
toxic oil syndrome in Spain in 1981. of white blood cells, comparing eosinophil granulocyte amount (shown in light red) with other cells Eosinophils play an important role in asthma as the number of accumulated eosinophils corresponds to the severity of asthmatic reaction.
Mepolizumab and
benralizumab are other treatment options that target the alpha subunit of the
IL-5 receptor, thereby inhibiting its function and reducing the number of developing eosinophils as well as the number of eosinophils leading to inflammation through antibody-dependent cell-mediated cytotoxicity and eosinophilic apoptosis. Lysosomotropic agents are an efficient means to target the lysosome-like eosinophil granules inducing eosinophil apoptosis. == Animal studies ==