Eosinophils
Eosinophils are a subtype of white blood cells involved in fighting parasites, allergic reactions, and regulating inflammatory processes. They are named for their ability to stain pink (eosinophilic) during laboratory analysis.
Normal eosinophil values:
- Absolute count: 0.03–0.48 × 10⁹/L (30–480 cells/μL) in adults[2][5][6]
- Percentage of total white blood cells: 1–5%[2][5]
Main functions of eosinophils:
- Destruction of parasites (helminths, protozoa)
- Participation in allergic reactions (including asthma, urticaria, anaphylaxis)
- Regulation of inflammation and utilization of histamine
- Phagocytosis (engulfing small particles and microbes)
Elevated eosinophils (eosinophilia) may occur with:
- Allergies: hay fever, dermatitis, asthma
- Parasitic infections: helminthic invasions (ascariasis, opisthorchiasis, etc.)
- Autoimmune diseases
- Certain malignancies (especially of the hematopoietic system)[1][2][4]
- Infections (especially viral and bacterial during recovery phase)
Decreased eosinophils (eosinopenia) may occur with:
- Acute stress (trauma, burns, surgery)
- Acute purulent infections
- Use of glucocorticoids
- Systemic infections and sepsis[2]
Features:
- Marked eosinophilia is an important diagnostic sign of parasitic and allergic diseases.
- Eosinophils often increase after antibiotics, vaccines, or with chronic inflammation.
- Interpretation requires correlation with clinical presentation and other CBC parameters.
How to take the test:
- The blood test is performed in the morning on an empty stomach.
- Before the test, it is advisable to avoid physical exertion and taking medications.