Eosinophilic granulocytes are the second smallest subgroup of granulocytes , which belong to the white blood cells, the so-called leukocytes . Physicians describe the granulocytes as eosinophils, since the components of the vesicle are stained red-orange to pink with the acidic dye eosin.
Eosinophilic granulocytes – second smallest group of the white defense
A vesicle is a detached, spherical or ovoid component of the cytoplasm. Like basophils and neutrophils, eosinophilic granulocytes are part of the immune system and within this part of the non-specific cellular immune system.
Genesis and physiology
Eosinophilic granulocytes arise from oligopotent myeloid stem cells (CMP). They have the potential to develop into different cells and are found in the bone marrow.
The CMPs become unipotent and bipotent stem cells, which come together to form so-called CFUs, the cell colonies. The specific cell colony in which the formation of eosinophilic granulocytes occurs is called CFU-EO.
The eosinophiloblasts emerge from the cell colony, from which the eosinophilic granulocytes arise through differentiation. The vesicles of the eosinophilic granulocytes contain basic proteins with which they cause cell damage. These proteins include:
- das Major Basic Protein (MBP),
- the eosinophil cationic protein (ECP),
- die eosinophile Peroxidase (EPO),
- das eosinophil-derived Neurotoxin (EDN).
Activated T-lymphocytes regulate the formation of eosinophilic granulocytes in the bone marrow via the messenger substance interleukin-5. Doctors call the increased concentration of eosinophilic granulocytes in the blood eosinophilia, and the reduced concentration eosinopenia.
Purpose and normal values
Eosinophilic granulocytes are found in the control of allergic reactions. They are also involved in defense against parasites. One to four percent of the leukocytes in a differential blood count are eosinophilic granulocytes. In absolute numbers, that’s 50 to 250 cells per microliter of blood.
In order to compare different values of the eosinophilic granulocytes , the doctor needs the respective reference value from the laboratory. This is because laboratories work with different reference values. Because of this, the information differs from laboratory to laboratory.
When are the levels of eosinophilic granulocytes elevated?
Eosinophilia often occurs with an increased level of basophilic granulocytes . Possible causes include:
- Allergies such as bronchial asthma, skin inflammation of urticaria or allergic vasculitis,
- Diseases associated with parasites such as helminth infestation or trichinosis,
- Skin diseases such as dermatitis herpetiformis or psoriasis,
- Autoimmune diseases such as dermatomyositis or lupus erythematosus
- Cancer diseases such as chronic myeloid leukemia (CML) or Hodgkin’s lymphoma,
- Forms of hormonal dysregulation such as Addison’s disease,
- Influence of drugs with the components acetylsalicylic acid, penicillin, phenprocoumon and dapsone.
In some infectious diseases, eosinophilia is the sign that convalescence is occurring. It also appears accompanying leprosy, amoebic dysentery and gonorrhea as well as in the incubation period of infectious diseases such as scarlet fever or measles.
When are the values lowered?
Eosinopenia is difficult to diagnose because the normal value is already so low. Reasons for a reduced value of eosinophilic granulocytes are:
- the acute phase of infectious diseases,
- the excess of the steroid hormone glucocorticoid associated with Cushing’s syndrome, for example
- as a side effect of radiotherapy,
- as a result of stress,
- under the influence of certain medications.
Individual laboratory values require interpretation by the attending physician. For his diagnosis, he considers the general state of health of the patient and his previous illnesses. He also consults other values from the differential blood count to come to a conclusion. Individual values are no cause for concern. There are always several factors to consider.
links and source
- Reinhard Andreesen, Hermann Heimpel: Clinical hematology. Munich 2009: Urban & Fischer/Elsevier-Verlag. ISBN-10: 343731498X.
- Article on wikipedia.de https://de.wikipedia.org/wiki/Neutrophiler_Granulocyt
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