Clinical significance of eosinophils
A basic introduction to eosinophils
Eosinophils are a type of white blood cells. White blood cells according to morphological differences can be divided into two categories of particles and non-particles. Granulocyte leukocytes (granulocytes) containing special staining particles, with Wright staining can distinguish three kinds of granulocyte leukocytes that neutrophils, eosinophils and basophils; non-granulocyte white blood cells including monocytes and lymphoid cell. Eosinophils with coarse eosinophilic granules, particles containing peroxidase and acid phosphatase.
The main features of eosinophils
Description of eosinophils: cells were round, diameter 13-15μm. Cytoplasm filled with coarse, tidy, uniform, closely arranged brick red or bright red eosinophilic particles, strong refraction. The shape of the nucleus and neutrophils similar, usually 2-3 leaves, was glasses-like, dark purple. Eosinophils easily broken, the particles can be dispersed in the cells around.
The main role of eosinophils
① limiting basophils in the role of hypersensitivity hypersensitivity reactions. When the basophils are activated, the release of chemokines, the eosinophils to the same part of the local, and limit the basophils from three aspects of activity: First, eosinophils can produce prostaglandins E basophils synthesis and release of bioactive substances in the process of inhibition; the second is eosinophils can be phagocytic basophils discharged particles, which contain bioactive substances can not play a role; third eosinophilic granulocyte Cells can release enzymes such as histamine, destruction of basophils released histamine and other active substances.
② participate in the immune response to worms. In the immune response to worms, eosinophils play an important role. These granulocytes have immunoglobulin Fc fragments and complement C3 receptors on the cell membrane. Specific immunoglobulin IgE has been produced in animals that have been immunized against such worms. Worm through the specific IgE and C3 conditioning effect, eosinophils with the help of the cell surface of the Fc receptor and C3 receptor adhesion to the worm, and the use of cell lysosomes contained peroxidase enzymes Damage to worms. In a parasitic infection, allergic reactions, etc., often accompanied by increased eosinophils.
Clinical significance of eosinophils
(1) allergic diseases: bronchial asthma, drug allergy, urticaria, food allergies, angioedema, serum disease and other peripheral blood eosinophilia up to 10% or more.
(2) parasitic diseases: schistosomiasis, ascariasis, hookworm and other blood eosinophilia, often up to 10% or more. Some parasitic infections in patients with eosinophils significantly increased, leading to a total number of tens of thousands of white blood cells, more than 90% of eosinophils, eosinophilic leukemia reaction.
(3). Dermatology: such as eczema, exfoliative dermatitis, pemphigus, psoriasis and other visible peripheral blood eosinophils mild to moderate increase.
(4) blood diseases: such as chronic myeloid leukemia, eosinophilic leukemia, lymphoma, multiple myeloma, eosinophilic granuloma, eosinophils may have different degrees of peripheral blood increased, and some may Accompanied by infantile eosinophilia.
(5) certain malignant tumors: some epithelial tumors such as lung cancer can cause eosinophils.
(6). Some infectious diseases: acute infectious diseases, eosinophils are mostly reduced, but scarlet fever can cause eosinophilia.
(7) Other: rheumatic diseases, pituitary hypothyroidism, allergic interstitial nephritis, often accompanied by eosinophilia.
- Eosinophilia:
Common in typhoid fever, paratyphoid early, major surgery, burns and other stress, or long-term application of adrenal cortex hormones, its clinical significance is very small.
Eosinophil-induced gastroenteritis
Etiology:
The etiology of eosinophilic gastritis is not clear, is generally believed to be exogenous or endogenous allergens caused by allergic reactions. Some patients have symptoms of asthma, allergic rhinitis, eczema, or urticaria. Some patients may be affected by certain foods such as milk, eggs, lamb, shrimp or certain drugs such as sulfa, furazolidone and indomethacin And other induced; some patients ingest certain food, the blood IgE (allergic) levels increased, accompanied by the corresponding symptoms, and thus that the disease and special food allergy.
Pathogenesis:
Food allergies caused by eosinophilic gastroenteritis may be due to the mechanism: 1. Because of the presence of a large number of lesions in eosinophil infiltration, some people think that food allergens and gastrointestinal sensitive tissue contact, the occurrence of antigen-antibody reaction in the gastrointestinal wall , Attracting eosinophils into antigen-antibody complex deposition site, which is due to the eosinophil surface C3 receptors; 2 is believed to be due to lymphocyte-derived eosinophilic chemokines (ECF) to attract eosinophils Cells; 3. that the mast cells in the gastrointestinal tissue through the Fc receptor and food antigen IgE antibodies caused by the combination, and then meet the corresponding antigen to promote mast cell degranulation, the release of histamine, ECF and bradykinin and other substances . ECF can attract eosinophils, histamine further enhance its chemotaxis. Some people hold the opposite view, that: 1. Not every patient has a history of allergies; 2. This person in the control of suspected allergic food intake, and can not make its gastrointestinal symptoms; 3. Serum IgE levels only In a small number of cases increased, other immune indicators such as IgG, complement, lymphocyte count and so no exception.