Increased eosinophils

Introduction Eosinophilia is called when the absolute value of eosinophils in the surrounding blood is greater than 400-450/mm3. It is often associated with a variety of diseases in the clinic, especially parasitic infections and allergic diseases. The normal value of eosinophil count is 50-250/mm3, which is often reduced in the morning when the level of endogenous glucocorticoids is elevated.

Cause

The cytokine IL-5 specifically promotes the development, differentiation and maturation of eosinophils and is an important factor in the increase of eosinophil production. Under normal circumstances, eosinophils mainly reside in tissues such as the interface between the epithelial cells of the respiratory tract, gastrointestinal tract and genitourinary tract and deep tissues, and can last for several weeks. The number of eosinophils in the blood does not exactly reflect the number of eosinophils in the tissue. This disease is mainly caused by an increase in eosinophil production in the bone marrow, resulting in excessive accumulation of eosinophils in the blood and tissues. Eosinophilic cytoplasm contains specific eosinophilic cationic proteins that determine the staining and functional characteristics of the cells. In addition to phagocytic function, eosinophils also have a series of immune functions. Cationic granule proteins with cytotoxicity have a killing effect on helminth parasites that cannot be phagocytosed, that is, they can participate in host anti-parasitic infections. Lipid mediators synthesized by eosinophils such as endoperoxide, leukotriene C4, and platelet activating factor can cause contraction of airway smooth muscle, increase mucosal secretion, and change vascular permeability. Infiltration of acidophilic and neutrophils can cause degranulation of mast cells and basophils to release allergic mediators and participate in allergic diseases. After a large amount of eosinophils are destroyed, Charcot-Leyden crystals obtained by polymerizing proteins in the granules can be found in the sputum, feces and tissues of patients, and are markers of eosinophil-related diseases. Eosinophils can also cause tissue damage while participating in normal immune defense responses.

an examination

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Doppler echocardiography eosinophil count antibody-dependent cell (K cell) toxicity

Blood picture: Common anemia and thrombocytopenia, white blood cell count is significantly increased, up to (50 ~ 200) × 109 / L, eosinophils in blood tablets accounted for 20% ~ 90%, most of them in more than 60%, of which eosinophilic young Grain and late granules increased mainly. Primary and early granules are rare. The absolute value of eosinophils in the surrounding blood is greater than 400 ~ 450 / mm3, the absolute value of eosinophils in the blood can be diagnosed. The key is the diagnosis of the cause, which must be thoroughly examined to determine the primary disease. Those who are not sure about the diagnosis should be followed up regularly.

Differential diagnosis

(1) Parasitic infection: It is the most common cause of eosinophilia. Single-cell protozoal infections generally do not cause eosinophils, while multicellular worms and trematodes can cause eosinophilia to a degree parallel to the number and extent of worms, especially larvae invading tissues. Infections limited to the intestinal lumen such as: aphids, aphids, generally do not cause eosinophilia. Clinically, patients with unexplained eosinophilia must carefully understand the patient's living environment and diet history, and check the stool to find eggs or larvae. However, some parasites such as Trichinella and Filaria are infected and cannot be detected from the feces. Therefore, those with a history of parasite contact, such as asthma attacks, translocation pneumonia, hepatomegaly and other aphid migration signs, must be related to blood and histological examination to determine the cause.

(B) allergic diseases: including allergic rhinitis, bronchial asthma, urticaria, angioedema, drug allergic reactions, etc. can occur eosinophilia. Drug allergic reactions can only be manifested as eosinophilia, and should be discontinued as soon as drug fever and organ involvement occur. Drug-induced interstitial nephritis, eosinophils not only increase in the blood, but also can be detected in the urine.

(3) Infectious diseases: Acute bacterial and viral infections often cause eosinophils to increase, and most of them return to normal during the recovery period. Eosinophilia can also be seen in some fungi (Aspergillus and Coccidioides) and chronic tuberculosis.

(4) Idiopathic high eosinophilic syndrome (idiopathichypereosinophilic syndrome): Intrinsic is a myeloproliferative disorder characterized by persistent and excessive production of eosinophils. The diagnostic criteria are: 1 absolute count of eosinophils in the blood>1500/mm3, lasting for more than half a year; 2 lack of clear cause of eosinophilia; 3 symptoms and signs of organ involvement. Because the patients are mainly affected by different organs, clinical manifestations are diverse, may have fever, cough, chest pain, palpitations, shortness of breath, neuropsychiatric symptoms, itching, rash, liver and spleen and lymphadenopathy, extremity edema. The most serious are subendocardial thrombosis and fibrosis, chordae fibrosis, leading to atrioventricular valve regurgitation, and eventually progressive congestive heart failure. Echocardiographic probing can be used for diagnosis and monitoring. Embolism from the heart, diffuse encephalopathy, peripheral neuropathy, especially multiple mononeuritis, are the main manifestations of nervous system involvement. The skin, respiratory system and digestive system are also often affected. The main organ involvement has a poor prognosis. Patients with angioedema, the heart is often not involved, and the prognosis is good.

(5) Tumor: Eosinophilic leukemia is rare. In addition to the common fever, anemia, hepatosplenomegaly and lymphadenopathy of leukemia, the heart, lung, nervous system and skin infiltration are more prominent, so it is also classified as high eosinophilic syndrome (see " Rare and special type of leukemia").

Chronic myeloid leukemia, a small number of acute non-lymphocytic leukemia, Hodgkin's disease, cancer, especially originated from mucin-producing epithelial cell carcinoma, mycosis fungoides, vascular immunoblastic lymphadenopathy, often accompanied by eosinophils increase.

(6) Skin diseases: various skin diseases including tumor, pemphigus, herpetic dermatitis, exfoliative dermatitis, eczema, psoriasis, hemorrhoids, angioedema, urticaria, etc., and certain skin diseases during pregnancy may be accompanied Eosinophilia.

(7) Pulmonary infiltration with eosinophilia (PIE): This is a group of diseases that are not uncommon. Its pathogenesis is mostly related to abnormal immune response, but the cause is not yet clear. Clinical features are cough, chest tightness, and shortness of breath. Blood eosinophilia. X-ray examination of the scattered or migratory infiltrating foci in the lungs and lung biopsy showed eosinophilia as a diagnostic point. The absolute value of eosinophils in the surrounding blood is greater than 400-450/mm3, and the absolute value of eosinophils in the blood can be diagnosed. The key is the diagnosis of the cause, which must be thoroughly examined to determine the primary disease. Those who are not sure about the diagnosis should be followed up regularly.

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