hereditary stomatocytosis in children
Introduction
Introduction to Pediatric Hereditary Oral Hypertrophy Hereditary vocabulary hypertrophy (HST) is a rare autosomal dominant hemolytic disease characterized by a marked increase in oral cells in the blood and more than 5%. There are often moderate to severe hemolytic anemia in the clinic. The peripheral blood smear shows a well-defined lip-shaped fissure in the light-stained area of the red blood cell, which is called a "mouth cell" under a scanning electron microscope. basic knowledge Sickness ratio: 0.0001% Susceptible people: children Mode of infection: non-infectious Complications: jaundice anemia
Cause
Causes of pediatric hereditary orthostatic syndrome
Causes
Autosomal dominant hemolytic anemia. The cause of the disease is not clear. It is generally believed that the abnormality of the erythrocyte membrane leads to cell defects, the permeability of the membrane to na+ and k+ changes, and the penetration of na+ exceeds the discharge of k+. As a result, the content of na+ and water in the cell increases. Oral cells appear in the blood. The specific structural defects are not known. A drug that increases the membrane area of the membrane in vitro can be used to make normal red blood cells into a mouth shape.
Pathogenesis
Observed by optical microscopy, in the ordinary blood film, there is a slender, lightly stained or unstained area in the middle of the diseased red blood cells, which is called a "mouth cell". A few mouth cells can be seen in normal human blood, but no more than 4%. The main pathophysiology of oral red blood cells is a significant increase in intracellular sodium and water, and a slight decrease in potassium. Since the sodium ion permeability of the erythrocyte membrane is increased, the sodium ion inflow is increased. Even if the sodium pump activity is significantly increased, it does not compensate for the increase in sodium influx, resulting in intracellular edema, increased volume, increased ATP and glucose consumption, and accumulation of lactic acid. Molecular lesions that cause changes in the above-described ion permeability of erythrocyte membranes are not fully understood. Recently, some patients have a decrease or lack of sbatin (stomatin), while many patients have normal 7-protein and stomatin cDNA. It is unclear whether partial or complete deficiency of the 7.2b protein is a primary or secondary change. Oral red blood cells are poorly deformed and are often retained in the spleen sinus. In the acidic environment of the spleen sinus, red blood cells are largely destroyed in the spleen due to glucose deficiency and insufficient ATP production, thereby further increasing the permeability of red blood cells to sodium ions.
Prevention
Pediatric hereditary oral cytokine prevention
There is no specific treatment for hereditary diseases. Precautions must be taken into account, from pre-pregnancy to prenatal. Once an abnormal result occurs, it is necessary to determine whether it is treatable, how to prognose, etc., and take practical measures for diagnosis and treatment.
Pre-marital medical examination plays an active role in preventing birth defects. The size of the effect depends on the examination items and contents, including serological examination (such as hepatitis B virus, treponema pallidum, HIV), reproductive system examination (such as screening for cervical inflammation), Ordinary medical examinations (such as blood pressure, electrocardiogram) and asking about the family history of the disease, personal medical history, etc., do a good job in genetic disease counseling.
Pregnant women should avoid harmful factors as much as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals. Systemic birth defect screening is required during antenatal care during pregnancy, including regular ultrasound, serological screening, and, if necessary, chromosomal examination.
Complication
Pediatric hereditary orthostatic complication Complications jaundice anemia
Concurrent jaundice, anemia, infection, severe anemia crisis.
1. Astragalus: Symptoms and signs of yellowing of the skin, mucous membranes and sclera due to elevated serum bilirubin. Certain liver diseases, gallbladder diseases, and blood diseases often cause symptoms of jaundice. Usually, when the blood bilirubin concentration is higher than 2-3 mg/dL (34-51), these parts will have a color that can be discerned by the naked eye.
2. Anemia: refers to the total amount of red blood cells in the circulating blood of the system is reduced below the normal value. In coastal and plain areas, the hemoglobin of adult men is less than 12.5g/dl, and the hemoglobin of adult women is less than 11.0g/dl, which can be considered as anemia.
3. Anemia crisis: The general symptoms of neonatal anemia crisis are pale skin, poor muscle tone, poor mental reaction, shallow breathing, sucking, hug reflection and disappearance.
Symptom
Pediatric hereditary orthostatic syndrome symptoms common symptoms erythrocytosis jaundice
Clinical features: According to clinical manifestations, peripheral blood erythrocytes greater than 10% and positive family history, most can be diagnosed. Mouth cell hyperplasia can also occur in a variety of hereditary or acquired diseases such as glutathione deficiency, hereditary spherocytosis, light marine anemia, systemic lupus erythematosus, infectious mononucleosis, cancer And hematopoietic malignant diseases, myocardial ischemia, heart failure, lung infections, gallstones, fractures, gastrointestinal bleeding and urinary system diseases.
1. Individual differences are large. The performance varies greatly among different families, and the degree of anemia can be different in different individuals in the same family. In light, only the oral red blood cells increase and there is no hemolysis.
2. Astragalus: Generally, children with mild jaundice appear after birth. Most patients develop pale and jaundice after infection, and a few can develop anemia crisis.
3. Increased spleen: After 6 months, the spleen increased, and the spleen increased significantly after 3 to 4 years old.
Examine
Examination of pediatric hereditary oral cytosis
1. Peripheral blood: See more oral cells, more than 10% is diagnostic (the normal blood cells in the surrounding blood cells generally do not exceed 4%); most patients with moderately increased reticulocytes (10% to 20%); MCV increased , MCHC decreased; can be combined with white blood cells or thrombocytopenia. The cation content in the red blood cells was abnormally determined.
2. Red blood cell osmotic fragility test: significantly increased, autolysis test positive, glucose and ATP can be partially corrected. Hemoglobin electrophoresis is normal.
3. The bone marrow image is characterized by a change in the bone marrow of proliferative anemia.
4. Others: more manifested as mild anemia, some children with heavier anemia; individual cases may be associated with spherical erythrocytosis, thalassemia or glutathione deficiency, liver disease.
5. Regular imaging examination, such as chest X-ray, B-ultrasound, pay attention to the presence or absence of lung infection, gallstones and liver and splenomegaly.
Diagnosis
Diagnosis and differential diagnosis of pediatric hereditary oral cytoplasm
diagnosis
According to clinical manifestations, peripheral blood erythrocytes greater than 10% and positive family history, most can be diagnosed.
Differential diagnosis
1. Secondary oral polycythemia: need to be differentiated from secondary oral polycythemia. The latter is mainly found in liver diseases, tumors, acute alcoholism and some medical treatments (vincristine, chlorpromazine, etc.), and can also occur in a variety of hereditary or acquired diseases such as glutathione deficiency, hereditary sphere Hypercytosis, mild marine anemia, systemic lupus erythematosus, infectious mononucleosis, cancer and hematopoietic malignancies, myocardial ischemia, heart failure, pulmonary infection, gallstones, fractures, gastrointestinal bleeding, and Urinary system diseases, etc. In addition to oral red blood cells, there is generally no hemolysis, with the characteristics of the primary disease, no family history.
2. Rh deficiency syndrome: The disease is autosomal recessive, rare. Clinically, it is mainly characterized by mild to moderate hemolytic anemia. Peripheral blood smears can be seen in oral cells, and sometimes spherical cells can be seen. The main reason is that the Rh-type antigen is completely deficient or significantly reduced due to gene deletion or gene expression disorder encoding the Rh antigen, the former is called Rhnull, and the latter is called Rhmod. Some patients with Rhnull have increased erythrocyte osmotic fragility and red blood cell dehydration. Splenectomy can improve hemolysis.
3. Hereditary dry cell hyperplasia and intermediate syndrome: the mechanism is still unclear. Oral red blood cells are visible in the wet blood membrane, but are not easily found in peripheral blood. Target red blood cells, dry red blood cells, and spinous red blood cells can be seen, and cellular hemoglobin aggregates in the peripheral loose area of the cells. The clinical symptoms are autosomal dominant hemolytic anemia with red blood cell dehydration and reduced osmotic fragility. The patient had moderate to severe hemolysis and elevated MCHC. Existing studies have demonstrated that intracellular K loss is not accompanied by a proportional uptake of Na, resulting in decreased intracellular ion concentration and water, 2.3-DPG reduction, in addition to membrane-associated glycerol-3-phosphate dehydrogenase increased restriction zone There were no abnormalities in membrane lipid protein analysis except for the band 3 protein. Lux and Becker classify it as an intermediate syndrome. The patient's characteristics are that there are oral red blood cells and target red blood cells in the peripheral blood. The osmotic fragility can be normal or slightly elevated, and the permeability of Na and K increases, but the intracellular cations. Concentration and red blood cell volume can be reduced normally or slightly. It has been reported that the glutathione content of these cells is lower than normal, and there is also a case where the red blood cells are dissolved at 5 ° C in vitro, so it is called cold water cell syndrome. It has also been reported that such a hemolytic anemia patient with a mouth shape, a target erythrocyte increase, and a reduced osmotic fragility, 50% of which may have a cell membrane abnormality. The disease should be treated with caution in the treatment of spleen, because it can cause hypertensive state and lead to severe thrombosis. In vitro tests show that the endothelial adhesion of oral red blood cells after spleen is increased.
4. Familial deficiency of high-density lipoproteins: It can be seen clinically that the tonsils are large and orange and hepatosplenomegaly. Cholesterol esters accumulate in many tissues due to severe or complete deficiency of high density lipoprotein. Heavier hemolytic anemia and mouth cell hyperplasia appear. Membrane lipid analysis showed a decrease in free cholesterol, a decrease in cholesterol/phospholipid ratio, and a relative increase in lecithin.
5. Acanthocytosis: The morphological characteristics of the thorn-like red blood cells are: the red blood cells are dense and concentrated, the central light-dyed area disappears, and there are many (5-10) elongated spines on the surface. Unlike echinocytes (also known as "burr" cells). The latter surface is fairly uniform and has a short spike shape. The spine cells seen on the blood smear can be caused by human factors (such as increased pH, contact with glass or blood storage), but can also be seen in mild hemolysis during long-distance running. Anemia and hypophosphatemia, hypomagnesemia (possibly caused by decreased intracellular ATP stores), uremia and pyruvate kinase deficiency. Mainly found in congenital beta lipoprotein deficiency, occasionally in the McLeod phenotype and other conditions (such as partial In phenotype, anorexia nervosa, etc.). In addition, spine cells can also be seen in peripheral blood smears of patients with liver disease (which may be related to the binding of abnormal high-density lipoproteins that cause spine cells to the surface of red blood cells).
