Anemia due to excessive hemolysis
Introduction
Introduction to anemia caused by excessive hemolysis Hemolytic anemia is an anemia that occurs when red blood cell destruction is accelerated and bone marrow hematopoietic function is insufficiently compensated. The average survival time of normal red blood cells is about 120 days, and the survival time of red blood cells of hemolytic anemia is often shortened to 15 to 20 days, and the shortest is only a few days. Premature destruction of red blood cells can occur extravascularly or intravascularly. Extravascular hemolysis, that is, red blood cells are destroyed and destroyed by phagocytosis by macrophages in the spleen and liver. Intravascular hemolysis is the rupture of red blood cells directly in the blood circulation, and hemoglobin is released into the plasma. When hemolysis increases, the hematopoietic function of the bone marrow can be compensated, and anemia can occur. This condition is called compensatory hemolytic disease. However, if the hematopoietic function of the bone marrow has accelerated and is still slower than the rate at which red blood cells are destroyed, hemolytic anemia occurs. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: renal failure, shock, heart failure
Cause
Causes of anemia caused by excessive hemolysis
Erythrocyte membrane defects (30%):
Defects in the structure of the erythrocyte membrane can cause membrane permeability, hardness abnormality, or instability and breakage. In most cases, the defect is one or more backbone proteins, and the morphology of red blood cells is also abnormal. These hereditary membrane diseases include hereditary spherocytosis and hereditary neutropenia. Paroxysmal nocturnal hemoglobinuria, whose erythrocyte membrane is abnormally sensitive to complement, but its membrane defect is an acquired abnormality.
Hemoglobin structure or production defects (30%):
Abnormal hemoglobin structure makes hemoglobin insoluble or unstable, leading to red blood cell stiffness and finally hemolysis. Such as sickle cell anemia or unstable hemoglobinopathy. In thalassemia, excessive globin chains precipitate, causing red blood cells to harden and destroy and cause hemolytic anemia.
Defects in erythrocyte enzymes (30%):
The lack of erythrocyte enzymes to maintain hemoglobin and membrane thiol (sulfhydryl) in a reduced state or to maintain a sufficient level of ATP for cation exchange can lead to hemolytic anemia, which can be divided into two categories: 1 erythrocyte anaerobic Lack of enzymes in glycolysis (such as pyruvate kinase), 2 lack of enzymes in erythrocyte phosphate hexose bypass (such as glucose 6 phosphate dehydrogenase).
Red blood cell external defects (5%)
External defects, usually acquired, can be hemolyzed by chemical, mechanical or physical factors, biological and immunological factors. Hemolysis can be in the blood vessels or outside the blood vessels.
Prevention
Anemia prevention caused by excessive hemolysis
The principles of treatment can be summarized as follows:
(1) Removal of the cause: Many hemolytic anemias have clear incentives, such as faba bean disease caused by eating broad beans; drug-induced hemolytic anemia is caused by taking drugs; infection can aggravate the original hemolysis or cause hemolysis, etc. Therefore, treatment The cause of hemolytic anemia should be removed first.
(2) Resection of the spleen: suitable for abnormal red blood cells mainly in the spleen destruction, such as hereditary spherocytosis.
(3) Blood transfusion: It is one of the important measures to treat anemia, which can alleviate the symptoms of anemia in patients, but it may also bring serious reactions, so it is necessary to pay attention to the indications of blood transfusion.
(4) Immunosuppressive agents: can inhibit the immune response, is effective against immune thrombolytic anemia, and is basically ineffective against other types of anemia.
(5) Prevention of serious complications: complications caused by hemolysis are more serious, such as renal failure, shock, heart failure, etc., in the treatment of hemolytic anemia should be early prevention of complications, and strive for early detection, early treatment.
Complication
Anemia complications caused by excessive hemolysis Complications, renal failure, shock, heart failure
Hemolysis caused more complications, some of which are very serious, such as renal failure, shock, heart failure and so on.
Symptom
Symptoms of anemia caused by excessive hemolysis Common symptoms: fatigue, jaundice, high fever, cold war, back pain, proteinuria, syncope
Diversified clinical manifestations, fatigue, anemia, jaundice, urine color changes, spleen enlargement, etc., when there is hemolytic crisis, low back pain, chills, high fever, syncope, hemoglobinuria, etc., some patients may be in a long-term hidden state, encountering incentives When it happens.
The clinical manifestations of hemolytic anemia are related to the urgency, extent and location of hemolysis.
Acute hemolysis
Rapid onset, sudden chills, high fever, pale, back pain, shortness of breath, fatigue, irritability, nausea, vomiting, abdominal pain and other gastrointestinal symptoms. This is due to the massive destruction of red blood cells and the toxic effects of their decomposition products on the body. When the concentration of free hemoglobin exceeds 130 mg% in plasma, it is excreted in urine, hemoglobinuria, urine color such as concentrated black tea or soy sauce, jaundice may appear after 12 hours, and hemolytic products damage renal tubular cells, causing necrosis and hemoglobin deposition. Renal tubules, as well as peripheral circulatory weakness, can cause acute renal failure. Due to anemia, hypoxia, severe cases can occur indifferent or coma, shock and heart failure.
Chronic hemolysis
The onset is slower. In addition to the common symptoms and signs of general anemia such as fatigue, paleness, shortness of breath, dizziness, etc., there may be varying degrees of jaundice, spleen and hepatomegaly are common, gallstones are more common complications, and obstructive jaundice may occur. The skin of the lower extremity is ulcerated and difficult to heal. It is common in patients with sickle cell anemia.
Examine
Examination of anemia caused by excessive hemolysis
1, blood routine: red blood cell count decreased, generally positive cells positive pigment anemia.
2. Increased serum indirect bilirubin.
3. The red blood cell survival time is shortened.
4, bone marrow elephant:
(1) Hyperplasia is obviously active.
(2) The ratio of grain red is significantly reduced or inverted.
(3) The red blood cell line is significantly proliferated, the percentage of young red blood cells is often >O.50, mainly in the middle and young red blood cells, and the young red blood cells in other stages are correspondingly increased, and the mitotic figures are easy to see. Large red blood cells, polychromatic red blood cells and Howell-Jolly bodies are easily seen in mature red blood cells.
(4) The granulocyte cell line was relatively reduced, and the proportion and cell morphology of each stage were almost normal.
(5) The megakaryocyte cell line is generally normal.
5, special tests: erythrocyte morphology observation; erythrocyte fragility test; anti-human globulin test; acidified serum hemolysis test; methemoglobin reduction test; autolysis test; isopropyl alcohol test and / or thermal denaturation test; hemoglobin electrophoresis and anti- Alkali hemoglobin test.
Diagnosis
Diagnosis and diagnosis of anemia caused by excessive hemolysis
diagnosis
Hemolytic anemia is usually divided into two types: endogenous and exogenous. This common classification is sometimes difficult to apply clinically because of the overlap phenomenon. The serial differential diagnosis is to consider the occurrence of this disease. Risk groups (such as geography, genetics, underlying diseases, etc.) and then further consider possible mechanisms:
(1) Red blood cell retention due to vascular complex lesions (ie hypersplenism or some form of extracorporeal circulation such as renal dialysis);
(2) immunological damage (mediated by warm antibodies or cold antibodies);
(3) mechanical damage to the erythrocyte membrane (red blood cell fragmentation);
(4) Red blood cell structure change (membrane abnormality);
(5) metabolic abnormalities (enzyme deficiency diseases);
(6) Abnormal hemoglobin.
Morphological cues are important in most anemia diagnosis, but the significance of diagnosing hemolytic anemia is limited. If spherical red blood cells are found, they can be regarded as active red blood cells because their surface area has been reduced. The best evidence of destruction, spheroidal red blood cells are a common feature of transfusion and warm antibody hemolytic anemia and rare congenital spherocytosis, and elevated mean erythrocyte hemoglobin concentrations may be indicative of the presence of spheroidal red blood cells, mean erythrocyte hemoglobin concentration (and The increase in mean red blood cell volume is also seen in cold antibody hemolytic anemia, which is normal when the blood is warmed (even before the automatic counting, even if the test tube is briefly held).
Differential diagnosis
1. "iron deficiency anemia", iron deficiency affects the anemia caused by hemoglobin synthesis, seen in malnutrition, a large number of small-term bleeding and hookworm disease; as long as women are more likely to suffer from iron deficiency anemia, this is Because women have a fixed loss of blood every month during their physiological period.
2. "Bleeding anemia", caused by acute massive bleeding (such as gastric and duodenal ulcer disease, rupture of esophageal varices or trauma).
3. "giant erythrocyte anemia", lack of red blood cell maturation caused by anemia, lack of folate or vitamin B12 caused by megaloblastic anemia, more common in infants and pregnant women long-term malnutrition; megaloblastic anemia refers to the presence of bone marrow A type of anemia of a large number of mega-cells.
4. "Malignant anemia", megaloblastic anemia lacking internal factors.
5. "aplastic anemia", accompanied by gastric acid deficiency and spinal column, atrophy of the posterior column, slow course of disease; anemia caused by hematopoietic dysfunction, aplastic anemia (AA, referred to as aplastic anemia), caused by a variety of reasons Bone marrow stem cells, hematopoietic microenvironment damage and changes in immune mechanisms lead to bone marrow hematopoietic failure, and diseases with a decrease in whole blood cells (erythrocytes, granulocytes, and platelets) are the main manifestations.
