Hemolytic Anemias Overview

Erythrocytes after their normal service life (about 120 days) from the circulation. When hemolysis a premature degradation of the erythrocytes takes place, and its lifetime is shortened (<120 days). If production in the bone marrow can not compensate longer the shortened life of erythrocytes, resulting in a so-called hemolytic anemia. If the bone marrow still able to compensate for the shortened life of erythrocytes, this condition is called compensated hemolytic anemia. Etiology Hemolysis can result from disorders Extraerythrozytäre intraerythrocytic anomalies (hemolytic anemias.) Extraerythrozytäre disorders Most extraerythrozytären disorders are acquired; the red cells are normal and transfused as well as autologous cells are broken down. The extrinsic (extraerythrozytären) diseases that affect the red blood cells include a reticuloendothelial hyperactivity (hypersplenism - hypersplenism), immunological changes (e.g., autoimmune hemolytic anemia, anemia isoimmunhämolytische.), Mechanical damage (traumatic hemolytic anemia) and certain infections. Infections can cause hemolytic anemia, either via a direct effect of toxins (eg. B. Clostridium perfringens, ?- or ?-hemolytic streptococcus or meningococcal) or by penetration into and destruction of red blood cells by the pathogen itself (eg. B ...., Plasmodium sp, Bartonella sp) intraerythrocytic anomalies Intrinsic (intraerythrocytic) defects which can lead to hemolysis, affect one or more components or functions of the erythrocyte: membrane, cell metabolism and hemoglobin. Among the disorders include congenital and acquired defects of the cell membrane (z. B. spherocytosis), disorders of red cell metabolism (eg., Glucose-6-phosphate dehydrogenase deficiency) and hemoglobinopathies (z. B. sickle cell anemia, thalassemia). Quantitative and functional changes of various proteins in the erythrocyte membrane (?- and ?-spectrin, protein 4.1, F-actin, Ancyrin) can lead to the formation of hemolytic anemia. Hemolytic anemias mechanism disorder or agent Extraerythrozytäre disorders reticuloendothelial hyperactivity hypersplenism Immunological changes autoimmune anemias cold antibody paroxysmal cold hemoglobinuria heat antibody infections Babesia sp. Bartonella bacilliformis Plasmodium falciparum P. malariae P. vivax toxin formation by pathogens Clostridium perfringens ?- and ?-hemolytic streptococci meningococcal mechanical trauma Marschhämoglobinurie skeletal trauma thrombotic thrombocytopenic purpura and hemolytic uremic syndrome valvular heart disease toxins compounds with oxidizing properties (eg. B. dapsone, phenazopyridine ) of copper (Wilson's disease) lead insecticide snake venom intraerythrocytic Congenital defects erythrocyte membrane defects hereditary elliptocytosis hereditary spherocytosis Acquired erythrocyte membrane defects hypophosphatemia paroxysmal nocturnal hemoglobinuria stomatocytosis disorders of erythrocyte metabolism, defects of the Embden-Meyerhof-cycle (eg. B. Pyruvatkinasemangel) defects of the hexose monophosphate shunt (eg., Glucose-6-phosphate dehydrogenase deficiency) Disorders of hemoglobin synthesis hemoglobin C disease hemoglobin SC disease hemoglobin E disease sickle cell disease thalassemia pathophysiology Hemolysis can acute, chronic or episodic run. Chronic hemolysis may be complicated by aplastic crises (temporary failure of erythropoiesis). This is common in infections, particularly in Parvovirusinfektionen, the case. Hemolysis may be extravascular, intravascular or both. Normal erythrocytes degradation Aging erythrocytes losing their membrane and are mainly removed by the phagocytic cells of the spleen, liver, bone marrow and reticuloendothelial system from the circulation. The hemoglobin degradation in these cells occurs primarily by the heme oxygenase system. This is associated with the storage and subsequent recycling of iron, the degradation of heme to bilirubin which is conjugated in the liver to Bilirubinglucoronid and excreted in the bile wird.Extravasale hemolysis The pathological hemolysis is especially extravascular place and occurs when damaged or abnormal erythrocytes circulation are taken up by cells of the spleen, liver and bone marrow, similar to the removal of aging erythrocytes. Hemolysis a destruction of geringgradig abnormal or loaded with heat antibodies erythrocytes is usually completed in the spleen. An enlarged spleen can lead to sequestration of normal erythrocytes. Erythrocytes which have severe changes or with cold antibodies or complement (C3) are loaded are degraded in the circulation and in the liver. Due to the high hepatic blood flow, the liver can damaged cells particularly efficient entfernen.Intravasale Hemolysis Intravascular hemolysis is for the premature red blood cell breakdown of significance when the cell membrane has been severely damaged by different mechanisms, such as autoimmune reactions, direct trauma (eg. As Marschhämoglobinurie) shear forces (z. B. defective mechanical heart valves) and toxins (eg. B. Clostridial toxins, venomous snake bite). Intravascular hemolysis may cause a haemoglobinemia when released into the plasma hemoglobin amount exceeds the hemoglobin-binding capacity of the plasma protein haptoglobin, a globulin, which is present usually in a concentration of about 100 mg / dl (1 g / l) in plasma. In haemoglobinemia unbound Hämoglobindimere be filtered into the urine and reabsorbed by renal tubular cells; hemoglobinuria occurs when the capacity for the reabsorption is exceeded. Iron is bound to hemosiderin within the tubular cells; a part of iron is assimilated for reuse and another part passes into the urine when the tubule cells ablösen.Folgen hemolysis Hyperbilirubinemia (unconjugated / indirect) and jaundice occur when the degradation of hemoglobin to the capacity of the liver bilirubin to conjugate bilirubin and excrete (Overview biliary), exceeds. The Bilirubinkatabolismus caused elevated levels of stercobilin in the stool and urobilinogen in urine. It occasionally happens to cholelithiasis. The bone marrow responds to the increased loss of red blood cells by increased erythropoiesis, resulting in Reticulocytosis. Symptoms and signs The clinical presentation is similar to that in other anemias and is manifested by pallor, fatigue, dizziness and possibly hypotension. Hemolytic crises (severe acute hemolysis) are rare. They may be accompanied by chills, fever, pain in the back and abdomen, weakness and shock. Severe hemolysis can cause jaundice and splenomegaly. In hemoglobinuria urine is red or red-brown. Diagnostic Peripheral blood smear, reticulocyte count, serum bilirubin, LDH and ALT levels Occasionally determination of hemosiderin in the urine and haptoglobin in serum rare determining the erythrocyte life by means of radioactive labeling, the suspicion of a hemolysis consists in patients with anemia and reticulocytosis, particularly when a splenomegaly, or another potential cause for hemolysis can be seen. Suspicion of hemolysis, a peripheral blood smear is examined and serum bilirubin, LDH and ALT determined. Are the results of these tests not diagnostic proving so hemosiderin in urine and haptoglobin in the serum. Spherocytes haemolytic anemia with permission of the publisher. From Tefferi A., Li C. In Atlas of Clinical Hematology. Edited by J. O. Armitage. Philadelphia, Current Medicine, 2004. var model = {thumbnailUrl: '/-/media/manual/professional/images/spherocytes_hemolytic_anemia_high_de.jpg?la=de&thn=0&mw=350' imageUrl: '/ - / media / manual / professional / images / spherocytes_hemolytic_anemia_high_de.jpg lang = en & thn = 0 ', title:'? spherocytes haemolytic anemia ', description:' u003Ca id = "v37895091 " class = ""anchor "" u003e u003c / a u003e u003cdiv class = ""para "" u003e u003cp u003eSphärozyten have in the peripheral blood smear either a hereditary spherocytosis (HS) or autoimmune hemolytic anemia (AIHA) out. Spherocytes have increased osmotic fragility (due to the reduced ductility by a reduced membrane surface) in hypotonic saline; this test (on osmotic fragility) is positive in HS and AIHA. Means antiglobulin (Coombs) test can distinguish between the two diseases; the result is positive for AIHA and negative in HS u003c / p u003e u003c / div u003e. 'credits' With permission of the publisher. From Tefferi A.

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