Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia caused by antibodies that react at temperatures ? 37 ° C (heat-antibody), or <37 ° C (from cold antibody) with the red cells. Hemolysis usually takes place extravascular. The direct antiglobulin (Coombs) test confirms the diagnosis and may indicate the cause. The treatment comprises the administration of corticosteroids, immunosuppressants or infusion of immunoglobulins, splenectomy and the avoidance of blood transfusions or discontinuation of medications may include, depending on the cause.

Autoimmune hemolytic anemia caused by antibodies that react at temperatures ? 37 ° C (heat-antibody), or <37 ° C (from cold antibody) with the red cells. Hemolysis usually takes place extravascular. The direct antiglobulin (Coombs) test confirms the diagnosis and may indicate the cause. The treatment comprises the administration of corticosteroids, immunosuppressants or infusion of immunoglobulins, splenectomy and the avoidance of blood transfusions or discontinuation of medications may include, depending on the cause. Etiology caused by heat antibodies hemolytic anemia caused by heat antibody haemolytic anemia is the most common form of autoimmune hemolytic anemia (AIHA). She is more common in women than in men. In this hemolytic anemia form autoantibodies react ? 37 ° C temperatures. The autoantibodies may occur. Spontaneously in connection with various diseases (SLE, lymphomas, chronic lymphocytic leukemia). After taking certain medicines Some medications (. Eg ?-methyldopa-type levodopa - medicines that may cause a heat-induced antibody hemolytic anemia), the production of autoantibodies against Rh antigens (?-methyldopa type of autoimmune hemolytic anemia) stimulate. Other drugs stimulate the production of autoantibodies against an antibiotic erythrocyte membrane complex as part of a temporary Haptenmechanismus. This hapten can both stable (z. B. high-dose penicillin, cephalosporins) or is unstable (eg. As quinidine, sulfonamides). When caused by heat antibodies hemolytic anemia, hemolysis occurs primarily in the spleen. They often is severe and can even be fatal. Most of these antibodies are of the IgG type. You are Panagglutinine and have a very limited Spezifität.Kälteagglutininkrankheit The Cold agglutinin is caused by autoantibodies that react at temperatures <37 ° C. Causes are: infections (especially pneumonia-mycoplasma or mononucleosis) lymphoproliferative disorders Idiopathic (about half of the cases) infections tend to cause acute hemolysis, whereas the idiopathic form (the common form in adults) often becomes chronic. Hemolysis occurs mostly on the extravascular mononuclear Phagozytosesystem the liver. Anemia is usually only weak (hemoglobin> 7.5 g / dl). The autoantibodies are in this disease mostly of the IgM type. The higher the reaction temperature, this antibody (i. E. The closer it is located at the normal body temperature), the stronger the Hämolyse.Paroxysmale cold hemoglobinuria Paroxysmal cold hemoglobinuria (PCH, Donath-Landsteiner syndrome) is a rare variant of the cold agglutinin disease. Hemolysis is in this case due to a cold exposure, which can also be isolated (eg. As by drinking or hand washing with cold water). An IgG Autohämolysin binds to red blood cells at low temperatures and caused by heating an intravascular hemolysis. They usually occurs after a nonspecific viral illness or in otherwise healthy patients. In some patients, one finds a congenital or acquired syphilis. The severity of the anemia and the speed at which it develops vary. The course may be fulminant. Drugs which may cause a heat-induced antibodies hemolytic anemia mechanism drug autoantibodies against Rh antigens cephalosporins diclofenac, ibuprofen interferon alpha levodopa mefenamic acid ?-methyldopa procainamide teniposide thioridazine tolmetin Stable hapten cephalosporins fluorescein penicillins, tetracyclines tolbutamide Unstable hapten or unknown mechanism p- Aminosalicylic amphotericin B antazoline cephalosporins chlorpropamide diclofenac diethylstilbestrol Doxepin hydrochlorothiazide isoniazid probenecid quinidine quinine rifampin sulfonamides thiopental tolmetin symptoms and complaints The symptoms caused by heat antibody hemolytic anemia are usually the result of the anemia. In severe disease fever, chest pain, syncope or heart failure may occur. A slight splenomegaly is typical. The Cold agglutinin occurs as acute or chronic hemolytic anemia. Other symptoms caused by cold or clinical signs may be present (eg. As Akrozyanosen, Raynaud’s syndrome, cold associated veno-occlusive changes). Symptoms of paroxysmal cold hemoglobinuria severe pain in her back and legs, headaches, vomiting, diarrhea and phased dark brown urine may belong. Also hepatosplenomegaly can occur. Diagnostic tests for hemolytic anemia (z. B. peripheral blood smear, reticulocyte, possibly hemosiderin in urine, serum haptoglobin) direct antiglobulin Suspicion of autoimmune hemolytic anemia, patients with hemolytic anemia, especially in severe symptoms or in the presence of other more indicative symptoms , The routine laboratory tests indicate mostly on extravascular hemolysis out (eg. As no hemosiderinuria, near normal haptoglobin), unless severe anemia develops in only a very short time or paroxysmal cold hemoglobinuria is the cause. Spherocytosis and high MCHC values ??are typical. Autoimmune hemolytic anemia is made by the detection of autoantibodies by a direct antiglobulin test (direct Coombs test). Antiglobulin serum is added to washed red blood cells of the patient. The agglutination indicates the presence of immunoglobulins or complement bound to red blood cells (C). While IgG is present at caused by heat antibody hemolytic anemia, C3 (C3b and C3d) occurs in mediated by cold antibody disease. The test is ? 98% sensitive for autoimmune hemolytic anemia. False-negative results can occur when only small amounts of antibody present or the autoantibodies of IgA or IgM type. In general, the intensity of the direct Coombs testing correlates with the number of IgG molecules bound to erythrocytes or of the C3 and thus approximately with the severity of hemolysis. In the indirect antiglobulin (indirect Coombs test) the patient’s plasma is mixed with normal red blood cells to detect the presence of free antibodies in the plasma. A positive indirect Coombs test and a negative direct Coombs test generally indicate the presence of an alloantibody (eg. As by pregnancy, previous transfusion or lectin cross-reactivity), but not prove the immunohemolysis. Even the evidence of heat antibody does not prove hemolysis, as about 1 / 10,000 of healthy blood donors has a positive test result. Direct antiglobulin (Coombs) test. With the direct antiglobulin (Coombs) test (direct antiglobulin test), it is determined whether antierythrozytäre antibody (IgG) or complement (C3) is present on the erythrocyte membranes. Antibody against human IgG and C3 is added to the red blood cells of the patient. If IgG or C3 is bound to erythrocyte membranes, there is an agglutination (positive result). A positive result indicates the presence of autoantibodies against erythrocytes if the patient has not received a transfusion in the last three months of alloantibodies against transfused RBCs (usually in acute or delayed hemolytic reaction) or drug-dependent or induced antibodies to erythrocyte out. After an autoimmune hemolytic anemia was diagnosed by an antiglobulin test should differentiated by further studies between a hemolytic anemia by warm antibodies and a Cold agglutinin and the person responsible for the formation of heat antibodies mechanism be identified. Often, this determination can already be done by the pattern of direct antiglobulin. There are three different patterns: The reaction is positive with anti-IgG and negative with anti-C3. This pattern occurs frequently in idiopathic autoimmune hemolytic anemia as well as in drug-associated type or in ?-methyldopa type. Most is a hemolytic anemia by warm antibodies. The reaction is positive with anti-IgG and anti-C3. This pattern is common in patients with SLE and find idiopathic autoimmune hemolytic anemia. Usually it is also about a hemolytic anemia by warm antibodies. In drug-associated cases it happens rarely. The reaction is positive with anti-C3 but negative with anti-IgG. This pattern occurs in the Cold agglutinin. It is rare in idiopathic autoimmune hemolytic anemia, when caused by heat antibody hemolytic anemia, when the IgG antibody has a low affinity for some drug-related cases and paroxysmal cold hemoglobinuria. Other studies may indicate the cause of autoimmune hemolytic anemia, but are not conclusive. In the Cold agglutinin erythrocyte clumping in the peripheral blood smear, and automatic cell counts often show the basis of which an increased MCV and seemingly low hemoglobin levels. The heating of the sample tube by hand and re-counting provide values ??that are significantly closer to normal values. Haemolytic anemia by warm antibodies can often be differentiated from the Cold agglutinin on the temperature at which the direct antiglobulin test positive. A test is positive at temperatures ? 37 ° C, indicates the presence of a hemolytic anemia out by heat antibody, whereas a test which is favorable at lower temperatures, suggesting a cold agglutinin disease. RBC clumping in the Cold agglutinin 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/rbc_clumping_cold_agglutinin_disease_high_de.jpg?la=de&thn=0&mw=350’ imageUrl: ‘/ – / media / manual / professional / images / rbc_clumping_cold_agglutinin_disease_high_de.jpg lang = en & thn = 0 ‘, title:’? RBC clumping in the Cold agglutinin ‘description:’ ‘credits’ with permission of the publisher. From Tefferi A., Li C. In Atlas of Clinical Hematology. Edited by J. O. Armitage. Philadelphia, Current Medicine, 2004. ‘hideCredits: false, hideTitle: false, hideFigure: false, hideDescription: true}; var panel = $ (MManual.utils.getCurrentScript ()) Closest ( ‘image-element-panel.’). ko.applyBindings (model, panel.get (0)); Suspicion of paroxysmal cold hemoglobinuria should be a Donath-Landsteiner test, which is specific to the paroxysmal cold hemoglobinuria, are performed. An investigation for the presence of syphilis is recommended. In treating drug induced hemolytic anemia by heat antibody discontinuation of the drug, sometimes i.v. Immunoglobulins In idiopathic hemolytic anemia by warm antibodies Corticosteroids In Cold agglutinin avoid cold Treatment depends on the underlying causes of hemolysis. caused by heat antibody hemolytic anemia When drug-induced hemolytic anemia due to heat antibodies of the discontinuation of the drugs leads to a reduction in hemolysis. When ?-methyldopa type of autoimmune hemolytic anemia, hemolysis usually resolves within 3 weeks, however, the antiglobulin test can be positive even> 1 year. In the hapten-mediated autoimmune hemolytic anemia, hemolysis stops after the disappearance of the drug from the plasma. Corticosteroids have only a small effect on the drug-induced hemolysis. The infusion of immunoglobulin appears to be more effective. In idiopathic, caused by heat antibody autoimmune hemolytic anemia corticosteroids (e.g., prednisone 1 mg / kg p.o. once per day or higher doses) the treatment of choice. For very severe hemolysis is an initial dose of 100-200 mg / day is recommended. Most patients respond very well to treatment, and in about a third of patients, this is even after 12 to 20 weeks of treatment duration of the case. If stable erythrocyte values ??are reached, the corticosteroid dose is slowly reduced. In patients who relapse after withdrawal of corticosteroids or where the corticosteroids are not sufficiently effective, a splenectomy is performed. then about one third to one half of patients showing a sustained response. In the case of fulminant hemolysis plasma exchange can be performed. For less severe but uncontrolled hemolysis same may be brought by the infusion of immunoglobulin temporarily under control. Long-term treatment with immunosuppressants (incl. Cyclosporine) may be effective in patients in whom corticosteroids and splenectomy have failed. In the heat-induced antibodies hemolytic anemia crossmatching of donor blood is complicated by the presence of Panagglutininen. Additionally, it can transfusion due to the formation of alloantibodies come overlay the autoantibodies and so enhance the hemolysis. Therefore transfusions should be avoided if possible. If necessary, they should be in small amounts (100-200 ml) for 1-2 h under surveillance for hemolytic signs administered werden.Kälteagglutininkrankheit Treatment is mainly supportive in acute cases because the anemia can run self-limiting. In chronic cases, treatment of the underlying disorder often results in the control of anemia. In idiopathic chronic cases, however, can live long mild anemia (hemoglobin 9-10 g / dL) persist. Avoiding exposure to cold is often helpful. Splenectomy has no therapeutic value. Also immunosuppressants are only moderately effective. Transfusions should be used with extreme caution and the blood to be tempered with a fluid warmer. Since the autologous erythrocytes are resistant against the already autoantibodies, the autologous cell survival is significantly better than that of transfused cells. Thus, the effectiveness of transfusions is limited. When paroxysmal cold hemoglobinuria is the therapy in the strict avoidance of cold exposure. Splenectomy has no therapeutic value. Immunosuppressants are effective, but should be limited to progressive or idiopathic cases. The treatment of concomitant syphilis can lead to healing of paroxysmal cold hemoglobinuria. Important points based on temperature at which respond autoantibodies with the erythrocytes, AIHA is divided into the heat-induced antibody hemolytic anemia and cold agglutinin disease, Hemolysis tends to be more severe when caused by heat antibody hemolytic anemia, and can be fatal , Immunoglobulin and / or complement that is bound to the erythrocytes of patients are indicated by the occurrence of agglutination after antiglobulin serum to washed red blood cells (direct antiglobulin test positive) is added. The pattern of direct Antiglobulinreaktion can help to distinguish the hemolytic anemia by warm antibodies from a Cold agglutinin, and sometimes identify those responsible for the formation of heat antibodies mechanism. The treatment aims to cause (including discontinuation of medications, cold avoidance); iv Immunoglobulin can be used for drug-induced AIHA and corticosteroids for idiopathic caused by heat antibody hemolytic disease.

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