Immune hemolytic anemia is a group of diseases caused by increased destruction of red blood cells due to the production of antibodies against unchanged red blood cells or haptens that appeared on the erythrocyte membrane. There are isoimmune, transimmune, heterogeneous and autoimmune hemolytic anemia. Clinical signs: pallor or jaundice of the skin, moderate enlargement of the liver and spleen, pain in the lumbar region, shortness of breath and other symptoms. Diagnostics is based on the study of clinical data, the results of laboratory and instrumental studies. Treatment: hemotransfusion, administration of blood products and corticosteroids, sometimes splenectomy.
General information
Immune hemolytic anemia is a group of diseases characterized by damage and premature death of erythrocytes or erythrocaryocytes due to the development of an immune reaction involving IgG and IgM or immune lymphocytes. The main factors causing the destruction of red blood cells are the autoimmune process, hemotransfusion complications, fetal erythroblastosis and hemolysis caused by the action of certain drugs.
Hemolysis can occur in the bloodstream itself or outside the vessels: in the liver, spleen, bone marrow. As a result of the mass death of red blood cells, anemic and jaundice syndromes develop, indicating a violation of the function of the liver, kidneys, respiratory system, circulatory system, other organs and systems of the body. According to statistics, the prevalence of immune hemolytic anemia is approximately 1 case per 70-80 thousand population.
Causes
The occurrence of this group of diseases is associated with the impact of various adverse factors of the external and internal environment, leading to the development of immune reactions against their own red blood cells. Most often there is an autoimmune mechanism in which antibodies are produced against unchanged natural antigens of the membrane of erythrocytes in the bloodstream, or their precursors – erythrocaryocytes of the bone marrow. The primary causal factor causing the destruction of red blood cells is unknown (idiopathic form).
In secondary anemia, the pathological process develops against the background of chronic lymphocytic leukemia, lymphoma, antiphospholipid syndrome or immunodeficiency conditions. The thermal form of autoimmune anemia is more common, in which the internal environment of the body has normal temperature parameters, and class G immunoglobulins and complement components C3 and C4 are located on erythrocytes. Red blood cells are destroyed by macrophages in the liver and spleen. A less common cold form may be idiopathic or secondary, associated with infection (infectious mononucleosis and mycoplasma pneumonia), hypothermia and lymphoproliferative diseases in patients older than 60 years. The antigen-antibody reaction with hemolysis develops in the peripheral bloodstream, where the temperature drops below 32 degrees.
Immune hemolytic anemia can occur when a fragment of medicinal, viral or bacterial origin (heteroimmune form) is fixed on the erythrocyte membrane. The resulting haptens turn red blood cells into foreign target cells for the immune system, which eventually leads to hemolysis. Most often, such a reaction is caused by antibiotics from the group of penicillins, cephalosporins and tetracyclines, anti-tuberculosis drugs, analgesics and antiarrhythmic agents.
The isoimmune form occurs when the blood of the mother and fetus is incompatible by blood group or Rh factor. At the same time, the mother’s anti-erythrocyte antibodies penetrate through the placenta to the fetus and cause the destruction of red blood cells. A similar mechanism is observed during transfusion (hemotransfusion) of incompatible blood from a donor to a patient.
Classification
Isoimmune, transimmune, heterogeneous and autoimmune hemolytic anemia are isolated.
- Isoimmune variants of the disease include posttransfusion complications associated with intolerance to donor blood or improper compliance with the transfusion procedure, as well as hemolytic disease of newborns.
- In transimmune anemia, hemolysis occurs when antibodies from a mother suffering from autoimmune anemia enter the fetus through the placenta.
- Heteroimmune (haptenic) anemia is the result of changes in the erythrocyte membrane when exposed to viruses or medications.
- Autoimmune hemolytic anemia (with thermal and cold agglutinins).
Symptoms
The disease often begins acutely: body temperature rises, chills appear, headache and dizziness, shortness of breath, pain in the epigastric region and lower back. The skin becomes pale, then jaundiced, hemorrhages may appear, the spleen, liver increases, the color of urine becomes dark.
In the cold form of immune hemolytic anemia, peripheral blood circulation is often disrupted with the development of Raynaud’s syndrome, blueness and swelling of the skin of the hands, face, and auricles. In some cases, a violation of the blood supply to the tissues of the extremities can lead to the development of gangrene of the toes.
Severe fetal erythroblastosis is characterized by the development of nuclear jaundice with damage to the central nervous system – bilirubin encephalopathy. At the same time, lethargy, lethargy, decreased appetite, frequent regurgitation, convulsive syndrome are noted. Palpation reveals an increase in the spleen, liver, and peripheral lymph nodes.
Diagnostics
To establish the correct diagnosis, to determine the form of the disease, it is necessary to thoroughly examine the patient with anamnesis collection, conducting a clinical physical examination by a hematologist, allergist-immunologist, infectious disease specialist, rheumatologist and other specialists. Already at the stage of examination, it is possible to detect pallor, jaundice of the skin and mucous membranes, to palpate the enlarged spleen and liver. The severity of splenomegaly and hepatomegaly is clarified during ultrasound examination (ultrasound of the liver and spleen).
Laboratory diagnostics confirms the presence of normal or hypochromic (rarely hyperchromic) anemia, reticulocytosis, increased ESR, hyperbilirubinemia. In the analysis of urine, proteinuria, urobilinemia, hemoglobinuria can be detected. When examining the bone marrow punctate, signs of hyperplasia are detected due to the activation of erythropoiesis. With hemolytic disease of newborns, pronounced erythroblastosis is detected (100-150 thousand in 1 µl).
The diagnosis of autoimmune hemolytic anemia is confirmed by a positive direct Coombs test (direct antiglobulin test) or a polybrene test (sensitized Coombs test). Differential diagnosis is carried out with other immune diseases, various forms of anemia, hemoblastosis, severe poisoning, liver and kidney diseases.
Treatment
Therapeutic tactics differ in different forms of the disease. With the autoimmune nature of hemolysis with thermal antigens, high doses of immunoglobulin, corticosteroids, sometimes cyclophosphamide and other immunosuppressive drugs are administered. Plasmapheresis may be used. If conservative therapy is ineffective, splenectomy is recommended. In cold immune hemolytic anemia, the administration of monoclonal antibodies (rituximab), plasmapheresis, transfusion of individually selected, washed and heated erythrocytes is used.
With erythroblastosis of the fetus, detoxification therapy, blood transfusion or erythrocyte mass is performed. With post-transfusion complications, it is necessary to carry out urgent anti-shock measures, the fight against disseminated intravascular coagulation syndrome.
