Immune hemolytic anemia

Immune hemolytic anemia is a heterogeneous group of diseases in which blood or bone marrow cells are destroyed by antibodies or sensitized lymphocytes directed against their own unchanged antigens.

Depending on the nature of the antibodies, 4 variants of immune hemolytic anemia are distinguished: alloimmune (isoimmune), transimmune, heteroimmune (hapten), autoimmune.

[1], [2], [3], [4]

Isoimmune hemolytic anemia

They are noted in cases of antigenic incompatibility of the maternal and fetal genes (hemolytic disease of newborns) or in the case of incompatible erythrocytes (grouping of incompatible blood) that lead to the reaction of the donor serum with the recipient's erythrocytes.

Hemolytic disease of newborns is most often associated with maternal and fetal blood incompatibility with RhD antigen, less often with antigens A B O, even more rarely with C, Kell and others antigens. Antibodies that penetrate the placenta are fixed on the erythrocytes of the fetus and then eliminated by macrophages. Intracellular hemolysis develops with the formation of indirect bilirubin, toxic for the central nervous system, with compensatory ergotroblastosis, the formation of extramedullary foci of hematopoiesis.

Transmissible hemolytic anemia

It is caused by transplacental transmission of antibodies from mothers suffering from autoimmune hemolytic anemia; antibodies are directed against the general antigen of erythrocytes both of the mother and the child. Transimmune hemolytic anemia in newborns requires systematic treatment, taking into account the half-life of maternal antibodies (IgG) in 28 days. The use of glucocorticoids is not shown.

Heteroimmune hemolytic anemia

It is associated with the fixation on the surface of the erythrocyte of a hapten of medicinal, viral, bacterial origin. Erythrocyte is a random target cell on which a hapten-antibody reaction occurs (the body produces antibodies against "foreign" antigens). In 20% of cases with immune hemolysis, the role of drugs can be revealed.

Autoimmune hemolytic anemia

With this variant of hemolytic anemia in the patient's body, antibodies directed against their own unchanged erythrocyte antigens are produced. There are at any age.

Types of immune hemolytic anemia

Autoimmune hemolytic anemia is considered as a peculiar state of "dissymunity" associated with a deficiency of the thymus derivative of the population of suppressor cells, a violation of the cooperation of cells during the immune response and the appearance of a clone of autoaggressive immunocytes (the proliferation of an "illegal" clone of immunologically competent cells that have lost the ability to recognize their own antigens) . The decrease in the number of T-lymphocytes in the blood is accompanied by an increase in the number of B- and zero-lymphocytes of peripheral blood.

Pathogenesis of immune hemolytic anemia

[5], [6], [7], [8]

Autoimmune hemolytic anemia associated with thermal antibodies

Clinical manifestations of the disease are the same both in idiopathic and symptomatic forms. According to the clinical course are divided into 2 groups. The first group is represented by an acute transient type of anemia, which is predominantly noted in young children and often appears after an infection, usually a respiratory tract. Clinically, this form is characterized by signs of intravascular hemolysis. The onset of the disease is acute, accompanied by fever, vomiting, weakness, dizziness, the appearance of pallor of the skin, icterism, abdominal pain and lower back, hemoglobinuria. In this group of patients, no major systemic diseases are observed.

Immune hemolytic anemia associated with thermal antibodies

[9], [10], [11], [12], [13]

Autoimmune hemolytic anemia associated with "cold" antibodies

Erythrocyte antibodies, which become more active at low body temperature, are called "Cold" antibodies. These antibodies belong to the IgM class, the presence of complement is necessary for the development of their activity, IgM activate complement in the limbs (hands, feet), where the temperature is lower than in other parts of the body; The cascade of complement reactions is interrupted when the red blood cells move to the warmer zones of the body. In 95% of healthy people, natural cold agglutinins are found in low titres (1: 1, 1: 8, 1:64).

Autoimmune hemolytic anemia associated with "cold" antibodies

[14], [15], [16], [17], [18], [19]

Autoimmune hemolytic anemia with incomplete thermal agglutinins

Autoimmune hemolytic anemia with incomplete thermal agglutinins is the most common form in adults and children, although the latter, according to some reports, paroxysmal cold hemoglobinuria occurs no less frequently, but is less often diagnosed. In children, autoimmune hemolytic anemia with incomplete thermal agglutinins is most often characterized by idiopathic, immunodeficiency syndromes and SLE - the most frequent causes of secondary autoimmune hemolytic anemia. In adults, this form of autoimmune hemolytic anemia often accompanies other autoimmune syndromes, CLL and lymphomas.

Autoimmune hemolytic anemia with incomplete thermal agglutinins

[20], [21]

Autoimmune hemolytic anemia with complete cold agglutinins

Autoimmune hemolytic anemia with complete cold agglutinin disease (cold agglutinin disease) in children is much less common than other forms. In adults, this disease is often found: this form is either secondary to lymphoproliferative syndromes, hepatitis C, infectious mononucleosis, or idiopathic. In the idiopathic form of anemia, however, the presence of clonal expansion of a population of morphologically normal lymphocytes producing monoclonal IgM is also shown.

Autoimmune hemolytic anemia with complete cold agglutinins

[22], [23], [24],