What is Immune Hemolytic Anemia?
Immune hemolytic anemia is a large heterogeneous group of diseases for which the participation of antibodies or immune lymphocytes in the damage and premature death of erythrocytes or erythrocaryocytes is common.
Pathogenesis during Immune Hemolytic Anemia
Immune hemolytic anemia can be divided into four groups: alloimmune, transimmune, heterogeneous, autoimmune.
In case of isoimmune or alloimmune hemolytic anemia, antibodies against the antigens of the patient’s erythrocytes or erythrocytes containing antigens against which the patient has antibodies, enter the body of the patient from the outside. This is observed in hemolytic disease of the newborn, when the mother’s body produces antibodies, and through the placenta they penetrate into the bloodstream of the child. Another example of an alloimmune hemolytic reaction is the destruction of red blood cells during red blood cell transfusions that are not compatible with the AB0 system, which is Rh, against which the patient has antibodies.
By transimmune hemolytic anemia is meant such that the antibodies of a mother suffering from autoimmune hemolytic anemia penetrate the placenta and cause hemolytic anemia in a child. These antibodies are directed against the common erythrocyte antigen present in the mother and child.
The third group of immune hemolytic anemias is heteroimmune (hapten) hemolytic anemias associated with the appearance of a new antigen on the surface of erythrocytes of a patient. This new antigen may be formed as a result of the fixation of the drug to the erythrocyte surface of the patient (penicillin, ceporin, sulfa drugs). A small number of individuals produce antibodies against this newly formed, foreign to the body antigen. They unite with this antigen, which leads to activation of complement and cell dissolution directly in the bloodstream or to increased destruction of the latter by phagocytes. A virus fixed on the surface of an erythrocyte can also be a hapten. Antibodies against the virus can be fixed together with it and lead to the erythrocyte death.