Warm Autoimmune Hemolytic Anemia Flashcards
What causes the hemolysis in immune hemolytic anemia?
From antibodies or complement, or both attaching to the RBC membrane
What kind of hemolysis results from the activation of the classical complement pathway?
Intravascular hemolysis
Why is IgM a very efficient complement activator?
Because of its pentameric structure. A single IgM can initiate complement activation by the classical pathway
What factors do IgG antibodies depend on to activate complement?
Factors such as the subclass, the number of locations of IgG molecules, the physical location of red cell antigens, and avidity
What is extravascular hemolysis?
The phagocytosis of red cells within the mononuclear phagocyte system (MPS)
What are the two major organs involved in extravascular hemolysis?
The spleen and the liver
What happens after antibody-coated red cells interact with the Fc receptors lining the splenic cord?
Complete or partial phagocytosis (and if the cell cannot repair itself, partial spherocytes are formed)
Why are spherocytes seen in the PB when there’s extravascular hemolysis?
They lack deformability and become physically trapped in the spleen, but the ones that escape are seen in a PBS
