Chapter 12: Red cell disorders - Blood loss and Hemolytic anemia Flashcards
What are three general causes of anemia?
Bleeding (hemorrhage)
Increased red cell destruction (hemolysis)
Decreased red cell production
Blood loss that causes anemia can be acute or chronic. Name examples of an acute cause of blood loss and a chronic cause of blood loss.
Acute: trauma Chronic: gastrointestinal tract lesions, gynecologic disturbances.
What can be the cause of impaired production (hematopoiesis)? (Name three examples)
- Disturbed proliferation and differentiation of stem cells
- Disturbed proliferation and maturation of erythroblasts
- Marrow displacement/infiltrations
What is an example of disturbed proliferation and differentiation of stem cells?
Aplastic anemia
What is an example of disturbed proliferation and maturation of erythroblasts?
Megaloblastic anemia
What can be a cause of disturbed proliferation and maturation of erythroblasts (megaloblastic anemia)?
Defective DNA synthesis due to deficiency/impaired use of vitamin B12 or folic acid.
What is an example of marrow displacement/infiltrations?
Metastasis or leukemia
Name three intrinsic hereditary causes of hemolytic anemia (increased destruction).
Membrane abnormalities
Enzyme deficiencies
Disorders of hemoglobin synthesis
Name an intrinsic acquired cause of hemolytic anemia (increased destruction).
Membrane defect
What is an example of a membrane abnormality during hemolytic anemia?
Spherocytosis
What is an example of an enzyme deficiency during hemolytic anemia?
Glucose-6 phosphate dehydrogenase (G6PD)
What is an example of a disorder of hemoglobin synthesis during hemolytic anemia?
Thalessemia and sickle cell anemia
What is an example of a membrane defect during hemolytic anemia?
Paroxysmal nocturnal hemoglobinuria (complement system targets membrane)
Name two extrinsic causes of hemolytic anemia.
Antibody mediated
Mechanic trauma to erythrocytes
What is an example of antibody mediated hemolytic anemia?
Transfusion, autoimmune disease
What is an example of mechanic trauma to erythrocytes during hemolytic anemia?
Defective cardiac valves
What are (six) symptoms of anemia?
Shortness of breath, fatique, whiteness (palor), nail defect, jaundice, splenomegaly.
What are the effects of acute bleeding (hemorrhage) mainly caused by?
By the loss of intravascular volume. If this is massive, it can lead to cardiovascular collapse, shock and death.
What is typical of chronic blood loss?
Iron stores are gradually depleted.
What are hallmarks of hemolytic anemia and why?
Erythroid hyperplasia and reticulocytosis are hallmarks of all hemolytic anemias. This is because the loss of red blood cells, results in low tissue O2 levels. This triggers the production of erythropoietin (kidneys) which in turn stimulates the growth of reticulocytes (immature red blood cells) from the bone marrow.
Extrinsic hemolysis is caused by defects that…
increase the destruction of red cells by phagocytes (particularly in the spleen).
Why does extrinsic hemolysis particularly happen in the spleen?
Because the spleen contains large numbers of macrophages, who are responsible for the removal of damaged or antibody-coated red cells. When deformed/coated red blood cells circulate through the spleen, they become stuck due to the narrow passage through the spleen.
When looking at the clinical manifestations of extrinsic hemolysis, what’s typical for extrinsic hemolysis compared to intrinsic hemolysis?
- Hyperbilirubinemia and jaundice, stemming from degradation of hemoglobin in macrophages.
- Varying degrees of splenomegaly due to work hyperplasia.
- If long-standing, formation of bilirubin-rich gallstones (pigment stones) and an increased risk of cholelithiasis.
When looking at the clinical manifestations of intrinsic hemolysis, what’s typical for intrinsic hemolysis compared to extrinsic hemolysis?
- Hemoglobinemia, hemoglobinuria and hemosiderinuria. When red cells burst they release hemoglobine in the circulation.
- Loss of iron (leads to iron deficiency)

