Sickle cell anemia is a severe form of which type of hemolytic anemia?

Sickle cell anemia is a severe form of which type of hemolytic anemia?

• A. Extravascular
• B. Intravascular
• C. Autoimmune
• D. Microangiopathic

Answer: (A)

Extravascular hemolysis is the main way red cells are destroyed in sickle cell anemia. The sickled HbS-containing red cells become rigid and abnormal, especially under low oxygen, and are readily recognized and removed by splenic macrophages. This leads to chronic destruction outside the vessels, with anemia, increased bilirubin, and signs like jaundice and pigmented gallstones. Intravascular hemolysis (destruction inside blood vessels) can occur but is not the predominant process in this disease. Autoimmune and microangiopathic hemolysis are different mechanisms not characteristically driving sickle cell anemia.

Extravascular hemolysis is the main way red cells are destroyed in sickle cell anemia. The sickled HbS-containing red cells become rigid and abnormal, especially under low oxygen, and are readily recognized and removed by splenic macrophages. This leads to chronic destruction outside the vessels, with anemia, increased bilirubin, and signs like jaundice and pigmented gallstones. Intravascular hemolysis (destruction inside blood vessels) can occur but is not the predominant process in this disease. Autoimmune and microangiopathic hemolysis are different mechanisms not characteristically driving sickle cell anemia.