Pernicious anemia differs from aplastic anemia in that pernicious anemia results from a lack of intrinsic factor leading to poor absorption of vitamin B12, whereas aplastic anemia is primarily due to:

Pernicious anemia differs from aplastic anemia in that pernicious anemia results from a lack of intrinsic factor leading to poor absorption of vitamin B12, whereas aplastic anemia is primarily due to:

• A. Pernicious anemia results from marrow suppression; aplastic anemia from intrinsic factor
• B. Pernicious anemia results from excessive intrinsic factor; aplastic anemia from increased red blood cell production
• C. Pernicious anemia results from lack of intrinsic factor; aplastic anemia from bone marrow suppression
• D. Pernicious anemia is caused by infection; aplastic anemia by autoimmune disease

Answer: (C)

Pernicious anemia and aplastic anemia differ by where the problem lies in blood formation. Pernicious anemia is a vitamin B12 deficiency caused by a lack of intrinsic factor, which is needed for B12 absorption in the gut. Without intrinsic factor, B12 isn’t absorbed efficiently, leading to impaired DNA synthesis in red blood cell precursors and a megaloblastic (macrocytic) anemia, with possible neurologic symptoms. Aplastic anemia, on the other hand, is bone marrow failure—the marrow stops producing adequate amounts of all blood cell lines (red cells, white cells, and platelets), causing pancytopenia. So the correct idea is that pernicious anemia arises from absence of intrinsic factor affecting B12 absorption, whereas aplastic anemia arises from bone marrow suppression.

Pernicious anemia and aplastic anemia differ by where the problem lies in blood formation. Pernicious anemia is a vitamin B12 deficiency caused by a lack of intrinsic factor, which is needed for B12 absorption in the gut. Without intrinsic factor, B12 isn’t absorbed efficiently, leading to impaired DNA synthesis in red blood cell precursors and a megaloblastic (macrocytic) anemia, with possible neurologic symptoms. Aplastic anemia, on the other hand, is bone marrow failure—the marrow stops producing adequate amounts of all blood cell lines (red cells, white cells, and platelets), causing pancytopenia. So the correct idea is that pernicious anemia arises from absence of intrinsic factor affecting B12 absorption, whereas aplastic anemia arises from bone marrow suppression.