Autoimmune gastritis leading to decreased intrinsic factor production by gastric parietal cells results in which anemia?

Autoimmune gastritis leading to decreased intrinsic factor production by gastric parietal cells results in which anemia?

• A. Iron-deficiency anemia
• B. Aplastic anemia
• C. Pernicious anemia
• D. Folate deficiency anemia

Answer: (C)

Intrinsic factor is essential for the intestinal absorption of vitamin B12. Autoimmune gastritis targets gastric parietal cells, reducing or eliminating intrinsic factor production. Without intrinsic factor, vitamin B12 cannot be absorbed properly, leading to vitamin B12 deficiency. This impairs DNA synthesis in hematopoietic cells, resulting in a macrocytic, megaloblastic anemia known as pernicious anemia when caused by autoimmune loss of intrinsic factor. This differs from iron-deficiency anemia (microcytic), aplastic anemia (bone marrow failure), or folate deficiency anemia (macrocytic due to folate shortage, not IF deficiency).

Intrinsic factor is essential for the intestinal absorption of vitamin B12. Autoimmune gastritis targets gastric parietal cells, reducing or eliminating intrinsic factor production. Without intrinsic factor, vitamin B12 cannot be absorbed properly, leading to vitamin B12 deficiency. This impairs DNA synthesis in hematopoietic cells, resulting in a macrocytic, megaloblastic anemia known as pernicious anemia when caused by autoimmune loss of intrinsic factor. This differs from iron-deficiency anemia (microcytic), aplastic anemia (bone marrow failure), or folate deficiency anemia (macrocytic due to folate shortage, not IF deficiency).