A 55-year-old with macrocytic anemia, a smooth tongue, and absent ankle jerks has serum B12 of 85 pg/mL (normal >200). Peripheral smear shows hypersegmented neutrophils. Anti-intrinsic factor antibodies are positive. The intrinsic factor in pernicious anemia is normally secreted by:
- A Parietal cells of the gastric corpus and fundus ✓
- B Chief cells of the gastric fundus
- C G cells of the gastric antrum
- D Enterochromaffin-like (ECL) cells of the gastric fundus
Correct answer: A. Parietal cells of the gastric corpus and fundus
Explanation
Intrinsic factor (IF) is secreted by parietal cells (oxyntic cells) in the gastric corpus and fundus; the same cells also secrete hydrochloric acid via H+/K+-ATPase. Pernicious anemia results from autoimmune destruction of parietal cells (anti-parietal cell antibodies) and/or blocking of IF by anti-IF antibodies. Chief cells secrete pepsinogen; G cells secrete gastrin; ECL cells secrete histamine.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.