What causes pernicious anemia?

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From the Guidelines

Pernicious anemia is caused by autoimmune gastritis, which leads to a deficiency in vitamin B-12 and results in macrocytic anemia.

Key Factors

  • Autoimmune gastritis: a condition where the immune system attacks the stomach lining, leading to atrophy of the gastric mucosa and a decrease in the production of intrinsic factor, a protein necessary for vitamin B-12 absorption 1.
  • Vitamin B-12 deficiency: a crucial factor in the development of pernicious anemia, as vitamin B-12 is essential for the production of red blood cells and the maintenance of the nervous system.
  • Macrocytic anemia: a type of anemia characterized by large red blood cells, which is a hallmark of pernicious anemia. It is essential to diagnose and manage pernicious anemia promptly to prevent long-term complications, such as neurological damage and increased risk of gastric cancer 1.

From the Research

Causes of Pernicious Anemia

  • Pernicious anemia is caused by a lack of intrinsic factor, which is essential for vitamin B12 absorption in the terminal ileum 2, 3.
  • The condition is based on autoimmune chronic atrophic gastritis, which leads to the destruction of parietal cells and a deficiency in intrinsic factor 2, 4.
  • The destruction of parietal cells causes a deficiency in intrinsic factor, resulting in vitamin B12 deficiency 2.
  • Pernicious anemia is linked to but different from autoimmune gastritis, and it occurs in a later stage of autoimmune atrophic gastritis when gastric intrinsic factor deficiency and consequent vitamin B12 deficiency may occur 5.

Underlying Factors

  • Autoimmune disorders, such as autoimmune atrophic gastritis, play a role in the development of pernicious anemia 6, 4.
  • The presence of anti-intrinsic factor antibodies and parietal cell antibodies is characteristic of pernicious anemia 6, 4.
  • H. pylori infection may also be involved in the development of pernicious anemia 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Pernicious anemia. From past to present.

Revista clinica espanola, 2015

Research

Pernicious anemia.

MLO: medical laboratory observer, 2007

Research

Optimal management of pernicious anemia.

Journal of blood medicine, 2012

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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