Iron deficiency anemia: Don’t forget gastric atrophy!

We read the paper by Apostolopoulos et al. with great interest [1]. In this paper, the authors point out the role of wireless capsule endoscopy in investigating unexplained iron deficiency anemia after negative standard endoscopic evaluation, and then recommend a gastrointestinal diagnostic algorithm. We agree. However, in a step by step approach to the evaluation of iron deficiency anemia, one should not forget that atrophic gastritis may be responsible for iron malabsorption. In our clinical practice, this hypothesis has to be investigated in women with iron deficiency refractory to oral supplementation. It is confirmed by high serum gastrin and is usually related to autoimmune atrophic gastritis, also called pernicious anemia or Biermer’s disease. It is related to fundic atrophy, and the patients present reduced secretion of gastric acid which compromises iron absorption. Vitamin B-12 deficiency occurs later than iron deficiency because of more abundant body reserves. Lagarde et al. recently demonstrated that iron deficiency is not rare in pernicious anemia, especially in premenopausal women, suggesting menstrual blood loss could play a role [2]. Other studies have suggested that some patients with unexplained iron deficiency anemia have presented atrophic gastritis [3] [4].

So, if initial evaluation fails to disclose a likely cause of iron deficiency, an increased likelihood of abnormal iron absorption should be considered. Tests for celiac disease, autoimmune atrophic gastritis (serum gastrin, antiparietal cells antibodies), and also H. pylori infection [5] may offer a high-sensitivity screening [6] and a very effective starting point for further investigations - such as wireless capsule endoscopy. Moreover, it should also not be forgotten that profound hypochlorhydria induced by proton pump inhibitor may also impair the optimal absorption of orally administered iron in iron-deficient individuals [7]. In the case of atrophic gastritis, microcytic anemia can then be easily cured by iron supplementation with parenteral infusion.

Competing interests: None

References

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• 2 Lagarde S, Jovenin N, Diebold M D. et al . Is there any relationship between pernicious anemia and iron deficiency?.  Gastroenterol Clin Biol. 2006;  30 1245-1249
• 3 Dickey W, Kenny B D, McMillan S A. et al . Gastric as well as duodenal biopsies may be useful in the investigation of iron deficiency anaemia.  Scand J Gastroenterol. 1997;  32 469-472
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• 7 Sharma V R, Brannon M A, Carloss E A. Effect of omeprazole on oral iron replacement in patients with iron deficiency anemia.  South Med J. 2004;  97 887-889