Autoimmune chronic gastritis and iron deficiency anemia

Severe Anemia Caused by Gastric Antral Vascular Ectasia and Autoimmune Gastritis

An 80-year-old man presented to our hospital with general fatigue on exertion that had gradually worsened over 6 months. His blood test revealed severe anemia, and gastroscopy revealed findings consistent with gastric antral vascular ectasia (GAVE) and autoimmune gastritis. We diagnosed the patient with severe anemia caused by GAVE and autoimmune gastritis. The present case suggested that GAVE is triggered by autoimmune gastritis, and the mechanism is likely related to hypergastrinemia. The reporting of this rare case may help elucidate the cause of GAVE, which is currently unknown.

Hepcidin is directly regulated by insulin and plays an important role in iron overload in streptozotocin-induced diabetic rats

Iron overload is frequently observed in type 2 diabetes mellitus (DM2), but the underlying mechanisms remain unclear. We hypothesize that hepcidin may be directly regulated by insulin and play an important role in iron overload in DM2. We therefore examined the hepatic iron content, serum iron parameters, intestinal iron absorption, and liver hepcidin expression in rats treated with streptozotocin (STZ), which was given alone or after insulin resistance induced by a high-fat diet. The direct effect of insulin on hepcidin and its molecular mechanisms were furthermore determined in vitro in HepG2 cells. STZ administration caused a significant reduction in liver hepcidin level and a marked increase in intestinal iron absorption and serum and hepatic iron content. Insulin obviously upregulated hepcidin expression in HepG2 cells and enhanced signal transducer and activator of transcription 3 protein synthesis and DNA binding activity. The effect of insulin on hepcidin disappeared when the signal transducer and activator of transcription 3 pathway was blocked and could be partially inhibited by U0126. In conclusion, the current study suggests that hepcidin can be directly regulated by insulin, and the suppressed liver hepcidin synthesis may be an important reason for the iron overload in DM2.

Gastrointestinal causes of refractory iron deficiency anemia in patients without gastrointestinal symptoms

BACKGROUND

The standard evaluation of a patient with iron deficiency anemia includes a complete evaluation of the gastrointestinal tract to identify a source of bleeding. However, even after a careful examination, many patients remain without a diagnosis. Because iron deficiency anemia results from iron loss or defective absorption, we sought to determine the prevalence of potential gastrointestinal sources for iron deficiency anemia in patients without gastrointestinal symptoms.

METHODS

Over a 10-month period, 668 outpatients were referred to the University Hematology Department with iron deficiency anemia, defined by a hemoglobin concentration less than 14 g/dL (less than 12 g/dL in women), mean corpuscular volume less than 80 fL, and ferritin level less than 30 microg/L. After excluding patients with obvious causes of blood loss, inadequate diet, chronic diseases, or malignancies, there were 81 eligible patients, 10 of whom refused investigation. The remaining 71 patients (51 women, median age 59 years) underwent colonoscopy, as well as gastroscopy with gastric (antrum and body) and duodenal biopsies.

RESULTS

A likely cause of iron deficiency anemia was detected in 60 patients (85%). Diseases associated with bleeding were found in 26 patients (37%), including colon cancer (10 patients), gastric cancer (2), peptic ulcer (7), hiatal hernia with linear erosions (5), colonic vascular ectasia (3), colonic polyps (2), and Crohn's disease (1). Causes not associated with bleeding were found in 36 patients (51%), including 19 with atrophic gastritis, 4 with celiac disease, and 13 with Helicobacter pylori gastritis. Six (8%) patients had coincident gastrointestinal findings, and 11 (15%) had no cause identified. Patients with an identified nonbleeding-associated cause were younger than those with a bleeding-associated cause (median, 56 vs 70 years; P = 0.001) and included 59% of women (n = 30) versus 30% of men (n = 6) (P = 0.04). Hemoglobin level was not related to the site and severity of disease.

CONCLUSION

Gastrointestinal diseases that do not usually cause bleeding are frequently associated with iron deficiency anemia in patients without gastrointestinal symptom or other potential causes of gastrointestinal bleeding.