High prevalence of atrophic body gastritis in patients with unexplained microcytic and macrocytic anemia: a...

Atrophic body gastritis (ABG) is characterized by atrophy of the gastric body mucosa, hypergastrinemia, and hypo/achlorhydria. Its association with pernicious anemia is well recognized. Gastric hypo/achlorhydria is known to affect iron absorption but ABG is rarely considered as a possible cause of iron deficiency (microcytic) anemia. The aims of this study were to validate a screening methodology for the detection of ABG in a consecutive series of patients with microcytic and macrocytic anemia and to investigate the clinical and gastric morphofunctional characteristics of the two hematological presentations of ABG.

A two-part prospective study was carried out. Part A aimed to validate the screening methodology to detect the presence of ABG in patients with macrocytic and microcytic anemia who have no specific GI symptoms, by measuring their gastrin levels and verified by performing gastroscopy with biopsy. Part B aimed to detect the presence of ABG in a larger sample of anemic patients by our validated method and, by pooling the data of ABG patients, to determine the clinical, gastric histological, and functional characteristics pertaining to the macrocytic and microcytic presentations of ABG.

In part A, ABG was detected in 37.5% of patients with macrocytic and in 19.5% of those with microcytic anemia. Pooling the data of the ABG patients from part A and part B, microcytic ABG patients were on average 20 yr younger than those with macrocytic anemia. The majority of microcytic ABG patients were female, most of whom were premenopausal. H. pylori infection was widely represented in the microcytic ABG group (61.1%). They also had a lesser grade of body mucosal atrophy and lower hypergastrinemia levels, suggesting a less severe oxyntic damage of shorter duration.

Macrocytic anemia is not the only hematological presentation of ABG. Physicians evaluating patients with unexplained iron deficiency anemia should consider ABG as a possible cause by determining fasting gastrin levels and performing gastroscopy with biopsies of the body mucosa.