Absorption of the oral iron preparation ferrous acetyl transferrin in achlorhydric patients: a pilot study

Abstract

Gastric acid secretion is an important factor in iron absorption in humans. Chronic corporal atrophic gastritis (CAG) is a pathologic condition characterized by oxyntic mucosal atrophy and hypochlorhydria that may cause unexplained iron-deficiency states that are difficult to treat with standard oral iron therapy. The molecule ferrous acetyl transferrin (FAT) displays a high degree of homology with human transferrin and may thus use the same transferrin receptor-mediated iron absorption system on ileal and duodenal crypts. We tested this oral iron preparation in nine achlorhydric CAG patients to evaluate its absorption in the total absence of gastric acid secretion. FAT 40 mg was administered twice daily by mouth for 7 days. Blood samples for determination of serum iron, ferritin, and transferrin levels were collected and calculation of the transferrin saturation index was performed before drug administration at 8 am on the first day of the study (when patients had been fasting), on day 8 (13 hours after the last dose of FAT), and on day 15 (7.5 days after the last dose of FAT). Serum iron levels on day 15 (median, 65 μg/dL) were significantly increased over pretreatment levels (median, 32.5 μg/dL) and over the levels observed on day 8 (median, 47.0 μg/dL). A similar increase in median transferrin saturation index was observed (17.52% on day 15 vs 7.33% before treatment and 11.53% on day 8). Serum transferrin levels decreased significantly from day 8 (median, 281.5 mg/dL) to day 15 (median, 264.5 mg/dL). The study shows that in CAG patients with achlorhydria, iron in the form of FAT administered by mouth can be absorbed, resulting in increases in serum iron level and transferrin saturation index, during short-term treatment.