Is there any relationship between pernicious anemia and iron deficiency?

Previous studies have suggested that iron deficiency could be due to atrophic gastritis of the body/fundus. The aim of this study was to determine the prevalence of iron deficiency among patients with pernicious anemia and associated factors.

All patients with pernicious anemia diagnosed at our institution between January 1990 and February 2005 were included. Inclusion criteria were: 1- histological diagnosis of atrophic fundic gastritis and 2- criteria of gastric autoimmune involvement. Histology of gastric biopsies was performed in a blinded manner. Iron deficiency was defined as serum ferritin level<15 microg/L in women and<40 microg/L in men.

Ninety-five patients (69 women), mean age 60 years (range: 23-90) were included. Twenty patients (21.1%) had normal blood cell counts; 12 patients (12.6%) had microcytosis with or without anemia and 53 patients (55.8%) macrocytosis with or without anemia. Serum ferritin levels were measured in 58 patients, 16 (27.6%) of whom, all women, had iron deficiency. They were significantly younger (39.2 years) than patients without iron deficiency (61.6 years, P<0.0001). Serum gastrin levels did not differ between the groups with and without iron deficiency. A significantly more severe inflammatory infiltrate of the fundus and endocrine cell hyperplasia was observed in iron deficiency patients. Multivariate analysis showed that iron deficiency was linked to female gender and age<50 years.

Iron deficiency and microcytic anemia are not rare in patients with pernicious anemia and should not rule out the diagnosis. Iron deficiency does not appear to be related to the degree of atrophic fundic gastritis but is linked to female gender and young age, suggesting menstrual blood loss could play a role. Whether decreased iron absorption due to reduced acid secretion favors the expression of gynecological iron loss cannot be ascertained.