Iron-refractory iron deficiency anemia

Individuals with iron-refractory iron deficiency anemia (IRIDA) typically do not respond to oral iron treatment, but may partially respond to parenteral iron administration (via injection or intravenously); therefore, IRIDA is typically treated with parenteral iron. Currently there are only a few reports addressing the effectiveness of iron treatment and follow up of individuals receiving treatment.^[1]

Pearson and Lukens proposed a treatment regimen involving iron dextran administration every 2 to 4 years, or when serum ferritin levels decreased to lower than 50-75 ng/mL, or if the mouth ulcerations observed in their patients recurred. Hartman et al described the course of five individuals with IRIDA who were followed for 15 years and noted that if repeated iron infusions were given (causing the serum ferritin to increase to levels greater than 200 ng/mL), considerable improvement in both anemia and microcytosis occurred. While the serum iron and transferrin saturation occasionally reached the normal range, their patients still generally remained hypoferremic. When iron infusions were stopped microcytosis returned, but not to the severe degree present in infancy.^[2] There has also been one case report of an affected infant who responded to oral iron therapy when supplemented with ascorbic acid.^[1]

In the limited published cases, children affected with IRIDA have shown normal growth and development and have been generally healthy. Despite laboratory evidence of severe iron deficiency, only some affected individuals appear to have clinical signs or symptoms. There has been no evidence of neurodevelopmental delay in affected individuals.

Given the small number of reported cases, experience with the clinical course and long-term management of IRIDA is currently limited. In affected individuals studied by Galanello and colleagues, it was observed that anemia appears to be more severe during childhood. It was proposed that the greater severity of the anemia during childhood could reflect the greater iron demands for body growth at this time.^[2]