IRON-DEFCIENCY ANEMIA INTRODUCTION • Iron deficiency: ID, a state in which there is insufficient iron to maintain normal physiologic functions • Anemia: A hemoglobin concentration SDs below the mean Hb concentration for a population of the same gender and age range • Iron-deficiency anemia: IDA, top cause of anemia Children are at risk of IDA: • < 24 months of age: rapid growth + frequently inadequate intake of dietary iron places children at the highest risk of any age group for ID • > 24 months of age, the growth rate of children slows and the diet becomes more diversified • > 36 months of age, dietary iron and iron status are usually adequate MODIFICATIONS OF IRON HOMEOSTASIS IN ID • Tightly regulated by hepcidin-based homeostatic controls • Hepcidin: • a peptide hormone, synthesized primarily in the liver • increases in response to high circulating and tissue levels of iron • [hepcidin] have a strong direct correlation with [serum ferritin] • inhibited by(1) • erythropoiesis • iron deficiency • tissue hypoxia In iron deficiency, • The transcription of hepcidin is suppressed, facilitates: • the absorption of iron • the release of iron from body stores SCREENING FOR ID AND IDA • Universal screening for anemia: Hb concentration at year old (AAP) • Risk factors associated with ID/IDA: • history of prematurity or low birth weight • exposure to lead • exclusive breastfeeding beyond mos of age without supplemental iron • weaning to whole milk or complementary foods that not include iron-fortified cereals or foods naturally rich in TREATMENT • Oral Iron Therapy: • Convenient, • Inexpensive, • Effective means of treating stable patients • A daily total dose of 3-6 mg/kg of elemental iron in divided doses is adequate, with the higher dose used in more severe cases • Maximum dose: 150-200 mg of elemental iron daily • The low hepcidin levels in patients with IDA ensure effective iron absorption and the rapid recovery of hemoglobin levels • to months of treatment are required for the repletion of iron stores and the normalization of serum ferritin levels • Long-term use of oral iron is limited by side effects: • nausea, vomiting, constipation, and metallic taste • Iron sulfate is the most frequently used • Ferrous sulfate is 20% elemental iron by weight and is ideally given between meals with juice, although this timing is usually not critical with a therapeutic dose Ferlin 6mg/mL 60mL • In addition to iron therapy, dietary counseling is usually necessary • Excessive intake of milk, particularly cow’s milk, should be limited FOLLOW-UP • If the anemia is mild, the only additional study is to repeat CBC approximately wk afer initiating therapy • At this point, the hemoglobin has usually risen by at least 1-2 g/dL and has often normalized • If the anemia is more severe, earlier confrmation of the diagnosis can be made by the appearance of a reticulocytosis usually within 48-96 hr of instituting treatment IRON REFRACTORY IRON DEFCIENCY ANEMIA • Iron-deficiency anemia is usually acquired • iron-refractory iron-deficiency anemia (IRIDA): rare autosomal recessive disorder • IDA is defined as “refractory” when • absence of hematologic response (an increase of < g/dL of hemoglobin) • after to weeks of treatment with oral iron • IRIDA caused by a mutation in TMPRSS6 gene • Constitutively high production of hepcidin => Blocks the intestinal absorption of iron • Typical findings include • a striking microcytosis • extremely low transferrin saturation • normal or borderline-low ferritin levels • high hepcidin levels • The diagnosis ultimately requires sequencing of TMPRSS6 • IRIDA represents less than 1% of the cases of irondeficiency anemia seen in medical practice(1) • Poor compliance (true intolerance of Fe is uncommon • Incorrect dose or medication • Malabsorption of administered iron • Ongoing blood loss, including gastrointestinal, menstrual • Concurrent infection or inflammatory disorder inhibiting the response to iron • Concurrent vitamin B12 or folate deficiency • In most cases, iron resistance is due to disorders of the gastrointestinal tract • Partial or total gastrectomy or any surgical procedure that bypasses the duodenum can cause resistance to oral iron • Hp infection ... functions • Anemia: A hemoglobin concentration SDs below the mean Hb concentration for a population of the same gender and age range • Iron-deficiency anemia: IDA, top cause of anemia Children... IRON REQUIREMENTS • IRON REQUIREMENTS FOR TODDLERS • mg/day • IRON REQUIREMENTS FOR TERM INFANTS • Term infants – months: 0.27 mg/day • Term infants – 12 months: 11 mg/day • IRON REQUIREMENTS FOR... deplete iron stores if additional supplemental iron is not provided ETIOLOGY • Most iron in neonates is in circulating hemoglobin • As the relatively high hemoglobin concentration of the newborn