Chapter 126 Iron Deficiency Anemia and Hypoproliferative Anemias Flashcards
What protein is most responsible for iron transport in the plasma?
Transferrin
Three conditions that need to be considered as differential diagnosis in hypochromic microcytic anemia
Thalassemia
Inflammation
Myelodysplastic Syndrome
From diet, absorption of iron is approximately __ in males and __ in females to maintain homeostasis
From diet
Men 1 mg/day
Women 1.4 mg/day
Iron transport protein that is NOT carrying iron is called
Apotransferrin
Diferric transferrin has the highest affinity for receptors
Average red cell life span?
120 days
Assuming an adult with red cell mass of 2L, how much iron is needed to replace red cells lost through senescence?
20mg/day
Additional iron needed can be taken from the diet
Iron absorption takes place largely in the
Proximal small intestine
Principal iron regulatory hormone
Hepcidin
First stage of iron deficiency - demands for or losses of iron exceed body’s ability to absorb iron from the diet
Negative iron balance
Expected iron studies findings in negative iron balance
Ferritin low due to mobilization of stores
Iron TIBC Tsat and protoporphyrin are all normal as long as stores are present
Stage of iron deficiency where hemoglobin synthesis becomes impaired and Tsat falls to 15-20%
Iron deficiency erythropoiesis
Expected iron studies in iron deficiency erythropoiesis
Ferritin low to absent (<15)
Serum iron starts to fall
Tsat 15-20%
TIBC increases to compensate
In males with iron deficiency, assume ___ as the cause until proven otherwise
Gastrointestinal blood loss
Sign of advanced iron deficiency: fissures at the corners of the mouth
Cheilosis
Sign of advanced iron deficiency: spooning of the fingernails
Koilonychia
Cells that are present in marrow smear when there is iron in excess of what is needed for hemoglobin synthesis
Sideroblasts
Will have visible ferritin granules in the cytoplasm
In myelodysplastic syndrome accumulation of iron in the mitochondria appears in a necklace fashion around the nucleus giving rise to these cells
Ringed sideroblasts
Intermediate in the pathway to heme synthesis, accumulates in the red cell
Protoporphyrin
Most common causes of increased red cell protoporphyrin
Iron deficiency
Lead poisoning
Differential diagnosis of microcytic anemia
Iron deficiency - low SI high TIBC absent ferritin
Inflammation - low SI low TIBC low ferritin
Thalassemia - normal SI TIBC ferritin but abnormal pattern on electrophoresis
Sideroblastic anemia
Expected RDW index for IDA vs Thalassemia
IDA - high RDW
Thalassemia - normal RDW
What compound enhances iron absorption and is given together with oral iron?
Ascorbic acid
Food may enhance/inhibit iron absorption?
Inhibit
Take oral iron on an empty stomach
Can be given to IDA if unable to tolerate oral iron
Parenteral iron (iron dextran)
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