Hypochromic Microcytic Anemias and Iron Metabolism

Vocabulary practice flashcards covering hypochromic microcytic anemias, iron metabolism, stages of iron deficiency, diagnostic laboratory tests, and blood smear findings.

Hypochromic Microcytic Anemias

A category of five anemias characterized by red blood cells that are smaller in size and contain less hemoglobin than normal cells, confirmed by a decreased MCV, MCH, and MCHC.

TAILS

A mnemonic representing the five hypochromic microcytic anemias: Thalassemia, Anemia of chronic disease, Iron deficiency anemia, Lead poisoning, and Sideroblastic anemia.

Iron Deficiency Anemia

The most common form of anemia found in outpatients, caused by blood loss, malabsorption, poor dietary intake, or increased physiological demand.

Anemia of Chronic Disease

The most common anemia observed in hospital inpatients, previously called anemia of chronic inflammation and often associated with inflammatory conditions like rheumatoid arthritis in older demographics.

Punched Out Artifact

A morphology artifact appearing as clear chunks within red blood cells, caused when methanol fixative absorbs atmospheric water in high humidity or when severely anemic blood dries too slowly on a slide.

Microcytosis

A state in which red blood cells are abnormally small, presenting with an MCV below normal at less than $80\text{ femtoliters}$.

Transferrin

A plasma transport protein that binds up to two iron molecules in the bloodstream and delivers them to bodily storage sites or directly to the bone marrow.

Ferritin

The stored form of iron found in the liver, spleen, kidney, and macrophages, serving as the most important laboratory measurement for identifying early iron deficiency before smear abnormalities appear.

Total Iron Binding Capacity (TIBC)

A laboratory measurement reflecting the capacity of available transferrin molecules to bind additional iron.

Hexanein

The regulatory gatekeeper of iron absorption that increases to close off absorption when iron levels are high and decreases to allow free iron flow when iron is deficient.

Adult Iron Recycling Rate

The proportion of total body iron recycled daily from broken down red blood cells, which equals $95\%$.

Infant Iron Recycling Rate

The proportion of iron recycled by infants from degraded red blood cells, which equals $70\%$.

Vitamin C

A dietary nutrient that enhances iron absorption in the gut by facilitating the conversion of iron from the $Fe^{3+}$ form down to the absorbable $Fe^{2+}$ form.

Tannins

Chemical compounds found in tea and red wine that inhibit the gastrointestinal absorption of iron.

Milk Babies

A bench term for infants around $5$ to $6\text{ months}$ of age presenting with hypochromic microcytic anemia from consuming low-iron cow's milk before starting iron-rich solid foods.

Hemoglobin Alert Limit

A laboratory threshold for hemoglobin values less than $80\text{ g}$, which requires phoning notification to clinicians during daylight hours ($06:00$ to $10:00$).

Hemoglobin Critical Limit

A laboratory threshold for hemoglobin values less than $60\text{ g}$, requiring immediate physician notification, including overnight calls, unless the patient is known and the value changed by less than $10\text{ g}$.

Dual Population

The presence of two distinct red blood cell populations on a blood film and histogram, typically seen after transfusing normochromic normocytic donor cells into a hypochromic microcytic patient and exhibiting an RDW over $20$.

Pearls Prussian Blue

A special histological stain used in bone marrow evaluations that stains iron particles blue within both mature and immature red blood cells.

Erythroid Hyperplasia

An increased production and proliferation of red cell precursors in the bone marrow stimulated by high levels of erythropoietin in response to tissue hypoxia.