Iron and Copper Deficiencies And Disorders (Schalm 27) Flashcards
Serum Iron Concentration measures what form of iron?
Iron in the plasma bound to transferrin. It typically does not include hemoglobin bound iron unless hemolysis is moderately increased
Name three conditions that result in serum iron below the pRI
- iron deficiency
- inflammatory disease
- glucocorticoid admin in ruminants
- (epo administration w/o iron supplementation)
What are three conditions that increase serum iron above pRI’s?
- hemolytic anemias
- dyserythropoiesis
- hypoplastic anemia
- aplastic anemia
- iron overload
- dogs and horses given glucocorticoids
What does iron percent saturation represent?
The number of filled iron binding sites on transferrin.
What may decrease percent iron saturation?
Iron deficiency
What does total iron-binding capacity represent?
TIBC is an indirect measure of total serum transferrin concentration. Measured similarly to total iron, but preliminary steps saturate transferrin to find out how much is subsequently released.
Absolute iron deficiency increases the TIBC in which species? In which species is TIBC not increased with iron deficiency?
- Increased in humans, horses, cattle, pigs
- not increased in dogs
Decreased TIBC may occur with what conditions?
Inflammatory diseases
Serum levels of what acute phase protein correlate with tissue iron stores in most domestic animals?
Ferritin
What disorders may be associated with increased serum ferritin?
- chronic hemolytic anemias
- repeated blood transfusions
- benign hemophagocytic disorders and malignant histiocytosis
- transient increase in horses after intense exercise
What may decrease serum ferritin?
Iron deficiency
How does inflammation and iron deficiency affect ferritin?
Iron deficiency decreases ferritin, but the ferritin increase from an acute phase response masks the decreased storage
What are the two broad categories of iron deficiency? What are primary differentials for each?
Absolute
- CHRONIC HEMORRHAGE
- insufficient GI iron absorption
- Iron poor diet
Functional
- Inflammation!
How might reticulocyte indices be affected by iron deficiency?
Reticulocyte hemoglobin content (CHr) and reticulocyte mean cell volume (MCVr) may both be decreased in iron deficiency, often before microcytosis and hypochromasia are noted on the mature RBC indices.
How do PSS affect peripheral blood film indices?
Dogs with PSS often have microcytosis and hypochromasia, but are not anemic. This is thought to represent some altered iron metabolism secondary to iron sequestration in the liver, but this has not been fully characterized.
What is the hallmark sign of sideroblastic anemia? What is its clinical disease association?
- > /= 5 large iron aggregates within RBC’s or erythroid precursors (sideroblasts), or the presence of iron distributed in a ring around the nucleus of erythroid precursor cells (ringed sideroblasts)
- rare in dogs, but has primarily seen with inflammatory disease
What mineral deficiency, other than iron, is associated with microcytic, hypochromic anemia (mostly in ruminants)?
Copper deficiency
- can also be seen with high dietary molybdenum or sulfate, impairing copper use
- this results in a functional iron deficiency with decreased ceruloplasmin, hephaestin, and cytochrome oxidase, which are required for iron transport
Define hemochromatosis
Define hemosiderosis
Hemochromatosis: Accumulation of iron in tissue with associated organ injury and dysfunction
Hemosiderosis: accumulation of iron without evidence of organ injury or dysfunction (usually at sites where hemorrhage has occurred or with chronic hemolytic conditions)
Describe primary and secondary hemochromatosis
Primary hemochromatosis: hereditary and described in Salers cattle - poor do-ers
Secondary hemochromatosis: usually associated with hemolytic anemias, repeated blood transfusions, or iron administration or overload.
