chapter 9 - iron kinetics & laboratory assessment

transferrin

how is iron transported in plasma?

ferritin

major metabolically available storage form of iron in the body

transferrin

total iron-binding capacity (TIBC) of the serum is an indirect measure of which iron-related protein

increased sTfR

decreased log ferritin

increased sTfR/log ferritin ratio

set of results that would indicate iron deficiency

divalent metal transporter 1

membrane-associated protein in enterocytes that transport iron from intestinal lumen into the enterocyte

ferroportin

membrane protein that transport iron out of macrophages, hepatocytes, and enterocytes

3, 4, 1, 5, 2

steps in the process from absorption & transport of iron to incorporation into heme

1. transferrin picks up ferric iron

2. iron is transferred to mitochondria

3. DMT1 transports ferrous iron into enterocyte

4. ferroportin transports iron from enterocyte to plasma

5. transferrin receptor transports iron into cell

it is recycled to plasma membrane, where it can bind its ligand again

fate of transferrin receptor when it has completed its role in delivery of iron into cell

hepcidin

regulates transfer of iron from enterocyte into plasma

15%

percent transferrin saturation for px with

total serum iron - 63 ug/dL

TIBC - 420 ug/dL

latent iron deficiency

into which quadrant of Thomas plot would px’s results fall with the ff. test results?

soluble transferrin receptor - increased above reference interval

ferritin - decreased below reference interval

Hgb content of reticulocytes - within reference interval

soluble transferrin receptor (sTfR)

most helpful information to differentiate IDA from anemia caused by functional iron deficiency

erythroferrone

developing erythroblasts in the bone marrow affects the supply of body iron by secreting which hormone

hepcidin

secreted by hepatocytes to regulate iron absorption & recycling

transferrin receptor 2

plays a role in body iron SENSING so as to adjust iron absorption & recycling