IRON AND BILIRUBIN Flashcards
(42 cards)
Describe the methodology of the serum iron assay
- transferrin releases ferric iron in acidic conditions
- ferric iron is reduced to ferrous iron
- ferrous iron complexes with a chromogen = increased absorbance is measured
Ref: Iron
8-35 μmol/L
Ref: TIBC
40-75 μmol/L
Ref: Saturation Index
Female: 0.12 - 0.60
Male: 0.10 - 0.55
Ref: Ferritin
Female: 20 - 300 μg/L
Male: 30 - 500 μg/L
Ref: Transferrin
1.8 - 4.5 g/L
Ref: Total bilirubin
<20 μmol/L
Ref: Conjugated (direct) bilirubin
<7 μmol/L
Less than 0.1% of the body’s iron is present in plasma as __.
Less than 0.1% of the body’s iron is present in plasma as transferrin.
What is apotransferrin ?
- plasma protein
- transports ferric iron (Fe3+)
Plasma iron levels are highest in the __ and progressively __ over the day.
Plasma iron levels are highest in the MORNING and progressively DECLINE over the day.
What conditions are associated with increased serum iron ?
- hemochromatosis
- iron medication intake
- hormonal contraceptives
- aplastic anemia
What conditions are associated with decreased serum iron ?
- iron deficiency anemia
- hemorrhage
- menstruation
- medication
- anemia of chronic disease
How is TIBC measured ?
- Serum iron bound to transferrin is measured
- Excess ferric iron is added to saturate binding sites of transferrin; unbound excess iron is removed
- Serum iron assay is performed again and compared to the first measurement
How is excess iron removed during TIBC measurement ?
- Using either a silica or anion exchange column
OR
- Addition of magnesium carbonate
What causes increased TIBC ?
- iron deficiency anemia
- pregnancy
- oral contraceptives
What causes decreased TIBC ?
- chronic inflammatory disease
- malignancy
- hemochromatosis
Transferrin Saturation Calculation
Tsat% = [serum iron] / TIBC x 100%
What is ferritin ?
- the major storage form of iron
- acute phase reactant
- found in bone marrow, liver, spleen
What causes increased ferritin ?
- malignancies
- chronic infections
- hemochromatosis
- chronic inflammatory diseases (ie. SLE)
- hepatitis
The iron/ apotransferrin complex is also called __.
The iron/ apotransferrin complex is also called TRANSFERRIN.
Transferrin migrates to the __ region in SPE
Transferrin migrates to the β region in SPE
List 2 methods used to measure transferrin
- Immunoturbidimetry
- immunonephelometry
What causes increased transferrin ?
- pregnancy
- administration of estrogen
- iron deficiency