Iron Flashcards
Iron is metal component of (4)
hemoglobin
myoglobin
cytochromes
some proteins of electron transport chain
Total iron in males and females (g)
male: 4-5g
female: 3-4g
Role of transferrin (2)
- transferrin binds to iron in Fe3+ state
- transferrins are iron-binding blood plasma glycoproteins that control level of free iron
Transferrin has _____ specific high-affinity Fe(III) binding sites
2
When iron stores become low, transferrin levels will_________.
When there is too much iron, transferrin levels are ___________
increase
low
Which type of anaemia is connected to low transferrin?
Hypo-chromic anemia
What is measured to determine iron deficiency/overload (2)?
iron
iron-binding capacity
Is serum iron enough for information on iron levels?
No, information is not complete
In which 5 compartments is body iron distributed?
- hemoglobin
- storage iron
- tissue iron
- myoglobin
- labile pool
Cyanmethemoblobin method (4)
- principle of method is based on the oxidation of Fe2+ to Fe3+
- by ferricyanide
- methemoglobin is converted to stable cyanomethemogline with addition of KCN
- absorbance is measured at 540nm and used to calculate concentration of hemoglobin
Total iron-binding capacity (4)
- measures blood’s capacity to bind iron with transferrin
- it measures max amount of iron, which is indirect measure of transferrin
- it is calculated by adding serum iron and unsaturated iron binding capacity (UIBC)
- it is mostly used for iron deficiency or hemochromatosis
Specimen requirements for iron (4)
- no anticoagulant in serum
- plasma with heparin oxalate, citrate or EDTA bind Fe so they are UNACCEPTABLE
- no hemolysis
- early morning sample preferred
Normal range serum iron
50 -160 μg/dl
Normal range TIBC
250 - 450 μg/dl
Normal range transferrin saturation
20-55%
Diurnal iron variation for male and female
Men: 65-165 µg/dL
Women: 45-160 µg/dL
Causes for decreased iron levels (3)
Decreased intake
Increased need
Increased loss
Causes for increased iron levels (6)
Increased absorption
Hemolytic anemia
Lead poisoning
Pernicious anemia
Megaloblastic anemia
Hepatitis
TIBC increased causes (4)
Late pregnancy
IDA-Iron-deficiency anemia
Following hemorrhage
Following destruction of liver cells
TIBC decreased causes (2)
Decreased synthesis of transferrin
Increased loss of urine proteins
HbS solubility test (3)
- Hemoglobin S, when deoxygenated, is insoluble in concentrated phosphate buffer and produces visible turbidity
- Almost all other hemoglobins, including hemoglobins A, F, C, E, and D, are soluble in such solutions.
- Thus, this test quickly identifies specimens of blood that contain HbS
Unstable hemoglobins
- Treatment of the blood sample with heat at 55 “C to 60 “C or with isopropanol is used to detect the presence of unstable hemoglobins.
- detected by increase in turbidity in 3-4min
Unstable hemoglobins
- Treatment of the blood sample with heat at 55 “C to 60 “C or with isopropanol is used to detect the presence of unstable hemoglobins.
- detected by increase in turbidity in 3-4min
For myoglobin test which sample is preferred?
Plasma
