Iron Studies Interpretation | A4 Medicine

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Iron Studies
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A chart to aid in the interpretation of iron
studies. These are set of blood tests which may
include ferritin, serum iron, transferrin,
transferrin saturation and TIBC. Serum
iron Means ferric ions Fe3 bound to serum
transferrin Only 0.1 of total body iron is
bound to transferrin at any one time Little
value if tested on its own as levels may
fluctuate through the day. Serum iron would be
decreased in Genuine iron deficiency Inadequate
Fe absorption Chronic blood loss Pregnancy 3 rd
trimester Chronic illnesses like SLE , Rh
arthritis. Serum iron increased in Haemolysis
Iron overdose Lead toxicity Hepatic necrosis
Haemochromatosis
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Transferrin Major iron binding protein carries
iron from the liver to the bone marrow A beta
globulin which is also an acute phase protein
Synthesized in liver and regulates iron
absorption Transferrin increases in iron
deficiency to maximise the utilsation of
available iron Also known as siderophilin Transfe
rrin reduced in chronic infections microcytic
anaemia as a result of chronic diseases protein
deficiency liver damage haemochromatosis kidney
injury loss of transferrin in urine malignancy
atransferrinemia genetic mutation Transferrin
elevated in Iron deficiency anaemia
Pregnancy Transferrin saturation Percentage of
transferrin and other iron binding proteins Helps
find the cause of abnormal iron and TIBC levels
Typically transferrin is 30 saturated with iron
Transferrin saturation rises in iron overload
and falls in iron deficiency A rise in serum
iron due to dietary iron intake can cause raised
transferrin saturation. Transferrin saturation
reduced in Iron deficiency anaemia Anaemia of
chronic disease Acute phase response. Transferrin
saturation elevated in haemolytic anaemia
sideroblastic anaemia megaloblastic anaemia
patient with iron overload or iron intoxication
Haemochromatosis
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Total iron binding capacity (TIBG) Indicates the
availability of iron binding sites on transferrin
It is an indirect measure of transferrin
concentration It is the sum of all the protein
bound to iron TIBC would be elevated in 70 of
of patients with Fe deficiency anaemia. It is
reduced in Haemochromatosis Hypoproteinaemia in
malabsorption Burns Cirrhosis Renal disease
Thalassemia Hyperthyroidism Non-iron deficiency
anaemia. TIBC elevated in Pregnancy Iron
deficiency Acute hepatitis Acute and chronic
blood loss. Isolated elevated transferrin
saturation- repeat a fasting sample. If
consistently raised consider HFE gene analysis
with pre-test counseling Acute hepatic injury can
present as raised iron , transferrin ,transferrin
saturation and ferritin . This is due to leakage
of hepatic content and can be easily confused
with iron overload
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• References
• Interpreting iron studies BMJ 2017357j2513 (
  2017 , June 15)
• Melbourne haematology A guide to the
  interpretation of iron studies Overview
• Deranged Physiology Interpretation of iron
  studies via www.derangedphysiology.com
• Ogun AS, Adeyinka A. Biochemistry, Transferrin.
  Updated 2019 Jan 16. In StatPearls
  Internet. Treasure Island (FL) StatPearls
  Publishing 2019
• TIBC , Transferrin and Transferrin saturation
  from www.labpedia.net
• www.Irondisorders.org- How do I know if I am
  anaemic