Iron studies
Transferrin / TIBC
Iron-transport protein; rises in deficiency, falls in inflammation and malnutrition.
Sample
Serum
Clinical reference range
200 to 360 mg/dL
Adult transferrin
Conv: 200–360 mg/dL
Biology
What it measures
Hepatocyte-secreted glycoprotein with two iron-binding sites. TIBC ≈ transferrin × 1.4.
Clinical use
Why we order it
Adjunct to ferritin and TSAT in classifying iron status.
Lens · Clinical
Interpretation by lens
Clinical interpretation
High TIBC + low ferritin + low TSAT = classic iron deficiency.
Differential
Causes of abnormal values
Causes of HIGH
- ↑Iron deficiency (compensatory)
- ↑Pregnancy
- ↑Estrogens / OCP
Causes of LOW
- ↓Inflammation (negative acute-phase reactant)
- ↓Liver failure
- ↓Malnutrition
- ↓Nephrotic syndrome (urinary loss)
Pitfalls
Pre-analytic & interpretation traps
- !TIBC may be normal in iron deficiency masked by inflammation.
Related