MLT GlobeTransferrin saturation (TSAT)
Iron Studies · also called TSAT, Iron saturation, % saturation
What it measures
The percentage of transferrin binding sites occupied by iron, calculated from serum iron and TIBC. It shows how much iron is available for red cell production and screens for iron overload.
Specimen and preparation
- Specimen: Serum
- Tube: Gold top
- Preparation: Fasting morning sample preferred.
Reference range
| Group | Range |
|---|---|
| Adult male | 20–50 % |
| Adult female | 15–50 % |
Reference ranges differ between laboratories, methods and populations. Always use the range printed on your own lab report.
Causes of high values
- Hereditary hemochromatosis (often >45%)
- Transfusional iron overload
- Iron therapy
- Ineffective erythropoiesis (thalassemia, sideroblastic anemia)
Causes of low values
- Iron deficiency (often <16%)
- Anemia of chronic disease
- Chronic kidney disease with functional iron deficiency
Method
Calculated: serum iron ÷ TIBC × 100
Good to know
A fasting TSAT above 45% with raised ferritin should prompt HFE genetic testing.
Related tests
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