Total Iron Binding Capacity (TIBC)
From Health Facts
Latest Edit: Hector 2014-03-21 (EDT)
See Also | Lab Tests |
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This test is used to assess iron metabolism in patients who are suspected of having iron deficiency, overload, or poisoning.
[1], [2]
Discussion
- Roughly 70% of the iron in the body is found in the hemoglobin of the red blood cells (RBCs), while the remaining 30% is stored in the form of ferritin and hemosiderin.
- Iron is supplied by the diet. About 10% of the ingested iron is absorbed in the small intestine and transported to the plasma, where the iron is then bound to a protein called transferrin and carried to the bone marrow to be incorporated into hemoglobin.
- TIBC is therefore a measurement of all proteins available for binding mobile iron. It is also an indirect yet accurate measurement of transferrin.
Patient Preparation
- Fasting is required for 12 hours before the blood test. Water is permitted.
- Factors which can cause increased levels
- Recent blood transfusions, ingestion of a meal high in iron content, hemolytic diseases
- Durgs: Fluorides and oral contraceptives
- Factors which can cause decreased levels
- Drugs: ACTH and chloramphenicol
Clinical Implications
High levels indicate:
- Estrogen therapy
- Pregnancy (late)
- Polycythemia vera
- Iron-deficiency anemia
Low levels indicate:
- Malnutrition
- Hypoproteinemia
- Inflammatory diseases
- Cirrhosis
- Hemolytic anemia
- Pernicious anemia
- Sickle cell anemia
Associated Tests
- Ferritin
References
- ↑ Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.
- ↑ Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain.