Iron Binding Capacity, Total (TIBC)

CPT Code(s):
83550

Turnaround Time:
4 hours

Specimen Requirements

Preferred Specimen:
Serum

Minimum Volume:
1.0 mL

Transport Container:
Serum Separator Tube (SST) or Red Top Tube

Transport Temperature:
Room Temperature

Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.

Rejection Criteria:
Plasma specimen; gross hemolysis; lipemia; improper labeling

Stability Criteria

Room Temperature:
4 days

Refrigerated:
7 days

Frozen:
60 days

Clinical Significance

The Total Iron Binding Capacity (TIBC) test is a blood test used to evaluate the body's ability to transport and bind iron. It measures the total amount of iron that can be bound by transferrin, a protein responsible for transporting iron in the blood. TIBC has specific clinical significance and diagnostic use in the following ways:

1. Assessing Iron Status: TIBC is commonly used as part of the evaluation of a patient's iron status. It helps determine whether iron levels in the body are within normal range, too low (indicating iron deficiency), or too high (indicating iron overload). By measuring the capacity of transferrin to bind iron, TIBC indirectly reflects the body's iron stores.

2. Diagnosing Iron Deficiency Anemia: Iron deficiency anemia is a common condition characterized by low levels of iron in the body, leading to reduced production of red blood cells. TIBC is an important component of the diagnostic workup for iron deficiency anemia. In this condition, the TIBC levels are typically elevated as the body attempts to increase its capacity to bind and transport iron. Combined with other iron-related markers such as serum iron and ferritin levels, TIBC helps confirm the diagnosis and guide appropriate treatment.

3. Monitoring Iron Therapy: For individuals receiving iron supplementation or undergoing treatment for iron deficiency anemia, TIBC is valuable for monitoring response to therapy. As iron stores are replenished and iron levels normalize, the TIBC levels may decrease. Periodic TIBC measurements allow healthcare providers to assess the effectiveness of treatment and adjust iron supplementation as needed.

4. Evaluating Iron Overload Disorders: TIBC can also provide valuable information in evaluating iron overload disorders such as hereditary hemochromatosis or secondary hemochromatosis. In these conditions, the body's ability to regulate iron absorption and storage is impaired, leading to excessive iron accumulation. TIBC, along with other iron-related markers, helps assess iron overload and guide further diagnostic evaluations.

In summary, TIBC is a useful tool in evaluating iron status, diagnosing iron deficiency anemia, monitoring iron therapy, and assessing iron overload disorders. It provides valuable information about the body's ability to transport and bind iron, helping healthcare providers make accurate diagnoses and develop appropriate treatment plans for iron-related disorders.