Home
HelpEpic Test Code LAB3798 Unbound Iron Binding Capacity
Performing Location(s)
BMC
Specimen Type
Serum
Preferred Container
Gold or Red top tube
Blood Tube Draw Volume
Min 50% draw volume
Minimum Volume to Submit for Testing
1 mL Serum
- Multiple test can be performed from this volume. For question please contact the lab at 547-3975.
Storage Requirements
Sample tubes should be centrifuged within 2 hours of collection followed by transfer of the serum (red or gold top) to a labeled plastic, aliquot tube
See Causes of Rejection for temperature requirements.
Transportation Needs
Deliver specimen to the laboratory within 1 hour of collection. If not possible see “Storage Requirements”
Causes for Rejection
Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes
> 7 days Refrigerated (Serum tubes are routinely stored at the lab for only 7 days therefore, an add-on may not be possible after 7 days.)
> 4 days RoomTemperature
> 40 days Frozen
Hemolysis > 50 mg/dL HgB
Lipemia > 400 mg/dL Trig
Bilirubin > 40 mg/dL Bili
Heparin,EDTA,NaF
Reference Values
| Population | Reference Range | Units |
| All Population | 130-375 | ug/dL |
Serum iron is carried by binding to the transport protein, Transferrin. The measurement of the maximum concentration of iron that Transferrin can bind is called the Total Iron Binding Capacity (TIBC).
Normally, only about one third of the iron binding sites of Transferrin are occupied by Fe; therefore, transferrin has considerable reserve iron binding capacity. This is called the serum Unsaturated Iron Binding Capacity (UIBC).
Unbound Iron Binding Capacity equals the Total Iron Binding Capacity minus serum iron
(UIBC = TIBC - Serum Iron)
Includes
The Unbound Iron Binding Capacity is a calculated test. It is calculated from the Serum Iron (IRN) and the Iron Binding Capacity (TIBC)
When the Unbound Iron Binding Capacity is ordered:
If a Serum Iron and TIBC have already been performed, the test will be calculated and reported at no charge.
If a Serum Iron and/or TIBC has not already been performed, they will be performed, reported and billed (CPT’S: 83540 and 83550)
Additional Information
Patient Preparation:
Patient should be drawn fasting in the morning
Have sample drawn before patient is given therapeutic iron or blood transfusion Contraindications:
Parenteral iron (Imferon) before sample is drawn will cause misleading high iron results.
Recent blood transfusion may have only a small positive effect on iron.
Studies have shown that gadodiamide containing contrast media used in Magnetic Resonance Imaging (MRI) can produce analytic interference, both positive and negative, with assays performed in the clinical Laboratory for Calcium, Iron Magnesium, TIBC and Zinc. The package insert for Gadodiamide recommends waiting 12 to 24 hours between contrast agent administration and blood specimen collection to ensure that the contrast agent has been cleared. A longer waiting period might be necessary for patients with renal insufficiency. The average half-life of gadodiamide in patients with severely reduced renal function is 34 hours.
Miscellaneous Information:
The measurement of serum iron, iron binding capacity, and transferrin saturation are only useful in screening for chronic iron overload diseases and for confirmation and monitoring of acute iron poisoning in children. Many factors influence serum iron concentration and TIBC. Changes that may be observed in various physiological or pathological conditions include: diurnal variation, menstrual cycle, pregnancy, ingestion of iron (including iron-fortified vitamins), oral contraceptives (progesterone-like), iron dextran injection, hepatitis, acute and chronic inflammation, iron deficiency, and iron overload (hemochromatosis). Furthermore, individuals with iron deficiency may have normal values for serum iron and TIBC. For these reasons, assays for serum iron, iron binding capacity and transferrin saturation should not be used as a test for iron deficiency.
Limitations
Gross hemolysis may interfere with serum iron. Hemoglobin of 50 mg/dL [0.03 mmol/L (monomer)] increases the iron result by 20 µg/dL [3.6 µmol/L] at an iron concentration of 88 µg/dL [15.8 µmol/L]. *Bilirubin of 20 mg/dL [342 µmol/L] decreases the IRN result by 14 µg/dL [2.5 µmol/L] at an iron concentration of 102 µg/dL [18.3 µmol/L].
Lithium heparin (280 U/mL [280000 U/L]) increases the iron result by 90 µg/dL [16.2 µmol/L] at an iron concentration of 100 µg/dL [17.9 µmol/L]. Sodium citrate of 30 mM increases the iron concentration by 10 µg/dL [1.8 µmol/L] at an iron concentration of 87 µg dL [15.6 µmol/L].
Iron values may be falsely elevated in the presence of therapeutic iron-containing compounds such as iron dextran.
Except for iron poisoning, a serum iron without TIBC or transferrin is of limited value.
Available STAT
No
Days of Analysis
M-F
CPT Code
See “Includes”
Last Updated
30-Mar-19