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Epic Test Code LAB94 Iron

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

0.5 mL

  • Multiple test can be performed from this volume. For question please contact the lab at 547-3975.  

Transportation Needs

Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements". 

Storage Requirements

Sample tubes should be centrifuged within 2 hours of collection 

Gold tops are stable in original tubes for 7 days DO NOT ALIQUOT

Aliquot Red tops

See Causes of Rejection for temperature requirements.

Causes for Rejection

Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes
 > 7 days refrigerated
> 4 days Room Temperature
> 40 days Frozen
Hemolysis > 50 mg/dL HgB
Lipemia > 400 mg/dL Trig
Bilirubin > 40 mg/dL Bili
Heparin, EDTA, NaF

Limitations

Hemoglobin of 50 mg/dL [0.03 mmol/L (monomer)] increases the IRN 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])e increases the IRN 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 IRN 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. Gross hemolysis may interfere with serum iron.

Reference Values

Population Units Reference Range
Less than 31 days old ug/dL 100 - 250
31 dasy - 1 year old ug/dL 40 - 100
1 year - 13 years ug/dL 50 - 120

≥ 13 years old

 ug/dL 50-212

 

Days of Analysis

All

Available STAT

No

Additional Information

Patient Preparation:
Patient Instructions for Fasting Laboratory Testing

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:

Percent Iron Saturation (aka Percent Transferrin Saturation) is calculated as follows:

 

Iron Saturation (%) = (Serum Ironx100)/TIBC

 

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

Methodology

Beckman AU/Dx Series

CPT Code

83540

Last Updated

26-OCT-24 MS