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Soluble Transferrin Receptor, Serum

sTfR

Test Codes

EPIC: LAB7197, STFR

Department

Special Chemistry

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.  (Minimum Whole Blood: 2.0 mL) 

Also acceptable: One plain Red-top tube. (Minimum Whole Blood: 2.0 mL)

Physician Office/Draw Specimen Preparation

Let specimen clot 30 – 60 minutes then centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged collection tube prior to transport. (Minimum Serum: 0.5 mL) 

Preparation for Courier Transport

Transport: Centrifuged collection tube, refrigerated (2-8°C or 36-46°F). (Minimum Serum: 0.5mL).

Rejection Criteria

Plasma specimens.

Severely hemolyzed, lipemic or icteric specimens.

In-Lab Processing

Let specimen clot 30 – 60 minutes then immediately centrifuge to separate serum from cells. Room temperature is acceptable for a maximum of two hours. (Minimum Serum: 0.5mL)

Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers^® with Separator Gels
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers^® without Separator Gels
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 60 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Laboratory

Royal Oak Special Testing Laboratory

Performed

Tuesday, Friday.
Results available within 3 business days.

Reference Range

12.2-27.3 nmol/L

Test Methodology

Chemilunimescent Enzyme immunoassay.

Test Background

The soluble transferrin receptor (sTfR) is a soluble truncated form of the transferrin receptor. sTfR levels rise significantly as the iron level in tissue decreases, and the demand for iron increases because of expansion of the erythroid marrow. Measurement of ferritin is used for the diagnosis of iron deficiency. However, since ferritin is an acute phase reactant, it can be elevated in hospitalized or acutely ill patients. sTfR is not an acute phase reactant, and therefore may be useful in evaluating patients suspicious for iron deficiency in which ferritin concentration does not correlate with iron status. This can occur in patients with inflammatory conditions or chronic diseases.

Clinical Utility

This assay aids in the diagnosis of iron deficiency anemia.

CPT Codes

84238
LOINC:  30248-9

Contacts

Last Updated

1/13/2023