Thyroid Stimulating Hormone (TSH), Reflexive
| Label Mnemonic: | TSHR |
| Epic code: | LAB840 |
| Order form: | Laboratory Requisition |
| Supply order: | Supply Order Form |
| Billing: | Billing Policies |
| CPT code: | 84443 |
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| Plasma Separator Tube 4.5 mL |
3 mL whole blood in light green top or THREE Microtainer® devices.
Serum/Plasma Normal Range*
| Age | Range |
|---|---|
| 0 up to 48 hours | 5.00 – 25.00 µIU/mL |
| 48 hours up to 1 month | 1.50 – 8.00 µIU/mL |
| 1 – <12 months | 1.03 – 6.80 µIU/mL |
| 1 – <15 years | 1.12 – 5.01 µIU/mL |
| 15 – <19 years | 0.68 – 4.09 µIU/mL |
| 19+ years | 0.27 – 4.20 µIU/mL |
*Ranges approved by Laboratory Director. Pediatric reference intervals are from the CALIPER study
Bohn MK, Higgins V, Asgari S, Leung F, Hoffman B, Macri J, Adeli K. Paediatric reference intervals for 17 Roche cobas 8000 e602 immunoassays in the CALIPER cohort of healthy children and adolescents. Clin Chem Lab Med. 2019 Nov 26;57(12):1968-1979. doi: 10.1515/cclm-2019-0707. PMID: 31377737.
Reference ranges updated 4/8/2026
The assay is unaffected by icterus (bilirubin is less than 41 mg/dL), hemolysis (Hb is less than 1000 mg/dL), lipemia (Intralipid is less than 1500 mg/dL) and biotin is less than 1200 ng/mL (criterion: recovery within plus or minus 10% of initial value).
This TSH assay is not significantly impacted by high-dose biotin. Studies have shown that serum concentrations of biotin did not exceed 1200 ng/mL in subjects taking a single dose of 300 mg biotin.
No interference was observed from rheumatoid factor (up to 1500 U/mL) and samples from dialysis patients.
There is no high-dose hook effect for TSH concentrations up to 1000 μIU/mL.
In vitro tests were performed on 17 commonly used pharmaceuticals. No interference with the assay was found.
The presence of autoantibodies may induce high molecular weight complexes (macro-TSH) which may cause unexpectedly high values of TSH.
As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or have received them for diagnostic purposes.
In rare cases, interference due to extremely high titers of antibodies to ruthenium can occur. TSH reagent contains additives which minimize these effects.
Extremely high titers of antibodies to streptavidin can occur in isolated cases and cause interference.
For diagnostic purposes, the TSH findings should always be assessed in conjunction with the patient's medical history, clinical examination and other findings.
Electrochemiluminescence Immunoassay
Assay updated with increased tolerance to biotin on 08-25-2020.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.
If TSH is outside the reference range, a Free T4 is automatically analyzed, at an additional charge to the patient.
Please print, complete and submit the Advance Beneficiary Notice (ABN) along with the Laboratory Requisition before shipping the specimen.