Thyroid Stimulating Hormone (TSH)
Label Mnemonic: TSH
Epic code: LAB129
Order form: Laboratory Requisition
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
4 mL whole blood in light green top or TWO Microtainer® devices.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
2 hours (upon receipt in laboratory)
Reference Range:
    AGE         MALES AND FEMALES
1 - 11 months   0.8-6.3 μIU/mL
1 - 5 years     0.7-5.9 μIU/mL
  > 5 years     Same as adult values
  Adults        0.27-4.20 μIU/mL
Comments:
This assay may be significantly impacted by high-dose biotin (>5 mg dose) taken within previous 12 hours. High concentrations of biotin may lead to falsely decreased results. These concentrations may be found in patients taking over-the-counter supplements with biotin content much higher than nutritional requirements for biotin. Specimens should not be collected until at least 12 hours after the last dose.

Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.

Samples which are part of a TRH stimulation test should be clearly identified as such.

Please print, complete and submit the Advance Beneficiary Notice (ABN) along with the Laboratory Requisition before shipping the specimen.
Test Limitations:
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 25 ng/mL (criterion: 
recovery within plus or minus 10% of initial value).

No interference was observed from rheumatoid factor (up to 3250 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 26 commonly used pharmaceuticals. No 
interference with the assay was found.

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.
Methodology:
Electrochemiluminescence Immunoassay
Sample Processing:
Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection. Send specimen in original tube. Do Not transfer to another tube.
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.
Sample Storage:
Refrigerate.
Transport Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
84443
 
See Additional Information:
Biotin Interference with Immunoassays