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Test Code LAB1230109 Thyroid Function Reflex Cascade

Useful For

This test utilizes an automatic cascading testing procedure to efficiently evaluate and monitor functional thyroid status.

Reflex Cascade:

  • If the TSH is low, a Free T4 (Lab127) is reflexed.
  • If the TSH is <0.1 uIU/mL, and the reflexed Free T4 is normal, a Total T3 (Lab5183) is reflexed to be sent to Mayo.
  • If the TSH is high, a Free T4 (Lab127) and Thyroperoxidase (Lab1232371) are reflexed.

Performing Laboratory

  • Asante Rogue Regional Medical Center (ARRMC)
  • Asante Three Rivers Medical Center (ATRMC)
  • Ashland Community Hospital (AACH)

 

Performing Department

Chemistry

Specimen Required

 

Outpatient clients MUST draw SST

Specimen Minimum Volume

2.0 mL

Specimen Stability Information

Centrifuge and refrigerate within 2 hours of collection

Serum stable 48 hours if aliquoted and refrigerated at 2° to 8° C and serum is separated from cells by either aliquoting or use of a gel separator tube.

Separate and freeze if testing is delayed greater than 48 hours.

Reject Due To

  • Gross Hemolysis or Lipemia
  • Quantity not sufficient (QNS)
  • Lack of Two Patient Identifiers:
    • 1-Patient's First & Last name 
    • 2-Patient's Date of Birth

Day(s) Performed

Report Available

  • Routine – same day
  • ASAP – 2 hours after receipt of specimen in lab
  • STAT – 1 hour after receipt of specimen in lab

Note: If reflex testing triggers Mayo (Lab5183) then turnaround time will be delayed for the full cascade

Method Name

  • TSH: Third Generation Chemiluminescence (ultra-sensitive) 
  • FT4:  Two Step Enzyme Immunoassay
  • TT3:  Electrochemiluminescence
  • TPO: Chemiluminescent Immunoassay

CPT Code Information

  • 84443  -   Thyroid stimulating hormone (TSH)
  • 84439 -    FT4          
  • 84480 -    TT3
  • 86376 -    TPO