Test Code THCSD Thyroid Function Cascade, Initial Screen (with Thyroid Peroxidase Antibody), Serum
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL Serum
Collection Instructions:
1. Within 2 hours of collection, centrifuge the specimen.
2. For serum gel tubes, serum may sit on gel refrigerated or be aliquoted into a plastic vial.
3. For red top tubes, aliquot serum immediately into a plastic vial.
Useful For
Screening for a diagnosis of thyroid disease
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| STSHC | TSH, Sensitive, S | Yes | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| FRT4C | T4 (Thyroxine), Free, S | Yes | No |
| TPOA | Thyroperoxidase Ab, S | Yes | No |
| T3C | T3 (Triiodothyronine), Total, S | Yes | No |
Testing Algorithm
If thyrotropin (TSH, formerly thyroid-stimulating hormone) is less than 0.3 mIU/L, then free T4 (thyroxine) will be performed at an additional charge.
If FT4 is normal and the TSH is less than 0.1 mIU/L, then T3 (triiodothyronine) will be performed at an additional charge.
If TSH is greater than 4.2 mIU/L, then free T4 and thyroperoxidase antibodies will be performed at an additional charge.
Method Name
Electrochemiluminescent Immunoassay (ECLIA)
Reporting Name
Thyroid Function Cascade, SSpecimen Type
SerumSpecimen Minimum Volume
Serum: 1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 7 days |
| Frozen | 30 days | |
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
0-5 days: 0.7-15.2 mIU/L
6 days-2 months: 0.7-11.0 mIU/L
3-11 months: 0.7-8.4 mIU/L
1-5 years: 0.7-6.0 mIU/L
6-10 years: 0.6-4.8 mIU/L
11-19 years: 0.5-4.3 mIU/L
≥20 years: 0.3-4.2 mIU/L
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 2 daysPerforming Laboratory
MCHS- MankatoTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
84443
84439-(if appropriate)
84480-(if appropriate)
86376 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| THCSD | Thyroid Function Cascade, S | 11579-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| STSHC | TSH, Sensitive, S | 11579-0 |