TSH, Free T4 and possibly Free T3 if TSH is abnormal
Performing Laboratory / Facility
Ronald Reagan UCLA Medical Center Clinical Laboratory UCLA Outreach Clinical Laboratory - Panorama City (BURL)
Performing Section
Chemistry
Availability
Ronald Reagan UCLA Medical Center Clinical Laboratory: Daily UCLA Outreach Clinical Laboratory - Panorama City (BURL): Monday through Friday 0600 - 0230, Saturday 1200-2030 (excluding holidays)
Turnaround Time
Ronald Reagan UCLA Medical Center Clinical Laboratory: Routine: 4 hours from receipt in the laboratory; STAT: 1 hour from receipt in the laboratory UCLA Outreach Clinical Laboratory - Panorama City (BURL): Routine: 24 hours; STAT: 4 hours from receipt in the laboratory
Methodology
Electrochemiluminescence
Use
TSH is a useful initial screen for hypo- or hyperthyroidism in most patients. TSH with reflex testing (test# 10158) is available to facilitate more timely and cost-effective workups. When this is ordered, reflex testing of free T4 (test# 9017) and possibly free T3 (test# 16073 ) is performed if the TSH is found to be abnormal, following the test rules below.; Reflex test rules for TSH with reflex testing (10158):; TSH normal (0.3-4.7 mcIU/mL): No reflex testing performed; TSH <0.3 or >4.7 mcIU/mL: Free T4 (automated) performed; TSH <0.1 mcIU/mL and free T4 normal: Free T3 (automated) performed
Replaces
TSH with Consult
Patient Preparation
Whenever possible patient should stop taking supplements containing high concentrations of biotin (vitamin B7) for at least 12 hours prior to blood collection.
Limitations
High concentrations of biotin in patient's blood may lead to falsely decreased TSH results.
Additional Information
References: Ladenson PW et al. American Thyroid Association guidelines for detection of thyroid dysfunction. Arch Intern Med. 2000 160(11):1573-5.
Specimen Type
Blood
Container
Light Green/Lithium Heparin Gold/SST Red Red Microtainer Dark Green Microtainer
Volume
2 mL (1 mL serum)
Shipping and Handling Instructions
Separate serum and freeze.
Test Information
CPT Codes
84443 84439 (FT4) 84481 (FT3)
Test Includes
TSH, Free T4 and possibly Free T3 if TSH is abnormal
Performing Laboratory / Facility
Ronald Reagan UCLA Medical Center Clinical Laboratory UCLA Outreach Clinical Laboratory - Panorama City (BURL)
Performing Section
Chemistry
Availability
Ronald Reagan UCLA Medical Center Clinical Laboratory: Daily UCLA Outreach Clinical Laboratory - Panorama City (BURL): Monday through Friday 0600 - 0230, Saturday 1200-2030 (excluding holidays)
Turnaround Time
Ronald Reagan UCLA Medical Center Clinical Laboratory: Routine: 4 hours from receipt in the laboratory; STAT: 1 hour from receipt in the laboratory UCLA Outreach Clinical Laboratory - Panorama City (BURL): Routine: 24 hours; STAT: 4 hours from receipt in the laboratory
Methodology
Electrochemiluminescence
Use
TSH is a useful initial screen for hypo- or hyperthyroidism in most patients. TSH with reflex testing (test# 10158) is available to facilitate more timely and cost-effective workups. When this is ordered, reflex testing of free T4 (test# 9017) and possibly free T3 (test# 16073 ) is performed if the TSH is found to be abnormal, following the test rules below.; Reflex test rules for TSH with reflex testing (10158):; TSH normal (0.3-4.7 mcIU/mL): No reflex testing performed; TSH <0.3 or >4.7 mcIU/mL: Free T4 (automated) performed; TSH <0.1 mcIU/mL and free T4 normal: Free T3 (automated) performed
Replaces
TSH with Consult
Patient Preparation
Whenever possible patient should stop taking supplements containing high concentrations of biotin (vitamin B7) for at least 12 hours prior to blood collection.
Limitations
High concentrations of biotin in patient's blood may lead to falsely decreased TSH results.
Additional Information
References: Ladenson PW et al. American Thyroid Association guidelines for detection of thyroid dysfunction. Arch Intern Med. 2000 160(11):1573-5.
Specimen Collection and Handling
Specimen Type
Blood
Container
Light Green/Lithium Heparin Gold/SST Red Red Microtainer Dark Green Microtainer
