Test Code LAB3231 Intraoperative Parathyroid Hormone (PTH)
Clinical System Name
Intraoperative PTH, Intact
Synonyms
PTH Intraop
ioPTH
Sample Requirements
Specimen: Whole blood
Container(s): Collect INTRAOPERATIVE PTH specimens in a DARK GREEN/SODIUM HEPARIN TUBE for expedited processing. Also acceptable Gold SST, Red, Lt. Green/Lithium Heparin Microtainer, Lavender/EDTA
Preferred Vol: 2.0 mL
Minimum Vol: 1.0 mL
Note: Microtainers used for capillary collections are unacceptable. If a series of PTH are being drawn, use the same tube type for all collections.
Processing Instructions
Reject due to: capillary collections
Spin: Y
Aliquot: Y
Temp: - 20 C
Storage location: Spin blood within one hour of collection; transfer a minimum of 0.5 mL serum/plasma to aliquot container.
Call Chemistry Lab at x72565 when sample is received.
Off-site collection: N/A
Stability
Specimen Type | Temperature | Time |
---|---|---|
serum/plasma | Room temp | 2 h |
Refrigerated | 2 d | |
Frozen | 6 mo |
Availability
STAT | Performed | TAT |
---|---|---|
Y | M - F | same day |
Order comment printed on surgery requisition: Call Chemistry Lab at x72565 when sample is collected. Send with OR runner to Forest B Level 2 Lab.
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Chemistry
Location: Chem West
Phone Number: (206) 987-2617
CPT Codes
83970
Methodology
Method: "intact PTH" chemiluminescent microparticle immunoassay by Alinity i
Analytical Volume: 0.3 mL serum/plasma
Limitations:
PTH exists as a single chain 84 amino acid polypeptide, numbered from the amino terminal. After secretion, PTH undergoes extensive fragmentation. Only the fragments that carry the amino terminus are biologically active. The half life of active PTH is approximately 5 minutes. Inactive PTH (large C-terminal; PTH 7-84) has a longer half-life; approximately 10 minutes, and smaller C-terminal fragments have even longer half lives. This test and other immunoassays detect the intact PTH molecule (PTH 1-84), along with the large PTH fragment (PTH 7-84) that builds up in renal failure. Smaller PTH fragments and PTHrP do not cross react.
Reference Range
PTH transitioned platforms from Ortho Vitros 3600 to Abbott Alinity i on August 8, 2022.
There is a 30% positive bias with the new method.
9 - 88 pg/mL