Test Code NTXPR NTX-Telopeptide, Urine
Reporting Name
NTX-Telopeptide, UUseful For
As an adjunct in the diagnosis of medical conditions associated with increased bone turnover
Monitoring effectiveness of antiresorptive therapy in patients treated for osteopenia, osteoporosis, Paget disease, or other metabolic bone disorders
Performing Laboratory

Specimen Type
UrineSpecimen Required
Patient Preparation: For 24 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
Container/Tube: Plastic, 13-mL urine tube
Specimen Volume: 4 mL
Collection Instructions:
1. Collect second morning void.
2. No preservative.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Frozen (preferred) | 28 days | |
Refrigerated | 14 days | ||
Ambient | 72 hours |
Reference Values
All units are reported in nmol bone collagen equivalents (BCE)/mmol creatinine.
Pediatric
Males:
Tanner Stage I: 55-508 nmol BCE/mmol creatinine
Tanner Stage II: 21-423 nmol BCE/mmol creatinine
Tanner Stage III: 27-462 nmol BCE/mmol creatinine
Tanner Stage IV: <609 nmol BCE/mmol creatinine
Tanner Stage V: <240 nmol BCE/mmol creatinine
Females:
Tanner Stage I: 6-662 nmol BCE/mmol creatinine
Tanner Stage II: 193-514 nmol BCE/mmol creatinine
Tanner Stage III: 13-632 nmol BCE/mmol creatinine
Tanner Stage IV: <389 nmol BCE/mmol creatinine
Tanner Stage V: <132 nmol BCE/mmol creatinine
Adult (≥18 years of age)
Males:
21-83 nmol BCE/mmol creatinine
Females:
Premenopausal: 17-94 nmol BCE/mmol creatinine
Postmenopausal: 26-124 nmol BCE/mmol creatinine
Day(s) Performed
Monday, Thursday
Test 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
82570
82523
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
NTXPR | NTX-Telopeptide, U | 44712-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
NTXCT | Creatinine, Random, U | 2161-8 |
NTX | NTX | 27939-8 |
NTXCR | NTX-Telopeptide, U | 44712-8 |
Clinical Reference
1. Baxter I, Rogers A, Eastell R, Peel N: Evaluation of urinary N-telopeptide of type I collagen measurements in the management of osteoporosis in clinical practice. Osteoporos Int. 2013 Mar;24(3):941-947
2. Miller PD, Baran DT, Bilezikian JP, et al: Practical clinical application of biochemical markers of bone turnover: Consensus of an expert panel. J Clin Densitom. 1999;2(3):323-342
3. Delmas PD, Eastell R, Garnero P, Seibel MJ, Stepan J, Committee of Scientific Advisors of the International Osteoporosis Foundation: The use of biochemical markers of bone turnover in osteoporosis. Committee of Scientific Advisors of the International Osteoporosis Foundation. Osteoporos Int. 2000;11 Suppl 6:S2-S17
4. Mora S, Prinster C, Proverbio MC, et al: Urinary markers of bone turnover in healthy children and adolescents: age-related changes and effect of puberty. Calcif Tissue Int. 1998 Nov;63(5):369-374
Method Description
The Vitros N-terminal telopeptide (NTx) assay is a competitive immunoassay that depends on competition between NTx in the sample with a synthetic NTx peptide coated on the wells for binding by a horseradish peroxidase (HRP)-labeled antibody conjugate (mouse monoclonal anti-NTx). The conjugate is captured by the peptide coated on the wells, and unbound materials are removed by washing.
A reagent containing luminogenic substrates (a luminol derivative and a peracid salt) and an electron transfer agent (a substituted acetanilide) are added to the wells. The HRP in the bound conjugate catalyzes the oxidation of the luminol derivative, producing light. The electron transfer agent increases the level of light produced and prolongs the duration of light produced. The light signals are read by the system. The amount of HRP conjugate bound is inversely proportional to the concentration of NTx in the sample. Assay values are corrected for urinary dilution by urinary creatinine analysis and expressed in nanomoles bone collagen equivalents per liter (nM BCE/L) per millimole creatinine per liter (mM creatinine/L).(Instruction manual: Vitros Instructions for Use, N-Telopeptide GEM1426. Ortho-Clinical Diagnostics, Inc; Version 7.1, 09/06/2019)
Report Available
Same day/1 to 5 daysReject Due To
Gross hemolysis | Reject |
Specimen with pH <5 Specimen containing preservatives |
Reject |
Method Name
NTXUR: Chemiluminescence Immunoassay
NTXCT: Enzymatic Colorimetric Assay
Secondary ID
61656Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
NTXCT | Creatinine, Random, U | No | Yes |
NTXUR | NTX-Telopeptide, U | No | Yes |