Test Code NTXSE N-terminal Telopeptide, Serum
Reporting Name
NTX-Telopeptide, SUseful For
Monitoring effectiveness of antiresorptive therapy in patients treated for osteoporosis or other metabolic bone disorders
As an adjunct in the diagnosis of medical conditions associated with increased bone turnover
This test is not useful for screening or diagnosing osteoporosis.
Performing Laboratory

Specimen Type
SerumSpecimen Required
Patient Preparation: Fasting is preferred due to diurnal variation of markers and food effects
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: A morning collection from fasting patients is preferred. If not possible, collect the baseline and subsequent specimens under the same circumstances (eg, at same time of day).
Specimen Minimum Volume
0.1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen (preferred) | 28 days | |
Refrigerated | 24 hours |
Reference Values
All units are reported in nmol bone collagen equivalents (BCE)
Adult (≥18 years of age)
Males:
5.4-24.2 nmol BCE
Females:
Premenopausal: 6.2-19.0 nmol BCE
The target value for postmenopausal adult females undergoing treatment for osteoporosis is the same as the premenopausal reference interval.
Day(s) Performed
Sunday, Wednesday
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
82523
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
SNTX | NTX-Telopeptide, S | 21215-9 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
65558 | NTX-Telopeptide, S | 21215-9 |
Clinical Reference
1. Lee J, Vasikaran S: Current recommendations for laboratory testing and use of bone turnover markers in management of osteoporosis. Ann Lab Med. 2012 Mar;32(2):105-112
2. Chopin F, Biver E, Funck-Brentano T, et al: Prognostic interest of bone turnover markers in the management of postmenopausal osteoporosis. Joint Bone Spine. 2012 Jan;79(1):26-31
3. Hlaing TT, Compston JE: Biochemical markers of bone turnover-uses and limitations. Ann Clin Biochem. 2014 Mar;51(Pt 2):189-202
Method Description
The Osteomark N-terminal telopeptide (NTx) serum assay is a competitive-inhibition enzyme-linked immunosorbent assay for quantitative determination of NTx in human serum.
NTx epitope is adsorbed onto a 96-well microplate. Diluted samples are added to the microplate wells, followed by a horseradish peroxidase-labeled monoclonal antibody. NTx in the patient sample competes with the NTx epitope in the microplate well for antibody-binding sites. Following a wash step, the amount of labeled antibody bound is measured by colorimetric generation of a peroxide substrate. Absorbance is determined spectrophotometrically and the NTx concentration calculated using a standard calibration curve. Assay values are reported in nanomoles bone collagen equivalents per liter (nM BCE).(Package insert: Osteomark NTx Serum. Alere Scarborough, Inc; REV 05/2016)
Report Available
2 to 5 daysReject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Method Name
Enzyme-Linked Immunosorbent Assay (ELISA)