Ordering Recommendation
Mnemonic
NTX
Methodology

Quantitative Chemiluminescent Immunoassay

Performed

Tue-Sat

Reported

1-4 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation

For monitoring therapy, a baseline specimen should be collected prior to initiation of therapy. Subsequent specimens for comparison should be collected at the same time of day as the baseline specimen.

Collect

Second-morning void or 24-hour urine. Refrigerate during collection. Collect without preservative.

Specimen Preparation

Transfer a 1 mL aliquot of urine from a well-mixed, second-morning void or 24-hour collection to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature

Frozen.

Unacceptable Conditions

Specimens contaminated with blood or extensive hemolysis.

Remarks
Stability

Ambient: 24 hours; Refrigerated: 1 week; Frozen: 2 years

Reference Interval
Age
Male
Female
7-9 years 167-578 nM BCE/mM creatinine 201-626 nM BCE/mM creatinine
10-12 years 152-505 nM BCE/mM creatinine 173-728 nM BCE/mM creatinine
13-15 years 103-776 nM BCE/mM creatinine 38-515 nM BCE/mM creatinine
16-17 years 34-313 nM BCE/mM creatinine 20-144 nM BCE/mM creatinine
18 years and older 21-83 nM BCE/mM creatinine
Premenopausal 17-94 nM BCE/mM creatinine
Postmenopausal 26-124 nM BCE/mM creatinine

Interpretive Data

NTx Units = nM BCE/mM creatinine

A decrease of 30-40% from the NTx baseline after three months of therapy is a typical response to anti-resorptive therapy.

NTx = Cross-linked N-telopeptide of Type I Collagen
BCE = Bone Collagen Equivalent

Compliance Category

FDA

Note
Hotline History
N/A
CPT Codes

82523

Components
Component Test Code* Component Chart Name LOINC
0020207 Creatinine, Urine - per volume 2161-8
0070061 NTx, Urine (nM BCE/mM Creatinine) 14115-0
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Collagen Crosslinks
  • Cross-Linked N-Telopeptide
  • Crosslinked N-telopeptide of Type I Collagen
  • N-Telopeptide, Urine
  • NTx
  • NTX Creatinine
  • NTX Urine
  • Osteomark
  • Osteoporosis
N-Telopeptide, Cross-Linked, Urine