24-Hour Urine Collagen Cross-Linked N-Telopeptide (NTx)

Message

Reference values were determined in subjects 20-40 years old. Higher values may be found in oldere patients, but results are generally interpreted relative to the younger age groups.

Day(s) Test Set Up: Monday, Wednesday, Friday

Test Code

NTX24US

Quest Code

36421

CPT Codes
82523, 82570

Includes

Includes: NTX-Telopeptide, U; Creatinine, U

Preferred Specimen

4.0 mL Urine

Minimum Volume

1 mL

Instructions

Second-morning voided and random specimens are perfered. No preservative. Send specimen refrigerated in a plastic, 13-mL urine tube.

Transport Temperature

Refrigerated or frozen

Specimen Stability

Room temperature: 72 hours
Refrigerated: 5 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Ambient

Methodology
Enhanced Chemiluminescence

Setup Schedule

Set up: Mon-Sat; Report available: Next day

Limitations

Collagen Cross-Linked N-Telopeptide is affected by diurnal variation.

Reference Range

Collagen Cross-Linked N-Telopeptide (NTx), 24-Hour Urine

Male
18-29 Years	5-88 nM BCE/mM creat
30-39 Years	7-51 nM BCE/mM creat
40-49 Years	5-47 nM BCE/mM creat
50-60 Years	6-43 nM BCE/mM creat
Female
Premenopausal	5-79 nM BCE/mM creat

Results are primarily used for monitoring the response to therapy. A value within the premenopausal reference range does not rule out osteoporosis nor the need for therapy.

Creatinine, 24-Hour Urine

<3 Years	Not established
3-8 Years	0.10-0.80 g/24 h
9-12 Years	0.20-1.40 g/24 h
13-17 Years	0.40-1.90 g/24 h
>17 Years	0.50-2.15 g/24 h

Clinical Significance

NTx is useful to assess bone resorption in patients with metabolic bone disease and monitor therapy to slow or halt osteoporotic bone loss. A decline of 30% or more of NTx over a six-month period suggests effective therapy.

Performing Laboratory

Quest Diagnostics Nichols Institute

14225 Newbrook Drive

Chantilly, VA 20153

Last Updated: January 29, 2020

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.