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

Test Code

36421

CPT Codes
82523, 82570

Includes

Creatinine

CPT code 81050 may be added at an additional charge for volume measurement

Preferred Specimen

2 mL of an unpreserved 24-hour urine collected in a plastic, leak-proof urine container

Minimum Volume

1 mL

Instructions

Do not include first morning specimen; collect all subsequent voidings. The last sample collected should be the first morning specimen voided the following morning at the same time as the previous morning's first voiding. Specify 24-hour total volume on container and test requisition.

Note: If submitting a random urine, use Test Code 36167.

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

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

Methodology
Chemiluminescence (CL)

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: August 27, 2019

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.