7448 Collagen Cross-linked N-telopeptide (ntx), Urine

Specimen Type Specimen Stability Reference Range
Random Urine 30 Days, Frozen
5 Days, Refrigerated
72 Hours, Ambient
See Report

Specimen Requirements

Specimen Type: Random Urine
Container: Sterile Container
Temperature: Refrigerated




Tuesday; Thursday; Saturday

Turn-Around Time



Collect sample without preservative.

Clinical Utility

Collagen cross-linked N-Telopeptides are present in mature collagen of bone. Bone undergoes a natural process of renewal in which bone turned over by a process of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Under normal physiological conditions bone formation and bone resorption are equivalent so no bone is gained or lost. During the process of bone resorption, the collagen matrix is degraded by an enzyme, collagenase. Cross-linked N-Telopeptides are released as by products into the circulation and are finally excreted in the urine. Measuring urinary concentration of collagen cross-linked N-Telopeptide permits an estimate of the amount of bone turnover occuring, in the metabolic bone disorders, such as Paget's disease and other bone related disorders, such as osteoporosis, the rate of bone turnover is affected and bone resorption occurs at an increased rate relative to bone formation. In these instances, cross-linked N-Telopeptide concentration in the urine increases and can be used as an indicator of the bone disease. Urinary cross-linked N-Telopeptides can also be used to measure the efficacy of therapy following treatment to reduce bone resorption; urinary cross-linked N-Telopeptides will typically decrease within a period of three to seven months.

CPT Codes

82523, 82570

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