What is this test?
Beta-CrossLaps (CTX) is a fragment of collagen degradation in bone and serves as a marker of bone resorption.
Why might it be ordered?
- To assess bone turnover in certain metabolic bone diseases.
- To monitor the response to osteoporosis treatment when the specialist prescribes it.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
The value changes during the day and after meals. Follow instructions for a morning fasting sample; for monitoring, use similar collection conditions each time. Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
CTX indicates the rate of bone resorption, but does not measure bone density and does not independently prove osteoporosis. Your result is interpreted using the reference interval on the laboratory report and in the context of your symptoms, medical history and other test findings.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.