Test Id : CTX
Beta-CrossLaps, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
Monitoring antiresorptive therapies (eg, bisphosphonates and hormone replacement therapy) in postmenopausal women treated for osteoporosis and individuals diagnosed with osteopenia
An adjunct in the diagnosis of medical conditions associated with increased bone turnover
Method Name
A short description of the method used to perform the test
Electrochemiluminescence Immunoassay (ECLIA)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
B-CTx
Beta CrossLaps
Beta-CTx
C-Telopeptide
C-terminal collagen crosslinks
Carboxy terminal collagen crosslinks
CTx
Specimen Type
Describes the specimen type validated for testing
Serum
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Patient Preparation: Patient should fast for 12 hours before specimen collection.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Collect specimen prior to 10 a.m.
2. Centrifuge and aliquot serum into plastic vial.
Forms
If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.75 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 90 days | |
| Refrigerated | 72 hours |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Monitoring antiresorptive therapies (eg, bisphosphonates and hormone replacement therapy) in postmenopausal women treated for osteoporosis and individuals diagnosed with osteopenia
An adjunct in the diagnosis of medical conditions associated with increased bone turnover
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Human bone is continuously remodeled through a process of bone formation and resorption. Approximately 90% of the organic matrix of bone is type I collagen, a helical protein that is crosslinked at the N- and C-terminal ends of the molecule. During bone resorption, osteoclasts secrete a mixture of acid and neutral proteases that degrade the collagen fibrils into molecular fragments, including C-terminal telopeptide (CTx). As bone ages, the alpha form of aspartic acid present in CTx converts to the beta form. Beta-CTx is released into the bloodstream during bone resorption and serves as a specific marker for the degradation of mature type I collagen. Elevated serum concentrations of beta-CTx have been reported in patients with increased bone resorption.
Bone turnover markers are physiologically elevated during childhood, growth, and fracture healing. The elevations in bone resorption markers and bone formation markers are typically balanced in these circumstances and are of no diagnostic value. By contrast, bone turnover markers may be useful when the bone remodeling process is unbalanced. Abnormalities in the process of bone remodeling can result in changes in skeletal mass and shape. Many diseases, in particular hyperthyroidism, all forms of hyperparathyroidism, most forms of osteomalacia and rickets (even if not associated with hyperparathyroidism), hypercalcemia of malignancy, Paget disease, multiple myeloma, and bone metastases, as well as various congenital diseases of bone formation and remodeling, can result in accelerated and unbalanced bone turnover. Unbalanced bone turnover is also found in age-related and postmenopausal osteopenia and osteoporosis.
Disease-associated bone turnover abnormalities should normalize in response to effective therapeutic interventions, which can be monitored by measurement of serum and urine bone resorption markers.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Males
<5 years: 242-1292 pg/mL
5-9 years: 351-1532 pg/mL
10-15 years: 447-2457 pg/mL
16-17 years: 478-1666 pg/mL
18-29 years: 238-1019 pg/mL
30-39 years: 225-936 pg/mL
40-49 years: 182-801 pg/mL
50-59 years: 161-737 pg/mL
60-69 years: 132-752 pg/mL
> or =70 years: 118-776 pg/mL
Females
<5 years: 347-1508 pg/mL
5-9 years: 383-1556 pg/mL
10-15 years: 311-1776 pg/mL
16-17 years: 146-1266 pg/mL
18-29 years: 148-967 pg/mL
30-39 years: 150-635 pg/mL
40-49 years: 131-670 pg/mL
50-59 years: 183-1060 pg/mL
60-69 years: 171-970 pg/mL
> or =70 years: 152-858 pg/mL
Premenopausal: 136-689 pg/mL
Postmenopausal: 177-1015 pg/mL
Interpretation
Provides information to assist in interpretation of the test results
Elevated levels of beta-C-terminal telopeptide (CTx) indicate increased bone resorption. Increased levels are associated with osteoporosis, osteopenia, Paget disease, hyperthyroidism, and hyperparathyroidism.
In patients taking antiresorptive agents (bisphosphonates or hormone replacement therapy), a decrease of 25% or more from baseline beta-CTx levels (ie, prior to the start of therapy) 3 to 6 months after initiation of therapy indicates an adequate therapeutic response.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Reduced kidney function may lead to reduced urinary excretion of beta-C-terminal telopeptide (CTx) and a consequent increase in the apparent serum beta-CTx concentration.
In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. The presence of antibodies to streptavidin or ruthenium can rarely occur and may interfere in this assay. Caution should be used in interpretation of results, and the laboratory should be alerted if the result does not correlate with the clinical presentation.
Serum biotin concentrations up to 1200 ng/mL do not interfere with this assay. Concentrations up to 1200 ng/mL may be present in specimens collected from patients taking extremely high doses of biotin up to 300 mg per day. In a study among 54 healthy volunteers, supplementation with 20 mg/day biotin resulted in a maximum serum biotin concentration of 355 ng/mL 1-hour postdose.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Christgau S, Bitsch-Jensen O, Hanover Bjarnason N, et al. Serum CrossLaps for monitoring the response in individuals undergoing antiresorptive therapy. Bone. 2000;26(5):505-511
2. Garnero P, Borel O, Delmas PD. Evaluation of a fully automated serum assay for C-terminal cross-linking telopeptide of type I collagen in osteoporosis. Clin Chem. 2001;47(4):694-702
3. Fraser W: Bone and mineral metabolism. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1422-1491
4. Delmas PD, Eastell R, Garnero P, Seibel MJ, Stepan J; Committee of Scientific Advisors of the International Osteoporosis Foundation]. The use of biochemical markers of bone turnover in osteoporosis. Committee of Scientific Advisors of the International Osteoporosis Foundation. Osteoporos Int. 2000;11 Suppl 6:S2-S17. doi:10.1007/s001980070002
5. Saint Paul LP, Debruyne D, Bernard D, Mock DM, and Defer GL. Pharmacokinetics and pharmacodynamics of MD1003 (high-dose biotin) in the treatment of progressive multiple sclerosis. Expert Opin Drug Metab Toxicol. 2016;12:3,327-344
6. Grimsey P, Frey N, Bendig G,et al: Population pharmacokinetics of exogenous biotin and the relationship between biotin serum levels and in vitro immunoassay interference. J Pharmacokinet Pharmacodyn. 2017;2(4),247-256
Method Description
Describes how the test is performed and provides a method-specific reference
The Roche Beta-CrossLaps/serum assay is a 2-site immunometric (sandwich) assay using electrochemiluminescence detection. Patient specimen, biotinylated monoclonal beta-CrossLaps-specific antibody, and monoclonal beta-CrossLaps-specific antibody labeled with ruthenium react to form a complex. Streptavidin-coated microparticles act as the solid phase to which the complex binds. Voltage is applied to the electrode, inducing a chemiluminescent emission from the ruthenium, which is then measured against a calibration curve to determine the amount of beta-CrossLaps in the patient specimen. This assay is specific for crosslinked isomerized type I collagen fragments, independent of the nature of the crosslink (eg, pyrrole, pyridinoline). The assay specificity is guaranteed through the use of 2 monoclonal antibodies, each recognizing linear beta-8AA octapeptides (EKAHD-beta-GGR). The assay, therefore, quantifies all type I collagen degradation fragments that contain the isomerized octapeptide beta-8AA twice (beta-CTx).(Package insert: Elecsys Beta-CrossLaps/serum. Roche Diagnostics; V2.0, 10/2022)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Saturday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
82523
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| CTX | Beta-CrossLaps (B-CTx), S | 41171-0 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| CTX | Beta-CrossLaps (B-CTx), S | 41171-0 |