Test Identifier Information
Roche Cobas E411 Beta-Crosslaps
|Diagnostic Use / Indications|
The assay is specific for an octapeptide in the C-terminus of the α1 chain of type 1 collagen and accurately reflects osteoclast-mediated bone resorption. There is a significant diurnal variation (peak serum CTX between 2-6am) which is blunted after fasting. Samples should thus optimally be collected fasting in the early morning and specimen collection should be consistent during monitoring visits.
See also C-telopeptide web page
|External Price||$34.19(Exclusive of GST)|
|Specimen Collection Protocols|
Collect blood between 0800 and 1000 hours. For repeat testing, sampling should be at the same time of day.
|Patient Specimen||0800-1000h, blood 2 mL EDTA (T53)|
|Paediatric Specimen||0800-1000h, blood 0.6 mL EDTA (must get 0.3 mL plasma).|
|Sample Delivery to Lab||Ambient if no haemolysis, otherwise on ice/water slurry|
Instructions for Referral to CHLabs
|Aliquot Instructions||>0.5 mL EDTA Plasma|
|Aliquot Transport to CHL||Ambient overnight, but if hemolysis >1g/L Hb send on ice or frozen.|
|Contact Phone Number||(03) 364 0884 | x80884|
|Turnaround Time||1 - 6 days|
Female (ug/L):<2 yr: 0.43-1.70; 2-4 yr: 0.55-1.91; 5-6 yr: 0.47-1.97; >6-10 yr: 0.80-2.06; 11-14 yr: 0.50-2.75; 15-18 yr: <1.59; Adult: <0.75.
Male (ug/L): <4 yr: 0.54-1.71; 5 yr: 0.68-1.80; 6-9 yr: 1.05-2.38; 10-15 yr: 1.00-2.90; >15-18 yr: 0.50-2.43; Adult: <0.75.
Increased levels of β-CTx occur in osteoporosis, Paget’s disease, primary hyperparathyroidism, renal insufficiency and bone metastases.
|Uncertainty of Measurement|
0.01 µg/L for < 0.1 µg/L; 13% for > 0.1 µg/L
C-telopeptide is more stable in EDTA plasma than in serum. In serum claimed stability is 6-8 hours (ambient to 4°C). The test manufacturers recommend a fasting sample but we find little difference between fasting and non-fasting. Fasting or non-fasting state, and time of day, should be consistent for repeated sampling of a patient.
Childhood ranges adapted from Clin.Chim.Acta 415(2013): 169-72 and Clin.Biochem. 44(2011): 771-8.
|Delphic Number Test Number||6557|