Comparison of analytical performance and biological variability of three bone resorption assays.
Author(s): Ju HS, Leung S, Brown B, Stringer MA, Leigh S, Scherrer C, Shepard K, Jenkins D, Knudsen J, Cannon R
Publication: Clin Chem, 1997, Vol. 43, Page 1570-6
PubMed ID: 9299935 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine the effects of freeze-thaw cycling and time of collection on markers of bone readsorption in urine from healthy women.
Conclusion of Paper
Regardless of thaw temperature, up to five freeze-thaw cycles had no effects on deoxypyridinoline (Dpd), N-telopeptides of bone type I collagen (NTx), or C-terminal telopeptides of type l collagen (CTx) levels in urine. Dpd, NTx and CTx levels peaked in urine specimen collected between 4 and 7 AM and were the lowest in specimens collected between 1 and 4 PM.
Studies
-
Study Purpose
The purpose of this study was to determine the effects of freeze-thaw cycling and time of collection on markers of bone readsorption in urine from healthy women. Urine was stored at or below 20 degrees C until analysis. Dpd, NTx, and CTx were measured using the Pyrilinks-D immunoassay, the Osteomark ELISA, and the CrossLaps ELISA, respectively.
Summary of Findings:
Regardless of thaw temperature, up to five freeze-thaw cycles had no effects on Dpd, NTx, or CTx levels in urine. Dpd, NTx and CTx levels peaked at 20-28% above the mean in specimens collected between 4 and 7 AM and were lowest (15-29% below the mean) in specimens collected between 1 and 4 PM. Day to day variations in Dpd, NTx and CTx were 16.3%, 23.1% and 22.8%, respectively. Good interassay and intraassay precision was achieved when the Dpd, NTx, and CTx concentrations were above 3 nmol/L, 30 nmol/L and 200 ug/L, respectively.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Peptide Immunoassay Peptide ELISA Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Freeze/thaw cycling 0 cycles
1 cycle
2 cycles
3 cycles
4 cycles
5 cycles
Storage Thaw temperature/condition 25 degrees C
37 degrees C
ELISA Specific Technology platform Osteomark ELISA
Pyrilinks-D immunoassay
CrossLaps ELISA
Biospecimen Acquisition Time of biospecimen collection 7-10 AM
10 AM -1 PM
1-4 PM
4-7 PM
7-10 PM
10 PM -1 AM
1-4 AM
4-7 AM