serum levels were studied in 184 patients in relation to joint damage progression during the next year.
These methods are limited by the lack of synthetic calibrators, controversy over molar fluorescence yield of pyridinolines
, and the variability of acid hydrolysis.
as a specific marker of collagen breakdown and bone metabolism in HD patients.
Assessment and recommendations on factors contributing to preanalytical variability of urinary pyridinoline
However, most markers of bone resorption are measured in urine, including total pyridinoline
(Pyd) and the more bone-specific deoxypyridinoline (Dpd).
Our focus in this review will be exclusively on the pyridinium cross-links pyridinoline
(PYD;10 hydroxylysylpyridinoline) and deoxypyridinoline (DPD; lysylpyridinoline) because they are part of an extensive laboratory standardization program at the CDC designed to improve the measurement of biochemical markers and risk factors associated with selected chronic diseases.
The pyridinium crosslinks pyridinoline
(PYD) and deoxypyridinoline (DPD) are well-characterized markers for bone resorption that have been available for several years (3).
Radioimmunoassay for the pyridinoline
cross-linked carboxy-terminal telopeptide of type I collagen: a new serum marker of bone collagen degradation.
Among the resorption markers, 29 laboratories reported results of simultaneous determination of total urinary pyridinoline
and urinary deoxypyridinoline using HPLC methods.
As bone resorption markers, serum osteocalcin (OC) and ICTP were determined by the Elecsys N-MID[R] OC assay (Roche Diagnostics) (12) and the pyridinoline
cross-linked ICTP [sup.
Of these, 29 were simultaneous determinations of urinary total pyridinoline
(uPYD) and uDPD by HPLC techniques.
These markers include the nonreducible pyridinoline
and deoxypyridinoline cross-links (3, 4), which can be measured in hydrolyzed urine sample by HPLC or ELISA (5, 6), and the related type I collagen telopeptides (7, 8).