Authors: E Calabresi L Lasagni F Franceschelli V de Leonardis A Becorpi M Serio Maria Luisa Brandi
Publish Date: 2014/04/09
Volume: 17, Issue: 8, Pages: 625-629
Abstract
Pyridinoline Pyr and deoxypyridinoline DPyr are two crosslinks of collagen molecules that are present in the extracellular matrix and released during its degradation Pyr is present in bone and cartilage but not in significant amounts in other connective tissues and DPyr appears to be specific for bone tissue Therefore the urinary excretion of Pyr and DPyr might be a sensitive marker of bone matrix degradation For the determination of urinary Pyr and DPyr two methods are available a chromatographic method HPLC by which it is possible to measure separately Pyr and DPyr and a new immunoassay which measures total free and low molecular weight pyridinoline released in the urine We compared the results obtained by HPLC analysis of 205 urinary samples from normal subjects and patients affected by various bone disorders with those obtained by the immunoassay The overall correlation coefficient between the results obtained by the two methods was 034 When calculated in a range of pyridinoline concentrations from 0 to 30 30 to 60 and over 60 pmol/μmol creatinine the correlation coefficient was respectively − 0094 038 and 012 The two methods yielded variable profiles in the detection of circadian rhythms and these differences did not segregate with normal or pathological conditions We conclude that the immunoassay proposed for the determination of urinary collagen crosslinks is not immediately applicable to clinical use The improvement of the antibody specificity will probably contribute to replace the HPLC method with the immunoassay
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