Comparison of the clinical performance of the immunoenzymometric assays for N-terminal and C-terminal type I collagen telopeptides and the HPLC assay for pyridinium cross-links.
We evaluated the clinical performances of the immunoenzymometric assays for type I collagen N-terminal and C-terminal telopeptides and the HPLC assay for total deoxypyridinoline, in distinguishing between subjects with a moderately increased bone resorption rate (women in postmenopause) and subjects with normal bone resorption rate (women in premenopause). The postmenopausal group consisted of 61 women who had been in menopause for no more than 10 years, while the premenopausal group consisted of 52 healthy women with normal menstrual cycles. The biochemical markers were measured in a 24 hour urine sample and the results expressed as the molar ratio with urinary creatinine. The clinical performances were estimated by calculating the accuracy (as the area under a Receiver Operated Characteristic (ROC) curve: mean +/- SEM) and the discriminating power (as score) of each assay in distinguishing postmenopausal subjects from premenopausal subjects. Type I collagen C-terminal telopeptide, type I collagen N-terminal telopeptide and total deoxypyridinoline were significantly higher in the postmenopausal than in the premenopausal group (p < 0.01). Accuracies of these three markers ranged from 66.8 +/- 5.1% to 76.8 +/- 4.3%, while Z scores ranged from 3.54 to 5.67. Type I collagen C-terminal telopeptide, type I collagen N-terminal telopeptide and total deoxypyridinoline were not significantly different in their accuracy or discriminating power. All markers were highly correlated with coefficients of correlation ranging from 0.61 to 0.77. In summary, this study shows that 1) the immunoenzymometric assays for type I collagen N-terminal telopeptide and type I collagen C-terminal telopeptide show a high accuracy and discriminating power in distinguishing subjects with different bone resorption rate; 2) the results obtained with these immunoenzymometric assays are comparable to those obtained with the HPLC assay for total deoxypyridinoline. In conclusion our data support the use of the immunoenzymometric assays for type I collagen N-terminal telopeptide and type I collagen C-terminal telopeptide for estimating bone resorption.
Bettica
P
P
Servizio di Endocrinologia, Ospedale L. Sacco, Milano, Italy.
Masino
M
M
Cucinotta
E
E
Vago
T
T
Norbiato
G
G
Moro
L
L
Suarez
K N
KN
Romanello
M
M
Bevilacqua
M
M
D000328:Adult; D015415:Biomarkers / Q000652:urine; D001862:Bone Resorption / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003094:Collagen / Q000737:chemistry / Q000652:urine*; D024042:Collagen Type I; D003404:Creatinine / Q000652:urine; D003432:Cross-Linking Reagents; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000706:statistics & numerical data; D008593:Menopause; D008875:Middle Aged; D010455:Peptides / Q000737:chemistry / Q000652:urine*; D011726:Pyridinium Compounds / Q000032:analysis; D012680:Sensitivity and Specificity
D015415:Biomarkers; D024042:Collagen Type I; D003432:Cross-Linking Reagents; D010455:Peptides; D011726:Pyridinium Compounds; C052929:collagen type I trimeric cross-linked peptide; D003094:Collagen; D003404:Creatinine