Immunoassay for quantifying type I collagen degradation products in urine evaluated

Bonde, Martin; Qvist, Per; Fledelius, Christian; Riis, Bente Juel; Christiansen, Claus

doi:10.1093/clinchem/40.11.2022

Cited by 297 publications

(92 citation statements)

References 16 publications

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“…Three urine bone resorption markers were all measured by ELISA assays, with results corrected for urine creatinine: free pyridinoline (PYD/Cr, Pyrilinks, Metra Biosystems, Mountain View, CA, U.S.A.) (30) ; cross-linked N-telopeptide of type 1 collagen (NTX/Cr, Osteomark, Ostex Int., Seattle, WA) (31) ; and cross-linked C-telopeptide of Type I collagen (CTX/Cr, Crosslaps, Osteometer, Glerupvej, Denmark). (32) The interassay and intraassay coefficients of variation were 13.4 and 2.6%; 9.2 and 6.1%; 9.2 and 6.2%, respectively.…”

Section: Biochemical Determinationsmentioning

confidence: 89%

Resistance to Bone Resorbing Effects of PTH in Black Women

Cosman

Morgan

Nieves

et al. 1997

Journal of Bone and Mineral Research

178

100

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Black women have a lower incidence of vertebral and hip fractures than white women, possibly due to differences in skeletal and mineral metabolism. One suggested mechanism is that blacks have decreased skeletal sensitivity to parathyroid hormone (PTH). To test this hypothesis, we infused h(1-34)PTH in healthy premenopausal black (n ‫؍‬ 15) and white (n ‫؍‬ 18) women over 24 h and measured serum and urine indices of bone turnover and calcium metabolism throughout the infusion. At baseline, the mean 25-hydroxyvitamin D (25(OH)D) concentration was significantly lower in black women (46%). There were also nearly significant trends toward higher PTH and lower urinary calcium and pyridinoline levels in black women. During infusion, there were no racial differences in the mean (1-34)PTH levels achieved or in resultant elevations of serum calcium or 1,25-dihydroxyvitamin D (1,25(OH) 2 D) levels. Endogenous parathyroid suppression (measured by (1-84)PTH levels) was also similar between blacks and whites. There was an initial decline in urinary calcium/creatinine in both groups with a greater reduction in black women early in the infusion period ( p < 0.05 at 8 h). Furthermore, blacks had lower levels of urinary calcium/creatinine throughout the infusion ( p < 0.05 group difference). Bone formation markers (carboxy-terminal propeptide of type I procollagen and osteocalcin) decreased within 8 h and continued to decline throughout the infusion with no distinguishable racial differences ( p < 0.05 time trend for both). The most dramatic difference between black and white women in response to PTH infusion was represented by the bone resorption markers. Three separate metabolites of bone resorption (cross-linked N-telopeptide of type I collagen, cross-linked C-telopeptide of type I collagen, and free pyridinoline) all showed substantially greater elevations in white (mean peak increments 399, 725, and 43%) compared with black women (mean peak increments 317, 369, and 17%) during the infusion ( p < 0.05 group differences for all three variables). These data strongly suggest that blacks have decreased skeletal sensitivity to the acute resorptive effects of increased PTH. This finding indicates that calcium homeostasis may be accomplished in blacks (during times of relative calcium deficiency) by greater conservation of calcium from nonskeletal sources (most likely renal) with relative preservation of skeletal tissue. These differences in calcium economy could account, at least in part, for the increased bone mass and lower incidence of osteoporotic fractures in black women. (J Bone Miner Res 1997;12:958-966)

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Section: Biochemical Determinationsmentioning

confidence: 89%

Resistance to Bone Resorbing Effects of PTH in Black Women

Cosman

Morgan

Nieves

et al. 1997

Journal of Bone and Mineral Research

178

100

View full text Add to dashboard Cite

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“…(19) Urinary type I C-telopeptide breakdown products (CTX) were measured by an ELISA (CrossLaps™ ELISA; Osteometer Biotech A/S, Herlev, Denmark) based on an immobilized synthetic peptide with an amino acid sequence specific for a part of the C-telopeptide of the ␣-1 chain of type I collagen (CrossLaps antigen). (20,21) Urinary free deoxypyridinoline (Dpyr) was measured by an ELISA that uses a monoclonal antibody with <1% crossreactivity with free pyridinoline (Pyrilinks®-D; Metra Biosystems, Mountain View, CA, U.S.A.) and no significant interaction with cross-linked peptides. (22) Urinary free pyridinolines (Pyr) were measured by an ELISA that uses a monoclonal antibody which reacts equally with free pyridinoline and free Dpyr (Pyrilinks®, Metra Biosystems) and has 2.5% cross-reactivity with crosslinked peptides.…”

Section: Methodsmentioning

confidence: 99%

Biochemical Markers of Bone Turnover and Prediction of Hip Bone Loss in Older Women: The Study of Osteoporotic Fractures

Bauer

Sklarin

Stone

et al. 1999

Journal of Bone and Mineral Research

162

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To examine the ability of commercially available biochemical markers of bone formation and resorption to predict hip bone loss, we prospectively obtained serum and timed 2-h urine specimens from 295 women age 67 years or older who were not receiving estrogen replacement therapy. Serum was assayed for two markers of bone formation: osteocalcin (OC) and bone-specific alkaline phosphatase (BALP). Urine specimens were assayed for four markers of bone resorption: N-telopeptides (NTX), free pyridinolines (Pyr), free deoxypyridinoline (Dpyr), and C-telopeptides (CTX). Measurements of hip bone mineral density were made at the time the samples were collected and then repeated an average of 3.8 years later. Higher levels of all four resorption markers were, on average, significantly associated with faster rates of bone loss at the total hip, but not at the femoral neck. Women with OC levels above the median had a significantly faster rate of bone loss than women with levels below the median, but there was no significant association between levels of BALP and hip bone loss. The sensitivity and specificity of higher marker levels for predicting rapid hip bone loss was limited, and there was considerable overlap in bone loss rates between women with high and low marker levels. We conclude that higher levels of urine NTX, CTX, Pyr, Dpyr, and serum OC are associated with faster bone loss at the hip in this population of elderly women not receiving estrogen replacement therapy, but these biochemical markers have limited value for predicting rapid hip bone loss in

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“…(24) Urinary type I collagen C-telopeptide (CTX) breakdown products were measured by an ELISA (Cross-Laps ELISA; CIS Biointernational) based on an immobilized synthetic peptide with an amino acid sequence specific for a part of the C-telopeptide of the ␣1-chain of type I collagen (Glu-Lys-Ala-His-␤Asp-Gly-Gly-Arg; CrossLaps antigen). (25) The intra-and interassay CVs are less than 5% and 8%, respectively. Serum CTX breakdown products were measured by a two-site ELISA (Serum Crosslaps one step; Osteometer Biotech, Ballerup, Denmark) using monoclonal antibodies raised against an amino acid sequence specific for a part of the C-telopeptide of the ␣1-chain of type I collagen (Glu-Lys-Ala-His-␤ Asp-Gly-Gly-Arg).…”

Section: Bone Turnover Hormones and Fracture Riskmentioning

confidence: 96%