Five Osteocalcin Assays Compared: Tracer Specificity, Fragment Interference, and Calibration

Colford, John W.; Sailer, Dawn E.; Langman, Craig B.

doi:10.1093/clinchem/43.7.1240

Cited by 13 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, older assays were limited by their inability to distinguish the intact molecule from fragments. 17 Recently, a new assay specific for the intact protein has been developed. As a secondary aim of this study, we set out to establish the feasibility of using a modified assay specific for the intact OC protein to measure physiological concentrations present in healthy women.…”

Section: Introductionmentioning

confidence: 99%

Concentrations of Follicle-Stimulating Hormone Correlate with Alkaline Phosphatase and a Marker for Vitamin K Status in the Perimenopause

Lukacs

Reame

2000

Journal of Women's Health & Gender-Based Medicine

View full text Add to dashboard Cite

Serum alkaline phosphatase (ALP), a gross marker of bone turnover, has been reported to be elevated after menopause, a period characterized by hallmark increases in follicle-stimulating hormone (FSH). Whether the ALP rise coincides with the perimenopausal transition when changes in FSH, estrogen levels, and menstrual cycles are first apparent is not known. The purpose of this cross-sectional study was twofold: (1) to characterize the influence of the perimenopausal transition on ALP activity and (2) to correlate ALP activity with more precise markers for bone, osteocalcin (OC), and vitamin K status assessed with undercarboxylated osteocalcin (ucOC). Thirty-eight studies of hourly FSH were conducted on cycle day 6 of the follicular phase in perimenopausal women volunteers, aged 40-54 years (mean body mass index [BMI] = 24.2 +/- 0.5). Mean FSH was used to define the perimenopausal stage (early perimenopausal, mean FSH 15 IU/L, n = 11). As expected, late perimenopausal women had irregular and longer menstrual cycles, lower estradiol (E(2)) and estrone (E(1)) levels, and a lower frequency of ovulations vs. the early group. ALP was higher (76.5 +/- 8.3 vs. 58.3 +/- 2.7 IU/L, p = 0.045) compared with the early perimenopausal group. In a subsample (n = 10), OC was associated with ALP (r = 0.69, p < 0.03), FSH was positively related to ucOC concentrations (r = 0.7, p < 0.03), and women with E(1) concentrations <40 pg/ml had double the percentage of ucOC compared with those where E(1) was >40 pg/ml (46.3% +/- 6.6% vs. 22.0% +/- 3. 1%, p < 0.006). Clinical markers of the perimenopause are associated with a nonspecific but inexpensive marker of enhanced bone turnover (i.e., higher ALP) and correlate well with more precise markers of bone activity. These findings suggest that health-promotion strategies for preserving bone should be instituted well before the last menstrual period.

show abstract

Section: Introductionmentioning

confidence: 99%

Concentrations of Follicle-Stimulating Hormone Correlate with Alkaline Phosphatase and a Marker for Vitamin K Status in the Perimenopause

Lukacs

Reame

2000

Journal of Women's Health & Gender-Based Medicine

View full text Add to dashboard Cite

show abstract

“…It is localized in the membrane of osteoblasts and released into the circulation during activation of osteoblasts. 9 It has been reported that ligature-induced periodontitis reduced the serum levels of B-ALP. 10 Tartrate-resistant acid phosphatase 5b (TRAP-5b) is a specific and sensitive marker of osteoclasts.…”

mentioning

confidence: 99%

“…Bone alkaline phosphatase (B‐ALP) is a bone‐specific isoenzyme of ALP. It is localized in the membrane of osteoblasts and released into the circulation during activation of osteoblasts 9 . It has been reported that ligature‐induced periodontitis reduced the serum levels of B‐ALP 10 .…”

mentioning

confidence: 99%

Therapeutic Effects of Systemic Vitamin K2 and Vitamin D3 on Gingival Inflammation and Alveolar Bone in Rats With Experimentally Induced Periodontitis

Aral

Alkan

Saraymen

et al. 2015

Journal of Periodontology

View full text Add to dashboard Cite

show abstract

“…The DBS matrix does not interfere with detection of osteocalcin as indicated by the linearity of dilution and spike and recovery results. In an earlier study, absence of dilutional linearity for serum samples (recovery values ranging from 200% to 700% for 1:8 dilution of serum) was found for several osteocalcin assays due to the presence of circulating osteocalcin fragments (Colford, Sailer, & Langman, ). In the current study, the variation in osteocalcin concentration between punches from duplicate blood spots run in wells on the same plate of around 8% was higher than that measured for plasma samples, but this result is reasonable given that this value encompasses well‐well variation in the osteocalcin concentration in addition to position‐based differences in analyte concentrations within a DBS.…”

Section: Discussionmentioning

confidence: 97%

“…Different assays vary in their ability to recognize the numerous fragments of osteocalcin, and specificity for one fragment vs another is, in many cases, not specified or evaluated by the manufacturer. Furthermore, even in cases where the specificity for a particular osteocalcin fragment or fragments has been reported by the manufacturer, this has been shown not to necessarily be accurate (Colford et al, ). Another limitation is that oral contraceptive use, hormone replacement therapy, diabetes mellitus, and body mass index <18 or >30 kg/m 2 can all affect (decrease) osteocalcin levels, but were not accounted for in our analyses.…”

Section: Discussionmentioning

confidence: 99%

Validation of an enzyme‐linked immunoassay assay for osteocalcin, a marker of bone formation, in dried blood spots

Eick

Madimenos

Cepon-Robins

et al. 2020

American J Hum Biol

View full text Add to dashboard Cite

Investigating factors that contribute to bone loss and accretion across populations in remote settings is challenging, particularly where diagnostic tools are scarce. To mitigate this challenge, we describe validation of a commercial ELISA assay to measure osteocalcin, a biomarker of bone formation, from dried blood spots (DBS). Methods: We validated the Osteocalcin Human SimpleStep ELISA kit from Abcam (ab1951214) using 158 matched plasma and DBS samples. Passing-Bablok regression analysis assessed the relationships between plasma and DBS osteocalcin concentrations. Dilutional linearity and spike and recovery experiments determined if the DBS matrix interfered with osteocalcin measurement, and intra-and inter-assay coefficients of variation (CVs) were calculated. Limit of detection, analyte stability, and specific forms of osteocalcin measured by the kit were also investigated. Results: Mean plasma osteocalcin value was 218.2 ng/mL (range 64.6-618.1 ng/mL). Linear relationships existed between plasma and DBS concentrations of osteocalcin, with no apparent bias in plasma vs DBS concentrations. There was no apparent interference of the DBS matrix with measurement of osteocalcin in DBS. Intra-assay CV for DBS was~8%, while average inter-assay CV was 14.8%. Limit of detection was 0.34 ng/mL. Osteocalcin concentrations were stable in DBS stored at −28 C and room temperature, but not those stored at 37 C. This ELISA kit detects total osteocalcin. Conclusions: Osteocalcin, a bone formation biomarker, can be measured from DBS. Combined with a previously validated DBS assay for TRACP-5b, a bone resorption biomarker, these assays have the potential to help researchers disentangle the many factors contributing to bone strength.

show abstract

Five Osteocalcin Assays Compared: Tracer Specificity, Fragment Interference, and Calibration

Cited by 13 publications

References 4 publications

Concentrations of Follicle-Stimulating Hormone Correlate with Alkaline Phosphatase and a Marker for Vitamin K Status in the Perimenopause

Concentrations of Follicle-Stimulating Hormone Correlate with Alkaline Phosphatase and a Marker for Vitamin K Status in the Perimenopause

Therapeutic Effects of Systemic Vitamin K2 and Vitamin D3 on Gingival Inflammation and Alveolar Bone in Rats With Experimentally Induced Periodontitis

Validation of an enzyme‐linked immunoassay assay for osteocalcin, a marker of bone formation, in dried blood spots

Contact Info

Product

Resources

About