scholarly journals Comparison of Two ELISA Methods and Mass Spectrometry for Measurement of Vitamin D-Binding Protein: Implications for the Assessment of Bioavailable Vitamin D Concentrations Across Genotypes

2016 ◽  
Vol 31 (6) ◽  
pp. 1128-1136 ◽  
Author(s):  
Michelle R Denburg ◽  
Andrew N Hoofnagle ◽  
Samir Sayed ◽  
Jayanta Gupta ◽  
Ian H de Boer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Binding Protein ◽  
Vitamin D Binding Protein ◽  
Bioavailable Vitamin D

scholarly journals Proteomics Approach for the Discovery of Rheumatoid Arthritis Biomarkers Using Mass Spectrometry

2019 ◽  
Vol 20 (18) ◽  
pp. 4368 ◽  
Author(s):  
Mun ◽  
Lee ◽  
Park ◽  
Kim ◽  
Lee ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Mass Spectrometry ◽  
Vitamin D ◽  
Binding Protein ◽  
Joint Destruction ◽  
Protein Profiling ◽  
Serum Amyloid ◽  
Healthy Controls ◽  
Vitamin D Binding Protein ◽  
Proteomics Approach

Rheumatoid arthritis is an autoimmune disease that causes serious functional loss in patients. Early and accurate diagnosis of rheumatoid arthritis may attenuate its severity. Despite a diagnosis guideline in the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for rheumatoid arthritis, the practical difficulties in its diagnosis highlight the need of developing new methods for diagnosing rheumatoid arthritis. The current study aimed to identify rheumatoid arthritis diagnostic biomarkers by using a proteomics approach. Serum protein profiling was conducted using mass spectrometry, and five distinguishable biomarkers were identified therefrom. In the validation study, the five biomarkers were quantitatively verified by multiple reaction monitoring (MRM) analysis. Two proteins, namely serum amyloid A4 and vitamin D binding protein, showed high performance in distinguishing patients with rheumatoid arthritis from healthy controls. Logistic analysis was conducted to evaluate how accurately the two biomarkers distinguish patients with rheumatoid arthritis from healthy controls. The classification accuracy was 86.0% and 81.4% in patients with rheumatoid arthritis and in healthy controls, respectively. Serum amyloid A4 and vitamin D binding protein could be potential biomarkers related to the inflammatory response and joint destruction that accompany rheumatoid arthritis.

scholarly journals Why don’t serum vitamin D concentrations associate with BMD by DXA? A case of being ‘bound’ to the wrong assay? Implications for vitamin D screening

2017 ◽  
Vol 52 (8) ◽  
pp. 522-526 ◽  
Author(s):  
Richard J Allison ◽  
Abdulaziz Farooq ◽  
Anissa Cherif ◽  
Bruce Hamilton ◽  
Graeme L Close ◽  
...  
Keyword(s):  
Vitamin D ◽  
Binding Protein ◽  
Serum Vitamin ◽  
Vitamin D Binding Protein ◽  
Mineral Density ◽  
Racially Diverse ◽  
Serum Vitamin D ◽  
Athletic Population ◽  
Vitamin D Levels ◽  
Bioavailable Vitamin D

BackgroundThe association between bone mineral density (BMD) and serum25-hydroxyvitamin D (25(OH)D) concentration is weak, particularly in certain races (eg, BlackAfrican vs Caucasian) and in athletic populations. We aimed to examine if bioavailable vitamin D rather than serum 25(OH)D was related to markers of bone health within a racially diverse athletic population.MethodsIn 604 male athletes (Arab (n=327), Asian (n=48), Black (n=108), Caucasian (n=53) and Hispanic (n=68)), we measured total 25(OH)D, vitamin D-binding protein and BMD by DXA. Bioavailable vitamin D was calculated using the free hormone hypothesis.ResultsFrom 604 athletes, 21.5% (n=130) demonstrated severe 25(OH)D deficiency, 37.1% (n=224) deficiency, 26% (n=157) insufficiency and 15.4% (n=93) sufficiency. Serum 25(OH)D concentrations were not associated with BMD at any site. After adjusting for age and race, bioavailable vitamin D was associated with BMD (spine, neck and hip). Mean serum vitamin D binding protein concentrations were not associated with 25(OH)D concentrations (p=0.392).ConclusionRegardless of age or race, bioavailable vitamin D and not serum 25(OH)D was associated with BMD in a racially diverse athletic population. If vitamin D screening is warranted, clinicians should use appropriate assays to calculate vitamin D binding protein and bioavailable vitamin D levels concentrations than serum 25(OH)D. In turn, prophylactic vitamin D supplementation to ‘correct’ insufficient athletes should not be based on serum 25(OH)D measures.

scholarly journals Vitamin D–Binding Protein Concentrations Quantified by Mass Spectrometry

2015 ◽  
Vol 373 (15) ◽  
pp. 1480-1482 ◽  
Author(s):  
Andrew N. Hoofnagle ◽  
John H. Eckfeldt ◽  
Pamela L. Lutsey
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Binding Protein ◽  
Vitamin D Binding Protein

scholarly journals Relationships between Total, Free and Bioavailable Vitamin D and Vitamin D Binding Protein in Early Pregnancy with Neonatal Outcomes: A Retrospective Cohort Study

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2495
Author(s):  
Melinda Fernando ◽  
Thisara G. Coster ◽  
Stacey J. Ellery ◽  
Deborah de Guingand ◽  
Siew Lim ◽  
...  
Keyword(s):  
Vitamin D ◽  
Early Pregnancy ◽  
Large Scale ◽  
Binding Protein ◽  
Current Data ◽  
Neonatal Outcomes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vitamin D Metabolites ◽  
Vitamin D Binding Protein ◽  
Bioavailable Vitamin D

Maternal vitamin D deficiency has been associated with adverse neonatal outcomes, however, existing results are inconsistent. Current data focus on total 25-hydroxyvitamin D (25(OH)D) as the common measure of vitamin D status, while additional measures including vitamin D-binding protein (VDBP) and free and bioavailable metabolites have not been explored in relation to neonatal outcomes. We examined whether VDBP and total, free, and bioavailable vitamin D metabolites in early pregnancy are associated with subsequent neonatal outcomes. In this retrospective analysis of 304 women in early pregnancy (<20 weeks gestation), demographic and anthropometric data were collected and total 25(OH)D (chemiluminescent assay), VDBP (polyclonal enzyme-linked immunosorbent assay (ELISA)) and albumin (automated colorimetry) were measured in bio-banked samples. Free and bioavailable 25(OH)D were calculated using validated formulae. Neonatal outcomes were derived from a medical record database. Higher maternal total and free 25(OH)D concentrations were associated with higher neonatal birthweight (β = 5.05, p = 0.002 and β = 18.06, p = 0.02, respectively), including after adjustment for maternal covariates including age, body mass index (BMI) and ethnicity (all p ≤ 0.04). Higher total 25(OH)D and VDBP concentrations were associated with a lower likelihood of neonatal jaundice (odds ratio [OR] [95%CI] = 0.997 [0.994, 1.000], p = 0.04 and 0.98 [0.96, 0.99], p = 0.03, respectively), but these were attenuated after adjustment for the above maternal covariates (both p = 0.09). Our findings suggest a novel association between free 25(OH)D and neonatal birthweight. Total 25(OH)D concentrations were also associated with birthweight, and both total 25(OH)D and VDBP were associated with jaundice, but the latter were not significant after adjustment. These results suggest a potential link between these metabolites and neonatal outcomes; however, further large-scale prospective studies are warranted.

scholarly journals Phenotyping and relative quantification of vitamin D binding protein in a paediatric population by using liquid chromatography–tandem mass spectrometry

2018 ◽  
Vol 56 (1) ◽  
pp. 56-63
Author(s):  
Ana I Cillero ◽  
Eduardo Martínez-Morillo ◽  
Laura Mantecón ◽  
María Agustina Alonso ◽  
Helena Gil-Peña ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Binding Protein ◽  
Tandem Mass ◽  
Relative Quantification ◽  
Vitamin D Binding Protein ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Background Adequate concentrations of vitamin D are required to ensure bone health and minimize the incidence of multiple extraskeletal diseases. Although total 25-hydroxyvitamin D (25OHD) remains the recommended biomarker for assessing vitamin D status, it has been speculated that free 25OHD correlates better with clinical outcomes. The calculation of free 25OHD depends on the concentrations of vitamin D binding protein (DBP), the determination of which involves different immunoassays and has led to varying results and conclusions. We developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for simultaneous identification and relative quantification of DBP isoforms. Methods We used serum samples from healthy children ( n = 79), mainly Caucasian (88%). Proteins were denatured, reduced, alkylated and digested with trypsin. Purified peptides were analysed by LC-MS/MS. The DBP phenotype was established by using the combinations of tryptic peptides associated with each of the three isoforms and one peptide common to all of them to perform relative quantification. The genotyping of volunteers ( n = 7) facilitated verification of the ability of our method to correctly identify the DBP phenotype. Results The DBP phenotype was correctly established in all samples from volunteers, based on the 100% correlation observed with the genotype. The most common DBP phenotype in Caucasian children was 2/1S (34%) and the rarest 1F/1F (2%). The relative quantification of DBP concentrations did not show statistically significant differences between phenotypes ( P = 0.11). Conclusions LC-MS/MS enabled simultaneous phenotyping and relative quantification of DBP, while avoiding the analytical limitations of immunoassays and confirming similar concentrations of DBP in all phenotypes.

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