How the reference values for serum parathyroid hormone concentration are (or should be) established?
; ; et al
in Journal of Endocrinological Investigation (in press)
Well-validated reference values are necessary for a correct interpretation of a serum PTH concentration. Establishing PTH reference values needs recruiting a large reference population. Exclusion criteria ... [more ▼]
Well-validated reference values are necessary for a correct interpretation of a serum PTH concentration. Establishing PTH reference values needs recruiting a large reference population. Exclusion criteria for this population can be defined as any situation possibly inducing an increase or a decrease in PTH concentration. As recommended in the recent guidelines on the diagnosis and management of asymptomatic primary hyperparathyroidism, PTH reference values should be established in vitamin D-replete subjects with a normal renal function with possible stratification according to various factors such as age, gender, menopausal status, body mass index, and race. A consensus about analytical/pre-analytical aspects of PTH measurement is also needed with special emphasis on the nature of the sample (plasma or serum), the time and the fasting/non-fasting status of the blood sample. Our opinion is that blood sample for PTH measurement should be obtained in the morning after an overnight fast. Furthermore, despite longer stability of the PTH molecule in EDTA plasma, we prefer serum as it allows to measure calcium, a prerequisite for a correct interpretation of a PTH concentration, on the same sample. Once a consensus is reached, we believe an important international multicentre work should be performed to recruit a very extensive reference population of apparently healthy vitamin D-replete subjects with a normal renal function in order to establish the PTH normative data. Due to the huge inter-method variability in PTH measurement, a sufficient quantity of blood sample should be obtained to allow measurement with as many PTH kits as possible. [less ▲]Detailed reference viewed: 29 (3 ULg)
Analytical and clinical validation of the new Abbot Architect 25(OH)D assay: fit for purpose?
Cavalier, Etienne ; LUKAS, Pierre ; BEKAERT, Anne-Catherine et al
in Clinical Chemistry & Laboratory Medicine (in press)
BACKGROUND: We provide a clinical and analytical evaluation of the reformulated version of the Abbott Architect 25-hydroxyvitamin D assay. We compared this assay with three commercial automated ... [more ▼]
BACKGROUND: We provide a clinical and analytical evaluation of the reformulated version of the Abbott Architect 25-hydroxyvitamin D assay. We compared this assay with three commercial automated immunoassays and against a VDSP-traceable liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in six different populations. We also supplemented 40 healthy volunteers with either 600,000 IU of vitamin D2 or 100,000 of vitamin D3 to evaluate the performance of the immunoassays vs. the LC-MS/MS. METHODS: Precision and limit of quantification were assessed, 25(OH)D2 and C3-epimer recovery were calculated. Two hundred and forty samples obtained in healthy Caucasians and Africans, osteoporotic, hemodialyzed and intensive care patients and 3rd trimester pregnant women were analyzed by all methods. Correlation was studied using Passing-Bablok and Bland-Altman analysis. Concordance correlation coefficient (CCC) was calculated to evaluate agreement between immunoassays and LC-MS/MS. We verified if patients were homogeneously classified with the immunoassays when they took vitamin D2 or vitamin D3 after 1, 7 and 28 days. RESULTS: We observed excellent analytical features and showed a very good correlation to the LC-MS/MS results in the overall population. Compared to the other immunoassays, concordance of the new Abbott assay with the LC-MS/MS was at least similar, and often better in diseased populations. Althought the cross-reactivity with 25(OH)D2 was not of 100%, there was no significant difference in the classifications of the patients, either supplemented with D2 or D3 or after 7 or 28 days. CONCLUSIONS: This modified version of the Abbott Architect assay is clearly improved compared to the previous one and presents a better agreement with the LC-MS/MS. [less ▲]Detailed reference viewed: 18 (7 ULg)
Perspective and priorities for improvement of parathyroid hormone (PTH) measurement - A view from the IFCC Working Group for PTH.
; ; et al
in Clinica Chimica Acta (in press)
Parathyroid hormone (PTH) measurement in serum or plasma is a necessary tool for the exploration of calcium/phosphate disorders, and is widely used as a surrogate marker to assess skeletal and mineral ... [more ▼]
Parathyroid hormone (PTH) measurement in serum or plasma is a necessary tool for the exploration of calcium/phosphate disorders, and is widely used as a surrogate marker to assess skeletal and mineral disorders associated with chronic kidney disease (CKD), referred to as CKD-bone mineral disorders (CKD-MBD). CKD currently affects >10% of the adult population in the United States and represents a major health issue worldwide. Disturbances in mineral metabolism and fractures in CKD patients are associated with increased morbidity and mortality. Appropriate identification and management of CKD-MBD is therefore critical to improving clinical outcome. Recent increases in understanding of the complex pathophysiology of CKD, which involves calcium, phosphate and magnesium balance, and is also influenced by vitamin D status and fibroblast growth factor (FGF)-23 production, should facilitate such improvement. Development of evidence-based recommendations about how best to use PTH is limited by considerable method-related variation in results, of up to 5-fold, as well as by lack of clarity about which PTH metabolites these methods recognise. This makes it difficult to compare PTH results from different studies and to develop common reference intervals and/or decision levels for treatment. The implications of these method-related differences for current clinical practice are reviewed here. Work being undertaken by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) to improve the comparability of PTH measurements worldwide is also described. [less ▲]Detailed reference viewed: 19 (0 ULg)
Vitamin K plasma levels determination in human health
; ; et al
in Clinical Chemistry & Laboratory Medicine (in press)Detailed reference viewed: 13 (2 ULg)
Clinical usefulness of bone turnover marker concentrations in osteoporosis.
; ; et al
in Clinica Chimica Acta (in press)
Current evidence continues to support the potential for bone turnover markers (BTM) to provide clinically useful information particularly for monitoring the efficacy of osteoporosis treatment. Many of the ... [more ▼]
Current evidence continues to support the potential for bone turnover markers (BTM) to provide clinically useful information particularly for monitoring the efficacy of osteoporosis treatment. Many of the limitations identified earlier remain, principally in regard to the relationship between BTM and incident fractures. Important data are now available on reference interval values for CTX and PINP across a range of geographic regions and for individual clinical assays. An apparent lack of comparability between current clinical assays for CTX has become evident indicating the possible limitations of combining such data for meta-analyses. Harmonization of units for reporting serum/plasma CTX (ng/L) and PINP (mug/L) is recommended. The development of international collaborations continues with an important initiative to combine BTM results from clinical trials in osteoporosis in a meta-analysis and an assay harmonization program are likely to be beneficial. It is possible that knowledge derived from clinical studies can further enhance fracture risk estimation tools with inclusion of BTM together with other independent risk factors. Further data of the relationships between the clinical assays for CTX and PINP as well as physiological and pre-analytical factors contributing to variability in BTM concentrations are required. [less ▲]Detailed reference viewed: 20 (3 ULg)
Fibroblast growth factor 23 in acute burn patients: Novel insights from an intact-form assay.
ROUSSEAU, Anne-Françoise ; ; DELANAYE, Pierre et al
in Burns : Journal of the International Society for Burn Injuries (in press)
INTRODUCTION: Fibroblast growth factor 23 (FGF23) is a key regulator in phosphate and vitamin D metabolism When measured with c-terminal assay, it has been shown to be increased following burn. Progress ... [more ▼]
INTRODUCTION: Fibroblast growth factor 23 (FGF23) is a key regulator in phosphate and vitamin D metabolism When measured with c-terminal assay, it has been shown to be increased following burn. Progress in understanding FGF23 physiology has emphasized the importance of assessing the intact form of FGF23. METHODS: The present cohort study is a complementary analysis of a previously published work. Patients >18 years, admitted within 24h after injury with burn surface area (BSA) >10% were included. C-terminal (c-term) and intact (i) FGF23 assay were performed at admission and every week during 4 weeks of follow-up. Inflammation and iron status were assessed at the same time points. RESULTS: Twenty patients were initially included and 12 were followed until day 28. The c-term FGF23 tended to gradually increase during the 4 weeks of follow-up while iFGF23 was quite stable into normal ranges. Iron status showed a typical inflammatory profile. C-term FGF23 was significantly positively correlated with c-reactive protein (CRP) and negatively correlated with iron levels. iFGF23 was not correlated with CRP or iron. CONCLUSION: FGF23 status following burn is characterized by a dissociation between c-term FGF23 and iFGF23. The hypothesis of an increased cleavage may be raised. Respective role of inflammation and iron levels in such deregulation need to be specified. Both c-term and intact assays should be performed in further studies aiming to increase knowledge on FGF23 regulation and effects in burn patients. [less ▲]Detailed reference viewed: 28 (2 ULg)
Impact of an ultra-marathonof 330km on plasma levels of cardiac biomarkers
Le Goff, Caroline ; Kaux, Jean-François ; et al
in British Journal of Sports Medicine (2017, February), 51(4), 347Detailed reference viewed: 17 (1 ULg)
Marqueurs osseux chez la personne souffrant de calculs urinaires récidivants: Intérêt ? Chez qui ? Pour en faire quoi ? Analyse ? (ex : problématiques des bornes de ces marqueurs chez l'homme jeune...)
Conference (2017, January 25)Detailed reference viewed: 12 (0 ULg)
The added value of plasma or urinary NGAL concentrations in clinical practice
Gregoire, Emilien ; ; GUIOT, Julien et al
Poster (2017, January 13)Detailed reference viewed: 39 (4 ULg)
Etude rétrospective du bilan thyroïdien: définition de valeurs de référence pédiatriques
LADANG, Aurélie ; VRANKEN, Laura ; LUYCKX, Françoise et al
in Revue Médicale de Liège (2017)
Defining reference range is an essential tool for diagnostic. Age and sexe influences on thyroid hormone levels have been already discussed. In this study, we are defining a new pediatric reference range ... [more ▼]
Defining reference range is an essential tool for diagnostic. Age and sexe influences on thyroid hormone levels have been already discussed. In this study, we are defining a new pediatric reference range for TSH, FT3 and FT4 for Cobas C6000 analyzer. To do so, we have taken in account 0 to 18 year old outclinic patients. During the first year of life, thyroid hormone levels change dramatically before getting stabilized around 3 years old. We also compared our results to those obtained in a Canadian large-scale prospective study (the CALIPER initiative). [less ▲]Detailed reference viewed: 23 (3 ULg)
Assessment of vitamin D status - a changing landscape.
; ; et al
in Clinical Chemistry & Laboratory Medicine (2017)
In recent years it has been shown that vitamin D deficiency is associated with an increased incidence as well as the progression of a broad range of diseases including osteoporosis, rickets ... [more ▼]
In recent years it has been shown that vitamin D deficiency is associated with an increased incidence as well as the progression of a broad range of diseases including osteoporosis, rickets, cardiovascular disease, autoimmune disease, multiple sclerosis and cancer. Consequently, requests for the assessment of vitamin D status have increased dramatically. Despite significant progress in the analysis of vitamin D metabolites and an expansion of our pathophysiological knowledge of vitamin D, the assessment of vitamin D status remains a challenging and partially unresolved issue. Current guidelines from scientific bodies recommend the measurement of 25-hydroxy vitamin D (25-OHD) in blood as the preferred test. However, growing evidence indicates significant limitations of this test, including analytical aspects and interpretation of results. In addition, the relationships between 25-OHD and various clinical indices, such as bone mineral density and fracture risk, are rather weak and not consistent across races. Recent studies have systematically investigated new markers of vitamin D status including the vitamin D metabolite ratio (VMR) (ratio between 25-OHD and 24,25-dihydroxy vitamin D), bioavailable 25-OHD [25-OHD not bound to vitamin D binding protein (DBP)], and free 25-OHD [circulating 25-OHD bound to neither DBP nor albumin (ALB)]. These parameters may potentially change how we will assess vitamin D status in the future. Although these new biomarkers have expanded our knowledge about vitamin D metabolism, a range of unresolved issues regarding their measurement and the interpretation of results prevent their use in daily practice. It can be expected that some of these issues will be overcome in the near future so that they may be considered for routine use (at least in specialized centers). In addition, genetic studies have revealed several polymorphisms in key proteins of vitamin D metabolism that affect the circulating concentrations of vitamin D metabolites. The affected proteins include DBP, 7-dehydrocholesterol synthase and the vitamin D receptor (VDR). Here we aim to review existing knowledge regarding the biochemistry, physiology and measurement of vitamin D. We will also provide an overview of current and emerging biomarkers for the assessment of vitamin D status, with particular attention methodological aspects and their usefulness in clinical practice. [less ▲]Detailed reference viewed: 25 (4 ULg)
Relevance of vitamin D in the pathogenesis and therapy of frailty.
Bruyère, Olivier ; Cavalier, Etienne ; Buckinx, Fanny et al
in Current Opinion in Clinical Nutrition & Metabolic Care (2017), 20(1), 26-29
PURPOSE OF REVIEW: This article reviews recently published evidence regarding the role of vitamin D in the physiopathology of physical frailty in elderly populations and its role in the management of this ... [more ▼]
PURPOSE OF REVIEW: This article reviews recently published evidence regarding the role of vitamin D in the physiopathology of physical frailty in elderly populations and its role in the management of this geriatric condition. RECENT FINDINGS: Some recent studies have found a low level of 25-hydroxyvitamin D, considered the best marker of vitamin D status, in frail individuals. All prospective studies consistently report that low vitamin D status is associated with an increased risk of becoming frail. Recent studies also suggest that the relationship between vitamin D status and frailty is largely mediated by the development of sarcopenia. Very few well designed randomized controlled trials are available that assess the effectiveness of vitamin D supplementation in the prevention or management of frailty. In the absence of specific guidelines, a minimal serum 25-hydroxyvitamin D level of 75 nmol/l is proposed for frail elderly patients by some scientific societies. The doses necessary to reach this target are between 800 and 2000 IU/day. SUMMARY: Several studies suggest a potential effect of vitamin D on physical frailty but large clinical trials are lacking at this time to provide solid evidence of clinical benefit. [less ▲]Detailed reference viewed: 19 (4 ULg)
Occurence of bone fracture in the 2 years following a prolonged ICU stay: a retrospective study including a control group.
ROUSSEAU, Anne-Françoise ; Bawin, Maxime ; CAVALIER, Etienne et al
in Osteoporosis International (2017), 28(Suppl 1), 504Detailed reference viewed: 28 (4 ULg)
When obtaining a blood sample from the right arm was not the right thing to do: a case of elevated parathyroid hormone levels 27 years after thyroidectomy.
; ; Cavalier, Etienne et al
in Clinical Chemistry & Laboratory Medicine (2016)Detailed reference viewed: 23 (1 ULg)
Association entre taux circulants de matrix-gla protéine et rigidité artérielle en transplantation rénale.
; ; DELANAYE, Pierre et al
Conference (2016, December)Detailed reference viewed: 18 (6 ULg)
Large variations between four methods for sclerotin determination in patients undergoing GFR measurement and in hemodialyzed patients before and after a single dialysis session.
CAVALIER, Etienne ; DELANAYE, Pierre
Poster (2016, November)Detailed reference viewed: 8 (1 ULg)
Measurement of glomerular filtration rate by plasma iohexol clearance: single versus multiple samples method.
DELANAYE, Pierre ; CAVALIER, Etienne
Poster (2016, November)Detailed reference viewed: 9 (1 ULg)
Myoferlin regulates cellular lipid metabolism and promotes metastases in triple-negative breast cancer
; Costanza, Brunella ; De Tullio, Pascal et al
in Oncogene (2016)
Myoferlin is a multiple C2-domain-containing protein that regulates membrane repair, tyrosine kinase receptor function and endocytosis in myoblasts and endothelial cells. Recently it has been reported as ... [more ▼]
Myoferlin is a multiple C2-domain-containing protein that regulates membrane repair, tyrosine kinase receptor function and endocytosis in myoblasts and endothelial cells. Recently it has been reported as overexpressed in several cancers and shown to contribute to proliferation, migration and invasion of cancer cells. We have previously demonstrated that myoferlin regulates epidermal growth factor receptor activity in breast cancer. In the current study, we report a consistent overexpression of myoferlin in triple-negative breast cancer cells (TNBC) over cells originating from other breast cancer subtypes. Using a combination of proteomics, metabolomics and electron microscopy, we demonstrate that myoferlin depletion results in marked alteration of endosomal system and metabolism. Mechanistically, myoferlin depletion caused impaired vesicle traffic that led to a misbalance of saturated/unsaturated fatty acids. This provoked mitochondrial dysfunction in TNBC cells. As a consequence of the major metabolic stress, TNBC cells rapidly triggered AMP activated protein kinase-mediated metabolic reprogramming to glycolysis. This reduced their ability to balance between oxidative phosphorylation and glycolysis, rendering TNBC cells metabolically inflexible, and more sensitive to metabolic drug targeting in vitro. In line with this, our in vivo findings demonstrated a significantly reduced capacity of myoferlin-deficient TNBC cells to metastasise to lungs. The significance of this observation was further supported by clinical data, showing that TNBC patients whose tumors overexpress myoferlin have worst distant metastasis-free and overall survivals. This novel insight into myoferlin function establishes an important link between vesicle traffic, cancer metabolism and progression, offering new diagnostic and therapeutic concepts to develop treatments for TNBC patients. [less ▲]Detailed reference viewed: 36 (8 ULg)
Impact of vitamin D binding protein on calculated free 25OH vitamin D
VRANKEN, Laura ; BEKAERT, Anne-Catherine ; GENDEBIEN, Anne-Sophie et al
Conference (2016, October 14)Detailed reference viewed: 13 (4 ULg)