M-protein diagnostics in multiple myeloma patients using ultra-sensitive targeted mass spectrometry and an off-the-shelf calibrator

Objectives: Minimal residual disease status in multiple myeloma is an important prognostic biomarker. Recently, personalized blood-based targeted mass spectrometry (MS-MRD) was shown to provide a sensitive and minimally invasive alternative to measure minimal residual disease. However, quantification of MS-MRD requires a unique calibrator for each patient. The use of patient-specific stable isotope labelled (SIL) peptides is relatively costly and time-consuming, thus hindering clinical implementation. Here, we introduce a simplification of MS-MRD by using an off-the-shelf calibrator. SILuMAB-based MS-MRD was performed by spiking a monoclonal stable isotope labeled IgG, Methods: SILuMAB-K1, in the patient serum. The abundance of both M-protein-specific peptides and SILuMAB-specific peptides were monitored by mass spectrometry. The relative ratio between M-protein peptides and SILuMAB peptides allowed for M-protein quantification. We assessed linearity, sensitivity and reproducibility of SILuMAB-based MS-MRD in longitudinally collected sera from the IFM-2009 clinical trial. Results: A linear dynamic range was achieved of over 5 log scales, allowing for M-protein quantification down to 0.001 » g/L. The inter-assay CV of SILuMAB-based MS-MRD was on average 11 » %. Excellent concordance between SIL- and SILuMAB-based MS-MRD was shown (R2&gt;0.985). Additionally, signal intensity of spiked SILuMAB can be used for quality control purpose to assess system performance and incomplete SILuMAB digestion can be used as quality control for sample preparation. Conclusion:Compared to SIL peptides, SILuMAB-based MS-MRD improves the reproducibility, turn-around-times and cost-efficacy of MS-MRD without diminishing its sensitivity and specificity. Furthermore, SILuMAB can be used as a MS-MRD quality control tool to monitor sample preparation efficacy and assay performance.</p

Interlaboratory study for coral Sr/Ca and other element/Ca ratio measurements

The Sr/Ca ratio of coral aragonite is used to reconstruct past sea surface temperature (SST). Twentyone laboratories took part in an interlaboratory study of coral Sr/Ca measurements. Results show interlaboratory bias can be significant, and in the extreme case could result in a range in SST estimates of 7°C. However, most of the data fall within a narrower range and the Porites coral reference material JCp- 1 is now characterized well enough to have a certified Sr/Ca value of 8.838 mmol/mol with an expanded uncertainty of 0.089 mmol/mol following International Association of Geoanalysts (IAG) guidelines. This uncertainty, at the 95% confidence level, equates to 1.5°C for SST estimates using Porites, so is approaching fitness for purpose. The comparable median within laboratory error is <0.5°C. This difference in uncertainties illustrates the interlaboratory bias component that should be reduced through the use of reference materials like the JCp-1. There are many potential sources contributing to biases in comparative methods but traces of Sr in Ca standards and uncertainties in reference solution composition can account for half of the combined uncertainty. Consensus values that fulfil the requirements to be certified values were also obtained for Mg/Ca in JCp-1 and for Sr/Ca and Mg/Ca ratios in the JCt-1 giant clam reference material. Reference values with variable fitness for purpose have also been obtained for Li/Ca, B/Ca, Ba/Ca, and U/Ca in both reference materials. In future, studies reporting coral element/Ca data should also report the average value obtained for a reference material such as the JCp-1

Decreased Numbers of Blood Dendritic Cells and Defective Function of Regulatory T Cells in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

BACKGROUND: Dendritic cells (DC) and regulatory cells (Treg) play pivotal roles in controlling both normal and autoimmune adaptive immune responses. DC are the main antigen-presenting cells to T cells, and they also control Treg functions. In this study, we examined the frequency and phenotype of DC subsets, and the frequency and function of Treg from patients with ANCA-associated vasculitis (AAV). METHODOLOGY/PRINCIPAL FINDINGS: Blood samples from 19 untreated patients with AAV during flares and before any immunosuppressive treatment were analyzed, along with 15 AAV patients in remission and 18 age-matched healthy controls. DC and Treg numbers, and phenotypes were assessed by flow cytometry, and in vitro suppressive function of Treg was determined by co-culture assay. When compared to healthy volunteers, absolute numbers of conventional and plasmacytoid DC were decreased in AAV patients. During the acute phase this decrease was significantly more pronounced and was associated with an increased DC expression of CD62L. Absolute numbers of Treg (CD4(+)CD25(high)CD127(low/-) Tcells) were moderately decreased in patients. FOXP3 and CD39 were expressed at similar levels on Treg from patients as compared to controls. The suppressive function of Treg from AAV patients was dramatically decreased as compared to controls, and this defect was more pronounced during flares than remission. This Treg functional deficiency occurred in the absence of obvious Th17 deviation. CONCLUSION: In conclusion, these data show that AAV flares are associated with both a decrease number and altered phenotype of circulating DC and point to a role for Treg functional deficiency in the pathogenesis of AAV

Caractérisation de la dysrégulation des hormones adipocytaires associée à l'obésité et aux troubles de la reproduction

Les conséquences délétères de l obésité, dont la prévalence ne cesse d'augmenter ces dernières années, se manifestent également sur la fertilité et sur les résultats en Assistance Médicale à la Procréation (AMP). L'objectif de ce travail est d'évaluer les répercussions de l'obésité sur le profil hormonal et sur la prise en charge en FIV. Celles-ci ont pu être mises en évidence grâce à une étude rétrospective qui a montré en particulier la nécessité de recourir à des doses de FSH recombinante plus élevées chez les femmes en surpoids ou obèses. Par ailleurs, bien que des tendances semblent se dessiner, aucun retentissement significatif sur les issues de stimulation n'a pu être constaté. Ces conséquences de l obésité sur la fertilité suggèrent l'intérêt de caractériser les dysrégulations adipocytaires associées et leur impact sur la physiologie ovarienne. A l interface entre le métabolisme énergétique et la reproduction, la leptine et l'adiponectine apparaissent comme deux médiateurs hormonaux essentiels. Les résultats préliminaires de l'étude prospective menée dans le but de caractériser ces dysrégulations permettent de mettre en évidence des modifications du profil adipocytaire et inflammatoire chez des patientes obèses. Parmi les paramètres étudiés, la leptine semble constituer une adipokine d'intérêt tout particulier, à la fois comme cible thérapeutique et comme marqueur prédictif de l'issue de la stimulation ovarienne.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

Recommandations de l’IFM (Intergroupe francophone du myélome) pour l’harmonisation de l’analyse des électrophorèses des protéines sériques et urinaires dans le diagnostic et le suivi du myélome multiple [IFM (Intergroupe francophone du myelome) recommendations for uniform interpretation of serum and urine protein electrophoresis in multiple myeloma diagnosis and follow-up]

National audienceSerum and urine proteins electrophoresis take a major place in multiple myeloma management, at time of diagnosis, during follow-up for treatment response evaluation and also in detection of relapse. The Intergroupe francophone du myelome (IFM) suggests recommendations to clinicians and biologists, to perform and interpret these biochemical analysis, with the objective of harmonizing practices between laboratories and improving patients' follow-up

Evaluation of sFlt-1/PlGF Ratio for Predicting and Improving Clinical Management of Pre-eclampsia: Experience in a Specialized Perinatal Care Center.

Management of pregnant women at high risk of pre-eclampsia (PE) requires frequent monitoring, with referral to specialized perinatal care centers. Reliable tests are necessary to improve prediction of PE and related complications and to assess disease severity and progression. An imbalance in two biomarkers, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF), is involved in PE pathogenesis. The sFlt-1 to PlGF ratio is increased in pregnant women before the onset of PE. An elevated ratio is highly predictive of PE, whereas the diagnosis of PE can be ruled out within one week for low ratios. The main objective of this study was to assess whether a low sFlt-1/PlGF ratio, below a cutoff of 38, can predict the absence of PE within one week.We performed a prospective, monocentric, observational study to evaluate serum sFlt-1/PlGF ratio (Roche Diagnostics Cobas e411 system) for predicting -PE in a group of 67 high-risk pregnant women (20-37 gestation weeks).Among the 67 patients included, 53 had a sFlt-1/PlGF ratio lower than 38; none developed subsequent PE leading to a negative predictive value of 100%. Eight patients developed clinical PE. The positive predictive value was 21% at one week and 18% at four weeks, in accordance with previous studies.The serum sFlt-1/PlGF ratio showed highly predictive performances for ruling out PE. Using these biomarkers in routine management of PE may improve clinical care and avoid inappropriate hospitalization, which has a significant economic impact

Biomarkers and algorithms for diagnosis of ovarian cancer: CA125, HE4, RMI and ROMA, a review

Abstract Ovarian cancer is the 5th leading cause of death for women with cancer worldwide. In more than 70% of cases, it is only diagnosed at an advanced stage. Our study aims to give an update on the biological markers for diagnosing ovarian cancer, specifically HE4, CA 125, RMI and ROMA algorithms. Serum CA125 assay has low sensitivity in the early stages and can be increased in certain conditions such as menstruation or endometriosis. The level of HE4 is overexpressed in ovarian tumors. Its specificity is 94% and its level is not affected by endometriosis cysts. The combined measures of CA125 and HE4 have proved to be highly efficient with an area under the curve (AUC) of up to 0.96. Furthermore, this combined measure of CA125 can correct the variations in HE4 which are due to smoking or contraception combining estrogen plus progestin. While the specificity of RMI sometimes reaches 92%, the rather low AUC of 0.86 does not make it the best diagnostic tool. The specificity of ROMA is lower than HE4 (84% compared to 94%). To date, the most efficient biological diagnostic tool to diagnose ovarian cancer is the combination of CA125 and HE4

Analytical performance of the serum free light chain assay

Peer Reviewe

Inactivation of Staphylococcus aureus in Calcium Phosphate Biomaterials via lsostatic Compression

International audienceHigh hydrostatic pressure is currently used as a sterilization technique in agroalimentary field. This study explores the potential use of high pressure for bacterial inactivation of bone substitute calcium phosphate materials. Staphylococcus aureus strain incorporated in calcium phosphate powder was subjected to isostatic compression. Several parameters of compression were tested: application of pressure, time of plateau, number of compressions, and waiting thine between two compressions. The results showed that the efficacy of compression increased with applied pressure and that time of plateau did not play an important role. The number of compressions influenced the efficiency of the technique and it was necessary to allow ample time between two compressions for bacteria to sufficiently multiply. The most effective protocol for preventing the growth of S. aureus in calcium phosphate involved two compressions of 5 minutes each at 140 MPa spaced at a 24-hour interval. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 91B: 348-353, 200

The monsoon imprint during the ‘atypical’ MIS 13 as seen through north and equatorial Indian Ocean records

International audienc