Lunel-Fabiani F.,Angers University Hospital Center |
Duburcq X.,Bio Rad |
Levayer T.,Etablissement Francais du Sang Pyrenees Mediterranee |
Descamps F.,Etablissement Francais du Sang Nord de France |
And 16 more authors.
Background: Accurate detection of Hepatitis B Surface Antigen (HBsAg) is an important aid in the diagnosis of patients infected with the hepatitis B virus (HBV). A multi-center study was conducted to characterize the performance of the HBsAg assay on the family of Access® immunoassay systems from Beckman Coulter. Methods: The Access HBsAg assay was characterized in a multi-center study and compared to the Abbott AxSYM* and PRISM* HBsAg assays. The bioMérieux VIDAS* assay was used to resolve discrepant results. Reproducibility studies (intra-assay, inter-assay and inter-lot) were performed with pooled serum samples (negative sample, close to cut off, low, medium and high positive samples). Analytical sensitivity, subtype and genotype detection were studied with various commercial panels (SFTS panel, WHO 80/549, WHO 00/588, Teragenix HBV Genotype panel). A panel of recombinant HBsAg mutant proteins was tested to investigate reactivity towards genetic mutations. Clinical sensitivity was verified with seroconversion panels and samples from subjects with known HBV infection. Analytical specificity was studied with samples from patients with potential cross-reactive infections. Clinical specificity was validated among blood donors and a hospitalized population. Results: The imprecision was <10%. Analytical sensitivity was ≤0.1 ng/mL (SFTS panel), 0.020 PEI Units/mL (ad panel), 0.024 PEI Units/mL (ay panel), 0.092 IU/mL with WHO 80/549 and 0.056 IU/mL with WHO 00/588. All genotype samples and HBsAg mutants were reactive with the Access HBsAg assay. Seroconversion panels tested showed no significant difference with the reference method. Sensitivity for subjects with known HBV infection was 100%. No interference with potentially cross-reactive infections was observed after confirmatory testing. Specificity was 99.96% (100% after confirmatory testing) in a blood donor population and 99.5% (100% after confirmatory testing) in a hospitalized population. Excellent separation of positive and negative populations was observed. Conclusions: The Access HBsAg and HBsAg Confirmatory assays meet all clinical and analytical performance requirements of assays for the detection of HBsAg. Source
Sensebe L.,Etablissement Francais du Sang Center Atlantique |
Bourin P.,Etablissement Francais du Sang Pyrenees Mediterranee |
Tarte K.,French Institute of Health and Medical Research
Human Gene Therapy
Because of their multi/pluripotency and immunosuppressive properties mesenchymal stem/stromal cells (MSCs) are important tools for treating immune disorders and for tissue repair. The increasing use of MSCs has led to production processes that need to be in accordance with Good Manufacturing Practice (GMP). In cellular therapy, safety remains one of the main concerns and refers to donor validation, choice of starting material, processes, and the controls used, not only at the batch release level but also during the development of processes. The culture processes should be reproducible, robust, and efficient. Moreover, they should be adapted to closed systems that are easy to use. Implementing controls during the manufacturing of clinical-grade MSCs is essential. The controls should ensure microbiological safety but also avoid potential side effects linked to genomic instability driving transformation and senescence or decrease of cell functions (immunoregulation, differentiation potential). In this rapidly evolving field, a new approach to controls is needed. © 2011 Mary Ann Liebert, Inc. Source
Bigot N.,French Institute of Health and Medical Research |
Bigot N.,University of Rennes 1 |
Guerillon C.,French Institute of Health and Medical Research |
Guerillon C.,University of Rennes 1 |
And 12 more authors.
Cell Death and Disease
Hypoxic niches help maintain mesenchymal stromal cell properties, and their amplification under hypoxia sustains their immature state. However, how MSCs maintain their genomic integrity in this context remains elusive, since hypoxia may prevent proper DNA repair by downregulating expression of BRCA1 and RAD51. Here, we find that the ING1b tumor suppressor accumulates in adipose-derived stromal cells (ADSCs) upon genotoxic stress, owing to SUMOylation on K193 that is mediated by the E3 small ubiquitin-like modifier (SUMO) ligase protein inhibitor of activated STAT protein B (PIAS4). We demonstrate that ING1b finely regulates the hypoxic response by triggering HIf1α proteasomal degradation. On the contrary, when mutated on its SUMOylation site, ING1b failed to efficiently decrease HIf1α levels. Consistently, we observed that the adipocyte differentiation, generally described to be downregulated by hypoxia, was highly dependent on ING1b expression, during the early days of this process. Accordingly, contrary to what was observed with HIf1α, the absence of ING1b impeded the adipogenic induction under hypoxic conditions. These data indicate that ING1b contributes to adipogenic induction in adipose-derived stromal cells, and thus hinders the phenotype maintenance of ADSCs. © 2015 Macmillan Publishers Limited All rights reserved. Source
Cappellesso-Fleury S.,Etablissement Francais du Sang Pyrenees Mediterranee |
Puissant-Lubrano B.,University Paul Sabatier |
Puissant-Lubrano B.,Toulouse University Hospital Center |
Apoil P.-A.,University Paul Sabatier |
And 6 more authors.
Journal of Clinical Immunology
Introduction: Bone marrow mesenchymal stem cells (BM-MSCs) and adipose tissue-derived stem cells share immunosuppressive capacities, suggesting that the latter could be a general property of stromal cells. Methods: To check this hypothesis, we compared human BM-MSC and fibroblasts for their in vitro multipotentiality, expandability and their immunomodulatory properties under normalized optimized culture conditions. Results: We report that, unlike BM-MSCs, fibroblasts cannot differentiate in vitro into adipocytes and osteoblasts and differ from BM-MSCs by the expression of membrane CD106, CD10 and CD26 and by the expression of collagen VII mRNA. Like BM-MSCs, fibroblasts are unable to provoke in vitro allogeneic reactions, but strongly suppress lymphocyte proliferation induced by allogeneic mixed lymphocyte culture (MLC) or mitogens. We show that fibroblasts' immunosuppressive capacity is independent from prostaglandin E2, IL-10 and the tryptophan catabolising enzyme indoleamine 2, 3-dioxygenase and is not abrogated after the depletion of CD8+ T lymphocytes, NK cells and monocytes. Conclusion: Finally, fibroblasts and BM-MSCs act at an early stage through blockage of lymphocyte activation, as demonstrated by down-regulation of GZMB (granzyme B) and IL2RA (CD25) expression. © Springer Science+Business Media, LLC 2010. Source
Daurat A.,University of Nimes |
Roger C.,University of Nimes |
Gris J.,University of Nimes |
Daurat G.,University of Nimes |
And 4 more authors.
BACKGROUND Controversy exists regarding the safety of the different types of platelet (PLT) concentrates. This study was aimed at comparing the rate of adverse reactions associated with apheresis PLT concentrates (APCs) and pooled PLT concentrates (PPCs) both in donors and in recipients. STUDY DESIGN AND METHODS From the French national hemovigilance system, types and numbers of recipient adverse reactions were compared over a period from 2009 to 2011. Donor adverse reactions were available for 2010 and 2011. This study involved 23 of 26 French regions. Main outcomes were the rates of adverse reaction in recipients and serious adverse reaction in donors. RESULTS There were 790,854 PLT transfusions during the study period (477,747 [60%] with APCs, 313,107 [40%] with PPCs). APCs were associated with more adverse reactions (6244 vs. 2469 per 1,000,000, p < 0.001) and more severe and life-threatening reactions (respectively, 241 vs. 131 per 1,000,000, p < 0.001; and 182 vs. 121 per 1,000,000, p = 0.04). Mortality rates due to an adverse transfusion reaction were similar (15 vs. 6 per 1,000,000, p = 0.5). In donors, the number of whole blood (WB) donations was 4,722,685 whereas 266,095 apheresis procedures were performed. Serious adverse reactions were more frequent for apheresis procedures than for WB donations (5445 vs. 803 per 1,000,000, p < 0.001). CONCLUSION Our findings suggest that apheresis PLTs may be more hazardous than pooled PLTs both in recipients and in donors. This study calls for randomized trials to confirm or refute these results. © 2016 AABB. Source