72 research outputs found

    Status of the LHC Superconducting Cable Mass Production

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    Six contracts have been placed with industrial companies for the production of 1200 tons of the superconducting (SC) cables needed for the main dipoles and quadrupoles of the Large Hadron Collider (LHC). In addition, two contracts have been placed for the supply of 470 tons of NbTi and 26 tons of Nb sheets. The main characteristic of the specification is that it is functional. This means that the physical, mechanical and electrical properties of strands and cables are specified without defining the manufacturing processes. Facilities for the high precision measurements of the wire and cable properties have been implemented at CERN, such as strand and cable critical current, copper to superconductor ratio, interstrand resistance, magnetisation, RRR at 4.2 K and 1.9 K. The production has started showing that the highly demanding specifications can be fulfilled. This paper reviews the organisation of the contracts, the test facilities installed at CERN, the various types of measurements and the results of the main physical properties obtained on the first batches. The status of the deliveries is presented

    Campylobacter infection in adult patients with primary antibody deficiency

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    International audiencePrimary antibody deficiency (PAD) is characterized by a defective immunoglobulin production and recurrent infections, mostly involving respiratory and gastrointestinal tracts. Chronic or recurrent diarrhea is reported in up to 23%. Campylobacter infection is a common cause of infectious diarrhea, reported in 1.2% to 7.5% of patients with common variable immunodefi-ciency (CVID), the most frequent PAD. The aim of this study was to describe Campylobacter infection in patients with PAD included in a large nationwide study and analyze factors associ-ated with susceptibility to this pathogen. The DEFI (DEFicit Immunitaire) study is an ongoing large cross-sectional French multicentric study of adults with PAD, with retrospective collection of clinical data. All patients with a history of bacteriologically documented Campylobacter infection were identified, and clinical data were collected for each episode. Factors associated with recurrent infection were assessed as oddsratio (OR) and 95% confidence interval (CI), calculated by means of simple regression analysis. In patients with available material, strains of each episode were characterized using molecular analysis and compared (Table E1, available in this article’s Online Repository at www.jaci-inpractice.org). A com-parison of immunodeficiency-related characteristics of patients with and without Campylobacter infection was performed in the homogeneous group of patients with CVID. The control group included patients with CVID from DEFI centers who confirmed that patients did not develop Campylobacter infection after enrollment (Figure E1, available in this article’s Online Repository at www.jaci-inpractice.org). After correction for multiple comparisons, P<.016 was considered significant. Since 2004, 790 patients with PAD were included in the DEFI study, and 51 presented with Campylobacter infection (6.5%). Medical chart was available for review in 45 patients. Characteristics of these patients at the time of enrollment in the DEFI study are detailed in Table E2 (available in this article’s Online Repository at www.jaci-inpractice.org). A total of 97 episodes were recorded (Table I). The overall distribution of Campylobacter species was unremarkable. Antimicrobial susceptibility testing revealed a higher resistance rate than in the general population for each antibiotic tested (see Figure E2, available in this article’s Online Repository at www.jaci-inpractice.org). A comorbidity was present in 55% of Campylobacter episodes, and a coinfection by other enteropathogens in 10%. Most patients were receiving concomitant therapy at the time of episode. One patient with end-stage cirrhosis died with Campylobacter bacteremia. Overall, bacteremia was observed in 24 episodes (13 patients) and was associated with extraintestinal complication in 10 episodes. Nineteen patients (42%) presented with recurrent (2-11) episodes. Factors associated with recurrent episodes were the presence of comorbidity (OR, 3.7 [95% CI, 1.1-13.1]) and undetectable serum IgA (OR, 8.6 [95% CI, 1.1-21.2]). None of these factors remain significant in multivariate analysis. A mo- lecular study of a subset of 18 strains from 5 patients with recurrent infections demonstrated that all strains were different, even when the antimicrobial susceptibility testing was similar and when the episodes occurred closely over time (Figure E3, available in this article’s Online Repository at www.jaci-inpractice.org). Compared with 288 patients with CVID without Campylobacter infection, patients with CVID with Campylo-bacter infection presented a higher prevalence of consanguinity and a more severe CVID phenotype, with more frequent disease- related complications, lower serum immunoglobulin levels, lower B and natural killer (NK) cells, and a trend for lower naive CD4þT cell at the time of enrollment in the DEFI study (Table II). This study is the first description of a large series of patients with PAD and Campylobacter infection. The 6.5% prevalence was probably underestimated because of the retrospective nature of the clinical data collection. In this population, symptoms were mostly restricted to an isolated, frequently severe, chronic watery diarrhea, with associated malnutrition, leading to repeated hospitalizations and impaired quality of life. Other digestive symptoms and fever were less frequent than those observed in the general population. In contrast, bacteremia and extra- digestive localizations were more frequent (25% vs 0.15% to 2%, and 22% vs 7%, respectively). Despite frequent hospitalizations, the overall prognosis was good. Recurrence rate was high (42%) compared with 1.2% in the general population, and was associated with extraintestinal comorbidity and unde- tectable IgA level in univariate analysis. Although limited by the number of available strains, molecular profiles of strains from patients with recurrent infections were all different. Thus, we could hypothesize that reinfection is more likely than persistent colonization, although colonization with multiple strains cannot be excluded. Conditions associated with the occurrence of Campylobacter infection were described in an analysis restricted to a large ho- mogeneous group of 325 patients with CVID. The present data suggest that hypochlorhydria, either proton pump inhibitor (PPI)-induced or associated with autoimmune gastritis, might play an important role in the pathogenesis of this infection. Almost all CVID-associated complications, particularly liver and gastrointestinal disease, were more frequent in patients with Campylobacter infection. A more severe immune deficiency at CVID diagnosis, with a lower serum immunoglobulin level, was also observed. Even in patients with immunoglobulin replacement therapy, IgM and IgA levels remain very low. IgA and IgM, almost absent in immunoglobulin batches, are more important than IgG in Campylobacter immunity. B-cell and specifically switch memory B-cell deficiency was also more severe in patients with CVID with Campylobacter infection than in patients without Campylobacter infection. This is in line with the high prevalence of Campylobacter infection observed in Good syndrome and X-linked agammaglobulinemia, 2 conditions associated with no circulating B cells (Figure E1, available in this article’s Online Repository at www.jaci-inpractice.org). B cells are also known to be important for the dialogue between the immune system and gut microbiota, whose composition is important for Campylobacter immunity. T cells may also play an important role, with a trend for decreased naive T cells. Indeed, 15 patients (40%) presented with a severe associated T-cell defect and could be considered as late-onset combined im-munodeficiency (data not shown). In patients with PAD, Campylobacter infection is quite frequent and seems to be related to various factors adding up together: severity of the immune deficiency, PAD complication, and associated antibiotics, immunosuppressive therapies, and PPI. It is characterized by a high frequency of recurrence and bacteremia. Recurrence is associated with the presence of comorbidity and IgA defect, and turned out to be due to rein- fection more than to persistent colonization, suggesting a specific susceptibility despite immunoglobulin substitution

    Hematopoietic Cell Transplantation Cures Adenosine Deaminase 2 Deficiency: Report on 30 Patients.

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    Deficiency of adenosine deaminase 2 (DADA2) is an inherited inborn error of immunity, characterized by autoinflammation (recurrent fever), vasculopathy (livedo racemosa, polyarteritis nodosa, lacunar ischemic strokes, and intracranial hemorrhages), immunodeficiency, lymphoproliferation, immune cytopenias, and bone marrow failure (BMF). Tumor necrosis factor (TNF-α) blockade is the treatment of choice for the vasculopathy, but often fails to reverse refractory cytopenia. We aimed to study the outcome of hematopoietic cell transplantation (HCT) in patients with DADA2. We conducted a retrospective study on the outcome of HCT in patients with DADA2. The primary outcome was overall survival (OS). Thirty DADA2 patients from 12 countries received a total of 38 HCTs. The indications for HCT were BMF, immune cytopenia, malignancy, or immunodeficiency. Median age at HCT was 9 years (range: 2-28 years). The conditioning regimens for the final transplants were myeloablative (n = 20), reduced intensity (n = 8), or non-myeloablative (n = 2). Donors were HLA-matched related (n = 4), HLA-matched unrelated (n = 16), HLA-haploidentical (n = 2), or HLA-mismatched unrelated (n = 8). After a median follow-up of 2 years (range: 0.5-16 years), 2-year OS was 97%, and 2-year GvHD-free relapse-free survival was 73%. The hematological and immunological phenotypes resolved, and there were no new vascular events. Plasma ADA2 enzyme activity normalized in 16/17 patients tested. Six patients required more than one HCT. HCT was an effective treatment for DADA2, successfully reversing the refractory cytopenia, as well as the vasculopathy and immunodeficiency. HCT is a definitive cure for DADA2 with &gt; 95% survival

    Altered T Cell Memory and Effector Cell Development in Chronic Lymphatic Filarial Infection That Is Independent of Persistent Parasite Antigen

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    Chronic lymphatic filarial (LF) infection is associated with suppression of parasite-specific T cell responses that persist even following elimination of infection. While several mechanisms have been implicated in mediating this T cell specific downregulation, a role for alterations in the homeostasis of T effector and memory cell populations has not been explored. Using multiparameter flow cytometry, we investigated the role of persistent filarial infection on the maintenance of T cell memory in patients from the filarial-endemic Cook Islands. Compared to filarial-uninfected endemic normals (EN), microfilaria (mf) positive infected patients (Inf) had a reduced CD4 central memory (TCM) compartment. In addition, Inf patients tended to have more effector memory cells (TEM) and fewer effector cells (TEFF) than did ENs giving significantly smaller TEFF ∶ TEM ratios. These contracted TCM and TEFF populations were still evident in patients previously mf+ who had cleared their infection (CLInf). Moreover, the density of IL-7Rα, necessary for T memory cell maintenance (but decreased in T effector cells), was significantly higher on memory cells of Inf and CLInf patients, although there was no evidence for decreased IL-7 or increased soluble IL7-Rα, both possible mechanisms for signaling defects in memory cells. However, effector cells that were present in Inf and CLInf patients had lower percentages of HLA-DR suggesting impaired function. These changes in T cell populations appear to reflect chronicity of infection, as filarial-infected children, despite the presence of active infection, did not show alterations in the frequencies of these T cell phenotypes. These data indicate that filarial-infected patients have contracted TCM compartments and a defect in effector cell development, defects that persist even following clearance of infection. The fact that these global changes in memory and effector cell compartments do not yet occur in infected children makes early treatment of LF even more crucial

    Development of a Quantitative Bead Capture Assay for Soluble IL-7 Receptor Alpha in Human Plasma

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    IL-7 is an essential cytokine in T-cell development and homeostasis. It binds to the IL-7R receptor, a complex of the IL-7Rα (CD127) and common γ (CD132) chains. There is significant interest in evaluating the expression of CD127 on human T-cells as it often decreased in medical conditions leading to lymphopenia. Previous reports showed the usefulness of CD127 as a prognostic marker in viral infections such as HIV, CMV, EBV and HCV. A soluble CD127 (sCD127) is released in plasma and may contribute to disease pathogenesis through its control on IL-7 activities. Measuring sCD127 is important to define its role and may complement existing markers used in lymphopenic disease management. We describe a new quantitative assay for the measurement of sCD127 in plasma and report sCD127 concentrations in healthy adults.We developed a quantitative bead-based sCD127 capture assay. Polyclonal CD127-specific antibodies were chosen for capture and a biotinylated monoclonal anti-CD127 antibody was selected for detection. The assay can detect native sCD127 and recombinant sCD127 which served as the calibrator. The analytical performance of the assay was characterized and the concentration and stability of plasma sCD127 in healthy adults was determined. The assay's range was 3.2–1000 ng/mL. The concentration of plasma sCD127 was 164±104 ng/mL with over a log variation between subjects. Individual sCD127 concentrations remained stable when measured serially during a period of up to one year.This is the first report on the quantification of plasma sCD127 in a population of healthy adults. Soluble CD127 plasma concentrations remained stable over time in a given individual and sCD127 immunoreactivity was resistant to repeated freeze-thaw cycles. This quantitative sCD127 assay is a valuable tool for defining the potential role of sCD127 in lymphopenic diseases

    Density of Common Complex Ocular Traits in the Aging Eye: Analysis of Secondary Traits in Genome-Wide Association Studies

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    Genetic association studies are identifying genetic risks for common complex ocular traits such as age-related macular degeneration (AMD). The subjects used for discovery of these loci have been largely from clinic-based, case-control studies. Typically, only the primary phenotype (e.g., AMD) being studied is systematically documented and other complex traits (e.g., affecting the eye) are largely ignored. The purpose of this study was to characterize these other or secondary complex ocular traits present in the cases and controls of clinic-based studies being used for genetic study of AMD. The records of 100 consecutive new patients (of any diagnosis) age 60 or older for which all traits affecting the eye had been recorded systematically were reviewed. The average patient had 3.5 distinct diagnoses. A subset of 10 complex traits was selected for further study because they were common and could be reliably diagnosed. The density of these 10 complex ocular traits increased by 0.017 log-traits/year (P = 0.03), ranging from a predicted 2.74 at age 60 to 4.45 at age 90. Trait-trait association was observed only between AMD and primary vitreomacular traction (P = 0.0009). Only 1% of subjects age 60 or older had no common complex traits affecting the eye. Extrapolations suggested that a study of 2000 similar subjects would have sufficient power to detect genetic association with an odds ratio of 2.0 or less for 4 of these 10 traits. In conclusion, the high prevalence of complex traits affecting the aging eye and the inherent biases in referral patterns leads to the potential for confounding by undocumented secondary traits within case-control studies. In addition to the primary trait, other common ocular phenotypes should be systematically documented in genetic association studies so that adjustments for potential trait-trait associations and other bias can be made and genetic risk variants identified in secondary analyses

    Dominant-negative mutations in human IL6ST underlie hyper-IgE syndrome

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    Autosomal dominant hyper-IgE syndrome (AD-HIES) is typically caused by dominant-negative (DN) STAT3 mutations. Patients suffer from cold staphylococcal lesions and mucocutaneous candidiasis, severe allergy, and skeletal abnormalities. We report 12 patients from 8 unrelated kindreds with AD-HIES due to DN IL6ST mutations. We identified seven different truncating mutations, one of which was recurrent. The mutant alleles encode GP130 receptors bearing the transmembrane domain but lacking both the recycling motif and all four STAT3-recruiting tyrosine residues. Upon overexpression, the mutant proteins accumulate at the cell surface and are loss of function and DN for cellular responses to IL-6, IL-11, LIF, and OSM. Moreover, the patients’ heterozygous leukocytes and fibroblasts respond poorly to IL-6 and IL-11. Consistently, patients with STAT3 and IL6ST mutations display infectious and allergic manifestations of IL-6R deficiency, and some of the skeletal abnormalities of IL-11R deficiency. DN STAT3 and IL6ST mutations thus appear to underlie clinical phenocopies through impairment of the IL-6 and IL-11 response pathways
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