Publications by authors named "Marc Michel"

Adult autoimmune haemolytic anaemias (AIHAs) include different subtypes of a rare autoimmune disease in which autoantibodies targeting autoantigens expressed on the membrane of autologous red blood cells (RBCs) are produced, leading to their accelerated destruction. In the presence of haemolytic anaemia, the direct antiglobulin test is the cornerstone of AIHA diagnosis. AIHAs are classified according to the isotype and the thermal optimum of the autoantibody into warm (wAIHAs), cold and mixed AIHAs.

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An open prospective, multicenter study enrolled 48 selected patients with chronic immune thrombocytopenia who achieved complete response for 1 year on thrombopoietin receptor agonists, half of the patients maintained a sustained response off treatment 4 years after treatment discontinuation. NCT03119974.

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Article Synopsis
  • Intravenous immunoglobulin (IVIg) is a preferred treatment for severe immune thrombocytopaenia (ITP), but its high cost and limited availability led to specific French guidelines on its use.
  • A study assessed IVIg prescribing practices in real-life situations, evaluating compliance with these French guidelines in a sample of 114 hospitalized patients from 2016 to 2020.
  • Findings showed that 84.4% of IVIg prescriptions were compliant with guidelines, and the use was notably more frequent among younger patients, with factors like corticosteroid resistance and need for surgical preparation influencing non-compliance.
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Predominantly antibody deficiencies have an estimated prevalence of >1 in 25 000. Their classical phenotype entails the association of autoimmune manifestations with increased susceptibility to infections. Up to 8% of these patients ultimately develop immune thrombocytopenic purpura (ITP).

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Article Synopsis
  • The human immune system continues to develop for several years after birth, affecting how young children respond to infections, such as SARS-CoV-2.
  • Researchers studied T cell responses in children and adults before, during, and after SARS-CoV-2 infection, revealing that younger children (under 5) had a weaker CD4 T cell response compared to older children and adults with mild disease.
  • Following infection, preschool-age children produced similar neutralizing antibodies to adults but had different T cell characteristics and fewer memory B cells, indicating a gradual maturation of their adaptive immune responses.
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Because Systemic Lupus Erythematosus (SLE) is a rare disease, and due to the significant prognostic impact of early management, a diagnosis confirmed by a physician with experience in SLE is recommended, for example from an expert center. Once the diagnosis is confirmed, existing manifestations should be identified in particular, renal involvement by an assessment of proteinuria, disease activity and severity should be determined, potential complications anticipated, associated diseases searched for, and the patient's socioprofessional and family context noted. Therapeutic management of SLE includes patient education on recognizing symptoms, understanding disease progression as well as when they should seek medical advice.

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Autoimmune hemolytic anemia (AIHA) is a rare and sometimes life-threatening disease. Infections are frequent and often severe during the course of AIHA. Rituximab is commonly used to treat patients with AIHA.

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Article Synopsis
  • Cold agglutinin disease (CAD) is a rare autoimmune condition causing anemia, and sutimlimab, which inhibits a key part of the immune system, showed effectiveness in reducing symptoms like hemolysis and fatigue in the CADENZA Part A study.
  • In Part B of the CADENZA study, 32 out of 39 patients continued treatment for about 99 weeks, showing sustained improvements in hemoglobin, bilirubin levels, and quality of life measures, with no severe adverse effects reported.
  • Despite the promising results, stopping sutimlimab led to a return of disease symptoms, indicating that while the treatment is effective, continuous management is necessary to maintain its benefits.
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Evans syndrome is a rare disease marked by a severe clinical course, high relapse rate, infectious and thrombotic complications, and sometimes fatal outcome. Management is highly heterogeneous. There are several case reports but few large retrospective studies and no prospective or randomised trials.

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The CARMEN-France registry is a prospective, multicenter registry in France including adult patients with a new diagnosis of immune thrombocytopenia or of autoimmune immune hemolytic anemia (2402 patients included in December 31, 2023). The recording of clinical, biological and treatment data allows detailed epidemiological and pharmacoepidemiological real-world studies. This review summarizes the CARMEN-France registry protocol, gives examples of studies conducted in the registry, and indicates future directions such as inclusion of patient reported outcomes, linkage with the French national health insurance database and linkage with other registries in Europe.

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Autoimmune hemolytic anemia (AIHA) is a rare autoantibody-mediated disease. For steroid and/or rituximab-refractory AIHA, there is no consensus on optimal treatment. Daratumumab, a monoclonal antibody targeting CD38, could be beneficial by suppression of CD38+ plasma cells and thus autoantibody secretion.

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The presence of oxyanions, such as nitrate (NO) and phosphate (PO), regulates the nucleation and growth of goethite (Gt) and hematite (Hm) during the transformation of ferrihydrite (Fh). Our previous studies showed that oxyanion surface complexes control the rate and pathway of Fh transformation to Gt and Hm. However, how oxyanion surface complexes control the mechanism of Gt and Hm nucleation and growth during the Fh transformation is still unclear.

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Interest is growing in nanoparticles made of earth abundant materials, like alumino(silicate) minerals. Their applications are expanding to include catalysis, carbon sequestration reactions, and medical applications. It remains unclear, however, what factors control their formation and abundance during laboratory synthesis or on a larger industrial scale.

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The aim of this study was to assess the prevalence and the burden of difficult-to-treat primary ITP (pITP), defined by the need for another ITP treatment after romiplostim and eltrombopag. Adult patients were selected in the prospective, real-world CARMEN-France registry up to December 2021. Out of 821 adult patients with pITP, 29 had difficult-to-treat ITP (3.

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Objectives: The objective of this study is to better characterize the features and outcomes of a large population of patients with mixed connective tissue disease (MCTD).

Methods: We performed an observational retrospective multicenter cohort study in France. Patients who fulfilled at least one diagnostic criterion set for MCTD and none of the criteria for other differentiated CTD (dCTD) were included.

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Article Synopsis
  • The CORIPLASM trial aimed to assess whether covid-19 convalescent plasma is effective in treating hospitalized adults with moderate covid-19, including those with weakened immune systems.
  • Conducted across 19 hospitals in France, the trial included 120 participants randomly assigned to receive either convalescent plasma or usual care between April 2020 and April 2021.
  • Key outcomes measured included the proportion of patients experiencing worsening symptoms by day 4 and survival without needing assisted ventilation by day 14, while secondary outcomes assessed overall survival and recovery times.
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More than 130 drugs have been suspected to induce immune hemolytic anemia. Comparative studies measuring the risk of drug-induced immune hemolytic anemia (DIIHA) are lacking. We aimed (1) to detect new signals of DIIHA, excluding vaccines, and (2) to assess the association between all suspected drugs and the occurrence of immune hemolytic anemia in a nationwide comparative study.

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Background: Primary immune thrombocytopenia is an autoimmune disorder mediated partly by platelet autoantibodies, resulting in thrombocytopenia, bleeding, and constitutional symptoms. Efgartigimod, a first-in-class novel human IgG1 Fc fragment, binds the neonatal Fc receptor with high affinity and thus reduces serum IgG concentrations, including autoantibodies. The objective of this study was to evaluate the efficacy and safety of efgartigimod in adults with persistent and chronic primary immune thrombocytopenia.

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Amorphous calcium carbonate is an important precursor for biomineralization in marine organisms. Key outstanding problems include understanding the structure of amorphous calcium carbonate and rationalizing its metastability as an amorphous phase. Here we report high-quality atomistic models of amorphous calcium carbonate generated using state-of-the-art interatomic potentials to help guide fits to X-ray total scattering data.

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  • - The study investigates the relationship between genetic factors and the severity of adult hemophagocytic lymphohistiocytosis (HLHa), focusing on gene variants related to HLH.
  • - Clinical data from 130 HLHa patients, including their genotypes for 8 specific HLH-related genes, were analyzed to assess disease outcomes, with findings showing a significant association between the number of genetic variants and severity of HLHa.
  • - Results indicate that HLH gene variants can impact the severity and treatment resistance in HLHa patients, highlighting their potential role in understanding the condition better.
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How infection by a viral variant showing antigenic drift impacts a preformed mature human memory B cell (MBC) repertoire remains an open question. Here, we studied the MBC response up to 6 months after SARS-CoV-2 Omicron BA.1 breakthrough infection in individuals previously vaccinated with three doses of the COVID-19 mRNA vaccine.

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