Caractérisation neuro-immunitaire d'un modèle d'encéphalomyélite auto-immune expérimentale spontanée

La sclérose en plaques est une maladie neuroinflammatoire idiopathique caractérisée par la formation de lésions focales de démyélinisation, qui apparaissent suite à l’infiltration périvasculaire de cellules immunitaires et à l’augmentation de la perméabilité de la barrière hémato-encéphalique. L’encéphalomyélite auto-immune expérimentale (EAE) est le modèle animal de cette maladie. Cependant, ce modèle présente des différences importantes avec la sclérose en plaques. L’objectif de ce projet de maîtrise était d’approfondir la caractérisation d’un nouveau modèle transgénique d’encéphalomyélite auto-immune expérimentale spontanée, le modèle TCR1640, afin de valider celui-ci pour l’étude des phénomènes physiopathologiques qui surviennent à différents stades de la sclérose en plaques, ainsi que pour le développement de nouveaux traitements de la maladie. La souris TCR1640 porte un récepteur des cellules T (TCR) transgénique autoréactif, qui reconnaît un peptide de la myéline et déclenche une réaction auto-immune contre la myéline endogène au sein du système nerveux central (SNC). Des observations faites in situ et in vitro ont permis d’identifier des changements qui surviennent de façon très précoce dans l’unité neurovasculaire chez les animaux TCR1640 présymptomatiques, et qui sont liés à la présence d’un profil immunitaire périphérique proinflammatoire. Lors des phases actives de l’EAE spontanée, les animaux TCR1640 au stade chronique présentent une inflammation accrue du système nerveux central associée à une infiltration leucocytaire massive, par rapport aux animaux au stade aigu de la maladie. Une étude in vivo a également permis de moduler la maladie développée par des animaux ayant subi une immunisation passive avec des cellules T auxiliaires en provenance de souris TCR1640. Enfin, l’implication de nouvelles molécules d’adhésion cellulaire dans le développement et le maintien de l’EAE spontanée a été suggérée par des observations in vitro. L’ensemble de ces résultats suggère que le modèle TCR1640 présente plusieurs avantages pour l’étude de la physiopathologie de maladies neuroinflammatoires telles que la sclérose en plaques, et servira d’outil afin de valider de nouvelles stratégies thérapeutiques.Multiple sclerosis is an idiopathic inflammatory disease of the central nervous system. It is characterized by the formation of focal perivascular lesions and demyelination of the surrounding area, which appear concomitantly to a massive immune cell infiltration and disruption of the blood brain barrier. Experimental autoimmune encephalomyelitis is the animal model most extensively used for the study of multiple sclerosis. Unfortunately, this model does not mimic many aspects of the human disease. The goal of this project is to further the characterization of a new transgenic model of spontaneous experimental autoimmune encephalomyelitis, the TCR1640 model, and to validate it as a relevant tool for the study of multiple sclerosis physiopathology and treatment. The TCR1640 mouse possesses a transgenic T cell receptor which recognizes a myelin peptide and triggers an autoimmune response against endogenous myelin in the central nervous system. In situ and in vitro observations have led to the identification of early changes which appear at the neurovascular unit in presymptomatic TCR1640 animals. This early disruption of blood brain barrier homeostasis is linked to the establishment of a proinflammatory immune profile in the periphery. Animals at the chronic stage show sustained inflammation of the central nervous system parenchyma and massive leukocyte infiltration, compared to animals in acute phase of disease. An in vivo experiment has allowed modulating the disease by treatment with a multiple sclerosis-approved therapy, in wild type mice which had received reactivated CD4+ T cells from TCR1640 animals. Finally, the implication of new cell adhesion molecules in the development and maintenance of spontaneous experimental autoimmune encephalomyelitis has been suggested by in vitro study of melanoma cell adhesion molecule (CD146) and activated leucocyte cell adhesion molecule (CD166). The results obtained in this study suggest that the TCR1640 model is a valuable asset in the study of neuroimmune diseases such as multiple sclerosis. It could also be used to validate new therapeutic strategies for the treatment of this disease

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Trémery, Moselle, ZAC de la Fontaine des Saints, site 19 : rapport de fouille

Le Néolithique ancien est marqué par la présence de fosses allongées. La céramique issue de leur remplissage montre des décors réalisés selon la technique du pointillé-sillonné ainsi que l'utilisation du peigne à deux dents et la forte proportion du motif en chevron simple ou double, permettant d'attribuer l'ensemble du mobilier céramique des fosses à l'horizon IIc du Rubané de la chronologie du Rhin moyen ou de la phase 5 régionale. Si du point de vue de la céramique, les fosses appartiennent au même horizon chronologique, en revanche il n'est pas établi qu'elles aient été associées au même habitat qui n'a d'ailleurs pas été conservé. Au regard du nombre de vestiges, on peut penser que le site ne comportait pas plus d'une ou deux habitations. Trois sépultures campaniformes ont été découvertes dans l’emprise, dont la première découverte au cours du diagnostic. L’une d’elle a livré un vase qui s'intègre tout à fait au style maritime/mixte du Campaniforme occidental : gobelet (à profil en S ?), teinte orangée, impressions conjointes d'outils à dents multiples et de cordelette pour la réalisation du décor. Le premier âge du Fer, marqué par des éléments céramiques, provient principalement d’un petit groupe de silos et de fosses. La plupart des vases rencontrés ici trouvent des comparaisons directes essentiellement en Lorraine mais aussi en Alsace et en Allemagne. La plupart des formes de vases et leur décor montrent des parallèles dans des ensembles du Hallstatt C alors que certaines formes évoquent déjà le Hallstatt D. La datation proposée pour ce site est la fin du Hallstatt C voire le Hallstatt D1. Trois plans de bâtiments lisibles dans l’emprise sud du décapage présentent tous un plan rectangulaire Ce type de plan est connu en Lorraine, il apparaît dès l’Âge du Bronze final et perdure à la période hallstattienne, et de façon plus sporadique durant le second Âge du fer. Un plan formant un quadrilatère est constitué de quatre poteaux porteurs d’une superficie de 27 m2 environ. Ce type de bâtisse peut être interprété comme un grenier surélevé, très répandu aux deux âges du Fer. Un chemin 2075 très arasée, orientée est-ouest et s’incurve vers le nord-ouest. Son parcours a été suivi sur l’emprise décapée sur une petite centaine de mètres linéaire. Cinq fossés ont été repérés dans l’emprise fouillée, quatre ont un tracé identique, parallèle, orienté nord-ouest-sud-est. On retrouve leur tracé sur l’emprise du site 30 fouillé par Marie-Pierre Petitdidier

French national diagnosis and care protocol (PNDS, protocole national de diagnostic et de soins): cystic lymphatic malformations

Abstract Cystic lymphatic malformations (LMs) are rare chronic conditions which management differs according to the type (macrocystic LMs, microcystic LMs or both). Studies are lacking due to rarity of the pathology. We aimed to establish a French National Diagnosis and Care Protocol (PNDS: Protocole National de Diagnostic et de Soins), to provide health professionals with free open access synthesis on optimal management and care of patients with LMs ( https://www.has-sante.fr/upload/docs/application/pdf/2021-03/malformations_lymphatiques_kystiques_-_pnds.pdf ). The process included a critical review of the literature and multidisciplinary expert consensus. LMs are congenital but are not always discovered at birth. Nearly 75% of them are located in the head and neck because of the highly dense lymphatic system in this region. Physical examination (showing painless masses with normal skin color and depressible consistency, or cutaneous/mucosal lymphangiectasia) and color Doppler ultrasonography, usually allow for diagnosis. MRI (involving T2 sequences with fat saturation in at least two spatial planes) is the tool of choice for evaluating anatomical extension, characterizing lesions (microcystic and macrocystic), and before considering therapeutic management. A biopsy, coupled to a blood sample, can also be used for molecular biology analyses, to search for activating mutations of the PIK3CA gene, particularly with LM integrating in a syndromic form (CLOVES or Klippel-Trenaunay syndrome) but also in certain isolated (or common) LMs. The spontaneous evolution of LMs, in particular microcystic forms, is often toward progressive aggravation, with an increase in the number of vesicles, thickening, increased oozing and bleeding, while pure macrocystic LMs may regress due to “natural sclerosis”, i.e. fibrosis secondary to an inflammatory reorganization after common infantile infections. In case of voluminous LMs or syndromic forms, functional and psychological repercussions can be major, deteriorating the patient’s quality of life. LMs must be treated by physicians integrated in multidisciplinary teams, and be personalized. Management is a life-long process that involves one or several of these therapies: conservative management, physical therapy (compression), sclerotherapy, surgery, drugs such as mTOR inhibitors (sirolimus), that has shown efficacy in decreasing the volume of LMs, and, more recently, PI3K-inhibitors in syndromic forms. Psychological and social support is necessary, taking into account the patient and his family

Dual role of ALCAM in neuroinflammation and blood-brain barrier homeostasis.

Activated leukocyte cell adhesion molecule (ALCAM) is a cell adhesion molecule found on blood-brain barrier endothelial cells (BBB-ECs) that was previously shown to be involved in leukocyte transmigration across the endothelium. In the present study, we found that ALCAM knockout (KO) mice developed a more severe myelin oligodendrocyte glycoprotein (MOG)35-55-induced experimental autoimmune encephalomyelitis (EAE). The exacerbated disease was associated with a significant increase in the number of CNS-infiltrating proinflammatory leukocytes compared with WT controls. Passive EAE transfer experiments suggested that the pathophysiology observed in active EAE was linked to the absence of ALCAM on BBB-ECs. In addition, phenotypic characterization of unimmunized ALCAM KO mice revealed a reduced expression of BBB junctional proteins. Further in vivo, in vitro, and molecular analysis confirmed that ALCAM is associated with tight junction molecule assembly at the BBB, explaining the increased permeability of CNS blood vessels in ALCAM KO animals. Collectively, our data point to a biologically important function of ALCAM in maintaining BBB integrity

Treatment, outcome, and prognostic factors in non-metastatic anal cancer: The French nationwide cohort study FFCD-ANABASE

International audienceIntroduction: International guidelines regarding the treatment of squamous cell carcinoma of the anus (SCCA) recommend intensity-modulated radiotherapy (IMRT) combined with mitomycin-based chemotherapy (CT). The French FFCD-ANABASE cohort aimed at evaluating clinical practices, treatment, and outcomes of SCCA patients.Methods: This prospective multicentric observational cohort included all non-metastatic SCCA patients treated in 60 French centers from January 2015 to April 2020. Patients and treatment characteristics, colostomy-free survival (CFS), disease-free survival (DFS), overall survival (OS), and prognostic factors were analyzed.Results: Among 1015 patients (male: 24.4 %; female: 75.6 %; median age: 65 years), 43.3 %presented with early-stage(T1-2, N0) and 56.7 % with locally advanced stage (T3-4 or N + ) tumors. IMRT was used for 815 patients (80.3 %) and a concurrent CT was administered in 781 patients, consisting of mitomycin-based CT for 80 %. The median follow-up was 35.5 months. DFS, CFS, and OS at 3 years were 84.3 %, 85.6 %, and 91.7 % respectively in the early-stage group compared to 64.4 %, 66.9 %, and 78.2 % in the locally-advanced group (p < 0.001). In multivariate analyses, male gender, locally-advanced stage, and ECOG PS ≥ 1 were associated with poorer DFS, CFS, and OS. IMRT was significantly associated with a better CFS in the whole cohort and almost reached significance in the locally-advanced group.Conclusion: Treatment of SCCA patients showed good respect for current guidelines. Significant differences in outcomes advocate for personalized strategies by either de-escalation for early-stage tumors or treatment intensification for locally-advanced tumors