Tumeur maligne des gaines nerveuses périphériques révélant une neurofibromatose type 1

La Neurofibromatose type 1 (NF1) ou maladie de Von Recklinghausen est une affection à expression clinique variable. La transformation maligne est rare et redoutable. Le but de ce travail est d’étudier les critères diagnostiques ainsi que la prise en charge thérapeutique de cette transformation maligne. Observation : A.B, âgé de 16 ans, a consulté pour une tuméfaction basicervicale antérieure d’apparition récente, ayant augmenté progressivement de taille sans signes de compression ni de dysthyroïdie. L’examen clinique a trouvé une masse dure, bien limitée, indolore, de 4 cm de grand axe siégeant en regard du manubrium sternal, adhérente au plan profond et débordant sur le creux sus sternal. A cette masse s’associaient des taches cutanées café au lait disséminées sur tout le corps, des nodules de Lish iriens et des neurofibromes occipitaux et parotidiens. Après une exérèse de la masse par voie cervicale, l’examen histologique a conclu à une tumeur maligne de la gaine nerveuse. Le malade a eu dans un 2ème temps, une exérèse plus large emportant le manubrium sternal et les tissus adjacents  avec une reconstruction par des fragments de côtes mais avec des limites chirurgicales envahies. L’évolution a été marquée par une poursuite évolutive précoce imposant une exérèse chirurgicale plus large suivie d’une chimiothérapie et d’une radiothérapie externe (RT). Le malade était cependant toujours en poursuite évolutive et le décès est survenu dans un contexte d'envahissement médiastinal.Mots-clés : Neurofibromatose type 1, Sarcome, tissus mous, gaines nerveuses périphériques, Chirurgie

Perceived risk of infection and death from COVID-19 among community members of low- and middle-income countries: A cross-sectional study [version 1; peer review: awaiting peer review]

Background: Risk perceptions of coronavirus disease 2019 (COVID-19) are considered important as they impact community health behaviors. The aim of this study was to determine the perceived risk of infection and death due to COVID-19 and to assess the factors associated with such risk perceptions among community members in low- and middle-income countries (LMICs) in Africa, Asia, and South America. Methods: An online cross-sectional study was conducted in 10 LMICs in Africa, Asia, and South America from February to May 2021. A questionnaire was utilized to assess the perceived risk of infection and death from COVID-19 and its plausible determinants. A logistic regression model was used to identify the factors associated with such risk perceptions. Results: A total of 1,646 responses were included in the analysis of the perceived risk of becoming infected and dying from COVID-19. Our data suggested that 36.4% of participants had a high perceived risk of COVID-19 infection, while only 22.4% had a perceived risk of dying from COVID-19. Being a woman, working in healthcare-related sectors, contracting pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, as well as seeing or reading about individuals infected with COVID-19 on social media or TV were all associated with a higher perceived risk of becoming infected with COVID-19. In addition, being a woman, elderly, having heart disease and pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, and seeing or reading about individuals infected with COVID-19 on social media or TV had a higher perceived risk of dying from COVID-19. Conclusions: The perceived risk of infection and death due to COVID-19 are relatively low among respondents; this suggests the need to conduct health campaigns to disseminate knowledge and information on the ongoing pandemic

SARS-CoV-2 seroprevalence in the urban population of Qatar: An analysis of antibody testing on a sample of 112,941 individuals

ABSTRACTBackgroundQatar has experienced a large SARS-CoV-2 epidemic. Our first objective was to assess the proportion of the urban population that has been infected with SARS-CoV-2, by measuring the prevalence of detectable antibodies. Our second objective was to identify predictors for infection and for having higher antibody titers.MethodsResidual blood specimens from individuals receiving routine and other clinical care between May 12-September 9, 2020 were tested for anti-SARS-CoV-2 antibodies. Associations with seropositivity and higher antibody titers were identified through regression analyses. Probability weights were applied in deriving the epidemiological measures.ResultsWe tested 112,941 individuals (∼10% of Qatar’s urban population), of whom 51.6% were men and 66.0% were 20-49 years of age. Seropositivity was 13.3% (95% CI: 13.1-13.6%) and was significantly associated with sex, age, nationality, clinical-care type, and testing date. The proportion with higher antibody titers varied by age, nationality, clinical-care type, and testing date. There was a strong correlation between higher antibody titers and seroprevalence in each nationality, with a Pearson correlation coefficient of 0.85 (95% CI: 0.47-0.96), suggesting that higher antibody titers may indicate repeated exposure to the virus. The percentage of antibody-positive persons with prior PCR-confirmed diagnosis was 47.1% (95% CI: 46.1-48.2%), severity rate was 3.9% (95% CI: 3.7-4.2%), criticality rate was 1.3% (95% CI: 1.1-1.4%), and fatality rate was 0.3% (95% CI: 0.2-0.3%).ConclusionsFewer than two in every 10 individuals in Qatar’s urban population had detectable antibodies against SARS-CoV-2 between May 12-September 9, 2020, suggesting that this population is still far from the herd immunity threshold and at risk from a subsequent epidemic wave.</jats:sec

Genetic analysis of Turner syndrome in Tunisian patients: from diagnosis to management

Background/aim Turner syndrome (TS) is a rare sex chromosome abnormality in women, occurring in approximately one in 2500 live births, associated with a wide range of clinical stigmata of which short stature, ovarian dysgenesis, and dysmorphic features are the most frequent. Morbidity and mortality are clearly increased compared with the general population, and the average age at diagnosis is quite delayed. Even if the majority of females with TS have a non-mosaic 45,X karyotype, several karyotype variations exist, including short or long arm deletion, ring X isochromosome of the long arm, and 45,X 46,XX mosaicism. This explains the large phenotypic and genetic heterogeneities of TS, which make the diagnosis and especially the management increasingly difficult. We present in this work a genetic study of TS in the Tunisian population to establish a genotype–phenotype correlation, which would be of great help for the diagnosis and the care of patients. Patients and methods A total of 26 unrelated Tunisian girls were included in this study. All patients underwent a complete clinical and biochemical examination as well as karyotyping. The screening for the SRY gene was carried out by fluorescence in-situ hybridization or by PCR. Results Cytogenetic results showed a prevalence of the 45,X karyotype in 46% of patients and various proportions of the other karyotypes. However, genotype–phenotype correlation revealed several discrepancies regarding the major signs and the age at diagnosis. The comparison of the approaches used for the screening of the SRY gene showed that karyotyping is unable to detect low 45,X/46,XY mosaicism and that it is the PCR that would be able to do, eliciting its role to make a reliable diagnosis. Conclusion The karyotype alone is not sufficient to make a TS diagnosis in cases of weak mosaicism, and the great heterogeneity that reigns the syndrome elicits an epigenetic and transcriptomic exploration of several genes that recently seem to be involved in the disease

Association of specific ACE2 and TMPRSS2 variants with circulatory cytokines of COVID-19 Emirati patients

Introduction: The COVID-19 pandemic represented one of the most significant challenges to researchers and healthcare providers. Several factors determine the disease severity, whereas none alone can explain the tremendous variability. The Single nucleotide variants (SNVs) in angiotensin-converting enzyme-2 (ACE2) and transmembrane serine protease type-2 (TMPRSS2) genes affect the virus entry and are considered possible risk factors for COVID-19. Methods: We compiled a panel of gene variants from both genes and used in-silico analysis to predict their significance. We performed biological validation to assess their capacity to alter the ACE2 interaction with the virus spike protein. Subsequently, we conducted a retrospective comparative genome analysis on those variants in the Emirati patients with different disease severity (total of 96) along with 69 healthy control subjects. Results: Our results showed that the Emirati population lacks the variants that were previously reported as associated with disease severity, whereas a new variant in ACE2 “Chr X:g.15584534” was associated with disease severity specifically among female patients. In-silico analysis revealed that the new variant can determine the ACE2 gene transcription. Several cytokines (GM-CSF and IL-6) and chemokines (MCP-1/CCL2, IL-8/CXCL8, and IP-10/CXCL10) were markedly increased in COVID-19 patients with a significant correlation with disease severity. The newly reported genetic variant of ACE2 showed a positive correlation with CD40L, IL-1β, IL-2, IL-15, and IL-17A in COVID-19 patients. Conclusion: Whereas COVID-19 represents now a past pandemic, our study underscores the importance of genetic factors specific to a population, which can influence both the susceptibility to viral infections and the level of severity; subsequently expected required preparedness in different areas of the world