Validation and shortcomings of the most common mouse model of chronic rhinosinusitis with nasal polyps

BACKGROUND: Chronic rhinosinusitis (CRS) is a highly prevalent airway disease worldwide. Whereas eosinophilic CRS with nasal polyps (eCRSwNP) represents its most severe phenotype, pathogenic mechanisms remain poorly understood despite a wide spectrum of in vitro and in vivo experimental models. A mouse model of experimental ovalbumin (OVA)-induced airway allergy with coadministration of Staphylococcus aureus enterotoxin B (SEB) has been widely used to study eosinophilic eCRSwNP. This study revisits the features of this model and its suitability for studying eCRS. METHODOLOGY: We implemented the most used eCRSwNP mouse model based on OVA+SEB intranasal challenges. Readouts including inflammatory features by (immuno)histology of the sinonasal epithelium (NP formation, eosinophils, epithelial and basement membrane thickness, fibrosis, goblet cells, Charcot-Leyden crystals (CLC)-like, tight junctions) and IgE production by enzyme-linked immunosorbent assay (ELISA), were compared to features of the corresponding human disease. RESULTS: The OVA+SEB model induced eosinophilic inflammation of upper and lower airways, with epithelial and basement membrane thickening, goblet cell hyperplasia and subepithelial fibrosis in the sinuses, along increased IgE production. Except local IgE in nasal lavage (NL), which was only increased in OVA+SEB group, all other features did not differ between OVA and OVA+SEB groups. Macro- or microscopic NP were not detected. CONCLUSIONS: With the notable exception of local IgE production, the addition of SEB did not induce additional inflammatory or structural change in the sinuses from mice exposed to and challenged with OVA. This model might represent a model for severe upper airway allergy rather than a specific model of human eCRSwNP.

SARS-CoV-2 seroprevalence in a Belgian cohort of patients with cystic fibrosis.

BACKGROUND: In Belgium, COVID-19 epidemy began on February 4, 2020 with a peak on April 10, 2020. Patients with cystic fibrosis (CF) followed in the Cliniques universitaires Saint-Luc were rapidly isolated before the government lockdown. METHODS: After the peak of the epidemy, we measured anti-SARS-CoV-2 IgM and IgG antibodies in 149 patients and collected clinical data. RESULTS: Only 3 asymptomatic patients presented IgG against the virus. In one patient hospitalized for COVID-19 (positive molecular testing), we did not detect any anti-SARS-CoV-2 antibodies, as in thirty-five other symptomatic patients considered as possible cases. CONCLUSIONS: Even if respiratory symptoms linked to CF are frequent and compatible with COVID-19, anti-SARS-CoV-2 IgG antibodies were detected only in 3 asymptomatic patients. This reassuring study concerning the risk of COVID-19 in patients with CF illustrates the difficulty to distinguish COVID-19 symptoms from respiratory exacerbations and the need of generalized molecular testing to make a precise diagnosis.

Chronic inflammatory airway diseases: the central role of the epithelium revisited.

The respiratory epithelium plays a critical role for the maintenance of airway integrity and defense against inhaled particles. Physical barrier provided by apical junctions and mucociliary clearance clears inhaled pathogens, allergens or toxics, to prevent continuous stimulation of adaptive immune responses. The "chemical barrier", consisting of several anti-microbial factors such as lysozyme and lactoferrin, constitutes another protective mechanism of the mucosae against external aggressions before adaptive immune response starts. The reconstruction of damaged respiratory epithelium is crucial to restore this barrier. This review examines the role of the airway epithelium through recent advances in health and chronic inflammatory diseases in the lower conducting airways (in asthma and chronic obstructive pulmonary disease). Better understanding of normal and altered epithelial functions continuously provides new insights into the physiopathology of chronic airway diseases and should help to identify new epithelial-targeted therapies.

[Management of adult bronchiectasis]. / Prise en charge des bronchectasies de l'adulte.

Non-cystic fibrosis bronchiectasis has been the subject of renewed interest over recent years. It is usually part of the evolutionary process of many infectious, autoimmune, genetic, developmental or allergic diseases. Its presentation and prognosis are heterogeneous and it causes significant morbidity and mortality with a real impact on the health care system. Thanks to increasingly available guidelines, it is now possible to define the optimal management that will include various therapeutic objectives : airway clearance, prevention and eradication of bacterial colonization, reduction of airway inflammation and exacerbations and improvement of quality of life.

Les bronchectasies non liées à la mucoviscidose font l'objet d'un regain d'intérêt. Elles font généralement partie du processus évolutif de nombreuses pathologies infectieuses, auto-immunes, génétiques, développementales ou allergiques. Leur présentation et leur pronostic sont hétérogènes et elles sont à l'origine d'une morbi-mortalité significative avec un impact important sur le système de soins de santé. Grâce à de récentes recommandations de bonne pratique, il est main¬tenant possible de définir une prise en charge optimale qui comportera différents objectifs thérapeutiques : le drainage des voies respiratoires, la prévention et l'éradication d'une colonisation bactérienne, la diminution de l'inflammation bronchique, la réduction des exacerbations et l'amélioration de la qualité de vie du patient.

Features of mesenchymal transition in the airway epithelium from chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis (CRS) defines a group of disorders characterized by persistent inflammation of the sinonasal tract. Epithelial changes and structural remodelling are present, but whether epithelial differentiation is altered remains uncertain. METHODS: To evaluate the differentiation state of the sinonasal epithelium in CRS, sinonasal biopsies from patients with CRS with nasal polyps (CRSwNP) or CRS without nasal polyps (CRSsNP), or with allergic rhinitis (AR), as compared to controls, were processed by immunohistochemistry and RT-qPCR for terminal differentiation (E-cadherin, high molecular weight cytokeratins (Hmw CK) and CK5, vimentin) and lineage differentiation (ß-tubulin IV+ ciliated cells, MUC5AC+ goblet cells, p63 + basal cells). Findings were correlated with subepithelial fibrosis and clinical CT score. RESULTS: Expression of E-cadherin was decreased at protein and mRNA levels in CRSwNP and CRSsNP, as compared to controls. Staining for Hmw CKs was also reduced in CRSwNP and CRSsNP, and CK5 mRNA was decreased in CRSwNP. These features were not due to changes in lineage specification, but associated with increases in vimentin-expressing epithelial cells. In addition, vimentin expression correlated with the basement membrane thickening and with CT score, as well as with tissue eosinophils. CONCLUSION: Features of epithelial dedifferentiation towards a mesenchymal phenotype are observed in CRSwNP and CRSsNP and correlate with airway fibrosis and inflammation.

[Unsuspected danger of a medicinal preparation]. / Danger inattendu d'une préparation magistrale.

INTRODUCTION: Inhaled foreign bodies are commonly reported in childhood but less so among adults. We report the case of a patient who inhaled a medicinal preparation containing meprobamate and quinine sulfate. The consequence of this was caustic damage to the airways. CASE REPORT: A 64-year-old woman came to the emergency room because of dyspnea, oropharyngeal pain and sialorrhea. She reported that she had inhaled a capsule containing meprobamate and quinine sulfate the previous day. Flexible bronchoscopy showed evidence of caustic damage to the larynx and lower airways. The patient was treated by fasting, corticoids and intravenous broad-spectrum antibiotics. All the lesions recovered and she was discharged from the hospital 15 days after the event. CONCLUSIONS: Inhalation of drugs mostly leads to airway obstruction. Risk of harm is influenced by neurological status, the motility of the digestive system and the properties of the drug. To the best of our knowledge, this is the first time that caustic airway disease has been described following inhalation of a medicinal preparation containing meprobamate and quinine. It highlights the need to be familiar with the chemical properties of medications when prescribing them to patients who are at risk of aspiration.

Correlation between the loss of thyroglobulin iodination and the expression of thyroid-specific proteins involved in iodine metabolism in thyroid carcinomas.

Progress in biotechnology has provided useful tools for tracing proteins involved in thyroid hormone synthesis in vivo. Mono- or polyclonal antibodies are now available to detect on histological sections the Na(+)/I(-) symporter (NIS) at the basolateral pole of the cell, the putative iodide channel (pendrin) at the apical plasma membrane, thyroperoxidase (TPO), and members of the NADPH-oxidase family, thyroid oxidase 1 and 2 (ThOXs), part of the H(2)O(2)-generating system. The aim of this study was to correlate thyroglobulin (Tg) iodination with the presence of these proteins. Tg, T(4)-containing Tg, NIS, pendrin, TPO, ThOXs, and TSH receptor (TSHr) were detected by immunohistochemistry on tissue sections of normal thyroids and various benign and malignant thyroid disorders. Tg was present in all cases. T(4)-containing Tg was found in the adenomas, except in Hurthle cell adenomas. It was never detected in carcinomas. NIS was reduced in all types of carcinomas, whereas it was detected in noncancerous tissues. Pendrin was not expressed in carcinomas, except in follicular carcinomas, where weak staining persisted. TPO expression was present in insular, follicular carcinomas and in follicular variants of papillary carcinomas, but in a reduced percentage of cells. It was below the level of detection in papillary carcinomas. The H(2)O(2)-generating system, ThOXs, was found in all carcinomas and was even increased in papillary carcinomas. Its staining was apical in normal thyroids, whereas it was cytoplasmic in carcinomas. The TSHr was expressed in all cases, but the intensity of the staining was decreased in insular carcinomas. In conclusion, our work shows that all types of carcinomas lose the capacity to synthesize T(4)-rich, iodinated Tg. In follicular carcinomas, this might be due to a defect in iodide transport at the basolateral pole of the cell. In papillary carcinomas, this defect seems to be coupled to an altered apical transport of iodide and probably TPO activity. The TSHr persists in virtually all cases.