Asthma-associated bacterial infections: Are they protective or deleterious?

Eosinophilic, noneosinophilic, or mixed granulocytic inflammations are the hallmarks of asthma heterogeneity. Depending on the priming of lung immune and structural cells, subjects with asthma might generate immune responses that are TH2-prone or TH17-prone immune response. Bacterial infections caused by Haemophilus, Moraxella, or Streptococcus spp. induce the secretion of IL-17, which in turn recruit neutrophils into the airways. Clinical studies and experimental models of asthma indicated that neutrophil infiltration induces a specific phenotype of asthma, characterized by an impaired response to corticosteroid treatment. The understanding of pathways that regulate the TH17-neutrophils axis is critical to delineate and develop host-directed therapies that might control asthma and its exacerbation episodes that course with infectious comorbidities. In this review, we outline clinical and experimental studies on the role of airway epithelial cells, S100A9, and high mobility group box 1, which act in concert with the IL-17-neutrophil axis activated by bacterial infections, and are related with asthma that is difficult to treat. Furthermore, we report critically our view in the light of these findings in an attempt to stimulate further investigations and development of immunotherapies for the control of severe asthma.

Ensino do exame respiratório: o que é história e o que é necessidade? / Teaching the respiratory physical examination: what is history and what is needed?

A semiologia é uma das técnicas mais utilizadas na prática médica há séculos. Ensinada por meio de roteiros sistematizados, estudantes de inúmeras escolas da área de saúde por todo o mundo aprendem as manobras semiológicas como fundamento na avaliação dos pacientes. No entanto, apesar de extremamente difundida, discute-se pouco sobre sua acurácia como manobra diagnóstica. Tendo este ponto em vista, este artigo aborda a precisão das diversas manobras semiológicas do exame físico do aparelho respiratório e a descrição comparativa do seu ensino em diferentes escolas médicas no mundo. Como resultados, tem-se valores de acurácia discordantes, o que pode ser justificado pela qualidade dos estudos ou pelas variáveis analisadas que diferem entre os estudos e propostas de padronização. Em conclusão, a semiologia é a base da avaliação médica, independentemente dos avanços e disponibilidade dos exames de imagens, e cada manobra deve ser ensinada com seu devido valor científico. Conhecer a aplicabilidade e individualizar a prática das etapas do exame respiratório pode ser um caminho possível de adequação aos tempos atuais, sem impor perdas de informações relevantes para o desenvolvimento do raciocínio clínico (AU)

Medical semiology has been one of the most common techniques used in medical practice for centuries. Health science students around the globe learn these techniques through a systematized model as a fundamental skill for patient evaluation. However, though being widespread, little is known about semiology's true accuracy as a diagnostic maneuver. Knowing that, through a literature review, this paper evaluated the precision of the preconized procedures that are used as part of the exam of the respiratory system and the comparative description of its teaching in different medical schools around the world. As a result, disagreement between several papers was found, which can be justified by the poor quality of the studies and the different variables that were studied in each one. However, one thing is still clear: respiratory physical examination continues to be essential in medical practice, independently of the recent advances and availability of imaging exams. Teaching each step should consider available scientific evidence. The knowledge of the applicability and practical individualization of the respiratory examination can be a possible way for the current times without missing relevant information for developing clinical reasoning (AU)

SARS-Cov-2 pneumonia phenotyping on imaging exams of patients submitted to minimally invasive autopsy.

Background: Correlation between pathology and imaging of the new SARS-Cov-2 disease (COVID-19) is scarce. This study aimed to characterize SARS-Cov-2 pneumonia on imaging of patients submitted to minimally invasive autopsy (MIA). Methods: This unicentric retrospective observational study included 46 consecutive patients with confirmed COVID-19 who underwent MIA. All clinical chest images were reviewed and classified for the presence and grade of viral pneumonia, as well as disease evolution. On CT, phenotypes were described as consistent with mild, moderate, or severe viral pneumonia, with or without radiological signs of organizing pneumonia (OP). In severe pneumonia, CT could also be classified as diffuse progressive OP or radiological diffuse alveolar damage (DAD). Specific features on CT were noted, including fibroproliferative signs that could indicate potential or initial fibrosis. Results: MIA showed a heterogeneous panel of alterations, with a high prevalence of OP and acute fibrinous and organizing pneumonia (AFOP). Also, signs of interstitial fibrosis corresponded to the most prevalent pathological feature. Initial chest radiography (CXR) findings were mainly consistent with moderate or severe viral pneumonia. Most patients showed stability or improvement (reduction of opacities) on imaging. CTs were performed on 15 patients. Consolidations were found in most patients, frequently showing features consistent with an OP phenotype. Fibroproliferative changes were also prevalent on CT. Conclusions: In this study, SARS-Cov-2 pneumonia showed heterogeneous radiological and pathological patterns. Signs of organization and potential or initial fibrosis were prevalent on both imaging and pathology. Imaging phenotyping may help to predict post-infection fibrosing interstitial pneumonitis in COVID-19.

Influence of asthma definition on the asthma-obesity relationship.

BACKGROUND: Epidemiological studies suggest an association between obesity and asthma in adults and children. Asthma diagnosis criteria are different among studies. The aim of this study was to test the influence of asthma definition on the asthma-obesity relationship. METHODS: In a cross-sectional analysis of 1922 men and women, subjects completed a translated questionnaire from the European Community Respiratory Health Survey and underwent spirometry and a bronchial challenge test. Weight, height and waist circumference were measured. Multiple logistic regression analysis was carried out to assess the association of variables related to obesity and asthma. Asthma was defined either by the presence of symptoms with bronchial hyperresponsiveness (BHR) or by a self-report of a physician-made diagnosis. The following variables were separately tested for associations with asthma: socioeconomic characteristics, schooling, physical activity, smoking status, anthropometry and spirometry. RESULTS: No association was detected between asthma confirmed by BHR and obesity indicators, odds ratio (OR) = 1.08 (95% confidence interval: 0.69 - 1.68) for obesity assessed by body mass index ≥ 30 kg/m2; OR = 1.02 (0.74 - 1.40) for obesity assessed by abnormal waist-to-height ratio; and, OR = 0.96 (0.69 - 1.33) for abnormal waist circumference. On the contrary, a previous diagnosis of asthma was associated with obesity, OR = 1.48 (1.01 - 2.16) for body mass index ≥ 30 kg/m2; OR = 1.48 (1.13 - 1.93) for abnormal waist-to-height ratio; and, OR = 1.32 (1.00 - 1.75) for abnormal waist circumference. Female gender, schooling ≥ 12 years and smoking were associated with BHR-confirmed asthma. Physically inactive subjects were associated with a previous diagnosis of asthma. CONCLUSIONS: Our findings indicate that the relationship between asthma and obesity in epidemiological studies depends on the definition adopted. Certain components of asthma, for instance, symptoms may be more prone to the obesity influence than other ones, like bronchial hyperresponsiveness.