New Directions in Pediatric Asthma

Maintenance Therapy for Children and Adolescents with Asthma: Guidelines and Recommendations from the Emilia-Romagna Asthma (ERA) Study Group

Asthma is the most frequent chronic disease of childhood, affecting up to 20% of children worldwide. The main guidelines on asthma maintenance therapy in pediatrics suggest different approaches and describe different stages of asthma to determine the most appropriate treatment. This project aims to summarize the most recent evidence regarding maintenance therapy for asthma in children and adolescents. A multidisciplinary panel of experts was asked clinical questions regarding the treatment of children and adolescents with asthma. Overall, 10 clinical questions were addressed, and the search strategy included accessing electronic databases and a manual search of gray literature published in the last 25 years. After data extraction and narrative synthesis of results, recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Results showed that the choice of medication depends on the severity of the child's asthma, phenotype, age, preference, and individual factors. In addition to medications, the identification of comorbidities and modifiable factors is crucial to obtaining good control. Asthma in children is heterogeneous, and its evolution varies over time. Since most recommendations for asthma management in childhood are extrapolated from clinical studies performed in adults, more clinical trials specifically designed for young children should be conducted.

Temporal changes of the respiratory microbiota as cats transition from health to experimental acute and chronic allergic asthma

In humans, deviation from a core airway microbiota may predispose to development, exacerbation, or progression of asthma. We proposed to describe microbiota changes using 16 rRNA sequencing in samples from the upper and lower airways, and rectal swabs of 8 cats after experimental induction of asthma using Bermuda grass allergen, in acute (6 weeks) and chronic (36 weeks) stages. We hypothesized that asthma induction would decrease richness and diversity and alter microbiota composition and structure in the lower airways, without significantly impacting other sites. After asthma induction, richness decreased in rectal (p = 0.014) and lower airway (p = 0.016) samples. B diversity was significantly different between health and chronic asthma in all sites, and between all time points for lower airways. In healthy lower airways Pseudomonadaceae comprised 80.4 ± 1.3% whereas Sphingobacteriaceae and Xanthobacteraceae predominated (52.4 ± 2.2% and 33.5 ± 2.1%, respectively), and Pseudomonadaceae was absent, in 6/8 cats with chronic asthma. This study provides evidence that experimental induction of asthma leads to dysbiosis in the airways and distant sites in both the acute and chronic stages of disease. This article has been published alongside "Respiratory dysbiosis in cats with spontaneous allergic asthma" (1).

NORAD Promotes the Viability, Migration, and Phenotypic Switch of Human Vascular Smooth Muscle Cells during Aortic Dissection via LIN28B-Mediated TGF-β Promotion and Subsequent Enhanced Glycolysis

Glucose metabolism reprogramming is an important reason for the functional remodeling, growth, and migration of vascular smooth muscle cells (VSMCs). It is also an important basis for the occurrence and development of aortic dissection (AD), but the specific regulatory factors are not clear. Noncoding RNA activated by DNA damage (NORAD) is dysfunctional in many diseases, but the role of NORAD in AD etiology is unclear. We first established a vascular remodeling cell model of AD, and the expression of NORAD in VSMCs was significantly increased. Functional experiments showed that inhibition of NORAD could downregulate the proliferation and migration of VSMCs. Meanwhile, silencing NORAD could also inhibit the flux of glycolysis, suggesting that NORAD may aggravate AD by promoting glycolysis. In addition, mechanism studies have shown that NORAD can exert VSMCs-regulating function by recruiting LIN28B to bind to TGF-β mRNA, which subsequently facilitates the expression of TGF-β1 (transforming growth factor β1). The recovery experiment also showed that overexpression of TGF-β could reverse the inhibitory effect of NORAD knockdown on VSMCs in terms of proliferation, migration, and glycolysis. Collectively, these results indicated that the NORAD/LIN28B/TGF-β axis promoted cell proliferation and migration through regulating aerobic glycolysis in VSMCs. Therefore, NORAD may regulate the occurrence of AD by affecting the reprogramming of glucose metabolism, and NORAD can be recognized as a good target for VSMC phenotypic intervention and AD treatment.

Heterogeneous Condition of Asthmatic Children Patients: A Narrative Review

Currently, asthma represents the most common chronic disorder in children, showing an increasingly consistent burden worldwide. Childhood asthma, similar to what happens in adults, is a diversified disease with a great variability of phenotypes, according to genetic predisposition of patients, age, severity of symptoms, grading of risk, and comorbidities, and cannot be considered a singular well-defined disorder, but rather a uniquely assorted disorder with variable presentations throughout childhood. Despite several developments occurring in recent years in pediatric asthma, above all, in the management of the disease, some essential areas, such as the improvement of pediatric asthma outcomes, remain a hot topic. Most treatments of the type 2 (T2) target phenotype of asthma, in which IL-4, IL-5, and IL-13 modulate the central signals of inflammatory reactions. Although, there may be an unresolved need to identify new biomarkers used as predictors to improve patient stratification using disease systems and to aid in the selection of treatments. Moreover, we are globally facing many dramatic challenges, including climate change and the SARS-CoV2 pandemic, which have a considerable impact on children and adolescent asthma. Preventive strategies, including allergen immunotherapy and microbiome evaluation, and targeted therapeutic strategies are strongly needed in this population. Finally, the impact of asthma on sleep disorders has been reviewed.

Miracles in my time: Reflections of a pediatric respiratory physician

Miracles, like London buses, just seem to come along. The truth is, there are no miracles, just lots of hard work behind the scenes, minds open to opportunity, serendipity, and possibly a little luck. In my time as a pediatric respiratory physician, I have borne witness to remarkable advances in treatment that have changed patients' fortunes overnight. Examples of these include artificial surfactant replacement for premature newborns, conjugate Haemophilus influenzae type b vaccination, propranolol for infants with subglottic haemangiomas, mandibular distraction for babies with micrognathia, cystic fibrosis transmembrane conductance regulator modulators therapy for patients with cystic fibrosis, and antisense oligonucleotide therapy for infants with spinal muscular atrophy. There are lessons to be learned from reflection upon these life-transforming treatments, and perhaps it is a good time just to pause and wonder.

PM2.5 and water-soluble components induce airway fibrosis through TGF-β1/Smad3 signaling pathway in asthmatic rats

Epidemiological studies have suggested that fine particulate matter (PM_2.5) and asthma have been independently associated with pulmonary fibrosis but rarely studied together. Furthermore, it is unknown whether airway fibrosis in asthma is more attributable to water-soluble ions of PM_2.5. Our current study was to explore the potential mechanism of PM_2.5 and water-soluble components on airway fibrosis in ovalbumin (OVA)-sensitized asthmatic rats. Rats were intratracheally instilled with PM_2.5 and water-soluble components every 3 days for 4 times or 8 times. Histopathological examination demonstrated that lung inflammatory and airway fibrosis were induced after PM_2.5 and water-soluble components exposure. Meanwhile, PM_2.5, in particular water-soluble extracts, increased expression of collagen 1 (COL-1), connective tissue growth factor (CTGF), interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1), Smad family member 3 (Smad3), and p-Smad3, whereas decreased secretion of heme oxygenase-1 (HO-1). However, pretreating asthmatic rats with SB432542, the inhibitor of TGF-β1, and SIS3 HCl, the antagonist of Smad3, both reversed the activation of airway fibrosis induced by water-soluble extracts. Therefore, TGF-β1/Smad3 signaling pathway may be responsible for the pathological process of airway fibrosis in asthmatic rats following PM_2.5 and water-soluble components exposure.

Preschool Wheezing and Gastro-Esophageal Reflux: --Causal or Casual Coincidence? Update from Literature

Gastroesophageal reflux (GER) and wheeze are two common conditions in children. GER has been advocated as a causative factor for explaining recurrent to persistent respiratory symptoms at any age. This association very often means that many children with cough, wheezing, or recurrent respiratory infections receive empirical anti-reflux medications. The causal relationship is still largely discussed. Compared to the large number of studies in infants and adolescents, literature on the relationship between GER and wheeze in preschool children is scarce and inconclusive. The aim of the present narrative review was to summarize what is known so far, and what the literature has proposed in the last 20 years, on the relationship between preschool wheezing and GER. In preschool children with respiratory symptoms there is a high rate of positivity of reflux testing, for this reason pH-MII testing and endoscopy are recommended. Flexible bronchoscopy may be useful to exclude anatomical abnormalities as the cause of wheezing in infancy and preschool years. Several biomarkers, as well as empirical anti-reflux therapy, have been proposed for the diagnosis of GER-related airway diseases, but the conclusions of these studies are controversial or even conflicting. There is a great need for future clinical trials to confirm or rule out the association.