Induction of Severe Eosinophilic Esophagitis and Multi-Organ Inflammation by Airborne Allergens is Associated with IL-4/IL-13 and CCL11 but Not IgE in Genetic Susceptible Mice

Biomarkers associated with the diagnosis and prognosis of Mycoplasma pneumoniae pneumonia in children: a review

Community-acquired pneumonia (CAP) is a major cause of death in children, and Mycoplasma pneumoniae (MP) is the main pathogen of CAP in children in China. Although Mycoplasma pneumoniae pneumonia (MPP) is usually a self-limiting disease, many children develop multiple complications due to drug resistance or untimely diagnosis and treatment, and may even progress to severe MPP or refractory MPP with a poor prognosis. It is important to explore the value of biomarkers that can be used in clinical practice to assess the severity of pneumonia and assist in clinical decision making. In this article, we searched the literature in the last four years to review the roles of various types of biomarkers in MPP and the associated clinical predictive models, with the aim of helping pediatricians to understand the evaluation indexes related to MPP in children other than microbiology.

Proinflammatory Cytokines in Chronic Respiratory Diseases and Their Management

Pulmonary homeostasis can be agitated either by external environmental insults or endogenous factors produced during respiratory/pulmonary diseases. The lungs counter these insults by initiating mechanisms of inflammation as a localized, non-specific first-line defense response. Cytokines are small signaling glycoprotein molecules that control the immune response. They are formed by numerous categories of cell types and induce the movement, growth, differentiation, and death of cells. During respiratory diseases, multiple proinflammatory cytokines play a crucial role in orchestrating chronic inflammation and structural changes in the respiratory tract by recruiting inflammatory cells and maintaining the release of growth factors to maintain inflammation. The issue aggravates when the inflammatory response is exaggerated and/or cytokine production becomes dysregulated. In such instances, unresolving and chronic inflammatory reactions and cytokine production accelerate airway remodeling and maladaptive outcomes. Pro-inflammatory cytokines generate these deleterious consequences through interactions with receptors, which in turn initiate a signal in the cell, triggering a response. The cytokine profile and inflammatory cascade seen in different pulmonary diseases vary and have become fundamental targets for advancement in new therapeutic strategies for lung diseases. There are considerable therapeutic approaches that target cytokine-mediated inflammation in pulmonary diseases; however, blocking specific cytokines may not contribute to clinical benefit. Alternatively, broad-spectrum anti-inflammatory approaches are more likely to be clinically effective. Herein, this comprehensive review of the literature identifies various cytokines (e.g., interleukins, chemokines, and growth factors) involved in pulmonary inflammation and the pathogenesis of respiratory diseases (e.g., asthma, chronic obstructive pulmonary, lung cancer, pneumonia, and pulmonary fibrosis) and investigates targeted therapeutic treatment approaches.

Understanding tissue injury and remodelling in eosinophilic oesophagitis: development towards personalised medicine

Eosinophilic oesophagitis (EoE) is a chronic, immune-mediated condition characterised by eosinophilic infiltration of the oesophagus, leading to significant morbidity due to oesophageal dysfunction. The pathogenic course of EoE begins with tissue injury, marked by the intricate interplay of oesophageal barrier dysfunction and T helper 2-mediated inflammation. In response to tissue damage, a subsequent phase of tissue remodelling features a complex interaction between epithelial cells and stromal cells, aimed at tissue repair. The persistence of inflammation drives these mechanisms towards oesophageal fibrostenosis, mainly through the transforming growth factor-dependent, myofibroblast-driven accumulation of the extracellular matrix. Currently, treatment options for EoE are limited, with dietary intervention, proton pump inhibitors and oral steroids serving as first-line therapies. Dupilumab, an antiinterleukin (IL) 4/IL-13 agent, is the only biologic that has been approved by European and American regulatory authorities. However, emerging OMIC technologies significantly advance our understanding of EoE pathogenesis, revealing novel cellular and molecular mechanisms driving the disease. This progress has accelerated the identification of new therapeutic targets and agents, some already under clinical investigation, potentially expanding our therapeutic arsenal and paving the way for more personalised approaches. In this evolving landscape, artificial intelligence (AI) has shown great potential to further elaborate on the complexities of EoE heterogeneity, offering standardised tools for diagnosis, disease phenotyping, and prediction of treatment response. Though still in their early stages, integrating OMICs and AI marks a pivotal step towards precision medicine in EoE.

Allergen immunotherapy and eosinophilic esophagitis: friends or foes?

PURPOSE OF REVIEW

The connection between eosinophilic esophagitis (EoE) and food and airborne allergens is complex. Exposure to allergens (mainly food) is often the trigger for EoE flares. The development of EoE has been described as a side effect of allergen immunotherapy, especially oral immunotherapy (OIT, with food allergens), while isolated cases of EoE have been reported during sublingual immunotherapy (SLIT, with extracts of aeroallergens).

RECENT FINDINGS

EoE is currently recognized as a common side effect of OIT, while a solid correlation between SLIT and EoE is missing. Animal models have been developed to study the pathophysiological link between sensitization to aeroallergens and the induction of EoE and will probably provide an interpretation of why there are cases of EoE developed during SLIT. Recent findings in animal models suggest a genetic connection to EoE development after sensitization and re-exposure to airborne allergens. Subcutaneous allergen immunotherapy does not have a causative effect on EoE; on the contrary, a beneficial effect on EoE has been reported. Moreover, epicutaneous immunotherapy with a vector containing milk has also been used to treat children with milk-induced EoE.

SUMMARY

Discovering the immune links between allergens and EoE will further guide the proper use of allergen immunotherapy and help define future strategies for the management of EoE.

Eosinophilic esophagitis and inhalant antigens: Pointing out the roles of allergic rhinitis, immunotherapy and biologic treatment

Eosinophilic esophagitis (EoE) and allergic rhinitis (AR) usually represent the latest manifestations of the atopic march, sharing a common type 2 inflammation response. A relevant prevalence of AR in EoE cohorts has been widely confirmed. An increasing literature assessed the involvement of aeroantigens in EoE pathogenesis, focusing foremost on the seasonality of new diagnoses, symptoms, and response to therapy. Unfortunately, no diriment direction has been achieved, probably due to the retrospective design of the studies so far available, which chose surrogate markers of EoE activity (mostly the date of new diagnosis) which may be affected by geographical, logistic and personal factors, probably not dependent by the disease itself. EoE exacerbations reported in the context of the pollen levels (preferably pollen counts) may represent a more reliable marker. AR might promote the onset and the re-exacerbation of EoE through mechanisms that are both local (ie, massive exposure to airborne antigens mediated by post-nasal drip) and systemic (type 2 inflammation). Furthermore, AR may facilitate EoE onset by predisposing to pollen food allergic syndrome (PFAS), and EoE patients with PFAS reported higher rate of AR, thus suggesting a bond among these 3 conditions whose causative relationship have still to be ascertained. In addition, because of its shifting activity from Th2 to Th1 inflammation, several case reports focused on the effect of allergen immunotherapy (AIT) employed to treat AR in EoE patients. Also in this instance, no certainties could be guaranteed, although sublingual immunotherapy (SLIT) is more frequently reported to exacerbate EoE, while SCIT is mostly described as a remission adjuvant. The real life experience reported from our allergy service appears to confirm such hypothesis. Finally, a watchful eye should be reserved to monoclonal antibodies as a potential future option for concomitant EoE and AR. In light of all this, an attentive evaluation of allergic history of EoE patients should be relevant. Future perspectives should be addressed on prospective studies targeted to shed light on causative relations among airborne antigens, AR and EoE, and to viable comprehensive treatments.

Animal models of eosinophilic esophagitis

Eosinophilic esophagitis is a chronic inflammatory disorder of the esophagus. Over the past 25 yr, great strides have been made toward understanding its pathogenesis, in part due to studies in several types of animal models. The vast majority of these models have been characterized in mice. In this review, we summarize the histopathological features of eosinophilic esophagitis recapitulated by these animal models, as well as discuss their strengths and weaknesses.

Food allergens and oral immunotherapy as indicators of eosinophilic oesophagitis

Eosinophilic esophagitis (EoE) is a chronic immune-mediated esophageal disease, clinically characterised by symptoms of esophageal dysfunction and histologically by eosinophilic infiltration of its wall. The last 3 decades have seen a sharp increase in its incidence to the point that it is called the second most common esophageal disease after reflux disease in some recent studies. The main indicators of EoE are food allergens and in recent years the extremely important role of oral immunotherapy (OIT) in the development of this disease has also been increasingly raised. To date, the appearance of EoE in the course of OIT is an absolute indication for discontinuation of this procedure; however, other therapeutic options that do not require termination of this procedure are increasingly being advocated. Unfortunately, our knowledge of EoE is full of gaps and requires numerous studies to fill in the missing elements of the pathogenesis and clinic of the described disease.