Epithelial Dysregulation in Chronic Rhinosinusitis with Nasal Polyposis (CRSwNP) and Aspirin-Exacerbated Respiratory Disease (AERD)

Exploring the immunopathology of type 2 inflammatory airway diseases

Significant advancements have been achieved in understanding the roles of different immune cells, as well as cytokines and chemokines, in the pathogenesis of eosinophilic airway conditions. This review examines the pathogenesis of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP), marked by complex immune dysregulation, with major contributions from type 2 inflammation and dysfunctional airway epithelium. The presence of eosinophils and the role of T-cell subsets, particularly an imbalance between Treg and Th17 cells, are crucial to the disease's pathogenesis. The review also investigates the pathogenesis of eosinophilic asthma, a unique asthma subtype. It is characterized by inflammation and high eosinophil levels, with eosinophils playing a pivotal role in triggering type 2 inflammation. The immune response involves Th2 cells, eosinophils, and IgE, among others, all activated by genetic and environmental factors. The intricate interplay among these elements, chemokines, and innate lymphoid cells results in airway inflammation and hyper-responsiveness, contributing to the pathogenesis of eosinophilic asthma. Another scope of this review is the pathogenesis of Eosinophilic Granulomatosis with Polyangiitis (EGPA); a complex inflammatory disease that commonly affects the respiratory tract and small to medium-sized blood vessels. It is characterized by elevated eosinophil levels in blood and tissues. The pathogenesis involves the activation of adaptive immune responses by antigens leading to T and B cell activation and eosinophil stimulation, which causes tissue and vessel damage. On the other hand, Allergic Bronchopulmonary Aspergillosis (ABPA) is a hypersensitive response that occurs when the airways become colonized by aspergillus fungus, with the pathogenesis involving activation of Th2 immune responses, production of IgE antibodies, and eosinophilic action leading to bronchial inflammation and subsequent lung damage. This analysis scrutinizes how an imbalanced immune system contributes to these eosinophilic diseases. The understanding derived from this assessment can steer researchers toward designing new potential therapeutic targets for efficient control of these disorders.

Nomenclature of allergic diseases and hypersensitivity reactions: Adapted to modern needs: An EAACI position paper

The exponential growth of precision diagnostic tools, including omic technologies, molecular diagnostics, sophisticated genetic and epigenetic editing, imaging and nano-technologies and patient access to extensive health care, has resulted in vast amounts of unbiased data enabling in-depth disease characterization. New disease endotypes have been identified for various allergic diseases and triggered the gradual transition from a disease description focused on symptoms to identifying biomarkers and intricate pathogenetic and metabolic pathways. Consequently, the current disease taxonomy has to be revised for better categorization. This European Academy of Allergy and Clinical Immunology Position Paper responds to this challenge and provides a modern nomenclature for allergic diseases, which respects the earlier classifications back to the early 20th century. Hypersensitivity reactions originally described by Gell and Coombs have been extended into nine different types comprising antibody- (I-III), cell-mediated (IVa-c), tissue-driven mechanisms (V-VI) and direct response to chemicals (VII). Types I-III are linked to classical and newly described clinical conditions. Type IVa-c are specified and detailed according to the current understanding of T1, T2 and T3 responses. Types V-VI involve epithelial barrier defects and metabolic-induced immune dysregulation, while direct cellular and inflammatory responses to chemicals are covered in type VII. It is notable that several combinations of mixed types may appear in the clinical setting. The clinical relevance of the current approach for allergy practice will be conferred in another article that will follow this year, aiming at showing the relevance in clinical practice where various endotypes can overlap and evolve over the lifetime.

Association Between Aspirin-Exacerbated Respiratory Disease and Atherosclerotic Cardiovascular Disease: A Retrospective Review of US Claims Data

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) consists of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and hypersensitivity to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs). Asthma is associated with increased risk of atherosclerotic cardiovascular diseases (ASCVD). However, there is lack of data on association between AERD and ASCVD.

OBJECTIVE

To investigate the relationship between AERD and subsequent risk of ASCVD.

METHODS

An algorithm to find patients with AERD was generated and validated through chart review at our home institution. This algorithm was applied to a national insurance claims database to obtain data for a retrospective cohort study. Demographic and comorbidity data were obtained for propensity matching. Several methods of analysis were performed on the data.

RESULTS

A total of 571 patients met criteria for AERD; 3909 met criteria for asthma, CRSwNP, and no allergy to aspirin or NSAIDs (group 1); and 75,050 met criteria for asthma, CRS without nasal polyps, and no allergy to aspirin or NSAIDs (group 2). After covariate adjustment, AERD was significantly associated with ASCVD, including severe ASCVD, over groups 1 and 2 regardless of asthma severity.

CONCLUSION

Patients with AERD are at higher risk of ASCVD than patients with asthma and CRSwNP or CRS without nasal polyps, underscoring the need for early ASCVD screening and a consideration for aspirin desensitization or use of a nonaspirin antiplatelet agent in the setting of AERD and comorbid ASCVD.

Advances in chronic rhinosinusitis in 2020 and 2021

Major progress has been achieved in the understanding and clinical practice of chronic rhinosinusitis, with or without nasal polyps. These advances resulted in a better understanding of the pathophysiology, the distribution into subgroups, and consequently in a better management perspective using classical approaches and biologics. Pathomechanisms, endotypes and biomarkers, and finally innovative therapeutic approaches are themes especially for the more severe forms of chronic rhinosinusitis, those with uncontrolled severe nasal polyps. Biologicals against key type 2 cytokines are gaining ground in the long-term treatment approaches of often recurrent nasal polyps, and should be integrated in care pathways making use of classical and innovative treatment pathways. These areas of interest show a fast development and will profoundly change our disease management within a decade.