Prevalence of atopy and allergic rhinitis in patients with adult non-cystic fibrosis bronchiectasis

ATP functions as a primary alarmin in allergen-induced type 2 immunity

Environmental allergens that interact with the airway epithelium can activate cellular stress pathways that lead to the release of danger signals known as alarmins. The mechanisms of alarmin release are distinct from damage-associated molecular patterns (DAMPs), which typically escape from cells after loss of plasma membrane integrity. Oxidative stress represents a form of allergen-induced cellular stress that stimulates oxidant-sensing mechanisms coupled to pathways, which facilitate alarmin mobilization and efflux across the plasma membrane. In this review, we highlight examples of alarmin release and discuss their roles in the initiation of type 2 immunity and allergic airway inflammation. In addition, we discuss the concept of alarmin amplification, where "primary" alarmins, which are directly released in response to a specific cellular stress, stimulate additional signaling pathways that lead to secretion of "secondary" alarmins that include proinflammatory cytokines, such as IL-33, as well as genomic and mitochondrial DNA that coordinate or amplify type 2 immunity. Accordingly, allergen-evoked cellular stress can elicit a hierarchy of alarmin signaling responses from the airway epithelium that trigger local innate immune reactions, impact adaptive immunity, and exacerbate diseases including asthma and other chronic inflammatory conditions that affect airway function.

Manifesto on united airways diseases (UAD): an Interasma (global asthma association - GAA) document

OBJECTIVE

The large amount of evidence and the renewed interest in upper and lower airways involvement in infectious and inflammatory diseases has led Interasma (Global Asthma Association) to take a position on United Airways Diseases (UAD).

METHODS

Starting from an extensive literature review, Interasma executive committee discussed and approved this Manifesto developed by Interasma scientific network (INES) members.

RESULTS

The manifesto describes the evidence gathered to date and defines, states, advocates, and proposes issues on UAD (rhinitis, rhinosinusitis and nasal polyposis), and concomitant/comorbid lower airways disorders (asthma, chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis, obstructive sleep apnoea) with the aim of challenging assumptions, fostering commitment, and bringing about change. UAD refers to clinical pictures characterized by the coexistence of upper and lower airways involvement, driven by a common pathophysiological mechanism, leading to a greater burden on patient's health status and requiring an integrated diagnostic and therapeutic plan. The high prevalence of UAD must be taken into account. Upper and lower airways diseases influence disease control and patient's quality of life.

CONCLUSIONS

Patients with UAD need to have a timely and adequate diagnosis, treatment, and, when recommended, referral for management in a specialized center. Diagnostic testing including skin prick or serum specific IgE, lung function, fractional exhaled nitric oxide (FeNO), polysomnography, allergen-specific immunotherapies, biological therapies and home based continuous positive airway pressure (CPAP) whenever these are recommended, should be part of the management plan for UAD. Education of medical students, physicians, health professionals, patients and caregivers on the UAD is needed.

Impact of asthma on bronchiectasis severity and risk of exacerbations

OBJECTIVE

Asthma is a frequent comorbidity of bronchiectasis, with possible implications for exacerbation and severity. We investigated the clinical impact of asthma on bronchiectasis in terms of disease severity and exacerbation risk.

METHODS

We collected demographic, clinical, and functional characteristics of patients with a confirmed diagnosis of bronchiectasis. All patients were investigated for concomitant diagnosis of asthma. The Bhalla score was used to assess radiological severity of bronchiectasis, and the Bronchiectasis Severity Index (BSI) was used to assess the clinical severity. Blood and sputum samples were collected to assess blood cell count, erythrocyte sedimentation rate, c-reactive protein, immunological status (IgA, IgE, IgM, IgG, and IgG subclasses), and microbiological analysis.

RESULTS

A total of 106 patients were enrolled in the study; 30.2% had concomitant asthma and were characterized by higher frequency of bronchiectasis exacerbation, despite higher Bhalla score and lower BSI compared to patients without asthma. Pseudomonas aeruginosa was more frequently isolated from the sputum of bronchiectasis patients without asthma. Total serum IgG, IgG1, and IgG3 were lower in patients with asthma. Blood eosinophils and exhaled nitric oxide were higher in patients with associated asthma. The presence of asthma and presence of Pseudomonas in sputum were the only significant determinants of frequent exacerbations in a binary logistic regression analysis.

CONCLUSION

The coexistence of asthma and bronchiectasis is associated with an independent increase in the risk of bronchiectasis exacerbation despite lower radiological and clinical severity indexes. Asthmatic airway inflammation could promote an enhanced "Cole's Cycle" that is responsible for a higher frequency of exacerbations.