Rhinitis associated with asthma is distinct from rhinitis alone: The ARIA-MeDALL hypothesis

Asthma, rhinitis, and atopic dermatitis (AD) are interrelated clinical phenotypes that partly overlap in the human interactome. The concept of “one-airway-one-disease,” coined over 20 years ago, is a simplistic approach of the links between upper- and lower-airway allergic diseases. With new data, it is time to reassess the concept. This article reviews (i) the clinical observations that led to Allergic Rhinitis and its Impact on Asthma (ARIA), (ii) new insights into polysensitization and multimorbidity, (iii) advances in mHealth for novel phenotype definitions, (iv) confirmation in canonical epidemiologic studies, (v) genomic findings, (vi) treatment approaches, and (vii) novel concepts on the onset of rhinitis and multimorbidity. One recent concept, bringing together upper- and lower-airway allergic diseases with skin, gut, and neuropsychiatric multimorbidities, is the “Epithelial Barrier Hypothesis.” This review determined that the “one-airway-one-disease” concept does not always hold true and that several phenotypes of disease can be defined. These phenotypes include an extreme “allergic” (asthma) phenotype combining asthma, rhinitis, and conjunctivitis. Rhinitis alone and rhinitis and asthma multimorbidity represent two distinct diseases with the following differences: (i) genomic and transcriptomic background (Toll-Like Receptors and IL-17 for rhinitis alone as a local disease; IL-33 and IL-5 for allergic and non-allergic multimorbidity as a systemic disease), (ii) allergen sensitization patterns (mono- or pauci-sensitization versus polysensitization), (iii) severity of symptoms, and (iv) treatment response. In conclusion, rhinitis alone (local disease) and rhinitis with asthma multimorbidity (systemic disease) should be considered as two distinct diseases, possibly modulated by the microbiome, and may be a model for understanding the epidemics of chronic and autoimmune diseases

Phénotypage de l’asthme professionnel par la réalisation d’expectoration induite après test d’exposition spécifique

CONTEXTE : Bien que l’évaluation de l’inflammation bronchique, par expectoration induite, permette d’identifier différents phénotypes, chez les patients asthmatiques, il n’y a que peu d’informations sur le déterminant du pattern d’inflammation bronchique chez les patients présentant un asthme professionnel par sensibilisation. OBJECTIF : Déterminer si le pattern d’inflammation bronchique, déterminé par expectoration induite, permet de définir des phénotypes cliniques distincts. MÉTHODE : Cette étude multicentrique rétrospective a été réalisée auprès de 372 patients, présentant un asthme professionnel diagnostiqué par test d’exposition spécifique, qui étaient recrutés par le biais de la cohorte du groupe European network for Phenotypique of Ocupational Asthma. Chaque patient a bénéficié d’une expectoration induite avant et après test d’exposition spécifique. L’éosinophilie bronchique était définie par un pourcentage d’éosinophiles supérieur ou égal à 3 % dans l’expectoration induite, après test d’exposition spécifique, alors que la neutrophilie bronchique était définie par un pourcentage de neutrophiles supérieur ou égal à 76 %. RÉSULTATS : Au total, 268 (72 %) et 42 patients (11 %) présentaient respectivement une éosinophilie et une neutrophilie bronchique. Les analyses de régression logistique ont mis en évidence une association entre l’éosinophilie bronchique et l’exposition aux agents de haut poids moléculaire (odds ratio [OR], 1,89 ; IC 95 % 1,18–3,04), l’asthme persistant modéré (OR, 3,17 ; IC 95 %, 1,43–7,0) et l’asthme persistant sévère (OR, 2,39 ; IC 95 %, 1,06–5,43). La neutrophilie bronchique était associée à l’âge (OR pour chaque année supplémentaire, 1,04 ; IC 95 % 1,01–1,08), au genre masculin (OR, 2,83 : IC 95 %, 1,14–6,87), à l’asthme persistant léger (OR, 3,26 ; IC 95 %, 1,24–8,88), et à la dysphonie (OR, 2,83 ; IC95 %, 1,14–6,87). CONCLUSIONS : La majorité des patients avec un asthme professionnel par sensibilisation présentait une éosinophilie bronchique post-test d’exposition spécifique. L’éosinophilie et la neutrophilie, dans les expectorations induites, permettaient de définir des phénotypes cliniques différents, notamment en termes de sévérité et selon l’agent causal.[Phenotypes of occupational asthma defined with induced sputum after specific inhalation challenge] RATIONALE : Although the non-invasive assessment of airway inflammation through the induced sputum (IS) technique identified distinct asthma phenotypes, there is few information on the determinants of airway inflammatory pattern in sensitizer-induced occupational asthma (OA). AIM : To investigate whether the pattern of airway inflammation in IS is associated with distinct clinical phenotypes of OA. METHODS : This retrospective multicentric study was conducted among 372 patients with OA confirmed by a positive specific inhalation challenge (SIC) who were recruited in the European network for the Phenotyping of OCupational Asthma cohort (2006–2018). Each patient underwent an analysis of IS before and 24 hours after the SIC. Sputum eosinophilia and neutrophilia were defined by the presence of ≥ 3% eosinophils and ≥ 76% neutrophils in sputum samples collected after the SIC. RESULTS : In total, 268 (72%) and 42 patients (11%) exhibited sputum eosinophilia and neutrophilia, respectively. Multivariate logistic regression analysis revealed that eosinophilia was associated with exposure to a high molecular weight agent (odds ratio [OR], 1.89; 95% CI, 1.18–3.04), moderate asthma (OR, 3.17; 95% CI, 1,43–7.0) and severe asthma (OR, 2.39; 95% CI, 1.06–5.43). Sputum neutrophilia was associated with age (OR for each additional year, 1.04; 95% CI, 1.01–1.08), male gender (OR, 2.74; 95% CI, 1,21–6.8), mild asthma (OR, 3.26; 95% CI, 1.24–8.88), and dysphonia (OR, 2.83; 95% CI, 1.14–6.87). CONCLUSIONS : Sputum eosinophilia post-SIC was predominant in OA patients. Sputum eosinophilia and neutrophilia were associated with distinct clinical phenotypes of OA, especially in terms of causal agents and asthma severity

Sputum Inflammatory Patterns are Associated with Distinct Clinical Characteristics in Subjects with Occupational Asthma Independently from the Causal Agent.

Clinical heterogeneity in sensitizer-induced occupational asthma (OA) and its relationship to airway inflammatory profiles remain poorly elucidated. To further characterize the interactions between induced sputum inflammatory patterns, asthma-related outcomes and the high- or low-molecular-weight category of causal agents in a large cohort of subjects with OA. This multicenter, retrospective, cross-sectional study was conducted among 296 subjects with OA ascertained by a positive specific inhalation challenge who completed induced sputum assessment before and 24 hours after challenge exposure. Multivariate logistic regression analysis revealed that sputum eosinophilia ≥3% was significantly associated with a high dose of inhaled corticosteroid (odds ratio [95% confidence interval], 1.31 [1.11-1.55] for each 250-µg increment in daily dose), short-acting b2-agonist use less than once a day (3.54 [1.82-7.00]), and the level of baseline nonspecific bronchial hyperresponsiveness (mild: 2.48 [1.21-5.08]); moderate/severe: 3.40 [1.44-8.29]). Sputum neutrophilia ≥76% was associated with age (1.06 [1.01-1.11]), male gender (3.34 [1.29-9.99]), absence of corticosteroid use (5.47 [2.09-15.16]), short-acting b2-agonist use once or more a day (4.09 [1.71-10.01]), ≥2 severe exacerbations during the last 12 months at work (4.22 [1.14-14.99]), and isolated early reactions during the SIC (4.45 [1.85-11.59]). The findings indicate that sputum inflammatory patterns in subjects with OA are associated with distinct phenotypic characteristics and further highlight the differential effects of neutrophils and eosinophils on asthma-related outcomes. These associations between inflammatory patterns and clinical characteristics share broad similarities with what has been reported in nonoccupational asthma and are not related to the type of causal agent

Characterization of Occupational Eosinophilic Bronchitis in a Multicenter Cohort of Subjects with Work-Related Asthma Symptoms

Background: Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports. Objective: We investigated the clinical and inflammatory characteristics of subjects with OEB identified in a cohort of subjects who completed a specific inhalation challenge (SIC) with occupational agents. Methods: In this retrospective multicenter study, OEB was defined by (1) a fall in FEV1 less than 15% during the SIC and the absence of nonspecific bronchial hyperresponsiveness both before and after the SIC and (2) a postchallenge increase of 3% or more in sputum eosinophils. The subjects who fulfilled these criteria were compared with 226 subjects with a negative SIC and 30 subjects with a positive SIC who failed to show baseline nonspecific bronchial hyperresponsiveness. Results: An isolated increase in postchallenge sputum eosinophils was documented in 33 of 259 subjects (13%) with a negative SIC. These subjects reported significantly more often an isolated cough at work compared with the negative and positive SIC controls. When compared with positive SIC controls, the subjects with OEB experienced less frequently work-related wheezing and reported a shorter duration of symptoms at work. The sensitivity of the post-SIC increase in fractional exhaled nitric oxide in identifying OEB among subjects with a negative SIC was low, ranging from 43% to 24% using cutoff values of 8 ppb to 17.5 ppb, whereas the specificity was high (90%-97%). Conclusions: This study highlights the relevance of induced sputum analysis in the investigation of work-related asthma symptoms to identify isolated increases in sputum eosinophils that are consistent with a diagnosis of OEB