One airway, one disease?

The NLRP3 inflammasome as a new target in respiratory disorders treatment

In recent years a continuous increase in new cases of respiratory disorders, such as rhinitis, asthma, and chronic obstructive pulmonary disease (COPD), has been observed. The exact pathomechanism of these diseases is still blurry, resulting in the lack of targeted and effective therapy. The conventional use of treatment strategies, such as antihistamine drugs and/or glucocorticosteroids act mainly symptomatically and have significant side effects. Specific allergen immunotherapy is only useful in the management of specific allergies and selected patients. Therefore, new therapeutic solutions are constantly being sought. The novelty of recent years has been the association between NLRP3 inflammasome activation and the development of airway inflammatory diseases. This seems to be an interesting therapeutic target that may support or even replace traditional therapies in the future. The review presented, discusses the contribution of NLRP3 inflammasome to the development of allergic rhinitis, allergic asthma, and COPD. Moreover, the modulatory properties of probiotics as potential inhibitors of NLRP3 inflammasome are emphasised.

(R)Evolution in Allergic Rhinitis Add-On Therapy: From Probiotics to Postbiotics and Parabiotics

Starting from the “Hygiene Hypothesis” to the “Microflora hypothesis” we provided an overview of the symbiotic and dynamic equilibrium between microbiota and the immune system, focusing on the role of dysbiosis in atopic march, particularly on allergic rhinitis. The advent of deep sequencing technologies and metabolomics allowed us to better characterize the microbiota diversity between individuals and body sites. Each body site, with its own specific environmental niches, shapes the microbiota conditioning colonization and its metabolic functionalities. The analysis of the metabolic pathways provides a mechanistic explanation of the remote mode of communication with systems, organs, and microflora of other body sites, including the ecosystem of the upper respiratory tract. This axis may have a role in the development of respiratory allergic disease. Notably, the microbiota is significant in the development and maintenance of barrier function; influences hematopoiesis and innate immunity; and shows its critical roles in Th1, Th2, and Treg production, which are necessary to maintain immunological balance and promote tolerance, taking part in every single step of the inflammatory cascade. These are microbial biotherapy foundations, starting from probiotics up to postbiotics and parabiotics, in a still-ongoing process. When considering the various determinants that can shape microbiota, there are several factors to consider: genetic factors, environment, mode of delivery, exposure to antibiotics, and other allergy-unrelated diseases. These factors hinder the engraftment of probiotic strains but may be upgradable with postbiotic and parabiotic administration directly on molecular targets. Supplementation with postbiotics and parabiotics could represent a very exciting perspective of treatment, bypassing probiotic limitations. At present, this avenue remains theoretical and to be explored, but it will certainly be a fascinating path to follow.

Identification of key genes and pathways in chronic rhinosinusitis with nasal polyps and asthma comorbidity using bioinformatics approaches

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and asthma comorbidity (ACRSwNP) present severe symptoms and are more likely to relapse. However, the pathogenesis of ACRSwNP is not fully understood. The aim of this study was to explore the underlying pathogenesis of ACRSwNP using bioinformatics approaches. ACRSwNP-related differentially expressed genes (DEGs) were identified by the analysis of the GSE23552 dataset. The clusterProfiler R package was used to carry out functional and pathway enrichment analysis. A protein–protein interaction (PPI) network was built using the STRING database to explore key genes in the pathogenesis of ACRSwNP. The bioinformatics analysis results were verified through qRT-PCR. The Connectivity Map (CMap) database was used to predict potential drugs for the treatment of ACRSwNP. A total of 36 DEGs were identified, which were mainly enriched in terms of regulation of immune response and detection sensory perception of taste. Thirteen hub genes including AZGP1, AQP9, GAPT, PIP, and PRR4 were identified as potential hub genes in ACRSwNP from the PPI network. Analysis of the GSE41861 dataset showed that upregulation of CST1 in nasal mucosa was associated with asthma. qRT-PCR detection confirmed the bioinformatics analysis results. Tacrolimus and spaglumic acid were identified as potential drugs for the treatment of ACRSwNP from the CMap database. The findings of this study provide insights into the pathogenesis of ACRSwNP and may provide a basis for the discovery of effective therapeutic modalities for ACRSwNP.

Real-life effectiveness of biological therapies on symptoms in severe asthma with comorbid CRSwNP

BACKGROUND

We aimed to evaluate the effectiveness of different antibody therapies on nasal polyp symptoms in patients treated for severe asthma.

METHODS

We performed a retrospective analysis of patients with severe asthma and comorbid CRSwNP who were treated with anti-IgE, anti-IL-5/R or anti-IL-4R. CRSwNP symptom burden was evaluated before and after 6 months of therapy.

RESULTS

Fifty patients were included hereof treated with anti-IgE: 9, anti-IL-5/R: 26 and anti-IL-4R: 15 patients. At baseline median SNOT-20 was similar among groups (anti-IgE: 55, anti-IL-5/R: 52 and anti-IL-4R: 56, p = 0.76), median visual analogue scale (VAS) for nasal symptoms was 4, 7 and 8 (p = 0.14) and VAS for total symptoms was higher in the anti-IL-4R group (4, 5 and 8, p = 0.002). After 6 months SNOT-20 improved significantly in all patient groups with median improvement of anti-IgE: -8 (p < 0.01), anti-IL-5/R: -13 (p < 0.001) and anti-IL-4R: -18 (p < 0.001), with larger improvement in the anti-IL-4R group than in anti-IgE (p < 0.001) and anti-IL-5/R (p < 0.001) groups. VAS nasal symptoms improved by median anti-IgE: 0 (n.s.), anti-IL-5/R: -1 (p < 0.01) and anti-IL-4R: -3 (p < 0.001), VAS total symptoms by anti-IgE: -1 (n.s.), anti-IL-5/R: -2 (p < 0.001) and anti-IL-4R: -2 (p < 0.001).

CONCLUSIONS

Treatment by all antibodies showed effectiveness in reducing symptoms of CRSwNP in patients with severe asthma, with the largest reduction observed in anti-IL-4R-treated patients.

Impact of Probiotic Bacteria on Respiratory Allergy Disorders

Respiratory allergy is a common disease with an increased prevalence worldwide. The effective remedy is still unknown, and a new therapeutic approach is highly desirable. The review elaborates the influence of probiotic bacteria on respiratory allergy prevention and treatment with particular emphasis on the impact of the current methods of their administration – oral and intranasal. The background of the respiratory allergy is complex thus, we focused on the usefulness of probiotics in the alleviation of different allergy factors, in particular involved in pathomechanism, local hypersensitive evidence and the importance of epithelial barrier. In this review, we have shown that (1) probiotic strains may vary in modulatory potential in respiratory allergy, (2) probiotic bacteria are beneficial in oral and intranasal administration, (3) recombinant probiotic bacteria can modulate the course of respiratory allergy.

A population-based clinical study of allergic and non-allergic asthma

BACKGROUND

The aim of this study was to describe differences between allergic and non-allergic asthma in a large community-based sample of Danish adolescents and adults.

METHODS

A total of 1,186 subjects, 14 to 44 years of age, who in a screening questionnaire had reported a history of airway symptoms suggestive of asthma and/or allergy, or who were taking any medication for these conditions were clinically examined. All participants were interviewed about respiratory symptoms, and furthermore skin test reactivity, lung function, and airway responsiveness were measured.

RESULTS

A total of 489 individuals had clinical asthma of whom 61% had allergic asthma, whereas 39% had non-allergic asthma. Subjects with non-allergic asthma were more likely to be females, OR = 2.24 (1.32-3.72), p = 0.003, and to have cough as the predominant symptom, OR = 1.96, (1.19-3.23), p = 0.008, but were less likely to have AHR, OR = 0.40, (0.24-0.66), p < 0.001, food allergy, OR = 0.28, (0.11-0.73), p = 0.009, and symptoms of rhinitis, OR = 0.08 (0.05-0.14) compared with subjects with allergic asthma. Subjects with non-allergic asthma had had persistent symptoms within the last 4 weeks more often than subjects with allergic asthma (68% vs. 53%), p = 0.001.

CONCLUSIONS

Non-allergic asthma accounts for two in every five cases of asthma in adults and constitutes symptomatically, and in terms of lung function, a more severe form of disease than allergic asthma.

Etiological relationships in atopy: a review of twin studies

The genetics of asthma and atopy has been studied frequently in twin populations from various parts of the world. However, emphasis has been put on univariate analysis of questionnaire data, whereas clinical and intermediate traits only sporadically have been studied, especially in multivariate settings. This review focuses on multivariate twin studies of atopy and related traits. We conclude that the genetic liability to most atopic traits is significantly correlated but that trait-specific genes also play a role. Previous studies have estimated the genetic correlation between upper and lower respiratory allergic symptoms, that is, asthma and hay fever, to be between .47 and .95. Furthermore, atopic traits share a portion of their genetic determinants with other complex disorders like obesity and behavioral traits. A correlation of about .3 and .34 has been reported between genes associated with asthma and obesity, and between genes associated with asthma and depression, respectively. We emphasize that multivariate methods applied to twin studies, especially when genetic marker information is available, provide a valuable framework within which complex etiological mechanisms underlying atopy can be disentangled.

Multivariate genetic analysis of atopy phenotypes in a selected sample of twins

BACKGROUND

Atopic traits often co-occur and this can potentially be caused by common aetiological relationships between traits, i.e. a common genetic or a common environmental background.

OBJECTIVE

To estimate to what extent the same genetic and environmental factors influence wheeze, rhinitis, airway hyper-responsiveness (AHR), and positive skin prick test (posSPT) in a sample of adult twins.

METHODS

Within a sampling frame of 21,162 twin subjects, 20-49 years of age, from the Danish Twin Registry, a total of 575 subjects (256 intact pairs and 63 single twins), who either themselves and/or their co-twins reported a history of asthma at a nationwide questionnaire survey, were clinically examined. Symptoms of wheeze and rhinitis were obtained by interview; airway responsiveness and skin test reactivity were measured using standard techniques. Correlations in liability between the different traits were estimated and latent factor models of genetic and environmental effects were fitted to the observed data using maximum likelihood methods.

RESULTS

The various phenotypic correlations between wheeze, rhinitis, AHR and posSPT were all significant and ranged between 0.50 and 0.86. Traits that showed highest genetic correlations were wheeze-rhinitis (rho(A)=0.95), wheeze-AHR (rho(A)=0.85) and rhinitis-posSPT (rho(A)=0.92), whereas lower genetic correlations were observed for rhinitis-AHR (rho(A)=0.43) and AHR-posSPT (rho(A)=0.59). Traits with a high degree of environmental sharing were rhinitis-posSPT (rho(E)=0.92) and wheeze-posSPT (rho(E)=0.71), whereas a lower environmental correlation was seen for wheeze-rhinitis (rho(E)=0.25). The estimates were corrected for ascertainment and adjusted for age, sex, inhaled corticosteroids and smoking.

CONCLUSIONS

Different atopic conditions share, to a large extent, a common genetic background. In particular, upper and lower respiratory symptoms seem to be different phenotypic expressions of a common set of genes. These results add new insight into the origins of clinical heterogeneity within atopy and should stimulate the search for pleiotropic genes of importance for these conditions.