IL-4 and IL-5 mRNA and protein in bronchial biopsies from patients with atopic and nonatopic asthma: evidence against "intrinsic" asthma being a distinct immunopathologic entity

Network pharmacology prediction, molecular docking, and molecular dynamics simulation-based strategy to explore the potential mechanism of Huashanshen dripping pill against asthma

OBJECTIVES

Asthma is a heterogeneous disease characterized by chronic airway inflammation. Huashanshen dripping pills (HSS) are commonly utilized for relieving asthma, relieving cough, and expelling phlegm. At present, the molecular mechanism against airway inflammation remains unclear.

METHODS

In this study, network pharmacology, molecular docking technology, and molecular dynamic simulation were used to predict the therapeutic pathways of HSS for asthma. The ovalbumin-induced mouse model was used to further validate the prediction by RT-qPCR, western blot, immunofluorescence, and related methods.

KEY FINDINGS

The findings indicate that HSS improves lung function and relieves lung inflammation by reducing inflammatory cell infiltration around the bronchus and reducing eosinophilic counts in bronchoalveolar lavage fluid (BALF). In addition, it lowers the levels of inflammatory cytokines and the expression levels of interleukin-4, interleukin-5, and interleukin-13 mRNA. HSS also inhibits the phosphorylation and nuclear translocation of NF-κB p65 protein.

CONCLUSIONS

All results suggested that HSS can decrease airway inflammation in asthmatic mice by inhibiting NF-κB signaling pathway. This finding will shed light on how it can be used to treat asthma.

Local receptor-interacting protein kinase 2 inhibition mitigates house dust mite-induced asthma

BACKGROUND

House dust mite is the most frequent trigger of allergic asthma, with innate and adaptive immune mechanisms playing critical roles in outcomes. We recently identified the nucleotide-binding oligomerisation domain 1 (NOD1)/receptor-interacting serine/threonine protein kinase 2 (RIPK2) signalling pathway as a relevant contributor to murine house dust mite-induced asthma. This study aimed to evaluate the effectiveness of a pharmacological RIPK2 inhibitor administered locally as a preventive and therapeutic approach using a house dust mite-induced asthma model in wild-type and humanised NOD1 mice harbouring an asthma-associated risk allele, and its relevance using air-liquid interface epithelial cultures from asthma patients.

METHODS

A RIPK2 inhibitor was administered intranasally either preventively or therapeutically in a murine house dust mite-induced asthma model. Airway hyperresponsiveness, bronchoalveolar lavage composition, cytokine/chemokine expression and mucus production were evaluated, as well as the effect of the inhibitor on precision-cut lung slices. Furthermore, the inhibitor was tested on air-liquid interface epithelial cultures from asthma patients and controls.

RESULTS

While local preventive administration of the RIPK2 inhibitor reduced airway hyperresponsiveness, eosinophilia, mucus production, T-helper type 2 cytokines and interleukin 33 (IL-33) in wild-type mice, its therapeutic administration failed to reduce the above parameters, except IL-33. By contrast, therapeutic RIPK2 inhibition mitigated all asthma features in humanised NOD1 mice. Results in precision-cut lung slices emphasised an early role of thymic stromal lymphopoietin and IL-33 in the NOD1-dependent response to house dust mite, and a late effect of NOD1 signalling on IL-13 effector response. RIPK2 inhibitor downregulated thymic stromal lymphopoietin and chemokines in house dust mite-stimulated epithelial cultures from asthma patients.

CONCLUSION

These data support that local interference of the NOD1 signalling pathway through RIPK2 inhibition may represent a new therapeutic approach in house dust mite-induced asthma.

Investigating Forkhead Box O Transcription Factor 1 Gene's Relation to Immunoglobulin E in House Dust Mite-Allergic Asthma Patients

House dust mite (HDM)-allergic asthma is an abnormal immune response to extrinsic aeroallergens found in human vicinities. Studying the role of the associated immunity biomarkers and their interplay helps in discovering novel therapeutic strategies that can be used in adjunct with effective long-term immunotherapy. This study investigates the total serum IgE, FoxO1, and Sirtuin 1 (SIRT1) gene expressions in HDM-allergic asthma patients. We enrolled 40 patients for each of the following three groups: an HV group of healthy volunteers and HDM/AA and HDM/SCIT groups of HDM-allergic asthma patients who did not and who did receive immunotherapy before recruitment in this study, respectively. The results elucidated that total IgE was strikingly elevated in the HDM/AA group and showed little decline in the HDM/SCIT group. Both FoxO1 and SIRT1 gene expressions showed the highest levels in the HDM/SCIT group. There was a negative correlation between total IgE and both FoxO1 and SIRT1 in the HDM/AA group while there was a positive correlation with SIRT1 in the HDM/SCIT group. In conclusion, the interplay of the three immunity biomarkers related to HDM-allergic asthma after the course of immunotherapy treatment suggests further, broader studies on the feasibility of their role as immunity biomarkers in the control and remission of HDM-allergic asthma.

Can omalizumab be an alternative treatment for non-atopic severe asthma? A real-life experience with omalizumab

Introduction

Omalizumab, a humanized monoclonal anti-IgE antibody, has largely demonstrated its efficacy in severe allergic asthma. There are limited data about the effectiveness of omalizumab in patients with non-atopic severe persistent asthma. In this study, we aimed to determine the effect of omalizumab in patients with non-atopic severe asthma and compare the data obtained with those in patients with allergic severe asthma.

Materials and Methods

This study was an observational, retrospective, tertiary single-center study that assessed and compared the clinical outcome of adult patients with severe asthma (165 atopic and 41 non-atopic) who have been on omalizumab for one year or longer between January 2008 and January 2020. Effectiveness was assessed by considering symptom scores (GINA symptom control score), daily systemic corticosteroids (SCS) dosage, blood eosinophil counts, pulmonary function, and number of severe exacerbations and hospitalizations within the last one year.

Result

Omalizumab exhibited significant improvement in the clinical status of non-atopic asthma patients as measured by GINA symptom score [decreased from 3.77 ± 0.63 to 1.36 ± 1.27 (p<0.001)], the number of emergency room visits for asthma [decreased from 11.25 ± 14.69 to 0.25 ± 0.55 (p<0.001)], and the number of hospitalizations [decreased from 1.17 ± 2.87 to 0.14 ± 0.36 (p= 0.036)]. These results were not significantly different from those obtained in allergic asthma patients. FEV1 improved significantly from 2.08 ± 0.86 to 2.14 ± 0.84 (p= 0.041) and oral corticosteroid doses decreased significantly from 1.67 ± 7.49 to 0.46 ± 2.74 (p= 0.015) in the only atopic group.

Conclusions

Omalizumab, which is a proven and effective treatment option for allergic asthma, may also be an efficacious alternative option in non-atopic severe asthma.

YKL-40 as a possible marker of neutrophilic asthma

Asthma is a heterogeneous chronic disorder of the airways, with inflammation and bronchial hyperresponsiveness as its major underlying phenomena. Asthmatics vary in terms of inflammation pattern, concomitant pathologies, and factors aggravating the course of the disease. As a result, there is a need for sensitive and specific biomarkers that could facilitate diagnosing asthma as well as phenotyping in everyday practice. Chitinases and chitinase-like proteins (CLPs) seem promising in this field. Chitinases are evolutionarily conserved hydrolases that degrade chitin. In contrast, CLPs bind chitin but do not have degrading activity. Mammalian chitinases and CLPs are produced by neutrophils, monocytes, and macrophages in response to parasitic or fungal infections. Recently, several questions have been raised about their role in chronic airway inflammation. Several studies demonstrated that overexpression of CLP YKL-40 was associated with asthma. Moreover, it correlated with exacerbation rate, therapy resistance, poor control of symptoms, and, inversely, with FEV₁. YKL-40 facilitated allergen sensitization and IgE production. Its concentration was elevated in bronchoalveolar lavage fluid after an allergen challenge. It was also found to promote the proliferation of bronchial smooth muscle cells and correlate with subepithelial membrane thickness. Thus, it may be involved in bronchial remodeling. Associations between YKL-40 and particular asthma phenotypes remain unclear. Some studies showed that YKL-40 correlates with blood eosinophilia and FeNO, suggesting a role in T2-high inflammation. Quite the opposite, cluster analyses revealed the highest upregulation in severe neutrophilic asthma and obesity-associated asthma. The main limitation in the practical application of YKL-40 as a biomarker is its low specificity. High serum levels of YKL-40 were also found in COPD and several malignancies, in addition to infectious and autoimmune diseases. To conclude, the level of YKL-40 correlates with asthma and some clinical features in the whole asthmatic population. The highest levels are found in neutrophilic and obesity-related phenotypes. However, due to its low specificity, the practical application of YKL-40 remains uncertain but could be useful in phenotyping, especially when combined with other biomarkers.

Severe non-atopic asthma: omalizumab can reduce severe asthma exacerbations

Introduction: Humanized monoclonal anti-IgE antibody (omalizumab) has demonstrated efficacy in severe atopic asthma. However, few studies have assessed its efficacy in non-atopic and even less in T2-low severe asthma. The objective was to determinate the omalizumab response according to atopic status.Methods: This retrospective, real-world study was performed in the Chest Diseases Department of Strasbourg University Hospital from January 1, 2006, to June 30, 2017. The response to omalizumab was assessed in 139 patients 4, 6, and 12 months after treatment and compared to data collected prior to omalizumab initiation.Results: Forty-four patients (31.7%) had severe non-atopic asthma and 95 (68.3%) had a severe atopic asthma. In the non-atopic group, omalizumab significantly reduced the severe exacerbation rate by 44% (95% CI 18-64%, p < 0.05), 43% (CI 95% 20-60%, p < 0.05), and 54% (CI 95% 36-67%, p < 0.05), at 4, 6 and 12 months, respectively. A trend toward improvement in FEV1, asthma control and oral corticosteroid use was also observed. These results were not significantly different from those obtained in atopic asthmatics except a more effective oral corticosteroid sparing in atopic group (p < 0.05). Similar reduction of severe exacerbation rates were observed in T2-low asthma subgroup (non-atopic, non-eosinophilic).Conclusion: Omalizumab was effective in severe asthma, regardless of atopic status.

Revisiting differences between atopic and non-atopic asthmatics: When age is shaping airway inflammatory profile

Background

Atopic asthma is one of the most common asthma phenotypes and is generally opposed to the non-atopic counterpart. There have been very few large-scale studies comparing atopic and non-atopic asthmatics in terms of systemic and airway inflammation across the age spectrum.

Methods

Here, we have undertaken a retrospective study investigating 1626 patients (924 atopic and 702 non-atopic asthmatics) recruited from our university asthma clinic who underwent extensive clinical investigations including induced sputum. Atopy was defined by any positive specific IgE to common aeroallergens (>0,35 kU/L). We performed direct comparisons between the groups and sought to appreciate the influence of age on the airway and systemic inflammatory components. The study was approved by the ethics committee of the University Hospital of Liege (Ref. 2016/276). Informed consents were obtained from healthy subjects.

Results

Atopic asthmatics were younger (P < .001), had a higher male/female ratio (P < .001), an earlier disease onset (P < .001) and a greater proportion of treated rhinitis (P < .001) while non-atopic asthmatics had greater smoke exposure (P < .001), lower FEV₁/FVC ratio (P = .01) and diffusing capacity (P < .001). There was no difference between the 2 groups regarding FEV₁ (% predicted), asthma control, asthma quality of life and exacerbations in the previous 12 months. Regarding inflammation, atopic patients had higher FeNO levels (median = 28 ppb, P < .001), were more eosinophilic both in blood (median = 2.8%, P < .001) and in sputum (median = 2.2%, P < .001) while non-atopic patients displayed greater blood (median = 57%, P = .01) and sputum (median = 58.8%, P = .01) neutrophilic inflammation. However, stratifying patients by age showed that non-atopic asthmatics above 50 years old became equally eosinophilic in the sputum (P = .07), but not in the blood, as compared to atopic patients. Likewise, FeNO rose in non-atopic patients after 50 years old but remained, however, lower than in atopic patients.

Conclusions

We conclude that, while sharing many features, atopic group still differentiates from non-atopic asthmatics by demographics, functional and inflammatory profiles. When atopic asthmatics showed a constant eosinophilic pattern across the age spectrum, non-atopic asthmatics were found to be neutrophilic before the age of 50 but eosinophilic above 50 years old.

Omalizumab and IgE in the Control of Severe Allergic Asthma

Omalizumab, a human immunoglobulin (Ig)G1 antibody against IgE, is a therapeutic agent for bronchial asthma. The Global Initiative for Asthma guidelines indicate that the use of omalizumab should be considered as an option in step 5 of treatment for patients with the most severe type of bronchial asthma. In patients with atopic asthma who are at a high risk of exacerbation, and in whom symptoms are poorly controlled despite treatment with inhaled corticosteroids, omalizumab is one of the few drugs that improves symptoms, reduces the risk of exacerbation, and improves the quality of life while offering a high level of safety. On the other hand, the associated treatment costs are high, and there are no clear methods to identify responders. A recent study suggested that evaluating the therapeutic effects and monitoring the pharmacokinetics of omalizumab could improve the success of omalizumab therapy. This review outlines the relationship between IgE-targeted therapy and the serum level of IgE to enhance the current understanding of the mechanism of omalizumab therapy. It also describes the clinical significance of measuring serum free IgE levels and monitoring omalizumab therapy.

Protective effects on ovalbumin-induced mouse asthma models and qualitative and quantitative analysis of multiple compounds in Gerberae Piloselloidis Herba

Gerberae Piloselloidis Herba is widely used to treat cough and asthma in China. However, its effects on allergic asthma as related to its chemical compositions have not been fully elucidated, and there is a scarcity of methods to determine multi-component contents for quality control. In this study, protective effects of Gerberae Piloselloidis Herba on ovalbumin-induced asthma models were investigated, while qualitative and quantitative analyses of multiple constituents in Gerberae Piloselloidis Herba were conducted by using an ultrahigh-performance liquid chromatography -Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry and an ultrahigh-performance liquid chromatography -photodiode array detection. The results showed that Gerberae Piloselloidis Herba could significantly mitigate asthma symptoms, reduce eosinophils counts in the bronchoalveolar lavage fluid, as well as decrease IgE, IL-5 and IL-13 concentration, and inflammatory cellular infiltration in lung tissues. A total of 51 compounds were tentatively identified, in which the content of 10 representative compounds was determined in 24 batches of Gerberae Piloselloidis Herba by using an ultrahigh-performance liquid chromatography method with good linearity, precision, repeatability, accuracy and stability. This research presents a comprehensive strategy combining biological activity evaluation with chemical profiling, providing a useful and comprehensive reference for further application and quality control of Gerberae Piloselloidis Herba. This article is protected by copyright. All rights reserved.

Total IgE Variability Is Associated with Future Asthma Exacerbations: A 1-Year Prospective Cohort Study

BACKGROUND

Few prospective studies have investigated the relationship between IgE variability and risk for asthma exacerbations (AEs).

OBJECTIVE

To explore the relationship between IgE variability and AEs.

METHODS

Recruited patients with stable asthma underwent two serum total IgE tests within a month (at screening [baseline IgE] and at 1 month) to obtain the coefficient of variation (CV) of base 10 log-transformed IgE. Patients with IgE CV were divided into IgE CV-high and IgE CV-low cohorts based on the CV median and were observed within 12 months, during which the association between IgE variability and AEs was explored using a negative binomial regression model.

RESULTS

The IgE CV levels obtained from 340 patients classified patients into two groups (n = 170 for the IgE CV-high and IgE CV-low groups, respectively) based on the serum total IgE CV median of 2.12% (quartiles 1 and 3: 0.98% and 3.91%, respectively). The IgE CV-high patients exhibited worse asthma control and lung function and more marked airway inflammation, and received more intensive medication use compared with IgE CV-low patients. The IgE CV-high patients exhibited increased rates of moderate-to-severe (adjusted rate ratio = 2.88; 95% confidence interval, 1.65-5.03; P < .001) and severe (adjusted rate ratio = 2.16; 95% confidence interval, 1.08-4.32; P = .029) AEs during the follow-up year compared with IgE CV-low patients. Furthermore, sputum IL-6 partially mediated the associations between IgE CV with moderate-to-severe and severe AEs.

CONCLUSIONS

Variability in total serum IgE levels is an easily obtained and practical measure for predicting AEs. Future studies are needed to investigate whether IgE variability can be used to guide precision medicine in asthma.

Diagnosis and Management of T2-High Asthma

Type 2 (T2) inflammation plays a key role in the pathogenesis of asthma. IL-4, IL-5, and IL-13, along with other inflammatory mediators, lead to increased cellular eosinophilic inflammation. It is likely that around half of all patients with asthma have evidence of T2-high inflammation. Sputum and blood eosinophils, exhaled nitric oxide, blood IgE levels, and airway gene expression markers are frequently used biomarkers of T2-high asthma. Individuals with T2-high asthma tend to have several features of increased asthma severity, including reduced lung function and increased rates of asthma exacerbations, and T2-high patients demonstrate distinct pathologic features including increased airway remodeling and alterations in airway mucus production. Several monoclonal antibodies are now available to treat individuals with T2-high asthma and these medications significantly reduce asthma exacerbation rates.

Asthmatics with concordant eosinophilic disease classified according to their serum IgE status

BACKGROUND

Eosinophilic inflammation has long been associated with asthma. Looking at systemic and airway eosinophilia, we have recently identified a group of patients exhibiting diffuse eosinophilic inflammation. Among the mechanisms governing eosinophilic inflammation, IgE-mediated mast cell activation is a key event leading to eosinophilia in atopic asthmatics.

METHODS

We conducted a retrospective study on our asthma clinic database containing more than 1500 patients and identified 205 asthmatics with successful sputum induction and concordant eosinophilic phenotype. This phenotype was defined as a sputum eosinophil count≥3% and a blood eosinophils concentration≥400cells/mm³. IgE-high atopic phenotype was characterized by the presence of at least one positive specific IgE (>0.35kU/L) to common aeroallergens and a raised total serum IgE (≥113kU/L).

RESULTS

The largest group of asthmatics displaying concordant eosinophilic phenotype had a raised total serum IgE and atopy (45%). IgE-low non-atopic concordant eosinophilic asthma was a predominantly late onset disease, exhibited a more intense airway eosinophilic inflammation (P<0.05), required more often maintenance treatment with oral corticosteroids (P<0.05) but, surprisingly, had a reduced level of bronchial hyperresponsiveness to methacholine (P<0.05) despite similar baseline airway calibre impairment.

CONCLUSION

The more severe airway eosinophilic inflammation in IgE-low non-atopic asthmatics despite similar treatment with ICS and a higher burden of OCS points to a certain corticosteroid resistance in this asthma phenotype.

Role of Cytokines in EGPA and the Possibility of Treatment with an Anti-IL-5 Antibody

Eosinophilic granulomatosis with polyangiitis (EGPA) is a type of systemic vasculitis with eosinophilia in the peripheral blood, which is preceded by bronchial asthma or allergic disease. EGPA is pathologically characterized by microangiopathy granulomatosis vasculitis. Vasculitis can be exacerbated and cause central nervous system and cardiovascular disorders and gastrointestinal perforation. Histological examination reveals eosinophil infiltration and granulomas in lesions in areas such as the lung, nervous system, and skin. Laboratory tests show inflammatory findings such as C-reactive protein (CRP) elevation, increased eosinophils, elevated serum IgE, and elevated myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA). MPO-ANCA is positive in approximately 40-70% of cases of this disease. EGPA is a necrotizing vasculitis that affects small- and medium-sized blood vessels; however, it differs from other types of ANCA-related vasculitis (such as microscopic polyangiitis and granulomatosis) because it is preceded by bronchial asthma and eosinophilia in the blood and tissues. Treatment with immunosuppressive agents such as steroids or cyclophosphamide depends on the Five Factor Score, which predicts the prognosis and severity of the condition. If the effect of appropriate treatment with steroids is insufficient, the anti-interleukin-5 antibody mepolizumab can be administered. The combination of mepolizumab with standard treatment leads to a significantly longer duration of remission, a higher proportion of patients who achieve sustained remission, and less steroid use than with a placebo.

The association between secondhand smoke and childhood asthma: A systematic review and meta-analysis

BACKGROUND

Secondhand smoke (SHS) exposure can trigger asthma exacerbations in children. Different studies have linked increased asthma symptoms and even deaths in children with SHS, but the risk has not been quantified uniformly across studies. We aimed to investigate the role of SHS exposure as a risk factor of asthma among children.

METHODS

We performed a systematic review in PubMed, Scopus, and Google Scholar from June 1975 to 10 March 2020. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk estimates and confidence intervals of all types of SHS exposure and childhood asthma.

RESULTS

Of the 26 970 studies identified, we included 93 eligible studies (42 cross-sectional, 41 cohort, and 10 case-control) in the meta-analysis. There were significantly positive associations between SHS exposure and doctor-diagnosed asthma (OR = 1.24; 95% confidence interval (CI) = 1.20-1.28), wheezing (OR = 1.27; 95% CI = 1.23-1.32) and asthma-like syndrome (OR = 1.34; 95% CI = 1.34-1.64). The funnel plots of all three outcomes skewed to the right, indicating that the studies generally favor a positive association of the disease with tobacco exposure. Subgroup analysis demonstrated that younger children tended to suffer more from developing doctor-diagnosed asthma, but older children (adolescents) suffered more from wheezing. There was no evidence of significant publication or small study bias using Egger's and Begg's tests.

CONCLUSION

The results show a positive association between prenatal and postnatal secondhand smoking exposure and the occurrence of childhood asthma, asthma-like syndrome, and wheezing. These results lend support to continued efforts to reduce childhood exposure to secondhand smoke.

Are We Meeting the Promise of Endotypes and Precision Medicine in Asthma?

While the term asthma has long been known to describe heterogeneous groupings of patients, only recently have data evolved which enable a molecular understanding of the clinical differences. The evolution of transcriptomics (and other 'omics platforms) and improved statistical analyses in combination with large clinical cohorts opened the door for molecular characterization of pathobiologic processes associated with a range of asthma patients. When linked with data from animal models and clinical trials of targeted biologic therapies, emerging distinctions arose between patients with and without elevations in type 2 immune and inflammatory pathways, leading to the confirmation of a broad categorization of type 2-Hi asthma. Differences in the ratios, sources, and location of type 2 cytokines and their relation to additional immune pathway activation appear to distinguish several different (sub)molecular phenotypes, and perhaps endotypes of type 2-Hi asthma, which respond differently to broad and targeted anti-inflammatory therapies. Asthma in the absence of type 2 inflammation is much less well defined, without clear biomarkers, but is generally linked with poor responses to corticosteroids. Integration of "big data" from large cohorts, over time, using machine learning approaches, combined with validation and iterative learning in animal (and human) model systems is needed to identify the biomarkers and tightly defined molecular phenotypes/endotypes required to fulfill the promise of precision medicine.

Analysis of 25-hydroxy cholecalciferol, immunoglobulin E, and vitamin D receptor single nucleotide polymorphisms (Apa1, Taq1, and Bsm1), among sample of Egyptian children with bronchial asthma: A case-control study

PURPOSE

The current study aimed to assess the serum levels of vitamin D and immunoglobulin E (IgE) among asthmatic Egyptian children and to find out the possible associations of vitamin D receptor (VDR) polymorphisms with bronchial asthma development.

METHODS

The study included 100 Egyptian children, 50 asthmatic children who were comparable with 50 age, sex, and body mass index-matched, unrelated healthy controls (HCs) clinical assessments of asthmatic children were done using global initiative of asthma. Pulmonary function tests (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC ratio) were performed. Enzyme-linked immunosorbent assays of serum vitamin D3 and total IgE were done. VDR-single nucleotide polymorphisms (SNPs) (ApaI, TaqI, and BsmI) detection has performed using polymerase chain reaction through restriction fragment length polymorphism technique. Data analysis was performed using SPSS version 20.0. The studied SNPs were followed the Hardy Weinberg equation.

RESULTS

The mean serum level of 25(OH) D3 was significantly lower among asthmatic children (13.46 ng/mL ± 10.50 SD) in comparison to HCs (37.53 ng/mL ± 13. 0.40 SD), P < .05. Vitamin D deficiency was detected in 72% of cases with no significant difference in its level regarding asthma control. There was significantly higher IgE level among asthmatic children (99.83 ku/L ± 233.81 SD) versus HCs (7.52 ku/L ± 3.32 SD), P < .05. Asthmatic children were presented more commonly with TaqI t allele (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28-3.96; P < .05) and BsmI b allele (OR, 1.83; 95% CI, 1.05-3.21; P < .05). ApaI a allele was not significantly different among patients versus controls (P > .05). TT + Tt and Bb + bb genotypes were significantly higher among cases versus the controls, P < .05 for all.

CONCLUSIONS

TaqI and BsmI were associated with risk of bronchial asthma development among Egyptian children. High IgE and Low vitamin D status were frequently occurring among asthmatic children.

Local Allergic Rhinitis Revisited

PURPOSE OF REVIEW

Local allergic rhinitis (LAR) represents a diagnostic and therapeutic challenge for clinicians. Even though it affects a considerable number of chronic rhinitis patients and a significant number of articles regarding prevalence, evolution, diagnosis, and treatment have been published, the condition remains still largely unrecognized and therefore misdiagnosed and mistreated.

RECENT FINDINGS

LAR is a unique form of chronic rhinitis; it is neither classical allergic rhinitis (AR) nor non-allergic rhinitis (NAR). The symptoms, duration, severity, and complications of LAR are similar to those of AR and can affect adults and children. Thus, a portion of patients diagnosed with NAR or chronic rhinitis of unknown etiology may have LAR. The relationship between LAR inflammation and systemic allergic inflammation is unclear. Patients are frequently misdiagnosed with idiopathic NAR, and distinguishing between both entities is difficult without specific diagnostic tests. Underdiagnosis of LAR has implications on the management of these patients, as they are deprived of allergen immunotherapy (AIT) that has been demonstrated to modulate the immune mechanisms underlying allergic diseases. This review aims to comprehensively summarize the current knowledge on LAR and address unmet needs in the areas of disease diagnosis and treatment.

Staphylococcus aureus and its IgE-inducing enterotoxins in asthma: current knowledge

While immunoglobulin (Ig) E is a prominent biomarker for early-onset, its levels are often elevated in non-allergic late-onset asthma. However, the pattern of IgE expression in the latter is mostly polyclonal, with specific IgEs low or below detection level albeit with an increased total IgE. In late-onset severe asthma patients, specific IgE to Staphylococcal enterotoxins (se-IgE) can frequently be detected in serum, and has been associated with asthma, with severe asthma defined by hospitalisations, oral steroid use and decrease in lung function. Recently, se-IgE was demonstrated to even predict the development into severe asthma with exacerbations over the next decade. Staphylococcus aureus manipulates the airway mucosal immunology at various levels via its proteins, including superantigens, serine-protease-like proteins (Spls), or protein A (SpA) and possibly others. Release of IL-33 from respiratory epithelium and activation of innate lymphoid cells (ILCs) via its receptor ST2, type 2 cytokine release from those ILCs and T helper (Th) 2 cells, mast cell degranulation, massive local B-cell activation and IgE formation, and finally eosinophil attraction with consequent release of extracellular traps, adding to the epithelial damage and contributing to disease persistence via formation of Charcot-Leyden crystals are the most prominent hallmarks of the manipulation of the mucosal immunity by S. aureus In summary, S. aureus claims a prominent role in the orchestration of severe airway inflammation and in current and future disease severity. In this review, we discuss current knowledge in this field and outline the needs for future research to fully understand the impact of S. aureus and its proteins on asthma.

Intersection of biology and therapeutics: type 2 targeted therapeutics for adult asthma

Asthma is a disease of reversible airflow obstruction characterised clinically by wheezing, shortness of breath, and coughing. Increases in airway type 2 cytokine activity, including interleukin-4 (IL-4), IL-5, and IL-13, are now established biological mechanisms in asthma. Inhaled corticosteroids have been the foundation for asthma treatment, in a large part because they decrease airway type 2 inflammation. However, inhaled or systemic corticosteroids are ineffective treatments in many patients with asthma and few treatment options exist for patients with steroid resistant asthma. Although mechanisms for corticosteroid refractory asthma are likely to be numerous, the development of a new class of biologic agents that target airway type 2 inflammation has provided a new model for treating some patients with corticosteroid refractory asthma. The objective of this Therapeutic paper is to summarise the new type 2 therapeutics, with an emphasis on the biological rationale and clinical efficacy of this new class of asthma therapeutics.

Total and specific immunoglobulin E in induced sputum in allergic and non-allergic asthma

Background

Most patients with nonallergic asthma have normal serum immunoglobulin E (IgE) levels. Recent reports suggest that total and aeroallergen-specific IgE levels in induced sputum may be higher in nonallergic asthmatics than in healthy controls. Our objective is to compare total and dust-mite specific (Der p 1) IgE levels in induced sputum in allergic and nonallergic asthmatics and healthy controls.

Methods

Total and Der p 1-specific IgE were measured in induced sputum (ImmunoCAP immunoassay) from 56 age- and sex-matched asthmatics (21 allergic, 35 nonallergic) and 9 healthy controls. Allergic asthma was defined as asthma with a positive prick test and/or clinically-significant Der p 1-specific serum IgE levels.

Results

Patients with allergic asthma presented significantly higher total and Der p 1-specific serum IgE levels. There were no significant between-group differences in total sputum IgE. However, Der p 1-specific sputum IgE levels were significantly higher (p = 0.000) in the allergic asthmatics, but without differences between the controls and nonallergic asthmatics. Serum and sputum IgE levels were significantly correlated, both for total IgE (rho = 0.498; p = 0.000) and Der p 1-specific IgE (rho, 0.621; p = 0001).

Conclusions

Total IgE levels measured in serum and induced sputum are significantly correlated. No significant differences were found between the differents groups in total sputum IgE. Nevertheless, the levels of Der p 1-specific sputum IgE levels were significantly higher in the allergic asthmatics, but without differences between the controls and nonallergic asthmatics. Probably due to the lack of sensitivity of the test used, but with the growing evidence for local allergic reactions better methods are need to explore its presence. The Clinical Trials Identifier for this project is NCT03640936.

Bronchial asthma triggered by house dust mites in patients with local allergic rhinitis

BACKGROUND

Over 30% of local allergic rhinitis (LAR) patients self-report bronchial symptoms suggestive of asthma, but the relationship between the allergen exposure and the bronchial symptoms has not been studied.

OBJECTIVE

To investigate whether a bronchial counterpart of LAR exists.

METHODS

Patients were classified by clinical history, skin prick test/serum specific IgE (sIgE), and nasal allergen provocation test (NAPT) into the LAR, allergic rhinitis (AR), and nonallergic rhinitis (NAR) phenotypes. Twenty-eight LAR, 18 AR, and 19 NAR patients self-reporting bronchial symptoms suggestive of asthma and 8 healthy controls (HC) were subjected to a methacholine test (MT) before (Visit 1) and 24 hours after (Visit 3) a bronchial provocation test with Dermatophagoides pteronyssinus (BPT-DP) (Visit 2). Induced sputum and peripheral blood obtained after each MT were analyzed for immune cell populations, tryptase, ECP, and sIgE.

RESULTS

A positive MT was found in 50% of LAR, 83.3% of AR, 57.89% of NAR, and 0% of HC individuals (P = 0.022 AR vs LAR) at V1. BPT-DP was positive in 8 LAR and 15 AR patients (28% vs 83.3%, P < 0.001), with no positive responses in NAR and HC. All BPT-DP+ patients experienced a significant decrease of PC₂₀ at V3 vs V1 (P = 0.016 LAR, P ≤ 0.001 AR). BPT-DP+ patients also showed a significant increase of eosinophils, monocytes, and ECP in induced sputum at V3 compared with V1.

CONCLUSION

The results suggest the existence of a new asthma phenotype (local allergic asthma) defined by absence of systemic atopy and positivity to BPT with allergen.

IgE Test in Secretions of Patients with Respiratory Allergy

PURPOSE OF REVIEW

IgE is a key player in multiple inflammatory airway diseases. Ample literature demonstrates its presence in mucosa of patients with allergic rhinitis (AR), local allergic rhinitis (LAR), asthma, or chronic rhinosinusitis with nasal polyposis (CRSwNP).

RECENT FINDINGS

Current evidence shows that high-affinity IgE in blood stream of allergic individuals derives mainly from the mucosae. Also, mucosal synthesis of IgE can occur in the absence of systemic atopy, and may be relevant in atopic and non-atopic phenotypes of rhinitis as demonstrated in LAR. Specific IgE (sIgE) detection varies depending on technique used for sample collection and its measurement. sIgE detection is highly specific for diagnosis of LAR. Moreover, measurement of sIgE in secretions could be useful in monitoring response to allergen-specific immunotherapy in both AR and LAR phenotypes. This review will focus on recent developments in the role of IgE in respiratory diseases, and the clinical implications of its measurement in secretions.

Roles of IL-22 in allergic airway inflammation in mice and humans

Asthma is a chronic inflammatory disease of the airways that is characterized by eosinophilic inflammation, mucus hypersecretion and airway remodeling that leads to airway obstruction. Although these pathognomonic features of asthma are primarily mediated by allergen-specific T helper type 2 cells (Th2 cells) and their cytokines, recent studies have revealed critical roles of lung epithelial cells in the pathogenesis of asthma. Lung epithelial cells not only form physical barriers by covering the surfaces of the airways but also sense inhaled allergens and initiate communication between the environment and the immune system. The causative involvement of lung epithelium in the pathogenesis of asthma suggests that some molecules that modulate epithelial function have a regulatory role in asthma. IL-22, an IL-10-family cytokine produced by IL-17A-producing T helper cells (Th17 cells), γδ T cells and group 3 innate lymphoid cells (ILC3s), primarily targets epithelial cells and promotes their proliferation. In addition, IL-22 has been shown to induce epithelial production of various molecules that regulate local immune responses. These findings indicate that IL-22 plays crucial roles in the pathogenesis of asthma by regulating epithelial function. Here, we review the current understanding of the molecular and cellular mechanisms underlying IL-22-mediated regulation of airway inflammation in asthma.

Targeting the interleukin-4 and interleukin-13 pathways in severe asthma: current knowledge and future needs

PURPOSE OF REVIEW

Severe asthma is a heterogeneous disease that can be classified into phenotypes and endotypes based upon clinical or biological characteristics. Interleukin (IL)-4 and IL-13 play a key role in type 2 (T2) asthma. This article reviews the signaling pathway of IL-4 and IL-13 and highlights its targeted therapy in severe asthma.

RECENT FINDINGS

Several clinical trials of biologics targeting the IL-4/IL-13 pathway have recently been completed. In patients with severe, uncontrolled asthma, targeting IL-13 alone with biologics including lebrikizumab and tralokinumab has not shown consistent reduction in asthma exacerbations. Simultaneous targeting of both IL-4 and IL-13 by blocking IL-4 receptor α using dupilumab has yielded more consistent results in reducing asthma exacerbations and improving lung function, especially in patients with increased blood eosinophils. Other biomarkers of T2 inflammation such as exhaled nitric oxide and serum periostin may also predict response to biologics targeting the IL-4/IL-13 pathway.

SUMMARY

No biologic targeting the IL-4/IL-13 pathway is currently available for treatment of asthma, but emerging data suggest that biologics targeting IL-4 and IL-13 together may benefit patients with T2 high asthma. Additional data are needed about long-term efficacy and safety prior to incorporating these drugs into routine clinical practice.

Effects of anthraquinones from Cassia occidentalis L. on ovalbumin-induced airways inflammation in a mouse model of allergic asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Cassia occidentalis Linn. is a traditional ayruvedic edible shrub containing anthraquinones (AQs) as the principle active constituents. In folk medicine, it has a variety of uses including treatment of whooping cough ('pertussis') and inflammatory diseases. Despite these applications, limited data are available to validate the effects of C. occidentalis AQs on airways inflammation in asthma.

AIM OF THE STUDY

To explore the anti-inflammatory potential of AQs extracted from C. occidentalis using an in vivo model of ovalbumin (OVA)-induced asthma.

MATERIALS AND METHODS

Extraction and optimization of AQs from C. occidentalis was performed by mechanochemistry. Allergic asthma in BALB/c mice was sensitized and challenged by OVA, and the effects of AQs investigated in a mouse model. OVA-specific IgE concentrations in serum, and Th1/Th2 cytokine (IL-4, IL-5, IL-13 and IFN-γ) concentrations, inflammatory cell counts and classification in bronchoalveolar lavage fluid (BALF) were determined. Histopathological evaluation of lung tissue was performed using hematoxylin and eosin (H&E), and periodic acid-schiff (PAS) staining. Th1/Th2 cytokine mRNA expression was analyzed using the 2^-ΔΔCt method.

RESULTS

Treatment with AQs decreased inflammatory cell counts and production of Th2 cytokines (IL-4, IL-5 and IL-13) in BALF, and OVA-specific IgE in serum. In contrast,Th1 cytokine IFN-γ production in BALF was promoted. AQs also decreased mRNA expression of Th1/Th2 cytokine in lung tissue. Histological studies demonstrated that AQs substantially inhibited OVA-induced cellular infiltration, mucus hypersecretion and goblet cell hyperplasia in the lung.

CONCLUSIONS

These findings demonstrated the inhibitory effects of AQs, derived from C. occidentalis, on OVA-induced allergic asthma in mice. The results suggest a promising ethnopharmacological use for AQs in patients with asthma.

Local allergic rhinitis: Implications for management

A significant proportion of rhinitis patients without systemic IgE-sensitisation tested by skin prick test and serum allergen-specific IgE (sIgE) display nasal reactivity upon nasal allergen provocation test (NAPT). This disease phenotype has been termed local allergic rhinitis (LAR). LAR is an underdiagnosed entity affecting children and adults from different parts of the world, with moderate-to-severe symptoms, impairment of quality of life and rapid progression to symptom worsening. LAR is a stable phenotype and not merely an initial state of AR. Allergic rhinitis and LAR share many clinical features including a positive NAPT response, markers of type 2 nasal inflammation including sIgE in nasal secretions and a significant rate of asthma development. LAR should be considered as a differential diagnosis in those subjects of any age with symptoms suggestive of AR but no evidence of systemic atopy. Although LAR pathophysiology is partially unknown, in some patients sIgE can be demonstrated directly in the nasal secretions and/or indirectly via positive responses in basophil activation test (BAT). LAR can coexist with other rhinitis phenotypes, especially AR. The diagnosis currently relies on the positivity of NAPT to a single or multiple allergens. NAPT has high sensitivity, specificity and reproducibility, and it is considered the gold standard. BAT and the measurement of nasal sIgE can also contribute to LAR diagnosis. LAR patients benefit from the same therapeutic strategies than AR individuals, including the avoidance of allergen exposure and the pharmacotherapy. Moreover, several recent studies support the effectiveness and safety of allergen immunotherapy for LAR, which opens a window of treatment opportunity in these patients.

Therapeutic antibodies: A new era in the treatment of respiratory diseases?

Respiratory diseases affect millions of people worldwide, and account for significant levels of disability and mortality. The treatment of lung cancer and asthma with therapeutic antibodies (Abs) is a breakthrough that opens up new paradigms for the management of respiratory diseases. Antibodies are becoming increasingly important in respiratory medicine; dozens of Abs have received marketing approval, and many more are currently in clinical development. Most of these Abs target asthma, lung cancer and respiratory infections, while very few target chronic obstructive pulmonary disease - one of the most common non-communicable causes of death - and idiopathic pulmonary fibrosis. Here, we review Abs approved for or in clinical development for the treatment of respiratory diseases. We notably highlight their molecular mechanisms, strengths, and likely future trends.

Allergic airway inflammation: key players beyond the Th2 cell pathway

Allergic asthma is characterized by eosinophilic airway inflammation, mucus hyperproduction, and airway hyperreactivity, causing reversible airway obstruction. Accumulating evidence indicates that antigen-specific Th2 cells and their cytokines such as IL-4, IL-5, and IL-13 orchestrate these pathognomonic features of asthma. However, over the past decade, the understanding of asthma pathogenesis has made a significant shift from a Th2 cell-dependent, IgE-mediated disease to a more complicated heterogeneous disease. Recent studies clearly show that not only Th2 cytokines but also other T cell-related cytokines such as IL-17A and IL-22 as well as epithelial cell cytokines such as IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) are involved in the pathogenesis of asthma. In this review, we focus on the roles of these players beyond Th2 pathways in the pathogenesis of asthma.

Revisiting Type 2-high and Type 2-low airway inflammation in asthma: current knowledge and therapeutic implications

Asthma is a complex respiratory disorder characterized by marked heterogeneity in individual patient disease triggers and response to therapy. Several asthma phenotypes have now been identified, each defined by a unique interaction between genetic and environmental factors, including inflammatory, clinical and trigger-related phenotypes. Endotypes further describe the functional or pathophysiologic mechanisms underlying the patient's disease. type 2-driven asthma is an emerging nomenclature for a common subtype of asthma and is characterized by the release of signature cytokines IL-4, IL-5 and IL-13 from cells of both the innate and adaptive immune systems. A number of well-recognized biomarkers have been linked to mechanisms involved in type 2 airway inflammation, including fractional exhaled nitric oxide, serum IgE, periostin, and blood and sputum eosinophils. These type 2 cytokines are targets for pharmaceutical intervention, and a number of therapeutic options are under clinical investigation for the management of patients with uncontrolled severe asthma. Anticipating and understanding the heterogeneity of asthma and subsequent improved characterization of different phenotypes and endotypes must guide the selection of treatment to meet individual patients' needs.

NKT cells contribute to basal IL-4 production but are not required to induce experimental asthma

CD1d-deficiency results in a selective deletion of NKT cells in mice that is reported to prevent murine allergic airway disease (AAD). Because we find 2–3 fold lower basal IL-4 production in CD1d^- mice than in wild-type (WT) mice, we hypothesized that the contribution made by NKT cells to AAD would depend on the strength of the stimulus used to induce the disease. Consequently, we compared CD1d-deficient mice to WT mice in the development of AAD, using several models of disease induction that differed in the type and dose of allergen, the site of sensitization and the duration of immunization. Surprisingly we found equivalent allergic inflammation and airway disease in WT and CD1d^- mice in all models investigated. Consistent with this, NKT cells constituted only ~2% of CD4⁺ T cells in the lungs of mice with AAD, and IL-4-transcribing NKT cells did not expand with disease induction. Concerned that the congenital absence of NKT cells might have caused a compensatory shift within the immune response, we administered an anti-CD1d monoclonal Ab (mAb) to block NKT function before airway treatments, before or after systemic sensitization to antigen. Such Ab treatment did not affect disease severity. We suggest that the differences reported in the literature regarding the significance of NKT cells in the induction of allergic airway disease may have less to do with the methods used to study the disease and more to do with the animals themselves and/or the facilities used to house them.

Omalizumab in non-allergic Asthma: A report of 13 cases

BACKGROUND

There are limited data regarding the effectiveness of omalizumab in patients with non-allergic asthma.

OBJECTIVE

To evaluate the clinical and functional effectiveness of omalizumab in patients with non-allergic asthma.

METHODS

The study was a single-center, retrospective chart review of patients with non-allergic asthma who were treated with add-on omalizumab between February 2014 and March 2016. After omalizumab was started, data of the asthma control test (ACT), pulmonary function test, and daily oral corticosteroid (OCS) dosage were collected at baseline, 16 weeks, 1 year, 2 and 3 years (if available). The number of exacerbations/hospitalizations were collected 1 year prior to and 6 months/1 year after omalizumab. To calculate the total daily dosage of OCS in milligrams, data for 6 months/1 year prior and after omalizumab treatment were recorded.

RESULTS

Thirteen patients were included. After omalizumab, the mean ACT was significantly increased at 16 weeks (n = 13, p = 0.002), 1 year (n = 7, p = 0.006), and 2 years (n = 5, p = 0.006). The mean daily OCS dose was significantly decreased at 16 weeks (n = 13, p = 0.001), 1 year (n = 7, p = 0.006), and 2 years (n = 5, p = 0.04). The mean number of exacerbations and hospitalizations were decreased at the 6th month (n = 13; p = 0.001, p = 0.005) and 1st year (n = 7; p = 0.01, p = 0.02). The mean total quantity of OCS decreased 42% from 1.4 to 0.8 g in the six-month period prior to and post-omalizumab treatment (n = 6, p = 0.02) and decreased 76% from 3.8 to 0.9 g at 1 year in the pre vs. post-omalizumab treatment comparison (n = 7, p = 0.01). Six (46.2%) patients responded perfectly and seven (53.8%) partially responded to treatment.

CONCLUSION

Omalizumab can be effective in non-atopic severe asthma.

Detection of IL-9 producing T cells in the PBMCs of allergic asthmatic patients

BACKGROUND

Interleukin-9 (IL-9) was reported as an active participant in the pathogenesis of allergic asthma. This study aimed to investigate the major source ofIL-9 and its effect on interferon γ (IFN-γ) and immunoglobulin (Ig) secretion by B cells.

METHODS

We isolated peripheral blood mononuclear cells from children with allergic asthma and healthy children. IL-9, IL-4 and IFN-γ expression were detected by ELISA, ELISpot and Flowcytometry. Expression of transcription factor PU.1 was measured by Western Blot. We evaluated the effect of IL-9 on B cell activation and Ig production.

RESULTS

Results showed that compared with healthy children, levels of IL-9, IL-4 and PU.1 were elevated and levels of IFN-γ were lower in children with allergic asthma. IL-9-expressing CD4⁺ T cells did not co-express IL-4. Exogenous IL-9 inhibited IFN-γ production in a dose-dependent manner. Antigen-specific Th9 cells existed in children with house dust mite allergic asthma. IL-9 up-regulated expression of CD69 and CD25 on B cells and combination of IL-9 and IL-4 enhanced IgE production.

CONCLUSIONS

In conclusion, our results showed that Th9 cells may be the major source of IL-9 in children with allergic asthma. In these patients, IL-9 impairs IFN-γ production and synergistically promotes IL-4-induced IgE secretion.

Increased Systemic Cytokine/Chemokine Expression in Asthmatic and Non-asthmatic Patients with Bacterial, Viral or Mixed Lung Infection

This study was aimed to determine the profiles of serum cytokines (IL-1β, TNF-α, IL-4, IL-5) and chemokines (MCP-1: monocyte chemoattract protein-1 and RANTES: regulated on activation normal T cell expressed and secreted) in individuals with an asthmatic versus a non-asthmatic background with bacterial, viral or mixed acute respiratory infection. Asthmatic (n = 14) and non-asthmatic (n = 29) patients with acute viral, bacterial or mixed (bacterial and viruses) respiratory infection were studied. Patients were also analysed as individuals with pneumonia or bronchitis. Healthy individuals with similar age and sex (n = 10) were used as controls. Cytokine/chemokine content in serum was determined by ELISA. Increased cytokine/chemokine concentration in asthmatic and non-asthmatic patients was observed. However, higher concentrations of chemokines (MCP-1 and RANTES) in asthmatic patients infected by viruses, bacteria or bacteria and viruses (mixed) than in non-asthmatic patients were observed. In general, viral and mixed infections were better cytokine/chemokine inducers than bacterial infection. Cytokine/chemokine expression was similarly increased in both asthmatic and non-asthmatic patients with pneumonia or bronchitis, except that RANTES remained at normal levels in bronchitis. Circulating cytokine profiles induced by acute viral, bacterial or mixed lung infection were not related to asthmatic background, except for chemokines that were increased in asthmatic status.

The safety of monoclonal antibodies in asthma

INTRODUCTION

In the last two decades the knowledge of the mechanisms of the inflammatory processes underlying asthma rapidly evolved, several key mediators (cytokines and receptors) were identified, and the laboratory techniques have allowed us to synthesize monoclonal antibodies highly specific for those target molecules. Nowadays, many biological agents are investigated in asthma (with anti IgE being the only commercially available). The clinical efficacy of some biologics was demonstrated in many cases, however, the safety issue has progressively emerged and has been recognized as a crucial aspect.

AREAS COVERED

We summarized the currently available knowledge on the safety and side effects of biologics in asthma, as derived by reviews, meta analyses and clinical trials. PubMed was searched with the terms anti IL-x [AND] safety [OR] side effects, within the categories "clinical trial", meta-analysis" and "review". Case reports were excluded. The authors collegially selected the relevant entries to be included.

EXPERT OPINION

Overall, the safety of most of the investigated agents seems to be satisfactory, a certain risk of side effects remains present, and is variable for the different molecules. Thus caution must be paid in evaluating the risk to benefit ratio. Specific biomarkers to predict the response to each biological are urgently needed to improve the safety profile.

Changing Paradigms in the Treatment of Severe Asthma: The Role of Biologic Therapies

Cytokine antagonists are monoclonal antibodies that offer new treatment options for refractory asthma but will also increase complexity because they are effective only for patients with certain asthma subtypes that remain to be more clearly defined. The clinical and inflammatory heterogeneity within refractory asthma makes it difficult to manage the disease and to determine which, if any, biologic therapy is suitable for a specific patient. The purpose of this article is to provide a data-driven discussion to clarify the use of biologic therapies in patients with refractory asthma. We first discuss the epidemiology and pathophysiology of refractory asthma. We then interpret current evidence for biomarkers of eosinophilic or type 2-high asthma so that clinicians can determine potential treatments for patients based on knowledge of their effectiveness in specific asthma phenotypes. We then assess clinical data on the efficacy, safety, and mechanisms of action of approved and pipeline biologic therapies. We conclude by discussing the potential of phenotyping or endotyping refractory asthma and how biologic therapies can play a role in treating patients with refractory asthma.

Allergen-Specific CD4(+) T Cells in Human Asthma

In allergic asthma, aeroallergen exposure of sensitized individuals mobilizes robust innate and adaptive airway immune responses, stimulating eosinophilic airway inflammation and the activation and infiltration of allergen-specific CD4(+) T cells into the airways. Allergen-specific CD4(+) T cells are thought to be central players in the asthmatic response as they specifically recognize the allergen and initiate and orchestrate the asthmatic inflammatory response. In this article, we briefly review the role of allergen-specific CD4(+) T cells in the pathogenesis of human allergic airway inflammation in allergic individuals, discuss the use of allergen-major histocompatibility complex class II tetramers to characterize allergen-specific CD4(+) T cells, and highlight current gaps in knowledge and directions for future research pertaining to the role of allergen-specific CD4(+) T cells in human asthma.

Nonallergic rhinitis and lower airway disease

In the past years, several investigators have demonstrated the existence of local nasal responses in some patients with typical allergic rhinitis symptoms but without atopy and have defined a new phenotype called local allergic rhinitis (LAR) or 'entopy'. In a percentage of LAR subjects, the upper airway disease is also associated with lower airway symptoms. After the description of this phenotype, the differential diagnosis between LAR and nonallergic rhinitis (NAR) has become a challenge for the clinician. To correctly identify LAR patients is of high importance for treatment and management of these patients, and for an appropriate inclusion of patients in clinical trials and genetics studies. The treatment of LAR patients, in contrast with NAR, is oriented to allergen avoidance and specific treatment. Allergen immunotherapy, the aetiological treatment for allergic respiratory diseases, has demonstrated to be an effective and safe treatment in LAR, increasing immunological tolerance, and reducing the clinical symptoms and the use of medication. In this article, the important and novel aspects of LAR in terms of mechanisms, diagnosis and treatment will be discussed. Also, the involvement of the lower airway and the potential role of IgE in the bronchial disease will be also reviewed.

STAT6 Regulates the Development of Eosinophilic versus Neutrophilic Asthma in Response to Alternaria alternata

Human asthma is a heterogeneous disease characterized by the expression of both Th2 and Th17 cytokines. In vitro and in vivo studies have shown a reciprocal regulation between Th2 and Th17 pathways, suggesting a potential induction of neutrophil-promoting Th17 inflammation in the absence of a Th2 response. Alternaria alternata is a clinically relevant allergen that is associated with severe and fatal asthma exacerbations. Exposure to A. alternata is characterized by a predominant Th2 response, but can also induce the production of factors associated with Th17 responses (e.g., CXCL8) from epithelial cells. Using a mouse model, we found that wild-type mice develop an eosinophilic Th2 airway disease in response to A. alternata exposure, whereas IL-4-, IL-13-, and STAT6-deficient mice exhibit a primarily neutrophilic response. Neutrophilic asthma in STAT6-/- mice was accompanied by elevated lung levels of TNF-α, CXCL1, CXCL2, and CXCL5, and was steroid resistant. Neutralization of Th17 signaling only partially reduced neutrophil numbers and total airway inflammation. Airway neutrophilia developed in RAG-deficient and CD4-depleted BALB/c mice, suggesting that the suppression of neutrophil responses is dependent on Th2 cytokine production by T cells and that airway neutrophilia is primarily an innate response to allergen. These results highlight the importance of combination therapies for treatment of asthma and establish a role for factors other than IL-17 as targets for neutrophilic asthma.

Omalizumab reduces bronchial mucosal IgE and improves lung function in non-atopic asthma

Omalizumab therapy of non-atopic asthmatics reduces bronchial mucosal IgE and inflammation and preserves/improves lung function when disease is destabilised by staged withdrawal of therapy.

18 symptomatic, non-atopic asthmatics were randomised (1:1) to receive omalizumab or identical placebo treatment in addition to existing therapy for 20 weeks. Bronchial biopsies were collected before and after 12–14 weeks of treatment, then the patients destabilised by substantial, supervised reduction of their regular therapy. Primary outcome measures were changes in bronchial mucosal IgE+ cells at 12–14 weeks, prior to regular therapy reduction, and changes in lung function (forced expiratory volume in 1 s) after destabilisation at 20 weeks. Quality of life was also monitored.

Omalizumab but not placebo therapy significantly reduced median total bronchial mucosal IgE+ cells (p<0.01) but did not significantly alter median total mast cells, plasma cells, B lymphocytes, eosinophils and plasmablasts, although the latter were difficult to enumerate, being distributed as disperse clusters. By 20 weeks, lung function declined in the placebo-treated patients but improved in the omalizumab treated patients, with significant differences in absolute (p=0.04) and % predicted forced expiratory volume in 1 s (p=0.015).

Omalizumab therapy of non-atopic asthmatics reduces bronchial mucosal IgE+ mast cells and improves lung function despite withdrawal of conventional therapy.

Mast cells in asthma--state of the art

Mast cells (MCs) play a central role in tissue homoeostasis, sensing the local environment through numerous innate cell surface receptors. This enables them to respond rapidly to perceived tissue insults with a view to initiating a co-ordinated programme of inflammation and repair. However, when the tissue insult is chronic, the ongoing release of multiple pro-inflammatory mediators, proteases, cytokines and chemokines leads to tissue damage and remodelling. In asthma, there is strong evidence of ongoing MC activation, and their mediators and cell-cell signals are capable of regulating many facets of asthma pathophysiology. This article reviews the evidence behind this.

Pheretima aspergillum decoction suppresses inflammation and relieves asthma in a mouse model of bronchial asthma by NF-κB inhibition

ETHNOPHARMACOLOGICAL RELEVANCE AND AIM OF THE STUDY

Guang-Pheretima, the live form of the earthworm Pheretima aspergillum, is a traditional Chinese medicine commonly used for the treatment of asthma, cough, stroke, epilepsy and other diseases due to its anti-inflammatory, anti-asthmatic, anti-seizure, thrombolytic and diuretic properties. Although Guang-Pheretima is effective in the relief of asthma, its pharmacological activity and the underlying molecular mechanisms are not fully understood. Hence, we investigated the effects of a Pheretima aspergillum decoction (PAD) against inflammation in a model of ovalbumin (OVA)-induced asthma in BALB/c mice, as well as the nuclear factor-κB (NF-κB) pathway involved in this process.

MATERIALS AND METHODS

OVA was used to sensitize and challenge the airway of the mice, and PAD was administrated by gavage. We measured airway hyperresponsiveness (AHR) in the mice 24h following a final methacholine challenge with whole-body plethysmography. The bronchoalveolar lavage fluid (BALF), serum and pulmonary tissues were collected 48h after the last challenge. The levels of inflammatory factors and the related mRNAs were determined by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR), respectively. The number of differential inflammatory cells in the BALF was counted. Serum total and OVA-specific IgE levels were measured with ELISA. The activation of NF-κB signaling in the lung was detected by western blotting. In addition, the lung tissues were stained with hematoxylin and eosin or periodic acid Schiff stain for histopathological examination.

RESULTS

PAD treatment significantly alleviated AHR in the asthmatic mice, decreased the mRNA and protein levels of IL-4, IL-5 and IL-13 and downregulated IgE. In addition, PAD treatment attenuated mucus secretion and infiltration of inflammatory cells in the lung while inhibiting the activation of NF-κB signaling.

CONCLUSIONS

PAD effectively inhibited the activation of NF-κB signaling in the lungs of mice with OVA-induced asthma, and mitigated AHR and Th2 type inflammatory reactions. Therefore, PAD may serve as a drug candidate for asthma treatment.

Update on local allergic rhinitis

We here provide an update on the literature regarding local allergic rhinitis (LAR). In reviewing LAR, we have included an updated definition, classifications, mechanisms, comorbidities, and recommendations for diagnosis and treatment for LAR, as well as the defined research areas for future evidence-based studies. LAR is a localised nasal allergic response in the absence of systemic atopy characterised by local production of specific IgE (sIgE) antibodies, a TH2 pattern of mucosal cell infiltration during natural exposure to aeroallergens, and a positive nasal allergen provocation test response, with the release of inflammatory mediators. The localised allergic response of LAR is an important topic for the study of allergies. This review provides an update on the current knowledge of LAR.

Current concepts of severe asthma

The term asthma encompasses a disease spectrum with mild to very severe disease phenotypes whose traditional common characteristic is reversible airflow limitation. Unlike milder disease, severe asthma is poorly controlled by the current standard of care. Ongoing studies using advanced molecular and immunological tools along with improved clinical classification show that severe asthma does not identify a specific patient phenotype, but rather includes patients with constant medical needs, whose pathobiologic and clinical characteristics vary widely. Accordingly, in recent clinical trials, therapies guided by specific patient characteristics have had better outcomes than previous therapies directed to any subject with a diagnosis of severe asthma. However, there are still significant gaps in our understanding of the full scope of this disease that hinder the development of effective treatments for all severe asthmatics. In this Review, we discuss our current state of knowledge regarding severe asthma, highlighting different molecular and immunological pathways that can be targeted for future therapeutic development.

Strategies targeting the IL-4/IL-13 axes in disease

IL-4 and IL-13 are pleiotropic Th2 cytokines produced by a wide variety of different cell types and responsible for a broad range of biology and functions. Physiologically, Th2 cytokines are known to mediate host defense against parasites but they can also trigger disease if their activities are dysregulated. In this review we discuss the rationale for targeting the IL-4/IL-13 axes in asthma, atopic dermatitis, allergic rhinitis, COPD, cancer, inflammatory bowel disease, autoimmune disease and fibrotic disease as well as evaluating the associated clinical data derived from blocking IL-4, IL-13 or IL-4 and IL-13 together.

Diagnosis and investigation in the severe asthma clinic

Severe asthma is recognised as an important and emerging area of unmet need in asthma. The assessment of severe asthma should include three steps; (1) determining the diagnosis of asthma, including verification that the disease is severe asthma, (2) assessing comorbidities and contributing factors that will impact on clinical severity, as well as (3) assessing asthma phenotypes. These steps recognize the importance of heterogeneity in asthma as a key factor that determines the disease course and increasingly the choice of successful therapy. This assessment should be undertaken systematically and is best done by an expert multidisciplinary team. Here, we will outline the important aspects that should be included in the clinical assessment of the patient in the severe asthma clinic, including diagnosis, clinical history, the assessment of important comorbidities and the key investigations needed to support them.