Phenotype-Driven Therapeutics in Severe Asthma

Evidence-Based Approach of Biologic Therapy in Bronchial Asthma

The emergence of biologic agents in the treatment of bronchial asthma has a wide impact on improving quality of life, reducing morbidity, and overall health care utilization. These therapies usually work by targeting specific inflammatory pathways involving type 2 inflammation and are particularly effective in severe eosinophilic asthma. Various randomized controlled trials have shown their effectiveness by reducing exacerbation rates and decreasing required glucocorticoid dosages. One of the relatively newer agents, tezepelumab, targets thymic stromal lymphoprotein and has proven its efficacy in patients independent of asthma phenotype and serum biomarker levels. This article reviews the pathophysiologic mechanism behind biologic therapy and offers an evidence-based discussion related to the indication, benefits, and adverse effects of such therapies.

Comparing bronchial thermoplasty with biologicals for severe asthma: Systematic review and network meta-analysis

BACKGROUND

Bronchial thermoplasty (BT) has shown favorable safety and efficacy in several randomized controlled trials (RCTs), but has not been directly compared to biological therapies.

METHODS

Electronic literature searches were performed on PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, to retrieve RCTs of BT or FDA-approved biologicals against controls in patients with severe asthma. Six outcomes were analyzed: Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ), the number of patients experiencing ≥1 asthma exacerbation, annualized exacerbation rate ratio (AERR), oral corticosteroid dose reduction (OCDR), and morning peak expiratory flow rate (amPEF). Random-effects, Frequentist network meta-analysis (NMA) were performed, and therapies were ranked using P-scores.

RESULTS

Twenty-nine RCTs (15,547 patients) were included. Fewer patients treated with BT experienced ≥1 asthma exacerbation (risk ratio [RR] = 0.66, 95%CI = 0.45-0.98) compared to control. AERR of BT versus control was non-significant, but significant improvements in ACQ score (mean difference [MD] -0.41, 95%CI -0.63 to -0.20), AQLQ score (MD = 0.54, 95%CI = 0.30-0.77), amPEF and OCDR were found. No significant differences between BT and biologics were seen across indirect comparisons of all studies.

CONCLUSIONS

Despite the lack of head-to-head comparative trials, this NMA suggests that BT is non-inferior to biologicals in terms of quality-of-life scores, and represents a promising alternative for patients with severe asthma.

Effects of Different Intervention Factors on Vascular Endothelial Growth Factor-Induced Human Airway Smooth Muscle Cell Migration

Background

Asthma airway remodeling is closely related to the abnormal migration of human airway smooth muscle cells (ASMCs), and vascular endothelial growth factor (VEGF) is involved in the pathophysiological process of asthma. This study aimed to investigate the effect of VEGF on ASMC migration through in vitro cell experiments and to intervene in ASMC migration with different asthma drugs and signaling pathway inhibitors to provide a basis for screening effective drugs for airway remodeling.

Methods

The effect of VEGF on the proliferation of ASMCs was detected by the CCK-8 method, and the effect of VEGF on the migration of ASMCs was proven by scratch and transwell assays. Different asthma drugs and signaling pathway inhibitors were used to interfere with the migration of ASMCs. The number of migrating cells was compared between the intervention and nonintervention groups.

Results

Our results showed that VEGF induction enhanced ASMC migration; pretreatment with the commonly used asthma drugs (salbutamol, budesonide, and ipratropium bromide) significantly attenuated VEGF-induced ASMC migration; and inhibitors SB203580, LY294002, and Y27632 blocked the VEGF-induced activation of p38 MAPK, PI3K, and ROCK signaling pathway targets in ASMCs and inhibited migration.

Conclusion

This study shows that the current commonly used asthma drugs salbutamol, budesonide, and ipratropium have potential value in the treatment of airway remodeling, and the p38 MAPK, PI3K, and ROCK signaling pathway targets are involved in the VEGF-induced ASMC migration process. Signaling pathway inhibitor drugs may be a new way to treat asthma-induced airway remodeling in asthma patients in the future. However, the related mechanism and safety profile still need further research.

Critical evaluation of asthma biomarkers in clinical practice

The advent of personalized medicine has revolutionized the whole approach to the management of asthma, representing the essential basis for future developments. The cornerstones of personalized medicine are the highest precision in diagnosis, individualized prediction of disease evolution, and patient-tailored treatment. To this aim, enormous efforts have been established to discover biomarkers able to predict patients' phenotypes according to clinical, functional, and bio-humoral traits. Biomarkers are objectively measured characteristics used as indicators of biological or pathogenic processes or clinical responses to specific therapeutic interventions. The diagnosis of type-2 asthma, prediction of response to type-2 targeted treatments, and evaluation of the risk of exacerbation and lung function impairment have been associated with biomarkers detectable either in peripheral blood or in airway samples. The surrogate nature of serum biomarkers, set up to be less invasive than sputum analysis or bronchial biopsies, has shown several limits concerning their clinical applicability. Routinely used biomarkers, like peripheral eosinophilia, total IgE, or exhaled nitric oxide, result, even when combined, to be not completely satisfactory in segregating different type-2 asthma phenotypes, particularly in the context of severe asthma where the choice among different biologics is compelling. Moreover, the type-2 low fraction of patients is not only an orphan of biological treatments but is at risk of being misdiagnosed due to the low negative predictive value of type-2 high biomarkers. Sputum inflammatory cell analysis, considered the highest specific biomarker in discriminating eosinophilic inflammation in asthma, and therefore elected as the gold standard in clinical trials and research models, demonstrated many limits in clinical applicability. Many factors may influence the measure of these biomarkers, such as corticosteroid intake, comorbidities, and environmental exposures or habits. Not least, biomarkers variability over time is a confounding factor leading to wrong clinical choices. In this narrative review, we try to explore many aspects concerning the role of routinely used biomarkers in asthma, applying a critical view over the "state of the art" and contemporarily offering an overview of the most recent evidence in this field.

Phenotyping, Precision Medicine, and Asthma

The traditional one-size-fits all approach based on asthma severity is archaic. Asthma is a heterogenous syndrome rather than a single disease entity. Studies evaluating observable characteristics called phenotypes have elucidated this heterogeneity. Asthma clusters demonstrate overlapping features, are generally stable over time and are reproducible. What the identification of clusters may have failed to do, is move the needle of precision medicine meaningfully in asthma. This may be related to the lack of a straightforward and clinically meaningful way to apply what we have learned about asthma clusters. Clusters are based on both clinical factors and biomarkers. The use of biomarkers is slowly gaining popularity, but phenotyping based on biomarkers is generally greatly underutilized even in subspecialty care. Biomarkers are more often used to evaluate type 2 (T2) inflammatory signatures and eosinophils (sputum and blood), fractional exhaled nitric oxide (FeNO) and serum total and specific immunoglobulin (Ig) E reliably characterize the underlying inflammatory pathways. Biomarkers perform variably and clinicians must be familiar with their advantages and disadvantages to accurately apply them in clinical care. In addition, it is increasingly clear that clinical features are critical in understanding not only phenotypic characterization but in predicting response to therapy and future risk of poor outcomes. Strategies for asthma management will need to leverage our knowledge of biomarkers and clinical features to create composite scores and risk prediction tools that are clinically applicable. Despite significant progress, many questions remain, and more work is required to accurately identify non-T2 biomarkers. Adoption of phenotyping and more consistent use of biomarkers is needed, and we should continue to encourage this incorporation into practice.

Classification of Distinct Endotypes in Human Skin Scarring: S.C.A.R.-A Novel Perspective on Dermal Fibrosis

Significance: Skin scarring is a permanent, irreversible end point of cutaneous injury. However, not everyone will acquire the same exact scar type. Skin scarring is generally recognized as complex with significant variability in individuals' scar type and response to treatment. Despite these tangible differences in treatment response, to date there has been no simplified approach in defining spectrum of skin scarring in relation to prediction and outcome post-treatment. Thus, in this study we propose that skin scarring consists of distinct endotypes, which is characterized by their specific pathology. Four distinct scar endotypes can be observed: (1) Stretched (flat), (2) Contracted, (3) Atrophic (depressed), and (4) Raised scarring, which can be abbreviated to S.C.A.R. endotypes. Each of these endotypes can certainly include subphenotypes and each phenotype can be present in more than one endotype. To define these endotypes, we also present a structured approach in assessment of all relevant parameters in skin scar evaluation including clinical (scar symptoms and signs) and nonclinical parameters (device measurements of structural, mechanical, and physiological properties of scars as well as gene and protein laboratory studies). Recent Advances: Scars can be phenotypically characterized based on a multitude of parameters assessed; however, not all scar types will share all the same characteristics. This leads to the question of whether skin scarring is a single disease entity with varying phenotypic characteristics or should be classed as several disease entities that have certain similar parameters. We suggest the latter and propose distinct scarring phenotypes arise mainly owing to genetic and environmental susceptibilities associated with the development of each specific scar endotype. Characteristic features of skin scarring, however, can be objectively and quantitively evaluated and used as an aid in the theranostic goal-directed management of scarring. Critical Issues: The concept of identifying different endotypes is key in formulating personalized treatments with improved outcomes beyond what is achieved with current nonspecific approaches in scar management. This approach has gained interest and significant traction in several other medical conditions including asthma, rheumatoid arthritis, and atopic dermatitis. Future Directions: To begin identifying distinct endotypic features in skin scarring, it is important to have a better understanding of underlying pathological mechanisms leading to further insight into the heterogeneous nature of skin scarring endotypes. This approach may lead to improved theranostic outcomes and further understanding of the pathophysiology of the complex nature of human skin scarring.

Human bone marrow-mesenchymal stem cell-derived exosomal microRNA-188 reduces bronchial smooth muscle cell proliferation in asthma through suppressing the JARID2/Wnt/β-catenin axis

The functions of exosomes in allergic diseases including asthma have aroused increasing concerns. This paper focuses on the effects of exosomes derived from human bone marrow-mesenchymal stem cells (hBM-MSCs) on the proliferation of bronchial smooth muscle cells in asthma and the mechanism involved. Exosomes were extracted from hBM-MSCs and identified. Human BSMCs were induced with transforming growth factor (TGF)-β1 to mimic an asthma-like condition in vitro and then treated with exosomes. A mouse model with asthma was induced by ovalbumin (OVA) and treated with exosomes for in vivo study. The hBM-MSC-derived exosomes significantly reduced the abnormal proliferation and migration of TGF-β1-treated BSMCs. microRNA (miR)-188 was the most enriched miRNA in exosomes according the microarray analysis, and JARID2 was identified as a mRNA target of miR-188. Either downregulation of miR-188 or upregulation of JARID2 blocked the protective effects of exosomes on BSMCs. JARID2 activated the Wnt/β-catenin signaling pathway. In the asthmatic mice, hBM-MSC-derived exosomes reduced inflammatory cell infiltration, mucus production, and collagen deposition in mouse lung tissues. In conclusion, this study suggestes that hBM-MSC-derived exosomes suppress proliferation of BSMCs and lung injury in asthmatic mice through the miR-188/JARID2/Wnt/β-catenin axis. This study may provide novel insights into asthma management.

Follistatin-Like 1 Induces the Activation of Type 2 Innate Lymphoid Cells to Promote Airway Inflammation in Asthma

Asthma is a chronic disease closely related to airway inflammation. It has been proven that type 2 innate lymphoid cells (ILC2s) play an essential role in airway inflammation in asthma. Furthermore, there is growing evidence that Follistatin-like 1 (FSTL1) can participate in various inflammatory reactions mediated by the JAK/STAT signaling pathway, among others. Therefore, we put forward a new hypothesis: FSTL1 promotes asthmatic airway inflammation by activating ILC2. This study generated an ovalbumin-sensitized asthma model in C57BL/6 and Fstl1^+/- mice. The results showed that the absolute number and the proportion of ILC2 in the ovalbumin-challenged Fstl1^+/- group were lower than in the ovalbumin-challenged wild-type group. We also measured the levels of Th2-type cytokines in the serum and bronchoalveolar lavage fluid (BALF) of mice and found that the corresponding cytokines in the Fstl1^+/- were lower than in the wild-type groups. Finally, we tested whether MEK-JAK-STAT-GATA3 is the specific pathway for FSTL1 to activate ILC2, and further tested our working hypothesis by adding various inhibitors of proteins from this pathway. Overall, these findings reveal that FSTL1 can activate ILC2 through MEK-JAK-STAT-GATA3 to promote airway inflammation and participate in the pathogenesis of asthma.

miR-135a inhibits airway inflammatory response in asthmatic mice via regulating JAK/STAT signaling pathway

The objective of this study was to investigate the inhibitory effect of miR-135a in regulating JAK/STAT signaling pathway on airway inflammation in asthmatic mice. An asthma model was established by sensitization and stimulation with ovalbumin (OVA), and the corresponding drug intervention was given from the day of stimulation by means of nasal drops. Airway hyperresponsiveness was tested. The content of miR-135a in the lung tissue of mice was detected by RT-PCR. The pathological changes of lung tissue were evaluated by HE staining. Tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-5, and eotaxin in bronchoalveolar lavage fluid (BALF) and lung tissue were detected by ELISA and immunohistochemistry, respectively. The expression of JAK/STAT signaling pathway-related protein in lung tissue was detected by western blot. To further validate the effect of miR-135a overexpression on the JAK/STAT signaling pathway, pathway activators and inhibitors were added. Compared with the OVA group, the airway hyperresponsiveness of the mice was significantly decreased after treatment with the miR-135a agonist. The expression of miR-135a was significantly increased in the lung tissue and the pathological changes of the lung tissue were alleviated. The contents of TNF-α, IL-6, IL-5, and eotaxin in BALF and lung tissues were decreased. The expression of JAK/STAT signaling pathway-related proteins p-JAK3/JAK3, p-STAT1/STAT1, and p-STAT3/STAT3 were significantly reduced in lung tissue (P<0.05). Addition of JAK inhibitor AG490 reduced airway inflammation in asthmatic mice. miR-135a agonists inhibit airway inflammation in asthmatic mice by regulating the JAK/STAT signaling pathway.

Applying personalized medicine to adult severe asthma

Background: Severe asthma is a heterogeneous disease that consists of various phenotypes driven by different pathways. Associated with significant morbidity, an important negative impact on the quality of life of patients, and increased health care costs, severe asthma represents a challenge for the clinician. With the introduction of various antibodies that target type 2 inflammation (T2) pathways, severe asthma therapy is gradually moving to a personalized medicine approach. Objective: The purpose of this review was to emphasize the important role of personalized medicine in adult severe asthma management. Methods: An extensive research was conducted in medical literature data bases by applying terms such as "severe asthma" associated with "structured approach," "comorbidities," "biomarkers," "phenotypes/endotypes," and "biologic therapies." Results: The management of severe asthma starts with a structured approach to confirm the diagnosis, assess the adherence to medications and identify confounding factors and comorbidities. The definition of phenotypes or endotypes (phenotypes defined by mechanisms and identified through biomarkers) is an important step toward the use of personalized medicine in asthma. Severe allergic and nonallergic eosinophilic asthma are two defined T2 phenotypes for which there are efficacious targeted biologic therapies currently available. Non-T2 phenotype remains to be characterized, and less efficient target therapy exists. Conclusion: Despite important progress in applying personalized medicine to severe asthma, especially in T2 inflammatory phenotypes, future research is needed to find valid biomarkers predictive for the response to available biologic therapies to develop more effective therapies in non-T2 phenotype.

[Clinical and economic comparison of utilization of reslizumab, mepolizumab and benralizumab in the treatment of severe eosinophilic asthma]

During last few years, the approaches to the management of patients with severe asthma have been revised. Monoclonal antibodies (MABs), inhibitors of interleukin-5 (reslizumab, mepolizumab, benralizumab) have been recently introduced for the treatment of severe eosinophilic asthma. The mentioned drugs were approved in Russia and included into the list of Vitally Essential Drugs.

AIM

The aim of this study was to compare the clinical and economic consequences of the use of biological agents that antagonize IL-5 in the treatment of severe eosinophilic asthma in adults.

MATERIALS AND METHODS

Two methods of clinical and economic research were used: assessment of the cost-effectiveness ratio and analysis of the budget impact. The effectiveness of the drugs was assessed using indirect comparison; special attention was paid to comparability of the patient groups in the studies chosen for such an assessment. Two approaches were used for calculation of the cost of therapy for severe asthma: using DRGs (applicable to most regions of Russia), and without the use of DRGs, which is relevant only for few Russian regions.

RESULTS

Basing on the data obtained from a budget impact study without the use of DRG, it was shown that reslizumab was dominating for patients with body mass of up to 70 kg, while for the patients with body mass of 70 to 110 kg, mepolizumab was dominating, while utilization of reslizumab appeared to be somewhat more expensive. In the group of patients with body mass over 110 kg, mepolizumab also was dominating. The calculation of the cost-effectiveness ratio (CER) showed that reslizumab appeared to be dominating over two other MABs, The results of the study using the DRG demonstrated that the cost of an annual course of benralizumab in most cases in Russia would exceed the amount that can be compensated by Territorial Funds for Mandatory Medical Insurance to a healthcare institution for therapy of bronchial asthma in one adult patient with genetically engineered drugs. Therefore, further comparisons were made for reslizumab and mepolizumab only. Analysis of the impact on the budget demonstrated that treatment with reslizumab and mepolizumab would represent a similar burden for the budget. When applying cost-effectiveness analysis, reslizumab was more cost-effective than mepolizumab (regardless of patient body mass).

CONCLUSION

Thus, the results of the clinical and economic study suggested that, basing on the cost-effectiveness analysis, reslizumab appeared to be the dominant IL-5 antagonist (regardless of body mass if DRG approach was used and in patients with body mass up to 110 kg, if such an approach was not used). Basing on budget impact analysis, calculations without use of DRG approach showed superiority of reslizumab over mepolizumab and benralizumab for the patients with body mass up to 70 kg and the DRG-based approach showed equal burden for the budget for reslizumab and mepolizumab for the patients with any body mass.

The enigmatic role of TIPE2 in asthma

Unlike other members of the tumor necrosis factor (TNF)-α-induced protein 8 (TNFAIP8/TIPE) family that play a carcinogenic role and regulate apoptosis, TNFAIP8-like 2 (TIPE2) can not only maintain immune homeostasis but also regulate inflammation. TIPE2 mainly restrains the activation of T cell receptor (TCR) and Toll-like receptors (TLR), regulating its downstream signaling pathways, thereby regulating inflammation. Interestingly, TIPE2 is abnormally expressed in many inflammatory diseases and may promote or inhibit inflammation in different diseases. This review summarizes the molecular target and cellular function of TIPE2 in immune cells and inflammatory diseases and the underlying mechanism by which TIPE2 regulates inflammation. The function and mechanism of TIPE2 in asthma is also explained in detail. TIPE2 is abnormally expressed in asthma and participates in the pathogenesis of different phenotypes of asthma through regulating multiple inflammatory cells' activity and function. Considering the indispensable role of TIPE2 in asthma, TIPE2 may be an effective therapeutic target in asthma. However, the available data are insufficient to provide a full understanding of the complex role of TIPE2 in human asthma. Further study is still necessary to explore the possible mechanism and functions of TIPE2 in different asthma phenotypes.

Phenotypes and endotypes of adult asthma: Moving toward precision medicine

Asthma is a chronic inflammatory disease of the airways that is challenging to dissect into subgroups because of the heterogeneity present across the spectrum of the disease. Efforts to subclassify asthma using advanced computational methods have identified a number of different phenotypes that suggest that multiple pathobiologically driven clusters of disease exist. The main phenotypes that have been identified include (1) early-onset allergic asthma, (2) early-onset allergic moderate-to-severe remodeled asthma, (3) late-onset nonallergic eosinophilic asthma, and (4) late-onset nonallergic noneosinophilic asthma. Subgroups of these phenotypes also exist but have not been as consistently identified. Advances in our understanding of the diverse immunologic perturbations that drive airway inflammation are consistent with clinical traits associated with these phenotypes and their response to biologic therapies. This has improved the clinician's approach to characterizing asthmatic patients in the clinic. Being able to define asthma endotypes using clinical characteristics and biomarkers will move physicians toward even more personalized management of asthma and precision-based care in the future. Here we will review the most prominent phenotypes and immunologic advances that suggest these disease subtypes represent asthma endotypes.

Efficacy of immunoglobulin replacement therapy and azithromycin in severe asthma with antibody deficiency

BACKGROUND

Although antibody deficiency (AD) is a well-known cause of recurrent respiratory infections, there are few data on its impact in adults with asthma. The objective of the present study was to assess outcomes in adults with severe asthma and AD after treatment with either azithromycin or subcutaneous immunoglobulins (SCIg).

METHODS

We performed a 5-year, prospective, observational, two-centre study of adults with severe asthma and AD in France. Bronchiectasis was ruled out by high-resolution computed tomography. Patients were treated for one year with either azithromycin (250 mg every other day) or SCIg (0.4-0.6 g/kg/months, weekly). All patients were evaluated for exacerbations, asthma control and lung function at baseline and then one year after treatment initiation.

RESULTS

Thirty-nine patients with severe asthma were included in the study: 14 had been treated with azithromycin and 25 had been treated with SCIg. Before the initiation of treatment for AD, all patients had an Asthma Control Questionnaire (ACQ-7) score > 1.5 (mean ± SD: 2.71 ± 0.53) despite treatment at GINA step 4 or 5, and had a high exacerbation rate requiring oral corticosteroids and/or rescue antibiotics (∼7.2 ± 2.1/patient/year). One year after treatment initiation, we observed a significantly higher FEV1 (mean: 0.18 ± 0.22 L) and ACQ-7 score (1.26 ± 0.68), and a significantly lower exacerbation rate (1.63 ± 1.24/patient/year).

CONCLUSIONS

Treatment of AD dramatically improved asthma outcomes - suggesting that adults with severe asthma and recurrent respiratory infections should be screened and (if appropriate) treated for AD.

Six gene and TH2 signature expression in endobronchial biopsies of participants with asthma

BACKGROUND

Both the six gene signature (6GS: CPA3, DNASE1L3, CLC, IL1B, ALPL, and CXCR2) and T-helper 2 signature (TH2S: CLCA1, SERPINB2, and POSTN) are proposed as biomarkers in the identification of inflammatory phenotypes of asthma in induced sputum and epithelial brushings, respectively. The aim of this study was to explore patterns of gene expression of known signatures, 6GS and TH2S in endobronchial biopsies.

METHODS

This was an exploratory cross-sectional study of gene expression in endobronchial biopsies of 55 adults with asthma and 9 healthy controls (HC). The expression of the 6GS and TH2S was determined by quantitative polymerase chain reaction. Correlations with clinical and cellular characteristics were performed, and receiver operating characteristic was utilized to assess signatures' ability to predict asthma from HC and inflammatory phenotypes.

RESULTS

Gene expression of DNASE1L3 (P = .045) was upregulated in asthma compared with HC, and IL1B (P = .017) was upregulated in neutrophilic asthma compared with non-neutrophilic asthma. In asthma, the expression of CPA3 was negatively associated with ICS daily dose (r = -.339; P = .011), IL1B expression was positively associated with bronchial lavage fluid (BLF) total cell count (r = .340; P = .013) and both CLC and POSTN expression were associated with lymphocytes percentage in BLF (r = -.355, P = .009; r = -.300, P = .025, respectively). Both 6GS (area under curve [AUC] = 86.3%; P = .017) and TH2S (AUC = 72.7%; P = .037) could significantly predict asthma from HC. In addition, 6GS can identify neutrophilic (AUC = 93.2%; P = .005) and TH2S identifies eosinophilic (AUC = 62.7%; P = .033) asthma.

CONCLUSIONS AND CLINICAL RELEVANCE

There was increased expression of DNASE1L3 in asthma and IL1B in neutrophilic asthma. These results show similar upregulated patterns of expression in two genes of the 6GS in endobronchial biopsies, previously identified in sputum. The upregulation of DNASE1L3 and IL1B suggests that common mechanisms may be at play throughout the airway.

Inhibition of airway remodeling and inflammatory response by Icariin in asthma

BACKGROUND

Icariin (ICA) is the major active ingredient extracted from Chinese herbal medicine Epimedium, which has the effects of improving cardiovascular function, inducing tumor cell differentiation and increasing bone formation. It is still rarely reported that ICA can exert its therapeutic potential in asthma via anti-airway remodeling. The point of the study was to estimate the role of ICA in anti-. airway remodeling and its possible mechanism of action in a mouse ovalbumin. (OVA)-induced asthma model.

METHODS

Hematoxylin and Eosin Staining were performed for measuring airway remodeling related indicators. ELISA, Western blot and Immunohistochemistr-. y (IHC) were used for analyzing the level of protein. RT-PCR was used for analyzing the level of mRNA.

RESULTS

On days 1 and 8, mice were sensitized to OVA by intraperitoneal injection. From day 16 to day 43, previously sensitized mice were exposed to OVA once daily by nebulizer. Interventions were performed orally with ICA (ICA low, medium and high dose groups) or dexamethasone 1 h prior to each OVA exposure. ICA improves pulmonary function, attenuates pulmonary inflammation and airway remodeling in mice exposed to OVA. Histological and Western blot analysis of the lungs show that ICA suppressed transforming growth factor beta 1 and vascular endothelial growth factor expression. Increase in interleukin 13 and endothelin-1 in serum and bronchoalveolar lavage fluid in OVA-induced asthmatic mice are also decreased by ICA. ICA attenuates airway smooth muscle cell proliferation, as well as key factors in the MAPK/Erk pathway.

CONCLUSIONS

The fact that ICA can alleviate OVA-induced asthma at least partly through inhibition of ASMC proliferation via MAPK/Erk pathway provides a solid theoretical basis for ICA as a replacement therapy for asthma. These data reveal the underlying reasons of the use of ICA-rich herbs in Traditional Chinese Medicine to achieve good results in treating asthma.

Asthma

This review provides an evidence-based guide for the diagnosis, evaluation, and treatment of patients with asthma. It addresses typical questions that arise in the clinic-based care of patients with asthma and provides a basic and comprehensive resource for asthma care.

The Effects of Obesity in Asthma

PURPOSE OF REVIEW

Rising costs and increasing morbidity makes the identification and treatment of high-risk asthma phenotypes important. In this review, we outline the complex relationship between obesity and asthma.

RECENT FINDINGS

Studies have confirmed a bi-directional relationship between obesity and asthma. Pathophysiological factors implicated include genetic risk, the effect of diet and microbiome, and obesity-related cytokines. There have been robust, albeit derived, efforts to phenotype this group with distinct clinical presentations based on age of onset of asthma. Unfortunately, the poor performance of biomarkers and traditional lung function testing has impeded diagnosis, phenotyping, and management of the obese asthma patient. There is also a lack of targeted interventions with weight loss showing some benefits. Obesity increases the prevalence of asthma and is associated with worse outcomes. There are unique research and clinical challenges while managing this group of patients.

Severe T2-high asthma in the biologics era: European experts' opinion

The European Respiratory Biologics Forum gathered participants from 21 countries in Madrid, Spain, to discuss the management and treatment of severe asthma in the era of biologics. The current insights on the pathophysiology of severe asthma were discussed, as well as the role of respiratory biologics in clinical practice and strategies for eliminating chronic use of oral corticosteroids. The participants also highlighted the key challenges in identifying patients with severe asthma based on phenotypes, biomarkers and treatable traits, and the existing problems in patient referral to specialist care. The monitoring of treatment was debated and the need for a change towards precision medicine and personalised care was emphasised throughout the meeting. This review provides a summary of the discussions and highlights important concerns identified by the participants regarding the current management of severe asthma.

Phenotypes/endotypes-driven treatment in asthma

PURPOSE OF REVIEW

Target therapy is the necessary step towards personalized medicine. The definition of asthma phenotypes and underlying mechanisms (endotypes) represent a key point in the development of new asthma treatments. Big data analysis, biomarker research and the availability of monoclonal antibodies, targeting specific cytokines is leading to the rapid evolution of knowledge. In this review, we sought to outline many of the recent advances in the field.

RECENT FINDINGS

Several attempts have been made to identify asthma phenotypes, sometimes with contrasting results. More success has been obtained concerning the pathogenetic mechanism of specific asthma patterns with the consequent identification of biomarkers and development of effective ad hoc treatment.

SUMMARY

We are in the middle of an extraordinary revolution of our mode of thinking about and approaching asthma. All the effort in the identification of clusters of patients with different disease clinical patterns, prognosis and response to treatment is closely linked to the identification of endotypes (Th2-low and Th2-high). This approach has allowed the development of the specific treatments (anti IgE, Anti IL5 and IL5R) that are now available and is leading to new ones.

Biomarkers and asthma management: analysis and potential applications

PURPOSE OF REVIEW

Asthma features a high degree of heterogeneity in both pathophysiology and therapeutic response, resulting in many asthma patients being treated inadequately. Biomarkers indicative of underlying pathological processes could be used to identify disease subtypes, determine prognosis and to predict or monitor treatment response. However, the newly identified as well as more established biomarkers have different applications and limitations.

RECENT FINDINGS

Conventional markers for type 2-high asthma, such as blood eosinophils, fraction of exhaled nitric oxide, serum IgE and periostin, feature limited sensitivity and specificity despite their significant correlations. More distinctive models have been developed by combining biomarkers and/or using omics techniques. Recently, a model with a positive predictive value of 100% for identification of type 2-high asthma based on a combination of minimally invasive biomarkers was developed.

SUMMARY

Individualisation of asthma treatment regimens on the basis of biomarkers is necessary to improve asthma control. However, the suboptimal properties of currently available conventional biomarkers limit its clinical utility. Newly identified biomarkers and models based on combinations and/or omics analysis must be validated and standardised before they can be routinely applied in clinical practice. The development of robust biomarkers will allow development of more efficacious precision medicine-based treatment approaches for asthma.

Severe asthma in children: Evaluation and management

Severe asthma in children is associated with significant morbidity. Children with severe asthma are at increased risk for adverse outcomes including medication-related side effects, life-threatening exacerbations, and impaired quality of life. It is important to differentiate between severe therapy resistant asthma and difficult-to-treat asthma due to comorbidities. The most common problems that need to be excluded before a diagnosis of severe asthma can be made are poor medication adherence, poor medication technique or incorrect diagnosis of asthma. Difficult to treat asthma is a much more common reason for persistent symptoms and exacerbations and can be managed if comorbidities are clearly addressed. Children with persistent symptoms and exacerbations despite correct inhaler technique and good medical adherence to standard Step 4 asthma therapies according to the guidelines^1,2, should be referred to an asthma specialist with expertise in severe asthma.

Mouse models of severe asthma for evaluation of therapeutic cytokine targeting

Severe asthma is a heterogeneous inflammatory disease of the airways, which requires treatment with high-dose inhaled corticosteroids or their systemic administration, yet often remains uncontrolled despite this therapy. Over the past decades, research efforts into phenotyping of severe asthma and defining the pathological mechanisms of this disease were successful largely due to the development of appropriate animal models. Recent identification of distinct inflammatory patterns of severe asthma endotypes led to novel treatment approaches, including targeting specific cytokines or their receptors with neutralizing antibodies. Here we discuss how different experimental mouse models contributed to generation of clinically relevant findings concerning pathogenesis of severe asthma and to identification of potential targets for biologic therapy.

Phenotypes of Recurrent Wheezing in Preschool Children: Identification by Latent Class Analysis and Utility in Prediction of Future Exacerbation

BACKGROUND

Recurrent preschool wheezing is a heterogeneous disorder with significant morbidity, yet little is known about phenotypic determinants and their impact on clinical outcomes.

OBJECTIVE

Latent class analysis (LCA) was used to identify latent classes of recurrent preschool wheeze and their association with future exacerbations and inhaled corticosteroid (ICS) treatment response.

METHODS

Data from 5 clinical trials of 1708 children aged 12 to 71 months with recurrent wheezing were merged. LCA was performed on 10 demographic, exposure, and sensitization variables to determine the optimal number of latent classes. The primary outcome was the annualized rate of wheezing exacerbations requiring systemic corticosteroids during the study intervention period; the secondary outcome was the time to first exacerbation. Exploratory analyses examined the effect of daily ICS treatment on exacerbation outcomes.

RESULTS

Four latent classes of recurrent wheezing were identified; these were not distinguished by current symptoms or historical exacerbations but differed with regard to allergen sensitization and/or exposures. Annualized exacerbation rates (mean ± SEM/year) were 0.65 ± 0.06 for class 1 ("minimal sensitization"), 0.93 ± 0.10 for class 2 ("sensitization with indoor pet exposure"), 0.60 ± 0.07 for class 3 ("sensitization with tobacco smoke exposure"), and 0.81 ± 0.10 for class 4 ("multiple sensitization and eczema") (P < .001). In a research setting of high adherence, daily ICS treatment improved exacerbation rates in classes 2 and 4 but not the other groups.

CONCLUSIONS

Sensitization and exposure assessments are useful in the prediction of future exacerbation and may identify children most likely to respond favorably to daily ICS treatment.

Children with Neutrophil-Predominant Severe Asthma Have Proinflammatory Neutrophils With Enhanced Survival and Impaired Clearance

BACKGROUND

Airway neutrophils are abundant in some children with severe asthma, but their functions are poorly understood.

OBJECTIVE

To characterize that the inflammatory airway environment of children with neutrophil-predominant severe asthma promotes neutrophil survival and disrupts neutrophil-associated innate immune defenses.

METHODS

Sixty-seven children with severe asthma refractory to high-dose inhaled corticosteroid treatment undergoing bronchoscopy with bronchoalveolar lavage (BAL) for clinical indications were stratified into neutrophil "high" versus "low" groups on the basis of BAL differential counts. Neutrophil activation markers, functional assays, and phenotyping studies were performed, as well as airway macrophage functional assays. Results were compared with those from children with moderate asthma treated with inhaled corticosteroids.

RESULTS

Children with neutrophil-predominant severe asthma had increased markers of neutrophil activation/degranulation and a greater magnitude of airway proinflammatory cytokine and chemokine release. Primary neutrophils exposed to BAL of these children exhibited greater phagocytic capability and greater neutrophil extracellular trap formation, but a more impaired respiratory burst. Despite greater abundance of airway TGF-β1, the neutrophils were not more apoptotic. Instead, neutrophils had a highly proinflammatory phenotype associated with a number of surface markers that regulate neutrophil activation, recruitment/migration, and granule release. Airway macrophages from children with neutrophil-predominant severe asthma were also more proinflammatory with impaired phagocytosis and increased apoptosis.

CONCLUSIONS

Children with neutrophil-predominant severe asthma have proinflammatory neutrophils with enhanced survival. Airway macrophages are also proinflammatory and dysfunctional and may contribute to global innate immune impairment. Therapies that target neutrophils and related inflammation may be warranted in this subset of children.

Controversies and opportunities in severe asthma

PURPOSE OF REVIEW

Despite currently available treatments, many asthma patients remain inadequately controlled, but identifying distinct patient populations (phenotypes/endotypes) may optimize their management. This review discusses some of the controversies and opportunities for improved disease control in severe asthma.

RECENT FINDINGS

Currently approved anti-immunoglobulin E and anti-interleukin 5 biologics, which target specific pathways instead of using a 'one size fits all' strategy, are efficacious and well tolerated therapies for severe asthma. The appropriate use of these biologics, and of those in development (e.g., benralizumab and dupilumab), should be aided by further understanding of asthma phenotypes and endotypes, utilizing appropriate biomarkers.Oral corticosteroids are often added as maintenance therapy for patients with severe uncontrolled asthma, but their use is associated with significant adverse effects and should be considered a last option. The true cost of this therapy, including the cost of morbidities associated with its use, remains to be determined.Severe asthma in pediatrics poses a unique opportunity for possible prevention strategies and the potential for primary prevention. Although several avenues for primary prevention are being explored and are out of the scope of this review, we focus our discussion on the use of omalizumab, which has been recently explored in clinical trials.

SUMMARY

Appropriate use of biologics in severe asthma should be supported by further understanding of biomarkers predicting response to targeted therapy. Because of their association with significant adverse effects, add-on oral corticosteroids should be considered a last treatment option for patients with uncontrolled severe asthma. Finally, severe asthma in pediatrics poses a unique opportunity for potential prevention strategies.

Very Poorly Controlled Asthma in Urban Minority Children: Lessons Learned

BACKGROUND

Very poorly controlled (VPC) asthma in children is associated with ongoing acute exacerbations but factors associated with VPC are understudied.

OBJECTIVE

To examine the risk factors associated with VPC asthma in urban minority children.

METHODS

This descriptive study examined asthma control levels (well-controlled [WC], not well-controlled [NWC], and VPC) at baseline and 6 months in children participating in an ongoing randomized controlled trial of an emergency department/home environmental control intervention. Data collection occurred during the index emergency department visit and included allergen-specific IgE and salivary cotinine testing and caregiver interview of sociodemographic and child health characteristics. Follow-up data were collected at 6 months. Unadjusted analyses examined the association of sociodemographic and health characteristics by level of asthma control. Multivariate analysis tested significant factors associated with VPC asthma at 6 months.

RESULTS

At baseline most children were categorized with VPC asthma (WC, 0%; NWC, 47%; VPC, 53%) and rates of VPC minimally improved at 6 months (WC, 13%; NWC, 41%; VPC, 46%). Risk for VPC asthma was twice as likely in children with allergic rhinitis (odds ratio [OR], 2.42), having 2 or more primary care provider asthma visits within the past 3 months (OR, 2.77), or caregiver worry about medication side effects (OR, 2.13) and 3 to 4 times more likely when asthma control was assessed during the fall or spring season (OR: fall, 3.32; spring, 4.14).

CONCLUSIONS

Improving asthma control in low-income, high-risk children with VPC asthma requires treatment of comorbidities, attention to caregiver medication beliefs, and adept use of stepwise therapy.

Severe Asthma Phenotypes - How Should They Guide Evaluation and Treatment?

Although patients with "severe" asthma tend to be characterized by ongoing symptoms and airway inflammation despite treatment with high doses of inhaled and systemic corticosteroids, there is increasing recognition of marked phenotypic heterogeneity within affected patients. Although "precision medicine" approaches for patients with severe asthma are needed, there are many hurdles that must be overcome in daily practice. The National Heart, Lung and Blood Institute's Severe Asthma Research Program (SARP) has been at the forefront of phenotype discovery in severe asthma for the past decade. SARP, along with other international groups, has described clinical severe asthma phenotypes in both adults and children that can be evaluated in the clinical setting. Although these clinical phenotypes provide a good "starting point" for addressing disease heterogeneity in severe asthma in everyday practice, more efforts are needed to understand how these phenotypes relate to underlying disease mechanisms and pharmacological treatment responses. This review highlights the clinical asthma phenotypes identified to date, their associations with underlying endotypes and potential biomarkers, and remaining knowledge gaps that must be addressed before precision medicine can become a reality for patients with severe asthma.

Attenuation of nociceptive pain and inflammatory disorders by total steroid and terpenoid fraction of Euphorbia tirucalli Linn root in experimental in vitro and in vivo model

The plant Euphorbia tirucalli Linn has been successfully used as a tribal folk medicine in India and Africa for the management of acute inflammatory, arthritic, nociceptive pain and asthmatic symptoms. The present study was conducted to assess the anti-inflammatory, analgesic, anti-asthmatic and anti-arthritic role of the total steroid and terpenoid rich fractions of the hydro-alcoholic extract of E. tirucalli root (STF-HAETR). STF-HAETR fraction demonstrated 71.25 ± 2.5 and 74.25 ± 5.1% protection against acetic acid-induced pain and central neuropathic pain at 75 and 100 mg/kg doses, respectively. It showed 96.97% protection against acute inflammation at 100 mg/kg with 1.6-fold better activity than the standard drug. The fraction exhibited such efficacy via inhibition of proinflammatory cytokines TNF-α, IFN-γ, by 61.12 and 65.18%, respectively, at 100 μg/mL. Inhibition of cyclooxygenase and Nitric oxide synthase in a dose-dependent manner affirms its analgesic and anti-inflammatory activity. The spectrophotometric analysis reveals that STF-HAETR induces ameliorative effect against heat-induced denaturation of Bovine serum albumin (BSA) and exhibits significant anti-proteinase activity. The plant fraction also demonstrated anti-asthmatic activity by displaying 62.45% protection against histamine induced bronchoconstriction or dyspnoea. Our findings suggest that STF-HAETR could be an effective safe therapeutic agent to treat nociceptive pain, acute inflammation, asthma, and arthritis which may authenticate its traditional use.

Comparing effectiveness and outcomes in asthma and cystic fibrosis

As technology yields new treatments, pediatric pulmonologists need determine how best to use them and how to decide which ones are best for any specific group or individual patient. Physicians have always customized therapies based upon patient response, but the new concept of "Personalized (or precision) medicine" focuses attention to a greater degree on the individual needs of patients based on their genetic, biomarker, phenotypic, or psychosocial characteristics. The newly developed biologics for treatment of asthma and CFTR modulators for treatment of cystic fibrosis (CF) highlight this newer approach. As we have more treatments available, new approaches to testing efficacy and effectiveness of these new therapies is necessary in order to efficiently bring them to market and compare their benefits in real world practice. While comparative effectiveness can be tested in pragmatic clinic trials, the most common approaches make use of observational data such as administrative databases and patient registries but their use for this is fraught with pitfalls that may or may not be methodologically surmountable. Once new therapies have been shown to be efficacious and effective, it is important to be cognizant of methods for ensuring that all patients actually receive the treatments that will be best for them. Comparisons of the effectiveness of clinical practice in the form of benchmarking is helpful for this, and consideration of costs and cost-effectiveness is essential to judging the best treatment for patients in a real-world setting.