The role of IgE-receptors in IgE-dependent airway smooth muscle cell remodelling

The Incredible Adventure of Omalizumab

The basis of our current understanding of allergies begins with the discovery of IgE in the mid-1960s. The whole theory of the physiology and pathophysiology of allergic diseases, including rhinitis and asthma, dates from that period. Among the key regions of IgE identified were the FAB (fragment antigen binding) portion that has the ability to capture allergens, and the Cε3 domain, through which IgE binds to its membrane receptor. It was then postulated that blocking IgE at the level of the Cε3 domain would prevent it from binding to its receptor and thus set in motion the allergic cascade. This was the beginning of the development of omalizumab, a monoclonal antibody with an anti-IgE effect. In this article, we review the pathophysiology of allergic disease and trace the clinical development of omalizumab. We also review the benefits of omalizumab treatment that are apparently unrelated to allergies, such as its effect on immunity and bronchial remodeling.

Omalizumab in Severe Asthma: Effect on Oral Corticosteroid Exposure and Remodeling. A Randomized Open-Label Parallel Study

INTRODUCTION

Data on the clinical efficacy and remodeling of omalizumab therapy in patients on oral corticosteroids (OC) are limited.

OBJECTIVE

The purpose of the study is to show that in patients with corticosteroid-dependent asthma, omalizumab is a corticosteroid-sparing therapy able to inhibit airway remodeling and to reduce disease burden (lung function impairment, exacerbations).

METHODS

This study is a randomised open-label study evaluating the addition of omalizumab to the standard of care in patients with severe asthma receiving oral corticosteroids. The primary endpoint was represented by the change in OC monthly dose by the end of treatment and secondary endpoints included spirometry changes, airway inflammation (FeNO), number of exacerbations and airways remodelling assessed by bronchial biopsies studied by transmission electron microscopy. As a safety variable, adverse effects were recorded.

RESULTS

Efficacy was assessed for 16 patients in the omalizumab group and 13 in the control group. The final cumulative mean monthly OC doses were 34.7 mg and 217 mg for the omalizumab and control group, respectively; the mean difference between groups adjusted for baseline was -148.1 [95% confidence interval (CI) -243.6, -52.5; p = 0.004]. OC withdrawal of 75% versus 7.7% (p = 0.001) was observed in the omalizumab and control group, respectively. Omalizumab provided a slowing of forced expiratory volume in one second (FEV₁) loss (70 mL versus 260 mL), a significant decrease in FeNO values and a reduction in the annual relative risk of clinically significant exacerbations of 54%. The treatment was well tolerated. The morphological study showed a significant decrease in basement membrane thickness in the omalizumab group (6.7 µm versus 4.6 µm) compared with controls (6.9 µm versus 7 µm) [mean difference between groups adjusted for baseline was -2.4 (95% CI -3.7, -1.2; p < 0.001], as well as a decrease in intercellular spaces (1.18 µm versus 0.62 µm and 1.21 µm versus 1.20 µm, p = 0.011, respectively). A qualitative improvement was also observed in the treated group.

CONCLUSIONS

Omalizumab showed a marked OC-sparing capacity and was associated with an improvement in clinical management that correlated with bronchial epithelial repair. In OC-dependent asthma, reversibility of remodelling is possible; the concepts that basement membrane enlargement is detrimental and that chronic airway obstruction is systematically irreversible are outdated (EudraCT: 2009-010914-31).

Pulmonary aspergillus infection with abnormal imaging successfully treated with omalizumab: A case report

BACKGROUND

Pulmonary aspergillosis is a pulmonary infectious disease that is clinically difficult to diagnose and treat. When the lower respiratory tract is invaded by Aspergillus, the clinical manifestations and imaging features vary among patients with different immune states. The use of antifungal drugs and glucocorticoids are important, but some patients do not respond satisfactorily to treatment.

CASE PRESENTATION

A 59-year-old female had a long history of asthma and poor symptom control, with long-term use of long-acting inhaled glucocorticoids combined with a long-acting β2 receptor agonists (ICS + LABA) (salmeterol fluticasone inhalation powder). The ground glass shadow, tree-in-bud sign, and bronchiectasis in the middle lobe of the right lung and the lower lobe of both lungs were first detected by chest CT over 5 years ago. Atelectasis in the middle lobe of the right lung was detected over 3 years ago. Over 2 years ago, the patient was hospitalized and a repeat chest CT showed persistent atelectasis in the middle lobe of the right lung, and more lesions in bilateral lower lungs than before. Aspergillus fumigatus was detected in alveolar lavage fluid and sputum pathogenic culture, which confirmed the diagnosis of pulmonary aspergillosis. After treatment with voriconazole and amphotericin B, the middle lobe of the right lung partially reopened, but the lesions in bilateral lower lungs persisted. After 21 weeks of treatment, the antifungal drugs were stopped because the patient refused to use oral/intravenous glucocorticoids, and omalizumab was finally chosen for treatment. After 1 month of treatment, the patient's clinical symptoms began to ease. After 1 year of treatment, imaging reexamination of lung showed that the lesions were completely cleared, accompanied by significant improvement in nutritional status and airway function.

CONCLUSIONS

We reported the case of a patient with pulmonary Aspergillus infection who was treated with omalizumab and showed significant improvement in clinical symptoms and imaging abnormalities, which provides a new option for patients with pulmonary Aspergillus infection who show unsatisfactory response with first-line drugs.

Development of Adaptive Immunity and Its Role in Lung Remodeling

Asthma is characterized by airflow limitations resulting from bronchial closure, which can be either reversible or fixed due to changes in airway tissue composition and structure, also known as remodeling. Airway remodeling is defined as increased presence of mucins-producing epithelial cells, increased thickness of airway smooth muscle cells, angiogenesis, increased number and activation state of fibroblasts, and extracellular matrix (ECM) deposition. Airway inflammation is believed to be the main cause of the development of airway remodeling in asthma. In this chapter, we will review the development of the adaptive immune response and the impact of its mediators and cells on the elements defining airway remodeling in asthma.

Advances and Challenges of Antibody Therapeutics for Severe Bronchial Asthma

Asthma is a disease that consists of three main components: airway inflammation, airway hyperresponsiveness, and airway remodeling. Persistent airway inflammation leads to the destruction and degeneration of normal airway tissues, resulting in thickening of the airway wall, decreased reversibility, and increased airway hyperresponsiveness. The progression of irreversible airway narrowing and the associated increase in airway hyperresponsiveness are major factors in severe asthma. This has led to the identification of effective pharmacological targets and the recognition of several biomarkers that enable a more personalized approach to asthma. However, the efficacies of current antibody therapeutics and biomarkers are still unsatisfactory in clinical practice. The establishment of an ideal phenotype classification that will predict the response of antibody treatment is urgently needed. Here, we review recent advancements in antibody therapeutics and novel findings related to the disease process for severe asthma.

The Impact of Monoclonal Antibodies on Airway Smooth Muscle Contractility in Asthma: A Systematic Review

Airway hyperresponsiveness (AHR) represents a central pathophysiological hallmark of asthma, with airway smooth muscle (ASM) being the effector tissue implicated in the onset of AHR. ASM also exerts pro-inflammatory and immunomodulatory actions, by secreting a wide range of cytokines and chemokines. In asthma pathogenesis, the overexpression of several type 2 inflammatory mediators including IgE, IL-4, IL-5, IL-13, and TSLP has been associated with ASM hyperreactivity, all of which can be targeted by humanized monoclonal antibodies (mAbs). Therefore, the aim of this review was to systematically assess evidence across the literature on mAbs for the treatment of asthma with respect to their impact on the ASM contractile tone. Omalizumab, mepolizumab, benralizumab, dupilumab, and tezepelumab were found to be effective in modulating the contractility of the ASM and preventing the AHR, but no available studies concerning the impact of reslizumab on the ASM were identified from the literature search. Omalizumab, dupilumab, and tezepelumab can directly modulate the ASM in asthma, by specifically blocking the interaction between IgE, IL-4, and TSLP, and their receptors are located on the surface of ASM cells. Conversely, mepolizumab and benralizumab have prevalently indirect impacts against AHR by targeting eosinophils and other immunomodulatory effector cells promoting inflammatory processes. AHR has been suggested as the main treatable trait towards precision medicine in patients suffering from eosinophilic asthma, therefore, well-designed head-to-head trials are needed to compare the efficacy of those mAbs that directly target ASM contractility specifically against the AHR in severe asthma, namely omalizumab, dupilumab, and tezepelumab.

The Role of Atopy in COPD and Asthma

Common to several allergic diseases is the generation of immunoglobulin E (IgE) by plasma cells, when exposed to an innocuous antigen. Asthma and chronic obstructive pulmonary disease (COPD) are two prevalent chronic airway inflammatory diseases. Asthma is mediated in some patients through eosinophilic inflammatory mechanisms that include allergic sensitization and Th2-mediated immune airway response. COPD, on the other hand is mainly considered a Th1-mediated inflammatory process with neutrophilic predominance or a non-Th2 inflammation, occasionally associated with the presence of airway bacteria or viruses. IgE production appears to play an important role in the development of both COPD and asthma, as it has been associated to respiratory symptoms, lung function, bacterial and viral infections, airway remodeling and bronchial hyperreactivity in both diseases. The aim of this review is to summarize all current data concerning the role of specific and total IgE in COPD and asthma and to highlight similarities and differences in view of possible therapeutic interventions.

Anti-IgE therapy inhibits chemotaxis, proliferation and transformation of circulating fibrocytes in patients with severe allergic asthma

BACKGROUND AND OBJECTIVE

Circulating fibrocytes act as precursors of myofibroblasts, contribute to airway remodelling in chronic asthma and migrate to injured tissues by expressing CXCR4 and CCR7. Anti-IgE therapy improves severe allergic asthma (SAA) control and airway remodelling in T2-high SAA. The effects of anti-IgE therapy on fibrocyte activities were investigated in this study.

METHODS

The expression of CCR7, CXCR4, ST2 and α-SMA (α-smooth muscle actin) in both circulating and cultured fibrocytes from all patients with asthma was measured, and was repeated after omalizumab treatment in SAA. Fibrocytes recruitment, proliferation and transformation were also measured in response to anti-IgE therapy.

RESULTS

Omalizumab effectively improved asthma control and pulmonary function in T2-high SAA, associated with a decline in serum levels of IL-33 and IL-13. Omalizumab down-regulates CXCR4 and CCR7 expression of fibrocytes, which could suppress fibrocyte recruitment into the lungs. Omalizumab also suppressed the increased number of fibrocytes and α-SMA⁺ fibrocytes within the cultured non-adherent non-T (NANT) cells after 3-7 days of culture. The decrease in serum levels of IL-33 by omalizumab contributed to the effectiveness in inhibiting fibrocyte recruitment, proliferation and myofibroblast transformation through IL-33/ST2 axis. The elevated IL-13 expression in SAA patients potentiated the effects of IL-33 by increasing ST2 expression.

CONCLUSION

Omalizumab reduced the number of circulating fibrocytes, cell and number of fibrocytes as well as α-SMA⁺ fibrocytes after 3-7 days of culture in SAA patients. IL-33 and IL-13 may be implicated in the effectiveness of omalizumab in inhibiting fibrocyte activation contributing partly to the clinical benefits in reducing lamina propria and basement membrane thickening.

Evolution of our view on the IgE molecule role in bronchial asthma and the clinical effect of its modulation by omalizumab: Where do we stand today?

Bronchial asthma is a heterogeneous disease whose definition and treatment are based on evidence of variable airway obstruction and airway inflammation. Despite the enormous increase in the amount of information on the pathogenesis of this disease, diagnosis is still an unresolved problem, as we still lack sensitive and specific biomarkers. On the other hand, at the turn of the 20th and 21st century, there was a rapid development of therapeutic modalities based on the principle of biological therapy. The first authorized drug matching these characteristics was omalizumab – a monoclonal antibody directed against immunoglobulin E (IgE). It has been used for the treatment of severe forms of bronchial asthma for more than 15 years, which is a sufficient time to acquire ways of its effective use and to assess whether the treatment with omalizumab has met our expectations. However, we continue to discover new and surprising facts about the effects of omalizumab treatment which leads to widening of therapeutic indications. In this work, a basic overview of the very complex role of the IgE molecule in the organism (with a special emphasis on allergic asthma) is discussed, and the most important practical and clinical consequences resulting from its modulation by targeted therapy with omalizumab are summarized.

Serum-free immunoglobulin E: A useful biomarker of atopy and type 2 asthma in adults with asthma

BACKGROUND

It has been known that a high serum total immunoglobulin E (IgE) level is a predisposing factor of allergic asthma; however, there are considerable limitations to apply it in clinical practice.

OBJECTIVE

To determine the clinical significance of the serum-free IgE level in patients with adult asthma.

METHODS

We measured free IgE levels using our homemade enzyme-linked immunosorbent assay by applying a novel IgE TRAP protein (GI innovation, Seoul, Republic of Korea) in sera of adults with asthma (n = 116) compared with healthy controls (n = 32); enzyme-linked immunosorbent assay inhibition test was performed to validate its binding specificity. Associations between asthma-related clinical and laboratory parameters were analyzed. The diagnostic value and cutoff point for detecting atopy and type 2 asthma were determined using receiver operating characteristic curve analysis.

RESULTS

The serum-free IgE levels were significantly higher in adults with asthma than in healthy controls and were significantly associated with atopic status and type 2 asthma (all P < .001). In the receiver operating characteristic analysis, serum-free IgE had a significantly greater area under the curve (AUC) than serum total IgE for assessing asthma, especially type 2 asthma (AUC, 0.810 vs 0.743; P = .006 and AUC, 0.729 vs 0.572; P < .001). The optimal cutoff points for predicting atopy and type 2 asthma were 82.8 and 120.8 ng/mL, respectively.

CONCLUSION

It is suggested that a higher serum-free IgE level may be a useful biomarker of atopy and type 2 asthma in adults with asthma.

Immunologic Pathophysiology and Airway Remodeling Mechanism in Severe Asthma: Focused on IgE-Mediated Pathways

Despite the expansion of the understanding in asthma pathophysiology and the continual advances in disease management, a small subgroup of patients remains partially controlled or refractory to standard treatments. Upon the identification of immunoglobulin E (IgE) and other inflammatory mediators, investigations and developments of targeted agents have thrived. Omalizumab is a humanized monoclonal antibody that specifically targets the circulating IgE, which in turn impedes and reduces subsequent releases of the proinflammatory mediators. In the past decade, omalizumab has been proven to be efficacious and well-tolerated in the treatment of moderate-to-severe asthma in both trials and real-life studies, most notably in reducing exacerbation rates and corticosteroid use. While growing evidence has demonstrated that omalizumab may be potentially beneficial in treating other allergic diseases, its indication remains confined to treating severe allergic asthma and chronic idiopathic urticaria. Future efforts may be bestowed on determining the optimal length of omalizumab treatment, seeking biomarkers that could better predict treatment response and as well as extending its indications.

[Phenotypes of bronchial asthma during the health resort period and personalized programs of medical rehabilitation]

INTRODUCTION

Bronchial asthma (BA) is a relevant social and medical problem in our country and around the world. Currently, phenotypes of the disease are distinguished. One of the original decisions in phenotypes distinguishing is the use of cluster analysis. However, the concept of BA phenotypes at the health resort period of rehabilitation has not yet been formed.

AIM

To determine the BA phenotypes upon admission of patients to a health resort medical rehabilitation (HRMR) using cluster analysis and to offer personalized rehabilitation programs.

MATERIAL AND METHODS

518 patients with asthma who underwent HRMR on the southern coast of Crimea were examined. Each patient received clinical, functional and laboratory examination. HRMR included correction of long-term treatment according to the severity of asthma, climate therapy, respiratory therapy, educational programs, and physiotherapeutic procedures. We applied cluster analysis in order to identify BA phenotypes. Description statistics methods were used for phenotype-cluster characterization, comparative analysis - for determination of reliable phenotypic characteristics and relation of the effectiveness of HRMR and phenotypes.

RESULTS

A model of three phenotype-clusters was developed. The first cluster included patients with BA of moderate severity, uncontrolled course, frequent exacerbations, history of atopy, a tendency to obesity, moderately reduced external respiration function, fixed airway obstruction, high adherence to long-term therapy with medium doses of inhaled glucocorticoids (ICS) combined with long-acting β-2 agonists (LABA). Cluster 2 included patients with mild asthma, controlled or partially controlled course of the disease, with rare short exacerbations, late onset, preserved external respiration function and exercise tolerance, but low adherence to long-term therapy with medium and low doses of ICS. Cluster 3 included patients with moderate to severe BA, uncontrolled course, with early onset, frequent and prolonged exacerbations, severe symptoms, significantly reduced external respiration function with fixed obstruction, decreased exercise tolerance, but low adherence to long-term therapy (4th stage) with high doses of ICS in combination with LABA and long-acting anticholinergics. A close relationship was found between phenotypes-clusters and the achieved effects: a significant increase in the control of BA and a high efficiency of rehabilitation in patients of the 1st and especially 3rd clusters and low in the 2nd cluster. The optimal rehabilitation programs for each of the selected cluster phenotypes were determined.

CONCLUSION

The cluster model developed with the help of artificial intelligence has demonstrated high prognostic value in the determination of the effectiveness and change of control over the course of asthma as a result of HRMR. Personalized HRMR programs are suggested.

Pediatric use of omalizumab for allergic asthma

INTRODUCTION

Severe pediatric asthma is associated with significant morbidity as well as with a high economic burden. It represents a heterogeneous disease with multiple clinical phenotypes. Currently, physicians are facing the challenge to provide a 'personalized medicine approach', which is tailored to the diverse pathomechanisms underlying clinical presentations. Three main endotypes of airway inflammation have been described in children with severe asthma. While neutrophilic and paucigranulocytic inflammatory patterns are quite uncommon in childhood, type Th2 inflammation asthma with elevated IgE is the most prevalent in pediatric asthma. Considering the pivotal role of IgE in type Th2 inflammation asthma, the blockade of IgE using anti-IgE therapy represents a potent therapeutic option for severe pediatric asthma in children.

AREAS COVERED

This review aims to focus on the role of omalizumab as a treatment option in pediatric patients (aged six years and above) with severe allergic asthma.

EXPERT OPINION

The clinical efficacy and safety of omalizumab for the treatment of pediatric asthma is well documented in clinical trials and observational studies. Further studies are still required to characterize the potential benefit of anti-IgE therapy in airway remodeling, identify additional biomarkers of clinical response and address current unmet needs, including the limit on omalizumab use in children younger than six years.

Airway-centered Fibroelastosis Accompanied by Subpleural Lesions of Unknown Cause in a Young Man Who Later Developed Pulmonary Hypertension

A 26-year-old man with a history of bronchial asthma was found to have high-density shadows along the bronchovascular bundle and in the subpleural area on computed tomography of the chest. Surgical lung biopsy specimens from the right S⁵ showed fibroelastosis in the subpleural and central airway area with alveolar destruction. He was diagnosed with airway-centered fibroelastosis of unknown cause after multidisciplinary discussions. The patient developed pulmonary hypertension and died 6 years later. The patient was younger in comparison to patients in earlier reports and had more obvious subpleural fibroelastic lesions in the upper lobes than in previously described cases.

Immunologic and Non-Immunologic Mechanisms Leading to Airway Remodeling in Asthma

Asthma increases worldwide without any definite reason and patient numbers double every 10 years. Drugs used for asthma therapy relax the muscles and reduce inflammation, but none of them inhibited airway wall remodeling in clinical studies. Airway wall remodeling can either be induced through pro-inflammatory cytokines released by immune cells, or direct binding of IgE to smooth muscle cells, or non-immunological stimuli. Increasing evidence suggests that airway wall remodeling is initiated early in life by epigenetic events that lead to cell type specific pathologies, and modulate the interaction between epithelial and sub-epithelial cells. Animal models are only available for remodeling in allergic asthma, but none for non-allergic asthma. In human asthma, the mechanisms leading to airway wall remodeling are not well understood. In order to improve the understanding of this asthma pathology, the definition of “remodeling” needs to be better specified as it summarizes a wide range of tissue structural changes. Second, it needs to be assessed if specific remodeling patterns occur in specific asthma pheno- or endo-types. Third, the interaction of the immune cells with tissue forming cells needs to be assessed in both directions; e.g., do immune cells always stimulate tissue cells or are inflamed tissue cells calling immune cells to the rescue? This review aims to provide an overview on immunologic and non-immunologic mechanisms controlling airway wall remodeling in asthma.

Predictors of reversible airway obstruction with omalizumab in severe asthma: a real-life study

Background:

Omalizumab may modulate airway remodeling in severe asthma. Using forced expiratory volume in 1 second (FEV₁) as a surrogate of airway remodeling, we aimed to investigate if an omalizumab add-on in severe allergic asthma may lead to a persistent reversal of airway obstruction and to evaluate the potential biomarkers of airway obstruction reversibility.

Methods:

Data were collected before (T0) and after omalizumab add-on for 1 year (T1, 32 patients), 2 years (T2, 26 patients) and 4 years (T4, 13 patients). All patients had baseline FEV₁ below 80 % predicted (60.5 ± 12.5 %). After omalizumab, 18 patients showed FEV₁ normalization (reversible airway obstruction; RAO+) already at T1 (88.7 ± 14.9 %, p < 0.0001) that persisted up to T4 (83.2 ± 7.9, p < 0.01), while 14 patients (RAO−) had FEV₁ persistently decreased, from T1 (65.2 ± 8.4%, p < 0.05) up to T4 (61.4 ± 6.2%, not significant). Both groups had significant improvement of symptoms and exacerbations after omalizumab at T1, which persisted up to T4. The comparison between pretreatment characteristics of the two groups showed that RAO+ patients, had higher values of circulating eosinophils, exhaled nitric oxide (F_ENO), prevalence of rhinitis and nasal polyps, need of oral corticosteroids, shorter asthma duration, higher FEV₁ and response to albuterol test. The optimal cut-off points predicting FEV₁ normalization after omalizumab add-on were 30.5 ppb for F_ENO and 305 cells/µl for eosinophils.

Conclusions:

This study suggests that omalizumab add-on contributes to the persistent reversal of airway obstruction in a consistent number of patients with severe allergic asthma, and this beneficial effect is predicted by elevated pretreatment F_ENO and circulating eosinophils.

What have recent advances in therapy taught us about severe asthma disease mechanisms?

Introduction: Severe asthma still represents a worldwide challenge. The need for further treatment options has stimulated basic and pharmacological research to focus on the immune and inflammatory background of asthma. The new biologic drugs express the considerable advances in the field and besides providing a revolutionary treatment option for severe asthma, contribute themselves to better understand the pathophysiologic mechanisms they address, paving the way to new potential targets.Areas covered: A selective search on PubMed and Medline was performed, including the evidence on immunology of severe asthma published up to May 2019 by focusing on the immunological effects of biologic drugs underlying their clinical outcomes.Expert opinion: The recent pharmacological research in the field of biologics has represented an exceptional opportunity for exploring severe asthma mechanisms. However, some points deserve to be addressed by further investigation. Although in the absence of safety warnings so far, interfering with the immune system may raise some safety concerns, especially in the long-term use. Particularly when interacting with epithelial and innate immunity the selection of candidates probably deserves special caution. Also, whether biologics exert a true disease-modifying effect is not completely clear. As a direct practical implication, the optimal treatment duration is still controversial.

Crosstalk Between Signaling Pathways Involved in the Regulation of Airway Smooth Muscle Cell Hyperplasia

Increased ASM mass, primarily due to ASM hyperplasia, has been recognized as a hallmark of airway remodeling in asthma. Increased ASM mass is the major contributor to the airway narrowing, thus worsening the bronchoconstriction in response to stimuli. Inflammatory mediators and growth factors released during inflammation induce increased ASM mass surrounding airway wall via increased ASM proliferation, diminished ASM apoptosis and increased ASM migration. Several major pathways, such as MAPKs, PI3K/AKT, JAK2/STAT3 and Rho kinase, have been reported to regulate these cellular activities in ASM and were reported to be interrelated at certain points. This article aims to provide an overview of the signaling pathways/molecules involved in ASM hyperplasia as well as the mapping of the interplay/crosstalk between these major pathways in mediating ASM hyperplasia. A more comprehensive understanding of the complexity of cellular signaling in ASM cells will enable more specific and safer drug development in the control of asthma.

Omalizumab may decrease the thickness of the reticular basement membrane and fibronectin deposit in the bronchial mucosa of severe allergic asthmatics

Introduction: Immunoglobulin E is an important modulator of the inflammatory reaction in allergic asthma. It also contributes to airway remodeling in the course of the disease. The authors evaluated airway structural changes in severe allergic asthma during the omalizumab therapy. Patients and methods: The study included 13 patients with severe allergic asthma treated with omalizumab for at least one year. In each patient clinical, laboratory, and spirometry parameters were evaluated before and after the treatment. In addition, bronchoscopy with bronchial mucosa biopsy and bronchoalveolar lavage was performed. The basal lamina thickness, inflammatory cell infiltration, fibronectin, as well as type I and III collagen accumulation were assessed in bronchial mucosa specimens, together with the assessment of bronchoalveolar lavage cellularity. Results: The omalizumab therapy led to a decrease in the basal lamina thickness (p = 0.002), and to a reduction in fibronectin (p = 0.02), but not collagen deposits in the bronchial mucosa. The decrease in fibronectin accumulation was associated with an improvement in asthma control and quality of life (p = 0.01, both), and a diminished dose of systemic corticosteroids (p = 0.001). It was also associated with a tendency towards reduction of the eosinophil count in the peripheral blood, bronchoalveolar lavage fluid, and bronchial mucosa specimens. Conclusion: Our study has shown that omalizumab, effective in the treatment of severe allergic asthma, may also decrease unfavorable structural airway changes in allergic asthmatics, at least with respect to the fibronectin deposit and an increased thickness of the basal lamina. However, more extensive observational studies are needed to verify the above hypothesis.

IgE Downregulates PTEN through MicroRNA-21-5p and Stimulates Airway Smooth Muscle Cell Remodeling

The patho-mechanism leading to airway wall remodeling in allergic asthma is not well understood and remodeling is resistant to therapies. This study assessed the effect of immunoglobulin E (IgE) in the absence of allergens on human primary airway smooth muscle cell (ASMC) remodeling in vitro. ASMCs were obtained from five allergic asthma patients and five controls. Proliferation was determined by direct cell counts, mitochondrial activity by expression of cytochrome c, protein expression by immunoblotting and immuno-fluorescence, cell migration by microscopy imaging, and collagen deposition by cell based ELISA and RNA expression by real time PCR. Non-immune IgE activated two signaling pathways: (i) signal transducer and activator of transcription 3 (STAT3)→miR-21-5p→downregulating phosphatase and tensin homolog (PTEN) expression, and (ii) phosphatidylinositol 3-kinases (PI3K)→protein kinase B (Akt)→mammalian target of rapamycin (mTOR)→ribosomal protein S6 kinase beta-1 (p70s6k)→peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1-α)→peroxisome proliferator-activated receptor-γ (PPAR-γ)→cyclooxygenase-2 (COX-2)→mitochondrial activity, proliferation, migration, and extracellular matrix deposition. Reduced PTEN expression correlated with enhanced PI3K signaling, which upregulated ASMC remodeling. The inhibition of microRNA-21-5p increased PTEN and reduced mTOR signaling and remodeling. Mimics of microRNA-21-5p had opposing effects. IgE induced ASMC remodeling was significantly reduced by inhibition of mTOR or STAT3. In conclusion, non-immune IgE alone is sufficient for stimulated ASMC remodeling by upregulating microRNA-21-5p. Our findings suggest that the suppression of micoRNA-21-5p may present a therapeutic target to reduce airway wall remodeling.

Immunomodulation in Pediatric Asthma

Childhood asthma is actually defined as a heterogeneous disease, including different clinical variants and partially sharing similar immune mechanisms. Asthma management is mainly focused on maintaining the control of the disease and reducing the risk of adverse outcomes. Most children achieve good control with standard therapies, such as low doses of inhaled corticosteroids (ICS) and/or one or more controller. These medications are targeted to suppress bronchial inflammation and to restore airway responsiveness. However, they are not disease-modifying and do not specifically target inflammatory pathways of asthma; in addition, they are not significantly effective in patients with severe uncontrolled asthma. The aim of this review is to update knowledge on current and novel therapeutic options targeted to immunomodulate inflammatory pathways underlying pediatric asthma, with particular reference on biologic therapies.

Overlapping Effects of New Monoclonal Antibodies for Severe Asthma

Among the monoclonal antibodies (mAbs) developed for severe asthma treatment, three have already been marketed. Omalizumab was the first, more than 10 years ago; today, mepolizumab and reslizumab are also available in the European Union and the US. Omalizumab blocks free immunoglobulin E (IgE), mepolizumab and reslizumab block an interleukin (IL-5). In the near future, dupilumab and benralizumab are expected to emerge as two new alternatives. Benralizumab blocks the receptor for IL-5 (IL5-Rα) and has a direct cytotoxic effect on eosinophils, and dupilumab blocks the α-unit of the heterodimeric receptor for IL-4 and IL-13 (IL-4Rα); as a result, dupilumab can block both IL-4 and IL-13. The purpose of this manuscript is to present the pathophysiology of some immunological aspects of severe asthma, describe the adaptive and innate immunity arms as well as their interrelations (stressing the subordination of the adaptive arm to the innate arm), outline the pharmacologic effects of these mAbs, clarify the overlapping effects of the different mAbs, and discuss the differences between mAbs based on their target molecules. Based on the data presented, I propose omalizumab for patients with an allergic phenotype regardless of their peripheral eosinophilic count, and anti-IL-5 as an alternative in allergic patients with blood eosinophilia in which omalizumab has failed; anti-IL5 for patients with an eosinophilic phenotype and omalizumab as an alternative in patients in whom anti-IL5 fails and IgE ≥30 IU/mL (compassionate use). Omalizumab is also proposed for patients with severe chronic asthma allergic to seasonal allergens.

Omalizumab lowers asthma exacerbations, oral corticosteroid intake and blood eosinophils: Results of a 5-YEAR single-centre observational study

Omalizumab is a humanized monoclonal antibody which binds to human immunoglobulins E (IgE), thus preventing their interactions with both high affinity and low affinity IgE receptors. Therefore, omalizumab is currently recommended for add-on biological therapy of uncontrolled allergic asthma, mainly characterized by type 2 airway eosinophilic inflammation. Because omalizumab has been the first, and for a long time the only available monoclonal antibody for add-on treatment of type 2 asthma, some long-term studies have been published which provide a clear evidence of the therapeutic effectiveness of the anti-IgE pharmacological strategy. Within this context, the present single-centre observational study refers to 15 patients with severe allergic asthma, treated with omalizumab for at least 5 years at the Respiratory Unit of "Magna Græcia" University Hospital located in Catanzaro, Italy. In these asthmatic subjects we observed significant increases in asthma control test (ACT) score, with respect to baseline (14.60 ± 2.97), after 1 year (19.20 ± 2.98; p < 0.0001) and 5 years (21.67 ± 2.38; p < 0.0001) of add-on treatment with omalizumab. More importantly, omalizumab significantly lowered the number of annual asthma exacerbations (baseline: 3.66 ± 2.01) after 1 year (0.83 ± 1.14; p < 0.0001) and 5 years (0.63 ± 0.99; p < 0.0001), respectively. This excellent therapeutic outcome made it possible to drastically decrease the daily oral intake of prednisone (baseline: 22.50 ± 5.17 mg) after 1 year (1.83 ± 4.06 mg; p < 0.0001), as well as after 5 years (1.66 ± 3.61 mg; p < 0.0001). With regard to lung function, omalizumab significantly and persistently enhanced FEV₁ (baseline: 1636 ± 628.4 mL) after 1 year (2000 ± 679.7 mL; p < 0.05) and 5 years (1929 ± 564.8 mL; p < 0.05), respectively. Such relevant clinical and functional improvements were associated with reductions of blood eosinophil counts (baseline: 646.0 ± 458.9 cells/μl), already detectable after 1 year (512.7 ± 327.8 cells/μl; not significant), which reached the threshold of statistical significance after 5 years (326.0 ± 171.8 cells/μl; p < 0.05). Therefore, these real-life data referring to our single-centre observational investigation further corroborate the long-term therapeutic ability of omalizumab to improve several clinical, functional and haematological signatures of severe type 2 asthma.

Real-world safety and efficacy of omalizumab in patients with severe allergic asthma: A long-term post-marketing study in Japan

BACKGROUND

Omalizumab (anti-IgE monoclonal antibody) is an approved add-on therapy for Japanese patients with severe allergic asthma. As directed by the Ministry of Health, Labor and Welfare Japan, a post-marketing surveillance (PMS) study on omalizumab was conducted between 2009 and 2017.

METHODS

The PMS observed safety and efficacy of omalizumab in patients treated with open-label omalizumab for 52 weeks (with optional 2-year extension period). Primary safety outcomes included incidence and severity of adverse events (AEs) and adverse drug reactions (ADRs). Primary efficacy outcomes included physician-assessed global evaluation of treatment effectiveness (GETE). Asthma-exacerbation-related events including requirement for additional systemic steroid therapy, hospitalization, emergency room visits, unscheduled doctor visits, and absenteeism were also evaluated.

RESULTS

Of 3893 patients registered, 3620 (age [mean ± SD] 59.3 ± 16.11 years) were evaluated for 52 weeks; 44.12% were aged ≥65 years and 64.45% were women. Overall, 32.24% reported AEs and 15.30% reported serious AEs. ADRs were seen in 292 (8.07%) patients. GETE results showed that the majority of patients experienced clinical improvements (58.29% at 16 weeks and 62.40% at 52 weeks). Nearly half of all patients (47.96%) were free from asthma exacerbations after therapy. Omalizumab also reduced all events related to asthma exacerbations. No specific ADRs were observed in the elderly population.

CONCLUSIONS

This post-marketing study confirmed the clinically meaningful benefits of omalizumab in a majority of patients from Japan, and showed safety and efficacy in a real-life clinical setting to be consistent with previous reports.

Is IgE or eosinophils the key player in allergic asthma pathogenesis? Are we asking the right question?

Bronchial asthma (BA) is a chronic inflammatory disease with a marked heterogeneity in pathophysiology and etiology. The heterogeneity of BA may be related to the inducing mechanism(s) (allergic vs non-allergic), the histopathological background (eosinophilic vs non-eosinophilic), and the clinical manifestations, particularly in terms of severity and frequency of exacerbations. Asthma can be divided into at least two different endotypes based on the degree of Th2 inflammation (T2 'high' and T2 'low'). For patients with severe uncontrolled asthma, monoclonal antibodies (mAbs) against immunoglobulin E (IgE) or interleukin (IL)-5 are now available as add-on treatments. Treatment decisions for individual patients should consider the biological background in terms of the "driving mechanisms" of inflammation as this should predict the patients' likely responses to treatment. The question is not whether an anti-IgE or an anti-eosinophilic strategy is more effective, but rather what the mechanism is at the origin of the airway. While IgE is involved early in the inflammatory cascade and can be considered as a cause of allergic asthma, eosinophilia can be considered a consequence of the whole process. This article discusses the different roles of the IgE and IL-5/eosinophil pathways in the pathogenic mechanisms of airway inflammation occurring in allergic asthma, and the possible reasons to choose an anti-IgE mAb or anti-IL-5 treatment.

Moving toward consensus on diagnosis and management of severe asthma in children

Children with severe asthma continue to experience symptoms despite long-term treatment with high doses of corticosteroids. Moreover, the heterogeneous nature of asthma and the presence of several phenotypes have limited our ability to develop an optimized management strategy for these patients. Adequate management of severe asthma in children necessitates a detailed understanding of what makes asthma difficult to control, knowledge of the causal factors, review of diagnosis for accurate identification of pediatric patients with severe asthma and a precise definition of the phenotypes to be able to better target the therapy. Advancement in all these aspects is likely to improve childhood asthma treatment in the future. Although our understanding of severe pediatric asthma has grown in recent years, there remains a lack of consensus and clarity around critical aspects of this condition. This review attempts to present a harmonized view on the definition of severe asthma in the pediatric age group, identification of phenotypes and diagnosis, the inflammatory cascade, pharmacological and non-pharmacological treatment strategies, considerations for follow-up and referral to specialists, and disease prevention strategies.

Moving toward consensus on diagnosis and management of severe asthma in adults

Asthma is a considerable health problem with an increasing global prevalence. The burden of severe asthma is expected to notably increase in the following years. Some misleading concepts that sometimes appear in the literature can drive the physician responsible for a patient's management to make incorrect decisions. Furthermore, some of the concepts that appear in the literature and in the guidelines may not be clear to understand, follow or adapt to regional and local realities. This could again drive the physicians responsible for a patient's management to make incorrect clinical judgments. In this article, we review the definition, prevalence and immunopathology of severe asthma, describe the asthma phenotypes, clinical features and comorbidities, the diagnosis of severe asthma and personalized asthma treatment. At the end, we offer a treatment approach based on literature publications, personalized medicine and marketed biologic treatment options.

Novel therapies for severe asthma in children and adults

Asthma is a heterogeneous disease usually characterised by chronic airway inflammation. It is defined by a history of symptoms such as wheeze, shortness of breath, chest tightness and cough, along with variable airflow limitation [1]. Recently, “cluster” analyses have provided insight into specific subtypes among asthma patients, which share phenotypic characteristics.

The heterogeneous nature of asthma requires personalised treatments. Monoclonal antibody treatments showed good efficacy, and should be considered when symptoms are poorly controlled despite good inhaler technique, compliance and controlled comorbidities.http://ow.ly/UWpg30hImQh

Omalizumab, the first available antibody for biological treatment of severe asthma: more than a decade of real-life effectiveness

Omalizumab was the first, and for a long time the only available monoclonal antibody for the add-on treatment of severe allergic asthma. In particular, omalizumab selectively targets human immunoglobulin (Ig)E, forming small-size immune complexes that inhibit IgE binding to its high- and low-affinity receptors. Therefore, omalizumab effectively blunts the immune response in atopic asthmatic patients, thus significantly improving the control of asthma symptoms and successfully preventing disease exacerbations. These very positive effects of omalizumab make it possible to drastically decrease both referrals to the emergency room and hospitalizations for asthma exacerbations. Such important therapeutic actions of omalizumab have been documented by several randomized clinical trials, and especially by more than 10 years of real-life experience in daily clinical practice. Omalizumab can also interfere with airway remodelling by inhibiting the activation of IgE receptors located on structural cells such as bronchial epithelial cells and airway smooth muscle cells. Moreover, omalizumab is characterized by a very good safety and tolerability profile. Hence, omalizumab represents a valuable therapeutic option for the add-on biological treatment of severe allergic asthma.

Pregnancy-associated plasma protein-A (PAPP-A) levels in patients with severe allergic asthma are reduced by omalizumab

BACKGROUND

Remodeling is a crucial feature of severe asthma and may be associated with activation of the allergic cascade by immunoglobulin E (IgE). Omalizumab, an anti-IgE monoclonal antibody, effectively targets the severe allergic asthma phenotype. Pregnancy-associated plasma protein-A (PAPP-A) is an insulin-like growth factor binding protein-4 (IGFBP-4) protease, increasing local insulin-like growth factor (IGF)-1 concentrations, which in turn initiating a cascade involved in the regulation of cell growth, differentiation, and proliferation in various tissues. In the present study, we evaluated the effects of omalizumab on serum PAPP-A, IGFBP-4, and IGF-1 levels in subjects with severe allergic asthma.

METHODS

We studied 36 asthmatic subjects and 36 healthy controls. An ultrasensitive enzyme-linked immunosorbent assay (ELISA) kit was used to measure serum PAPP-A levels, and routine commercial ELISA kits were employed to assess serum levels of IGF-1, IGFBP-4 in control subjects and asthmatic subjects before therapy (baseline) and after six months of omalizumab therapy in patients with severe asthma.

RESULTS

Compared to control subjects, serum PAPP-A and IGFB-4 levels were significantly higher in asthmatic subjects (both p values < 0.001). However, the serum IGF-I levels of asthmatic subjects were similar to those of control subjects (p > 0.05). In asthma subjects, 6-month omalizumab treatment significantly decreased the serum PAPP-A (p < 0.001), IGF-I (p = 0.031), and IGFB4 (p = 0.025) levels.

CONCLUSION

PAPP-A level may be a useful biomarker for predicting airway remodeling in patients with severe asthma receiving omalizumab, and may also reflect the response to treatment.

New approaches for identifying and testing potential new anti-asthma agents

INTRODUCTION

Asthma is a chronic disease with significant heterogeneity in clinical features, disease severity, pattern of underlying disease mechanisms, and responsiveness to specific treatments. While the majority of asthmatic patients are controlled by standard pharmacological strategies, a significant subgroup has limited therapeutic options representing a major unmet need. Ongoing asthma research aims to better characterize distinct clinical phenotypes, molecular endotypes, associated reliable biomarkers, and also to develop a series of new effective targeted treatment modalities. Areas covered: The expanding knowledge on the pathogenetic mechanisms of asthma has allowed researchers to investigate a range of new treatment options matched to patient profiles. The aim of this review is to provide a comprehensive and updated overview of the currently available, new and developing approaches for identifying and testing potential treatment options for asthma management. Expert opinion: Future therapeutic strategies for asthma require the identification of reliable biomarkers that can help with diagnosis and endotyping, in order to determine the most effective drug for the right patient phenotype. Furthermore, in addition to the identification of clinical and inflammatory phenotypes, it is expected that a better understanding of the mechanisms of airway remodeling will likely optimize asthma targeted treatment.

An Update on Anti-IgE Therapy in Pediatric Respiratory Diseases

Anti-IgE treatment represents a major breakthrough in the therapeutic management of severe allergic asthma. Omalizumab is the unique biologic treatment registered for asthma therapy in children. The clinical efficacy and safety of omalizumab treatment in the pediatric population has been extensively documented in specific trials and consistently expanded from real-life studies. In addition, new experimental evidence suggests that omalizumab may also interfere with the cellular and molecular mechanisms underlying airway remodeling. Novel investigational anti-IgE monoclonal antibodies with improved pharmacodynamic properties are in the pipeline, potentially offering alternative mechanisms of modulating IgE pathway.

The aim of this review is to update current knowledge on anti-IgE therapy in pediatric respiratory diseases.

Targeted therapy in severe asthma today: focus on immunoglobulin E

Asthma is a complex chronic inflammatory disease of multifactorial etiology. International guidelines increasingly recognize that a standard "one size fits all" approach is no longer an effective approach to achieve optimal treatment outcomes, and a number of disease phenotypes have been proposed for asthma, which has the potential to guide treatment decisions. Among the many asthma phenotypes, allergic asthma represents the widest and most easily recognized asthma phenotype, present in up to two-thirds of adults with asthma. Immunoglobulin E (IgE) production is the primary and key cause of allergic asthma leading to persistent symptoms, exacerbations and a poor quality of life. Therefore, limiting IgE activity upstream could stop the entire allergic inflammation cascade in IgE-mediated allergic asthma. The anti-IgE treatment omalizumab has an accepted place in the management of severe asthma (Global Initiative for Asthma [GINA] step 5) and represents the first (and, currently, only) targeted therapy with a specific target in severe allergic asthma. This review summarizes current knowledge of the mechanisms and pathogenesis of severe asthma, examines the actual role of IgE in asthma and the biological rationale for targeting IgE in allergic asthma and reviews the data for the efficacy and safety of omalizumab in the treatment of severe asthma. Current knowledge of the role of IgE in asthma, extensive clinical trial data and a decade of use in clinical practice has established omalizumab as a safe and effective targeted therapy for the treatment of patients with severe persistent IgE-mediated allergic asthma.

dIvergEnt: How IgE Axis Contributes to the Continuum of Allergic Asthma and Anti-IgE Therapies

Asthma is an airway disease characterised by chronic inflammation with intermittent or permanent symptoms including wheezing, shortness of breath, chest tightness, and cough, which vary in terms of their occurrence, frequency, and intensity. The most common associated feature in the airways of patients with asthma is airway inflammation. In recent decades, efforts have been made to characterise the heterogeneous clinical nature of asthma. The interest in improving the definitions of asthma phenotypes and endotypes is growing, although these classifications do not always correlate with prognosis nor are always appropriate therapeutic approaches. Attempts have been made to identify the most relevant molecular and cellular biomarkers underlying the immunopathophysiological mechanisms of the disease. For almost 50 years, immunoglobulin E (IgE) has been identified as a central factor in allergic asthma, due to its allergen-specific nature. Many of the mechanisms of the inflammatory cascade underlying allergic asthma have already been elucidated, and IgE has been shown to play a fundamental role in the triggering, development, and chronicity of the inflammatory responses within the disease. Blocking IgE with monoclonal antibodies such as omalizumab have demonstrated their efficacy, effectiveness, and safety in treating allergic asthma. A better understanding of the multiple contributions of IgE to the inflammatory continuum of asthma could contribute to the development of novel therapeutic strategies for the disease.

Can the response to Omalizumab be influenced by treatment duration? A real-life study

OBJECTIVE

It is unknown whether Omalizumab effectiveness changes over the course of time. Our retrospective real-life study tried to analyze whether Omalizumab response may be influenced by treatment duration.

METHODS

340 severe asthmatics treated with Omalizumab for different periods of time were recruited. They were subdivided into 4 groups according to the Omalizumab treatment length: <12, between 12 and 24, between 24 and 60 and >60 months. Omalizumab treatment results (FEV₁, exacerbations, ACT, SABA use, asthma control levels, medications used e and ICS doses) were compared.

RESULTS

ACT, exacerbations, GINA control levels, ICS doses and SABA use were similar in all groups with different Omalizumab treatment durations. Using a linear regression model, corrected for all confounding variables, a higher significant positive increase in FEV₁% in subjects treated for 12-24 (β = 9.49; p = 0.034) or 24-60 months (β = 8.56; p = 0.043) was found when compared with subjects treated for a shorter period. Treatment duration was positively associated with a step down of the other associated therapies (OR: 1.013; p = 0.019). This association was more relevant (OR: 4.167; p = 0.005) when we considered Omalizumab treatment duration >60 months compared to the shorter therapy. In particular, the percentage of subjects that were taking Montelukast, LABAs and oral corticosteroids was lower in the group treated with Omalizumab for a longer period of time.

CONCLUSION

In real-life, the positive Omalizumab response remained stable for over 60 months. Long term Omalizumab treatment may lead to a discontinuation of some associated medications and to a slowing down of FEV₁ decline.

[Omalizumab: Beyond anti-IgE properties]

INTRODUCTION

Omalizumab is used as a treatment for severe allergic asthma. Its intended mechanism of action is based on its anti-IgE proprieties. However, recent studies have highlighted other mechanisms of action.

STATE OF THE ART

Omalizumab treatment is associated with a decrease in the number of dendritic cells, T and B lymphocytes and eosinophils. This anti-inflammatory activity is characterized by a decrease in the levels of several cytokines involved in the recruitment, activation and survival of eosinophils and mastocytes, and in a Th2 orientation of the immune response. A modulation of bronchial remodeling by omalizumab has recently been shown. A decrease in the production of extracellular matrix components and in the proliferation of smooth muscle cells could be involved in this modulation. These mechanisms of action could explain in part the clinical efficiency of omalizumab in non-allergic conditions such as non-allergic asthma, non-allergic urticaria or nasal polyposis.

CONCLUSION

A precise knowledge of the mechanisms of action of omalizumab could allow the identification of biomarkers predictive of efficacy of this treatment. These could be useful tools in the phenotyping of severe asthma.

An orally active geranyl acetophenone attenuates airway remodeling in a murine model of chronic asthma

2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) is a synthetic compound that is naturally found in Melicope ptelefolia. We had previously demonstrated that parenteral administration of tHGA reduces pulmonary inflammation in OVA-sensitized mice. In this study, we evaluated the effect of orally administered tHGA upon airway remodeling in a murine model of chronic asthma. Female BALB/C mice were sensitized intraperitoneally with ovalbumin (OVA) on day 0, 7 and 14, followed by aerosolized 1% OVA 3 times per week for 6 weeks. Control groups were sensitized with saline. OVA sensitized animals were either treated orally with vehicle (saline with 1% DMSO and Tween 80), tHGA (80, 40, 20mg/kg) or zileuton (30mg/kg) 1h prior to each aerosolized OVA sensitization. On day 61, mice underwent methacholine challenge to determine airway hyperresponsiveness prior to collection of bronchoalveolar lavage (BAL) fluid and lung samples. BAL fluid inflammatory cell counts and cytokine concentrations were evaluated while histological analysis and extracellular matrix protein concentrations were determined on collected lung samples. Oral tHGA treatment attenuated airway hyperresponsiveness and inhibited airway remodeling in a dose-dependent fashion. tHGA's effect on airway remodeling could be attributed to the reduction of inflammatory cell infiltration and decreased expression of cytokines associated with airway remodeling. Oral administration of tHGA attenuates airway hyperresponsiveness and remodeling in OVA-induced BALB/c mice. tHGA is an interesting compound that should be evaluated further for its possible role as an alternative non-steroidal pharmacological approach in the management of asthma.

Where does current and future pediatric asthma treatment stand? Remodeling and inflammation: Bird's eye view

Airway remodeling is the chronic outcome of inflammation in asthma and a point of intervention between pediatric and adult ages. Pediatric asthma has been of great interest in the efforts to find a valuable time to interrupt remodeling. Various experimental and clinical research have assessed the effect of current therapeutic modalities on airway remodeling in asthma and many new agents are being developed with promising results. The heterogeneity in the results of these studies may lie in the heterogeneity of pathogenesis leading to asthma and remodeling; underlying the need for individualized treatment of the unique pathogenetic characteristics of each child's asthma. The aim of this review is to summarize the evidence about the influence of current and future therapeutic modalities in the concept of inflammation and remodeling in pediatric asthma. Pediatr Pulmonol. 2016;51:1422-1429. © 2016 Wiley Periodicals, Inc.

IgE regulates airway smooth muscle phenotype: Future perspectives in allergic asthma

The purpose of this commentary is to highlight the emerging role of IgE on airway smooth muscle (ASM) cells function through activation of the high-affinity Fc receptor for IgE. We discuss the potential implications of IgE-mediated ASM sensitization in airway inflammation and remodeling, the hallmark features of allergic asthma.

Anti-IgE treatment, airway inflammation and remodelling in severe allergic asthma: current knowledge and future perspectives

Asthma is a disorder of the airways involving various inflammatory cells and mediators and characterised by bronchial hyperresponsiveness, chronic inflammation and structural alterations in the airways, also known as remodelling. IgE is an important mediator of allergic reactions and has a central role in allergic asthma pathophysiology, as it is implicated in both the early and late phase allergic response. Moreover, clinical and mechanistic evidence has lately emerged, implicating IgE in the development of airway remodelling. The use of monoclonal antibodies targeting IgE, such as omalizumab, has proven very effective in improving respiratory symptoms and quality of life, while reducing asthma exacerbations, emergency room visits and the use of systemic corticosteroids in allergic severe asthma. These effects are believed to be mainly mediated by omalizumab's inhibitory effect on the initiation and further propagation of the allergic inflammation cascade. However, there is evidence to suggest that anti-IgE treatment remains effective long after it has been discontinued. In part, these findings could be attributed to the possible ameliorating effects of anti-IgE treatment on airway remodelling. In this review, we discuss recent findings supporting the notion that anti-IgE treatment modulates the complex immune responses that manifest clinically as asthma and ameliorates airway remodelling changes often observed in allergic severe asthma phenotypes.

Inhaled corticosteroids do not reduce initial high activity of matrix metalloproteinase (MMP)-9 in exhaled breath condensates of children with asthma exacerbation: a proof of concept study

Inhaled corticosteroids (ICS) are the key component of asthma treatment. However, it is unclear whether they could control the activity and level of matrix metalloproteinase (MMP)-9, which is an important factor in asthma-associated inflammation and airway remodeling. Therefore, the aim of this proof of concept study was to analyze the influence of increased doses of ICS on MMP-9 in exhaled breath condensates (EBC) of patients with allergic asthma exacerbation. Apart from MMP-9, the assessment concerned selected inflammation markers – exhaled nitric oxide (eNO) and cytokines (IL-8 and TNF).

The study involved a small group (n = 4) of individuals with asthma exacerbation. The intervention concerned increased doses of ICS with β-mimetics for 4 weeks. In addition to clinical evaluation, eNO measurements and EBC collections were done before and after 4 weeks of intense ICS treatment. The biochemical assessment of EBC concerned MMP-9, IL-8 and TNF. The data were compared to results of healthy controls (n = 6).

The initial levels of eNO, MMP-9 and TNF in EBC were higher in the asthma group than in controls. In all subjects IL-8 levels were below the detection limit. After 4 weeks of ICS treatment in all patients we observed improvement of clinical and laboratory parameters. Interestingly, despite reduction of eNO and TNF, the activity of MMP-9/EBC remained on the initial level.

Practical relevance of our results is limited by a small group. Nevertheless, our data suggest that ICS, although sufficient to control symptoms and inflammatory markers, may be ineffective to reduce MMP-9/EBC activity in asthma exacerbation and, possibly, airway remodeling.

Anti-IgE treatment, airway inflammation and remodelling in severe allergic asthma: current knowledge and future perspectives

Asthma is a disorder of the airways involving various inflammatory cells and mediators and characterised by bronchial hyperresponsiveness, chronic inflammation and structural alterations in the airways, also known as remodelling. IgE is an important mediator of allergic reactions and has a central role in allergic asthma pathophysiology, as it is implicated in both the early and late phase allergic response. Moreover, clinical and mechanistic evidence has lately emerged, implicating IgE in the development of airway remodelling. The use of monoclonal antibodies targeting IgE, such as omalizumab, has proven very effective in improving respiratory symptoms and quality of life, while reducing asthma exacerbations, emergency room visits and the use of systemic corticosteroids in allergic severe asthma. These effects are believed to be mainly mediated by omalizumab's inhibitory effect on the initiation and further propagation of the allergic inflammation cascade. However, there is evidence to suggest that anti-IgE treatment remains effective long after it has been discontinued. In part, these findings could be attributed to the possible ameliorating effects of anti-IgE treatment on airway remodelling. In this review, we discuss recent findings supporting the notion that anti-IgE treatment modulates the complex immune responses that manifest clinically as asthma and ameliorates airway remodelling changes often observed in allergic severe asthma phenotypes.

Aclidinium bromide combined with formoterol inhibits remodeling parameters in lung epithelial cells through cAMP

Combined muscarinic receptor antagonists and long acting β2-agonists improve symptom control in chronic obstructive pulmonary disease (COPD) significantly. In clinical studies aclidinium bromide achieved better beneficial effects than other bronchodilators; however, the underlying molecular mechanisms are unknown. This study assessed the effect of aclidinium bromide combined with formoterol on COPD lung (n=20) and non-COPD lung (n=10) derived epithelial cells stimulated with TGF-β1+carbachol on: (i) the generation of mesenchymal cells in relation to epithelial cells, (II) extracellular matrix (ECM) deposition, and (iii) the interaction of ECM on the generation of epithelial and mesenchymal cells. TGF-β1+carbachol enhanced the generation of mesenchymal cells, which was significantly reduced by aclidinium bromide or formoterol. The effect of combined drugs was additive. Inhibition of p38 MAP kinase and Smad by specific inhibitors or aclidinium bromide reduced the generation of mesenchymal cells. In mesenchymal cells, TGF-β1+carbachol induced the deposition of collagen-I and fibronectin which was prevented by both drugs dose-dependently. Formoterol alone reduced collagen-I deposition via cAMP, this however, was overruled by TGF-β1+carbachol and rescued by aclidinium bromide. Inhibition of fibronectin was cAMP independent, but involved p38 MAP kinase and Smad. Seeding epithelial cells on ECM collagen-I and fibronectin induced mesenchymal cell generation, which was reduced by aclidinium bromide and formoterol. Our results suggest that the beneficial effect of aclidinium bromide and formoterol involves cAMP affecting both, the accumulation of mesenchymal cells and ECM remodeling, which may explain the beneficial effect of the drugs on lung function in COPD.

Airway Remodeling in Preschool Children with Severe Recurrent Wheeze

RATIONALE

Airway wall structure in preschoolers with severe recurrent wheeze is poorly described.

OBJECTIVES

To describe airway wall structure and inflammation in preschoolers with severe recurrent wheeze.

METHODS

Flexible bronchoscopy was performed in two groups of preschoolers with severe recurrent wheeze: group 1, less than or equal to 36 months (n = 20); group 2, 36-59 months (n = 29). We assessed airway inflammation, reticular basement membrane (RBM) thickness, airway smooth muscle (ASM), mucus gland area, vascularity, and epithelial integrity. Comparisons were then made with biopsies from 21 previously described schoolchildren with severe asthma (group 3, 5-11.2 yr).

MEASUREMENTS AND MAIN RESULTS

RBM thickness was lower in group 1 than in group 2 (3.3 vs. 3.9 μm; P = 0.02), was correlated with age (P < 0.01; ρ = 0.62), and was higher in schoolchildren than in preschoolers (6.8 vs. 3.8 μm; P < 0.01). ASM area was lower in preschoolers than in schoolchildren (9.8% vs. 16.5%; P < 0.01). Vascularity was higher in group 1 than in group 2 (P = 0.02) and group 3 (P < 0.05). Mucus gland area was higher in preschoolers than in schoolchildren (16.4% vs. 4.6%; P < 0.01). Inflammatory cell counts in biopsies were not correlated with airway wall structure. ASM area was higher in preschoolers with atopy than without atopy (13.1% vs. 7.7%; P = 0.01). Airway morphometrics and inflammation were similar in viral and multiple-trigger wheezers.

CONCLUSIONS

In preschoolers with severe recurrent wheeze, markers of remodeling and inflammation are unrelated, and atopy is associated with ASM. In the absence of control subjects, we cannot determine whether differences observed in RBM thickness and vascularity result from disease or normal age-related development.