Markers that can Reflect Asthmatic Activity before and after Reduction of Inhaled Corticosteroids: A Pilot Study

Early Prediction of Asthma

The clinical manifestations of asthma in children are highly variable, are associated with different molecular and cellular mechanisms, and are characterized by common symptoms that may diversify in frequency and intensity throughout life. It is a disease that generally begins in the first five years of life, and it is essential to promptly identify patients at high risk of developing asthma by using different prediction models. The aim of this review regarding the early prediction of asthma is to summarize predictive factors for the course of asthma, including lung function, allergic comorbidity, and relevant data from the patient's medical history, among other factors. This review also highlights the epigenetic factors that are involved, such as DNA methylation and asthma risk, microRNA expression, and histone modification. The different tools that have been developed in recent years for use in asthma prediction, including machine learning approaches, are presented and compared. In this review, emphasis is placed on molecular mechanisms and biomarkers that can be used as predictors of asthma in children.

Bronchial Asthma as a Cardiovascular Risk Factor: A Prospective Observational Study

Introduction: Asthma as a chronic inflammatory disorder has been suggested as a risk factor for endothelial dysfunction (ED), but studies on the association between asthma and cardiovascular disease (CVD) risk are limited. Background: We assessed associations of ED with the severity of asthma, eosinophilic inflammation, lung function, and asthma control. Methods: 52 young asthmatics (median age of 25.22 years) and 45 healthy individuals were included. Demographic, clinical, and laboratory findings were recorded. We evaluated microvascular responsiveness by recording the reactive hyperemia index (RHI) indicating post-occlusive peripheral endothelium-dependent changes in vascular tone using the Itamar Medical EndoPAT2000. VCAM-1, ADMA, high-sensitive CRP (hsCRP), and E-selectin were measured. Results: Asthmatics had considerably lower RHI values (p < 0.001) with a dynamic decreasing trend by asthma severity and higher hsCRP levels (p < 0.001). A substantial increase in hsCRP and E-selectin with asthma severity (p < 0.05) was also observed. We confirmed a higher body mass index (BMI) in asthmatics (p < 0.001), especially in women and in severe asthma. Conclusions: We demonstrated the progression of CVD in asthmatics and the association of the ongoing deterioration of ED with the inflammatory severity, suggesting that the increased risk of CVD in young asthmatics is dependent on disease severity. The underlying mechanisms of risk factors for CVD and disease control require further study.

Establishment of a novel ELISA system for measuring periostin independently of formation of the IgA complex

BACKGROUND

Periostin, a matricellular protein that modulates cell functions having various pathophysiological roles, has the potential to be a useful biomarker for various diseases. We recently found that periostin forms a complex with IgA in human serum, which may affect the periostin measurement.

METHODS

We investigated (1) whether the formation of the periostin-IgA complex affects the original periostin ELISA system, decreasing the values of serum periostin? (2) bow each domain of periostin affects periostin measurement by the original periostin ELISA system? (3) whether we can establish a novel ELISA system that is not affected by formation of the IgA complex?

RESULTS

The periostin value at the reducing condition was significantly higher than that of the non-reducing condition, demonstrating that formation of the IgA complex affects periostin measurement. The monoclonal antibodies (mAbs) for periostin recognizing the EMI and R1 domains immunoprecipitated serum periostin in the reducing condition more than in the non-reducing condition, whereas the mAbs recognizing the R2 or R3 domain immunoprecipitated comparable amounts of serum periostin in the reducing and non-reducing conditions, suggesting the EMI and R1 domains contribute to formation of the complex with IgA. Using SS16A recognizing the R3 domain combined with SS17B recognizing the R4 domain, we established an ELISA system that was able to measure periostin independently of the IgA complex.

CONCLUSIONS

We have established a novel ELISA system that measures periostin independently of the IgA complex. This system is promising in identifying periostin as a biomarker for various diseases.

Role of serum periostin in the management of asthma and its comorbidities

Type-2 airway inflammation is a major characteristic of asthma. Assessing its degree of severity is, therefore, essential in asthma management. Periostin, a matricellular protein belonging to the fasciclin family, is a key molecule linking type-2 airway inflammation and airway remodeling. Fortunately, periostin can be detected in the blood and used to provide sustaining airway information on type-2 inflammation and remodeling. Serum periostin is elevated in the eosinophilic/type 2 subtype of severe asthma, and its levels remain relatively stable and reflect genetic backgrounds. This suggests that serum periostin may serve as a marker of geno-endophenotype with type-2 airway inflammation and thus could be a predictive marker of the long-term prognosis of asthma under treatment. As expected, serum periostin is particularly elevated in comorbidities associated with the eosinophilic/type 2 subtype of severe asthma, including eosinophilic chronic rhinosinusitis, aspirin-exacerbated respiratory diseases, allergic bronchopulmonary aspergillosis, and eosinophilic granulomatosis with polyangiitis. Conversely, serum periostin levels are relatively lower in the overweight/obese. Serum periostin measurements may help to significantly improve the management of patients with severe asthma.

Diagnostic accuracy of periostin in predicting asthma: a systematic review and Meta-analysis

OBJECTIVE

We sought to evaluate the accuracy of periostin for the diagnosis of asthma through a systematic review and meta-analysis.

METHODS

we searched the electronic databases (PubMed, EMBASE, Web of science) to find relevant studies through December 31, 2018. Studies selecting, data extraction and quality assessment were conducted by two researchers independently according to inclusion and exclusion criteria. We used bivariate mixed effects model to conduct the meta-analysis.

RESULTS

A total of 9 studies including 1448 subjects with asthma were analyzed. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) were 0.68 (95% CI, 0.42-0.86), 0.87 (95% CI, 0.76-0.93) and 13.78 (95% CI, 4.64-40.93) respectively. The area under the summary receiver operating curves (SROC) was 0.87 (95% CI, 0.84-0.90). The Spearman correlation coefficient indicated that no threshold effect existed in the included studies. The study design had statistical significance for sensitivity results (p < 0.001) through regression analysis. Heterogeneity might be caused by non-threshold effect.

CONCLUSION

Periostin has moderate accuracy in the diagnosis of asthma.

Periostin: An emerging biomarker for allergic diseases

Periostin is a matricellular protein as well as an extracellular matrix (ECM) protein belonging to the fasciclin family. Periostin plays important roles as a matricellular protein in the setting of allergic diseases by binding to several integrins on various cells. Since periostin is induced mainly by IL-4 and IL-13, signature type 2 cytokines, and it is highly expressed in the subepithelial regions of many chronic allergic diseases, periostin has emerged as a novel biomarker reflecting type 2 inflammation in allergic diseases. It has, moreover, been revealed that periostin has characteristics different from other type 2 biomarkers such as eosinophil count and fractional exhaled nitric oxide (FeNO), reflecting fibrosis or tissue remodeling. From this, we may say that serum periostin is a "chronic" type 2 biomarker, whereas FeNO and possibly the eosinophil count are "acute" type 2 biomarkers. In contrast, it is still uncertain how we can apply periostin measurement to the use of biologics for allergic diseases. By examining the roles of periostin in allergy and the utility and potential of periostin in developing diagnostics against allergic diseases, it is hoped that in the near future, we can develop a new strategy to treat allergic patients.

Roles of Periostin in Asthma

Periostin is a matricellular protein that is deeply involved in type-2/eosinophilic airway inflammation and remodeling in asthma. While its expression in airway epithelial cells is correlated with the thickness of airway basement membrane, more importantly, periostin can be detected stably in blood with little variability, reflecting airway type-2 inflammation and remodeling. As for a result, serum periostin can serve as a valuable marker to identify patients with type-2 severe asthma who are insensitive to inhaled corticosteroids, and consequently have the excess decline of pulmonary function with asthma exacerbations. Serum periostin may significantly help to improve management of patients with severe asthma.

Elevated serum levels of periostin in patients with allergic bronchopulmonary aspergillosis

BACKGROUND

Serum periostin levels have been reported to be an indicator of Th2 inflammation in asthmatic patients.

OBJECTIVE

This study aimed to investigate serum levels of periostin in patients with allergic bronchopulmonary aspergillosis (ABPA) and to evaluate its diagnostic and monitoring value in the disease.

METHODS

Patients with ABPA (n = 19) and asthma (n = 24), including severe asthma with fungal sensitisation (SAFS, n = 11) and severe asthma without fungal sensitization (SAwFS, n = 13), were enrolled. Serum levels of periostin were analysed by enzyme-linked immunosorbent assay. Serum total IgE and Aspergillus fumigatus specific IgE, IgG were measured by ImmunoCAP. Levels of cytokines (IFN-γ, IL-4, IL-5, IL-8, IL-10, IL-13 and IL-17A) were measured by Meso Scale Discovery (MSD).

RESULTS

Serum levels of periostin in ABPA patients (85.55 ng/mL, [68.28-166] ng/mL) were higher than those in SAFS (50.99 ng/mL, [32.02-71.80] ng/mL; P < 0.01). Among the analysed cytokines, IL-5 levels in ABPA (1.55 pg/mL, [0.96-3.33] pg/mL) were higher than those in SAFS (0.31 pg/mL, [0.26-0.56] pg/mL; P < 0.05) or SAwFS (0.34 pg/mL, [0.21-0.56] pg/mL; P < 0.01). Serum periostin levels was positively associated with total IgE levels (r = 0.319, P < 0.05), serum IL-5 levels (r = 0.484, P < 0.01) and blood eosinophil counts (r = 0.428, P < 0.05). In ROC analysis, the clinical reference value of periostin was 68.8 ng/mL for differential diagnosis of ABPA and SAFS, with the area under the curve (AUC) of 0.81. Longitudinally, serum periostin levels did not change significantly after treatment in ABPA.

CONCLUSIONS

These findings suggested that serum levels of periostin were up-regulated in ABPA patients, which may be associated with eosinophilic inflammation.

Biomarkers for severe allergic asthma in children: could they be useful to guide disease control and use of omalizumab?

INTRODUCTION

Although symptom controls in asthmatic children can be achieved through compliant use of conventional medication, some children have uncontrolled severe persistent asthma, especially if they are allergic. For these children, omalizumab (approved by the EMA and FDA in children aged > 6 years) could be a therapeutic option. However, response to omalizumab varies from one child to another. Predictive biomarkers of omalizumab effectiveness could be useful to monitor response to treatment. Area covered: The authors searched in the PubMed database for publications related to the use of biomarkers in allergic asthma. Supported by their own experience in phenotyping asthma in children, they analyzed whether these biomarkers could be useful in assessing response to omalizumab. Expert commentary: Th2 inflammation in children with allergic asthma can be assessed by measuring several biomarkers (blood eosinophil, serum ECP or periostin, FeNO). While a single measurement may be insufficient, a combination of biomarkers assessments may improve the follow-up of children treated by omalizumab.

The current and future role of biomarkers in type 2 cytokine-mediated asthma management

Assessment and management of asthma is complicated by the heterogeneous pathophysiological mechanisms that underlie its clinical presentation, which are not necessarily reflected in standardized management paradigms and which necessitate an individualized approach to treatment. This is particularly important with the emerging availability of a variety of targeted forms of therapy that may only be appropriate for use in particular patient subgroups. The identification of biomarkers can potentially aid diagnosis and inform prognosis, help guide treatment decisions and allow clinicians to predict and monitor response to treatment. Biomarkers for asthma have been identified from a variety of sources, including airway, exhaled breath and blood. Biomarkers from exhaled breath include fractional exhaled nitric oxide, measurement of which can help identify patients most likely to benefit from inhaled corticosteroids and targeted anti-immunoglobulin E therapy. Biomarkers measured in blood are relatively non-invasive and technically more straightforward than those measured from exhaled breath or directly from the airway. The most well established of these are the blood eosinophil count and serum periostin, both of which have demonstrated utility in identifying patients most likely to benefit from targeted anti-interleukin and anti-immunoglobulin E therapies, and in monitoring subsequent treatment response. For example, serum periostin appears to be a biomarker for responsiveness to inhaled corticosteroid therapy and may help identify patients as suitable candidates for anti-IL-13 treatment. The use of biomarkers can therefore potentially help avoid unnecessary morbidity from high-dose corticosteroid therapy and allow the most appropriate and cost-effective use of targeted therapies. Ongoing clinical trials are helping to further elucidate the role of established biomarkers in routine clinical practice, and a range of other circulating novel potential biomarkers are currently being investigated in the research setting.

Periostin in inflammation and allergy

We found for the first time that IL-4 and IL-13, signature type 2 cytokines, are able to induce periostin expression. We and others have subsequently shown that periostin is highly expressed in chronic inflammatory diseases-asthma, atopic dermatitis, eosinophilc chronic sinusitis/chronic rhinosinusitis with nasal polyp, and allergic conjunctivitis-and that periostin plays important roles in the pathogenesis of these diseases. The epithelial/mesenchymal interaction via periostin is important for the onset of allergic inflammation, in which periostin derived from fibroblasts acts on epithelial cells or fibroblasts, activating their NF-κB. Moreover, the immune cell/non-immune cell interaction via periostin may be also involved. Now the significance of periostin has been expanded into other inflammatory or fibrotic diseases such as scleroderma and pulmonary fibrosis. The cross-talk of periostin with TGF-β or pro-inflammatory cytokines is important for the underlying mechanism of these diseases. Because of its pathogenic importance and broad expression, diagnostics or therapeutic drugs can be potentially developed to target periostin as a means of treating these diseases.

Utility of serum periostin in combination with exhaled nitric oxide in the management of asthma

Type-2/eosinophilic inflammation plays a pivotal role in asthma. The identification of severe type-2/eosinophilic asthma is important for improving the management of patients with asthma. Therefore, efforts to develop non-invasive biomarkers for type-2/eosinophilic airway inflammation have been made during this decade. Currently, fraction of exhaled nitric oxide (FeNO) and serum periostin levels are considered markers of type-2/eosinophilic inflammation in asthma. However, a single-marker approach has limited the ability to diagnose severe type-2/eosinophilic asthma accurately and predict disease outcomes precisely. The present article reviews the utility of FeNO and serum periostin levels in a single-marker approach and in a multiple-marker approach in identifying patients with severe type-2/eosinophilic asthma. Furthermore, based on a sub-analysis of the Kinki Hokuriku Airway disease Conference (KiHAC), geno-endo-phenotypes of patients were stratified into four groups according to the FeNO and serum periostin levels.

Using Periostin as a Biomarker in the Treatment of Asthma

Periostin acts both as an extracellular matrix protein belonging to the fasciclin family and as a matricellular protein functioning in cell activation by binding to its receptors on the cell surface. It has been established that periostin is a downstream molecule of interleukin (IL)-13, a signature type 2 cytokine, and that periostin plays an important role in the pathogenesis of allergic diseases, including asthma. Based on these findings, much attention has been paid to periostin as a biomarker useful in the treatment of asthma. Periostin is a surrogate biomarker for type 2 immunity; it has been shown that serum periostin can predict the efficacy of anti-IL-13 antibodies (lebrikizumab) and anti-IgE antibodies (omalizumab), and that this usefulness can be potentially expanded to other type 2 antagonists. Moreover, it has been shown that periostin is not a simple surrogate biomarker for type 2 immunity; periostin-high asthma patients have several unique characteristics, including eosinophilia, high fraction of nitric oxide, aspirin intolerance, nasal disorders, and late onset. These characteristics are likely to be correlated with the involvement of periostin in the tissue remodeling of asthma. Periostin is also associated with hyporesponsiveness to inhaled corticosteroids, probably reflecting tissue remodeling. Thus, periostin has 2 characteristics as a biomarker for early diagnosis of asthma: surrogate biomarkers for type 2 immunity and tissue remodeling. Based on these characteristics, we will be able to apply serum periostin to treatment of asthma.

Relationships between adult asthma and oxidative stress markers and pH in exhaled breath condensate: a systematic review

Oxidative stress has a recognized role in the pathophysiology of asthma. Recently, interest has increased in the assessment of pH and airway oxidative stress markers. Collection of exhaled breath condensate (EBC) and quantification of biomarkers in breath samples can potentially indicate lung disease activity and help in the study of airway inflammation, and asthma severity. Levels of oxidative stress markers in the EBC have been systematically evaluated in children with asthma; however, there is no such systematic review conducted for adult asthma. A systematic review of oxidative stress markers measured in EBC of adult asthma was conducted, and studies were identified by searching MEDLINE and SCOPUS databases. Sixteen papers met the inclusion criteria. Concentrations of exhaled hydrogen ions, nitric oxide products, hydrogen peroxide and 8-isoprostanes were generally elevated and related to lower lung function tests in adults with asthma compared to healthy subjects. Assessment of EBC markers may be a noninvasive approach to evaluate airway inflammation, exacerbations, and disease severity of asthma, and to monitor the effectiveness of anti-inflammatory treatment regimens. Longitudinal studies, using standardized analytical techniques for EBC collection, are required to establish reference values for the interpretation of EBC markers in the context of asthma.

Assessing biomarkers in a real-world severe asthma study (ARIETTA)

The prognostic value of asthma biomarkers in routine clinical practice is not fully understood. ARIETTA (NCT02537691) is an ongoing, prospective, longitudinal, international, multicentre real-world study designed to assess the relationship between asthma biomarkers and disease-related health outcomes. The trial aims to enrol and follow for 52 weeks approximately 1200 severe asthma patients from approximately 160 sites in more than 20 countries. Severe asthmatics, treated with daily inhaled corticosteroid (≥500 μg of fluticasone propionate or equivalent) and at least 1 second controller medication are to be included. In this real-world study, patients will be treated according to the investigator's routine clinical practices and no treatment regimen will be implemented as part of the trial. At baseline and again at 26 and 52 weeks, FEV1, FeNO, serum periostin, blood eosinophil count and serum IgE will be measured. Asthma-related symptom and quality of life questionnaires will be administered at the visits and during telephone interviews at Weeks 13 and 39. Data about medication use, asthma exacerbation data, asthma-related healthcare utilization and events raising safety concerns will also be collected. This study design, unique in both its scope and scale, will address fundamental unanswered questions regarding asthma biomarkers and their interrelationship, as well as predict deviations in the course of asthma in a real-world setting.

Recent developments regarding periostin in bronchial asthma

Although it is currently recognized that bronchial asthma is not a single disease but a syndrome, we have not yet made use of our new understanding of this heterogeneity as we treat asthma patients. To increase the efficacy of anti-asthma drugs and to decrease costs, it is important to stratify asthma patients into subgroups and to develop therapeutic strategies for each subgroup. Periostin has recently emerged as a biomarker for bronchial asthma, unique in that it is useful not in diagnosis but in categorizing asthma patients. We first found that periostin is a novel component of subepithelial fibrosis in bronchial asthma downstream of IL-13 signals. Thereafter, it was shown that periostin can be a surrogate biomarker of type 2 immune responses, the basis of the notion that a detection system of serum periostin is potentially a companion diagnostic for type 2 antagonists. Furthermore, we have recently shown that serum periostin can predict resistance or hyporesponsiveness to inhaled corticosteroids, based on its contribution to tissue remodeling or fibrosis in bronchial asthma. Thus, serum periostin has two characteristics as a biomarker for bronchial asthma: it is both a surrogate biomarker of type 2 immune responses and a biomarker reflecting tissue remodeling or fibrosis. We can take advantage of these characteristics to develop stratified medicine in bronchial asthma.

Clinical and biological markers of asthma control

Asthma has substantial impact on the patient, their family and health systems, and its control has gained increasing attention. Perception of asthma control has varied widely among patients as well as healthcare providers. Several clinical markers have been developed to define and standardize the measurement of asthma control. They are based primarily on patients' symptoms and have been popular in clinical practice and in clinical studies. With the advances in basic research on the pathology of asthma, several biological markers have evolved that have the advantages of being objective, quantitative and more reflective of the underlying pathology, which makes them a better guide for selecting optimal therapy. In addition to the cost and expertise required, biological makers are influenced by multiple factors that limit their application in clinical practice. Ongoing research is expected to define the role of individual biological markers, the optimal method of their application, and their appropriate interpretation.

Serum periostin: a novel biomarker for asthma management

Chronic airway inflammation and remodeling are fundamental features of asthma. Even with adequate inhaled corticosteroid (ICS) treatment, there are still patients who exhibit Th2/eosinophilic inflammation and develop airflow limitation, a functional consequence of airway remodeling. There are few biomarkers that are applicable in the clinical setting that reflect refractory Th2/eosinophilic inflammation and remodeling of the asthmatic airways. Therefore, establishing such biomarkers is essential for managing patients who suffer from these conditions. This review addresses the importance of serum periostin measurements by describing observations made in a KiHAC multicenter cohort with periostin used as a marker of pulmonary function decline and refractory Th2/eosinophilic inflammation in patients with asthma receiving long-term ICS treatment. Furthermore, serum periostin could be a companion diagnostic for targeted therapy against refractory Th2/eosinophilic inflammation. Finally, the distinct characteristics of serum periostin as compared to conventional biomarkers are addressed.

Periostin in allergic inflammation

Periostin, an extracellular matrix protein belonging to the fasciclin family, has been shown to play a critical role in the process of remodeling during tissue/organ development or repair. Periostin functions as a matricellular protein in cell activation by binding to their receptors on cell surface, thereby exerting its biological activities. After we found that periostin is a downstream molecule of interleukin (IL)-4 and IL-13, signature cytokines of type 2 immune responses, we showed that periostin is a component of subepithelial fibrosis in bronchial asthma, the first formal proof that periostin is involved in allergic inflammation. Subsequently, a great deal of evidence has accumulated demonstrating the significance of periostin in allergic inflammation. It is of note that in skin tissues, periostin is critical for amplification and persistence of allergic inflammation by communicating between fibroblasts and keratinocytes. Furthermore, periostin has been applied to development of novel diagnostics or therapeutic agents for allergic diseases. Serum periostin can reflect local production of periostin in inflamed lesions induced by Th2-type immune responses and also can predict the efficacy of Th2 antagonists against bronchial asthma. Blocking the interaction between periostin and its receptor, αv integrin, or down-regulating the periostin expression shows improvement of periostin-induced inflammation in mouse models or in in vitro systems. It is hoped that diagnostics or therapeutic agents targeting periostin will be of practical use in the near future.