Biomarkers in asthma and allergic rhinitis

Choosing the right biologic treatment for individual patients with severe asthma - Lessons learnt from Picasso

Severe asthma represents a true challenge for clinicians from two basic perspectives, i.e.: a rational assessment of the underlying endo/phenotype and the subsequent selection of the best fitted (personalized) and effective treatment. Even though asthma is a heterogeneous disease, in the majority of therapy-compliant patients, it is possible to achieve (almost) complete disease control or even remission through conventional and quite uniform step-based pharmacotherapy, even without phenotyping. However, the absence of deeper assessment of individual patients revealed its handicap to its fullest extent during the first years of the new millennium upon the launch of biological therapeutics for patients with the most severe forms of asthma. The introduction of differentially targeted biologics into clinical practice became a challenge in terms of understanding and recognizing the etiopathogenetic heterogeneity of the asthmatic inflammation, pheno/endotyping, and, consequently, to choose the right biologic for the right patient. The answers to the following three questions should lead to correct identification of the dominant pheno/endotype: Is it really (severe) asthma? Is it eosinophilic asthma? If eosinophilic, is it (predominantly) allergen-driven? The identification of the best achievable and relevant alliance between endotypes and phenotypes ("euphenotypes") should be based not only on the assessment of the actual clinical characteristics and laboratory biomarkers, but more importantly, on the evaluation of their development and changes over time. In the current paper, we present a pragmatic three-step approach to severe asthma diagnosis and management.

Eosinophils-from cradle to grave: An EAACI task force paper on new molecular insights and clinical functions of eosinophils and the clinical effects of targeted eosinophil depletion

Over the past years, eosinophils have become a focus of scientific interest, especially in the context of their recently uncovered functions (e.g. antiviral, anti-inflammatory, regulatory). These versatile cells display both beneficial and detrimental activities under various physiological and pathological conditions. Eosinophils are involved in the pathogenesis of many diseases which can be classified into primary (clonal) and secondary (reactive) disorders and idiopathic (hyper)eosinophilic syndromes. Depending on the biological specimen, the eosinophil count in different body compartments may serve as a biomarker reflecting the underlying pathophysiology and/or activity of distinct diseases and as a therapy-driving (predictive) and monitoring tool. Personalized selection of an appropriate therapeutic strategy directly or indirectly targeting the increased number and/or activity of eosinophils should be based on the understanding of eosinophil homeostasis including their interactions with other immune and non-immune cells within different body compartments. Hence, restoring as well as maintaining homeostasis within an individual's eosinophil pool is a goal of both specific and non-specific eosinophil-targeting therapies. Despite the overall favourable safety profile of the currently available anti-eosinophil biologics, the effect of eosinophil depletion should be monitored from the perspective of possible unwanted consequences.

Standardization of clinical outcomes used in allergen immunotherapy in allergic asthma: An EAACI position paper

INTRODUCTION

In allergic asthma patients, one of the more common phenotypes might benefit from allergen immunotherapy (AIT) as add-on intervention to pharmacological treatment. AIT is a treatment with disease-modifying modalities, the evidence for efficacy is based on controlled clinical trials following standardized endpoint measures. However, so far there is a lack of a consensus for asthma endpoints in AIT trials. The aim of a task force (TF) of the European Academy of Allergy and Clinical Immunology (EAACI) is evaluating several outcome measures for AIT in allergic asthma.

METHODS

The following domains of outcome measures in asthmatic patients have been evaluated for this position paper (PP): (i) exacerbation rate, (ii) lung function, (iii) ICS withdrawal, (iv) symptoms and rescue medication use, (v) questionnaires (PROMS), (vi) bronchial/nasal provocation, (vii) allergen exposure chambers (AEC) and (viii) biomarkers.

RESULTS

Exacerbation rate can be used as a reliable objective primary outcome; however, there is limited evidence due to different definitions of exacerbation. The time after ICS withdrawal to first exacerbation is considered a primary outcome measure. Besides, the advantages and disadvantages and clinical implications of further domains of asthma endpoints in AIT trials are elaborated in this PP.

CONCLUSION

This EAACI-PP aims to highlight important aspects of current asthma measures by critically evaluating their applicability for controlled trials of AIT.

New insights into the pathophysiology and therapeutic targets of asthma and comorbid chronic rhinosinusitis with or without nasal polyposis

Asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) or without (CRSsNP) are chronic respiratory diseases. These two disorders often co-exist based on common anatomical, immunological, histopathological, and pathophysiological basis. Usually, asthma with comorbid CRSwNP is driven by type 2 (T2) inflammation which predisposes to more severe, often intractable, disease. In the past two decades, innovative technologies and detection techniques in combination with newly introduced targeted therapies helped shape our understanding of the immunological pathways underlying inflammatory airway diseases and to further identify several distinct clinical and inflammatory subsets to enhance the development of more effective personalized treatments. Presently, a number of targeted biologics has shown clinical efficacy in patients with refractory T2 airway inflammation, including anti-IgE (omalizumab), anti-IL-5 (mepolizumab, reslizumab)/anti-IL5R (benralizumab), anti-IL-4R-α (anti-IL-4/IL-13, dupilumab), and anti-TSLP (tezepelumab). In non-type-2 endotypes, no targeted biologics have consistently shown clinical efficacy so far. Presently, multiple therapeutical targets are being explored including cytokines, membrane molecules and intracellular signalling pathways to further expand current treatment options for severe asthma with and without comorbid CRSwNP. In this review, we discuss existing biologics, those under development and share some views on new horizons.

Allergen immunotherapy for allergic asthma: The future seems bright

Allergen specific immunotherapy (AIT) is the only causal therapeutic option for allergic airway diseases including asthma and allergic rhinitis. AIT has been shown to restore the allergen immune tolerance, can modify both the early and late-onset allergen-specific airway hyperreactivity, helps to achieve disease control/remission and prevents new sensitisations. Recent real life data on long-term effectiveness of house dust mite (HDM) AIT in a large group of patients with HDM-driven asthma further underscored its unique therapeutic potential as well as confirmed previous data with pollen AIT. More widespread use of this causal treatment in select patient populations should further move this promising therapeutic field. In this mini-review, we discuss updates on new insights based on real world patient data.

Gut Microbiome Proteomics in Food Allergies

Food allergies (FA) have dramatically increased in recent years, particularly in developed countries. It is currently well-established that food tolerance requires the strict maintenance of a specific microbial consortium in the gastrointestinal (GI) tract microbiome as alterations in the gut microbiota can lead to dysbiosis, causing inflammation and pathogenic intestinal conditions that result in the development of FA. Although there is currently not enough knowledge to fully understand how the interactions between gut microbiota, host responses and the environment cause food allergies, recent advances in '-omics' technologies (i.e., proteomics, genomics, metabolomics) and in approaches involving systems biology suggest future headways that would finally allow the scientific understanding of the relationship between gut microbiome and FA. This review summarizes the current knowledge in the field of FA and insights into the future advances that will be achieved by applying proteomic techniques to study the GI tract microbiome in the field of FA and their medical treatment. Metaproteomics, a proteomics experimental approach of great interest in the study of GI tract microbiota, aims to analyze and identify all the proteins in complex environmental microbial communities; with shotgun proteomics, which uses liquid chromatography (LC) for separation and tandem mass spectrometry (MS/MS) for analysis, as it is the most promising technique in this field.

HSP70 upregulation in nasal mucosa of symptomatic children with allergic rhinitis and potential risk of asthma development

Allergic rhinitis and asthma are the most common causes of chronic inflammation of the upper and lower airways in childhood. However, a nasal biomarker that can link to pulmonary inflammation is yet to be found. The present paper aims to investigate the possible role in inflammation of two inducible 70-kDa Heat Shock Proteins (HSP70) members, HSPA1A/B and HSPA6, in nasal mucosa cells of allergic children through their mRNA expression analysis, and their correlation to both spirometric and FeNO values. The relationship between FeNO in lower airways and ∆Cts of HSPA1A/B in nasal mucosa seems to be influenced by clinical symptoms regardless of age, sex, and sensitization patterns. Therefore, HSP70 expression, as well as FeNO levels, could have a predictive capability to identify lower airways inflammation and thus to recognize rhinitic children having a potential risk of asthma development.

Cell-Type Specific Expression of Hyaluronan Synthases HAS2 and HAS3 Promotes Goblet Cell Hyperplasia in Allergic Airway Inflammation

Allergic rhinitis (AR) is a multifactorial airway disease characterized by basal and goblet cell hyperplasia. Hyaluronic acid (HA) is a major component of extracellular matrix and a critical contributor to tissue repair and remodeling after injury. We previously demonstrated that the intermediate progenitor cell (IPC) surface marker CD44v3 is upregulated in the basal and suprabasal layers of well-differentiated primary human nasal epithelial (HNE) cells after stimulation with the Th2 cytokine interleukin (IL)-4, and an antibody blocking the CD44v3-HA interaction suppressed IL-4-induced goblet cell hyperplasia. We now show that the expression of HA and two HA synthases, HAS2 and HAS3, was upregulated in both the nasal surface epithelium of subjects with AR and IL-4-stimulated HNE cells. Inhibition of HA synthesis by 4-methylumbelliferone (4-MU) suppressed IL-4-induced goblet cell hyperplasia. Moreover, HAS2 and HAS3 were expressed in IPCs depending on the differentiation events, as follows: the rapid, transient upregulation of HAS2 induced basal IPC proliferation and basal-to-suprabasal transition, whereas the delayed upregulation of HAS3 promoted the transition of suprabasal IPCs to a goblet cell fate. 4-MU treatment in house dust mite-induced murine AR model attenuated goblet cell metaplasia. Lastly, HA levels in nasal epithelial lining fluids from AR patients positively correlated with the levels of mediators causing allergic inflammation. These data suggest that HA produced following the sequential upregulation of HAS2 and HAS3 contributes to goblet cell hyperplasia in allergic airway inflammation and modulates disease progression.

Current Insights on the Impact of Proteomics in Respiratory Allergies

Respiratory allergies affect humans worldwide, causing extensive morbidity and mortality. They include allergic rhinitis (AR), asthma, pollen food allergy syndrome (PFAS), aspirin-exacerbated respiratory disease (AERD), and nasal polyps (NPs). The study of respiratory allergic diseases requires new technologies for early and accurate diagnosis and treatment. Omics technologies provide the tools required to investigate DNA, RNA, proteins, and other molecular determinants. These technologies include genomics, transcriptomics, proteomics, and metabolomics. However, proteomics is one of the main approaches to studying allergic disorders' pathophysiology. Proteins are used to indicate normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. In this field, the principal goal of proteomics has been to discover new proteins and use them in precision medicine. Multiple technologies have been applied to proteomics, but that most used for identifying, quantifying, and profiling proteins is mass spectrometry (MS). Over the last few years, proteomics has enabled the establishment of several proteins for diagnosing and treating respiratory allergic diseases.

Allergen Provocation Tests in Respiratory Research: Building on 50 Years of Experience

Allergen provocation test is an established model of allergic airway diseases, including asthma and allergic rhinitis, allowing the study of allergen-induced changes in respiratory physiology and inflammatory mechanisms in sensitised individuals as well as their associations. In the upper airways, allergen challenge is focused on the clinical and pathophysiological sequelae of the early allergic response and applied both as a diagnostic tool and in research settings. In contrast, the bronchial allergen challenge has almost exclusively served as a research tool in specialised research settings with a focus on the late asthmatic response and the underlying type 2 inflammation. The allergen-induced late asthmatic response is also characterised by prolonged airway narrowing, increased non-specific airway hyperresponsiveness and features of airway remodelling including the small airways, and hence, allows the study of several key mechanisms and features of asthma. In line with these characteristics, the allergen challenge has served as a valued tool to study the crosstalk of the upper and lower airways and in proof of mechanism studies of drug development. In recent years, several new insights into respiratory phenotypes and endotypes including the involvement of the upper and small airways, innovative biomarker sampling methods and detection techniques, refined lung function testing as well as targeted treatment options, further shaped the applicability of the allergen provocation test in precision medicine. These topics, along with descriptions of subject populations and safety, in line with the updated GINA2021, will be addressed in this paper.

Aberrant expressions of circulating lncRNA NEAT1 and microRNA‐125a are linked with Th2 cells and symptom severity in pediatric allergic rhinitis

Objective

Long noncoding RNA nuclear enriched abundant transcript 1 (lnc‐NEAT1) and its target microRNA‐125a (miR‐125a) are reported to regulate immune and inflammation process in allergic rhinitis (AR). Hence, this study intended to investigate the correlation between lnc‐NEAT1 and miR‐125a expressions, as well as their clinical values in pediatric AR patients.

Methods

Peripheral blood mononuclear cell samples from 80 pediatric AR patients, 40 disease controls (DCs), and 40 healthy controls (HCs) were collected to detect lnc‐NEAT1 and miR‐125a expressions by reverse transcription‐quantitative polymerase chain reaction. For pediatric AR patients only, serum interferon‐gamma (IFN‐γ) and interleukin (IL)‐10 were measured by enzyme linked immunosorbent assay; meanwhile, T helper (Th) 1 and Th2 cells in CD4⁺ T cells were analyzed by flow cytometry.

Results

Lnc‐NEAT1 was overexpressed, while miR‐125a downregulated in pediatric AR patients compared to DCs and HCs (all p < 0.001). Moreover, lnc‐NEAT1 expression negatively correlated with miR‐125a expression in pediatric AR patients (p = 0.002), but not in DCs (p = 0.226) or HCs (p = 0.237). Furthermore, in pediatric AR patients, lnc‐NEAT1 expression positively associated with TNSS (p < 0.001), sneezing score (p = 0.006), and congestion score (p = 0.008); miR‐125a expression was negatively related to TNSS (p < 0.001), itching score (p = 0.040), and sneezing score (p = 0.005). Additionally, lnc‐NEAT1 expression positively, while miR‐125a expression negatively correlated with Th2 cells and IL‐10 (all p < 0.05), but they were not correlated with Th1 cells or IFN‐γ in pediatric AR patients.

Conclusion

Circulating lnc‐NEAT1 and miR‐125a are aberrantly expressed and linked with Th2 cells and symptom severity in pediatric allergic rhinitis.

The Similarity of Biomarkers Level between Direct Nasal Fluid and Nasal Lavage Fluid in Allergic Rhinitis Patients

Background and Objectives: Biomarkers of allergic rhinitis (AR) have been studied; however, little is known regarding their practical application in the diagnosis of AR. Previous studies collected samples using saline lavage, nasal brushing, or nasal biopsy. To utilize nasal fluid as a diagnostic tool, we need to standardize the method of sample collection. Therefore, this study aimed to evaluate the difference in concentration of biomarkers depending on the method of nasal fluid collection.Materials and Method: Forty-five AR patients who had greater than moderate AR symptoms and who had positive results on skin prick test and serum-specific IgE tests were enrolled in this study. Nasal fluid was collected using the direct method or saline lavage method. The concentration of each biomarker was analyzed using enzyme-linked immunosorbent assay and the values compared.Results: Nasal fluid samples were collected directly from 14 patients and were collected via saline lavage in 31 patients. No significant differences were found in the median value of each biomarker between the two methods of nasal sample collection.Conclusion: Nasal fluid collection method does not significantly affect biomarker concentration.

Measurement of Tryptase and CC16/Albumin in Nasal Lavage Fluid as a Screening Tool of Allergic Rhinitis

BACKGROUND

There is no trial to make a diagnostic tool of allergic rhinitis (AR) utilizing biomarkers from nasal fluid. Base on previous studies, we selected following five biomarkers in nasal fluids that represent the characteristics of allergic reactions: tryptase, eosinophil cationic protein (ECP), interleukin 5 (IL-5), Clara cell protein 16 (CC16) and CC16-to-albumin ratio.

OBJECTIVE

This study aimed to identify biomarkers in nasal discharge that may be used in biosensors to diagnose AR as an additional diagnostic tool.

METHODS

Patients showed rhinorrhea and tested positive on allergic skin and specific immunoglobulin E (IgE) tests were included in the AR group. The non-AR group included individuals no dominant nasal symptoms and tested negative on allergy tests. Nasal lavage fluid samples were collected from all participants. Biomarkers in the samples were quantified using enzyme-linked immunosorbent assay.

RESULTS

Forty-five patients with AR and 28 non-AR subjects were enrolled in this study. Comparing the concentrations of biomarkers, the concentrations of tryptase and IL-5 were significantly higher in the AR group than in the NAR group. And CC16 level and CC16-to-albumin ratio were significantly lower in the AR group. In the combination of tryptase or CC16-to-albumin ratio, the sensitivity was 90.7% and the specificity was 64.3% (p = 0.013).

CONCLUSION

The combination of "tryptase or CC16-to-albumin" could be used as a screening tool for AR. Although this diagnostic method could not replace conventional diagnostic tools, we could consider the method we proposed as an additional screening tool for patients who could not undergo allergy tests.

Allergen bronchoprovocation test: an important research tool supporting precision medicine

PURPOSE OF REVIEW

Allergen bronchoprovocation test (ABT) has been used to study asthma pathophysiology and as a disease-modelling tool to assess the properties and efficacy of new asthma drugs. In view of the complexity and heterogeneity of asthma, which has driven the definition of several phenotypes and endotypes, we aim to discuss the role of ABT in the era of precision medicine and provide guidance for clinicians how to interpret and use available data to understand the implications for the benefits of asthma treatment.

RECENT FINDINGS

In this review, we summarize background knowledge and applications of ABT and provide an update with recent publications on this topic. In the past years, several studies have been published on ABT in combination with non-invasive and invasive airway samplings and innovative detection techniques allowing to study several inflammatory mechanisms linked to Th2-pathway and allergen-induced pathophysiology throughout the airways.

SUMMARY

ABT is a valuable research tool, which has strongly contributed to precision medicine by helping to define allergen-triggered key inflammatory pathways and airway pathophysiology, and thus helped to shape our understanding of allergen-driven asthma phenotypes and endotypes. In addition, ABT has been instrumental to assess the interactions and effects of new-targeted asthma treatments along these pathways.

Biomarkers for diagnosis and prediction of therapy responses in allergic diseases and asthma

Modern health care requires a proactive and individualized response to diseases, combining precision diagnosis and personalized treatment. Accordingly, the approach to patients with allergic diseases encompasses novel developments in the area of personalized medicine, disease phenotyping and endotyping, and the development and application of reliable biomarkers. A detailed clinical history and physical examination followed by the detection of IgE immunoreactivity against specific allergens still represents the state of the art. However, nowadays, further emphasis focuses on the optimization of diagnostic and therapeutic standards and a large number of studies have been investigating the biomarkers of allergic diseases, including asthma, atopic dermatitis, allergic rhinitis, food allergy, urticaria and anaphylaxis. Various biomarkers have been developed by omics technologies, some of which lead to a better classification of distinct phenotypes or endotypes. The introduction of biologicals to clinical practice increases the need for biomarkers for patient selection, prediction of outcomes and monitoring, to allow for an adequate choice of the duration of these costly and long‐lasting therapies. Escalating healthcare costs together with questions about the efficacy of the current management of allergic diseases require further development of a biomarker‐driven approach. Here, we review biomarkers in diagnosis and treatment of asthma, atopic dermatitis, allergic rhinitis, viral infections, chronic rhinosinusitis, food allergy, drug hypersensitivity and allergen immunotherapy with a special emphasis on specific IgE, the microbiome and the epithelial barrier. In addition, EAACI guidelines on biologicals are discussed within the perspective of biomarkers.

Associations between household renovation and rhinitis among preschool children in China: A cross-sectional study

During 2010-2012, we surveyed 40,010 3- to 6-year-old children in seven Chinese cities (Beijing, Taiyuan, Urumqi, Shanghai, Nanjing, Changsha, and Chongqing). Their parents reported information on household renovation, including the timing of renovation and the choice of materials for walls and floors in the child's room, and the incidence of their child's rhinitis. Multivariate and two-level (city-child) logistic regression analyses yielding adjusted odds ratios (AOR) with 95% confidence intervals were performed. Sensitivity analyses stratifying data for location and economic level were also performed. About 48.0% of the children had ever had allergic rhinitis, 41.2% had current allergic rhinitis, and 9.0% had had doctor-diagnosed rhinitis. Exposure to household renovation during early lifetime (birth to 1-year-old) had an AOR of 1.43 (1.04-1.9) for allergic rhinitis. The incidence of allergic rhinitis was significantly different in children exposed to different floor and wall covering materials. Floor or wall covering material composed of organic materials significantly increased the risk of childhood allergic rhinitis compared with tile flooring or lime wall covering. Oil paint had an AOR of 1.66 (1.28-2.14) for diagnosed rhinitis compared with lime wall covering. Adding new furniture the year before pregnancy was associated with an AOR of 1.18 (1.10-1.27) and 1.18 (1.11-1.25) for lifetime and current rhinitis. Solid wood or tiles/ceramic as floor materials, and using wallpaper, oil paint, or emulsion panels as wall materials were risk factors for doctor-diagnosed rhinitis. Sensitivity analyses showed that children living in southern or higher economic level China cities were more likely to have allergic rhinitis with household renovation.

Correlation of Nasal Fluid Biomarkers and Symptoms in Patients with Persistent Allergic Rhinitis

OBJECTIVES

This study investigated whether the biomarkers present in nasal fluid reflect the severity of symptoms in patients with persistent allergic rhinitis (PAR).

METHODS

We enrolled 29 PAR patients complaining of nasal symptoms and testing positive to skin prick test. Patients' total nasal symptom score (TNSS) was measured and their nasal lavage fluid (NALF) was collected. The levels of biomarkers including Clara cell protein 16 (CC16), tryptase, and interleukin 5 (IL-5) in NALF were determined via enzyme-linked immunosorbent assay (ELISA).

RESULTS

PAR patients were classified into persistent mild and persistent moderate-to-severe groups according to the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. The CC16 alone was significantly negatively correlated with TNSS (P < .05). Further, the CC16 level was significantly lower in persistent moderate-to-severe group than persistent mild group of patients (P < .05).

CONCLUSIONS

The levels of CC16 alone among several NALF biomarkers showed an inverse correlation with symptoms of PAR patients.

The current state of omics technologies in the clinical management of asthma and allergic diseases

OBJECTIVE

To review the state of omics science specific to asthma and allergic diseases and discuss the current and potential applicability of omics in clinical disease prediction, treatment, and management.

DATA SOURCES

Studies and reviews focused on the use of omics technologies in asthma and allergic disease research and clinical management were identified using PubMed.

STUDY SELECTIONS

Publications were included based on relevance, with emphasis placed on the most recent findings.

RESULTS

Omics-based research is increasingly being used to differentiate asthma and allergic disease subtypes, identify biomarkers and pathological mediators, predict patient responsiveness to specific therapies, and monitor disease control. Although most studies have focused on genomics and transcriptomics approaches, increasing attention is being placed on omics technologies that assess the effect of environmental exposures on disease initiation and progression. Studies using omics data to identify biological targets and pathways involved in asthma and allergic disease pathogenesis have primarily focused on a specific omics subtype, providing only a partial view of the disease process.

CONCLUSION

Although omics technologies have advanced our understanding of the molecular mechanisms underlying asthma and allergic disease pathology, omics testing for these diseases are not standard of care at this point. Several important factors need to be addressed before these technologies can be used effectively in clinical practice. Use of clinical decision support systems and integration of these systems within electronic medical records will become increasingly important as omics technologies become more widely used in the clinical setting.

Serum IL-1β can be a biomarker in children with severe persistent allergic rhinitis

Background

Allergic rhinitis (AR) is one of the most common diseases globally and usually persists throughout life. In the present study, we aimed to determine whether the expression of inflammatory biomarkers has a relationship with the severity of allergic rhinitis and with comorbid asthma or other allergic diseases in children.

Methods

For diagnosis of AR, the skin prick test was performed to measure the responses to 18 allergens. Blood levels of eosinophils and immunoglobulin E (IgE) were examined. We classified the patients into 2 groups based on the severity of the condition as Group 1 [intermittent AR (IAR) or mild persistent AR (PAR)] and Group 2 (moderate to severe PAR). To determine the expression of inflammatory biomarkers, in serum and several biomarkers (caspase-1, IL-1β, CCL-11, CCL-24 and IL-33) were measured in the serum using enzyme-linked immunosorbent assay (ELISA). Additionally, we analyzed the correlation between clinical variables and the expression of biomarkers (eosinophils count, IL-1β and CCL-24) and the severity of AR.

Results

We found that eosinophils count, IL-1β, a marker of activation of inflammasomes, and CCL-24 were significantly increased in the moderate to severe PAR group (p = 0.008, p = 0.003, p = 0.039). Additionally, the expressions of eosinophil count, IL-1β and CCL-24 were significantly higher in patients with active asthmatic symptoms than in those without these conditions. On univariate analysis, allergic rhinitis in sibling, paternal allergic rhinitis, high expression of eosinophils count, IL-1β and CCL-24, history of active asthma and atopy correlated with severity of AR. Multivariate analysis showed only paternal allergic rhinitis and high expression of IL-1β as significant risk factors of moderate to severe PAR with 6.4 fold and 4.7 fold-increase in risk, respectively (p = 0.011 and p = 0.030).

Conclusion

In conclusion, this study provides the first evidence that an excessive release of biologically active IL-1β may promote inflammation in severe PAR. It demonstrates that IL-1β can be a biomarker for active allergic diseases such as AR, asthma, and atopy. Moreover, this finding suggests that IL-1B should be investigated as a therapeutic target in severe PAR and other allergic diseases.

Development of an effective sample transfer device for biomarker detection in nasal secretions

Nasal secretions (NS) reflect inflammatory activity of the nasal mucosa and thus can be utilized for disease diagnosis and determining treatment effects in Allergic rhinitis (AR). However, non-standardized collection of samples can affect the measured concentration of inflammatory biomarker in NS. In this study, we aimed to develop and evaluate new devices capable of standardizing the collection, storage, and preprocessing methods of NS samples. First, we chose the best swab as polyester (PE) and selected a stimulation method, twirling for 10 s at 1 Hz, to efficiently release AR biomarkers from a PE swab. Storage of sample solutions at -20 °C was optimal for the stability of biomarkers for the detection of AR. The new swab sample transfer device showed excellent concentration recovery efficiency (90-100%) for tryptase (Trp) and eosinophil cationic protein (ECP) without crosstalk between the two biomarkers. Finally, we compared the concentration of Trp in human NS samples of AR patients (n = 6) pre-processed by the new device with that by centrifuge as a standard method. As a result, the concentrations of Trp in NS were very similar in both groups. Therefore, this device can be utilized as an effective sample transfer and pre-processing device for point-of-care testing of AR.

Evaluation of nasal fluid β-defensin 2 levels in children with allergic rhinitis

AIM

Knowledge about the role of the innate immune system in the pathogenesis of allergic diseases has been expanding in recent years. Defensins are antimicrobial peptides that are components of the innate immune system. Defensins have strong efficacy against bacterial, viral, and fungal infections. Moreover, they have regulatory functions in many physiologic processes such as antitumoral immunity, chemotaxis, inflammation, and wound healing. In this study, we aimed to investigate β-defensin 2 levels in the nasal fluids of children with allergic rhinitis.

MATERIAL AND METHODS

Study and control groups consisted of 28 patients with newly diagnosed allergic rhinitis who were not taking any medication, and 23 healthy children. Skin prick tests were performed on patients with allergic rhinitis and disease severity was assessed using the total symptom score. Nasal fluid samples were obtained using a modified polyurethane sponge absorption method from patients and control subjects. Nasal fluid β-defensin 2 levels were determined using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The median value of nasal fluid β-defensin 2 levels were 173.8 pg/mL (interquartile range; 54.8-205.9 pg/mL) in allergic rhinitis group and 241.6 pg/mL (163.5-315.2 pg/mL) in the control group. There was a statistically significant difference between the two groups (p=0.01). Moreover, nasal fluid β-defensin 2 levels showed a significant negative correlation with total symptom scores (rho= -0.78, p<0.001).

CONCLUSIONS

Children with allergic rhinitis have reduced nasal fluid β-defensin 2 levels compared with controls, and β-defensin 2 levels were negatively correlated with disease severity. A more definite understanding of the roles of defensins and other antimicrobial peptides in allergic inflammation can open up new horizons in the management and treatment of these common diseases.

A rapid differential display analysis of nasal swab fingerprints to distinguish allergic from non-allergic rhinitis subjects by mesoporous silica particles and MALDI-TOF mass spectrometry

Discriminating different rhinitis cases can sometimes be difficult as the diagnostic criteria used to identify the various subgroups are not always unambiguous. The nasal fluid (NF) highly reflects the pathophysiology of these inflammatory diseases. However, its collection, as nasal lavage fluid, may cause discomfort. Due to the non-invasiveness and rapidity of collection, nasal swab might represent an alternative to overcome these problems and also an ideal source of biomarkers. In this study, we demonstrate that the combined use of mesoporous silica (MPS) with MALDI-TOF MS allows the rapid detection of differential nasal peptide profiles from nasal swabs of healthy (H), allergic rhinitis (AR) and non-allergic rhinitis (NAR) subjects. NF peptides from nasal swabs were captured by the mean of MPS then profiled by MALDI-TOF MS. As a proof-of-principle, we also explored the ability of our platform to discriminate between nasal swabs of patients with AR and NAR, and between these groups and H controls. Four peaks resulted differentially expressed between NAR and AR, two peaks discriminated AR from H while one peak segregated NAR from H group. Therefore, peptides selected and enriched by our platform could form a part of a diagnostic ''rhinomic'' profile of the allergic and non-allergic patients.

A review on emerging frontiers of house dust mite and cockroach allergy research

Currently, mankind is afflicted with diversified health issues, allergies being a common, yet little understood malady. Allergies, the outcome of a baffled immune system encompasses myriad allergens and causes an array of health consequences, ranging from transient to recurrent and mild to fatal. Indoor allergy is a serious hypersensitivity in genetically-predisposed people, triggered by ingestion, inhalation or mere contact of allergens, of which mite and cockroaches are one of the most-represented constituents. Arduous to eliminate, these aeroallergens pose constant health challenges, mostly manifested as respiratory and dermatological inflammations, leading to further aggravations if unrestrained. Recent times have seen an unprecedented endeavour to understand the conformation of these allergens, their immune manipulative ploys and other underlying causes of pathogenesis, most importantly therapies. Yet a large section of vulnerable people is ignorant of these innocuous-looking immune irritants, prevailing around them, and continues to suffer. This review aims to expedite this field by a concise, informative account of seminal findings in the past few years, with particular emphasis on leading frontiers like genome-wide association studies (GWAS), epitope mapping, metabolomics etc. Drawbacks linked to current approaches and solutions to overcome them have been proposed.

Evaluation of the improvement effect of laser acupuncture biostimulation in asthmatic children by exhaled inflammatory biomarker level of nitric oxide

Variable therapy of asthma is not sufficient yet to achieve good asthma control. Therapy decision requires serial investigations. Low-level laser acupuncture is a suitable non-invasive modality of complementary medicine. The exhaled breath condensate (EBC) is easy and useful to evaluate the efficacy of drugs or novel therapy. This study aimed to evaluate the effectiveness of low-level laser biostimulation of acupuncture points on asthma improvement in children. Forty-eight asthmatic children were subdivided into case (laser) group, which received 12 direct contact low-power laser acupuncture sessions (three sessions/week) on specific traditional Chinese acupuncture points for bronchial asthma, and control asthmatic group, which received sham laser acupuncture on the same acupoints and number of sessions of the case (laser) group. Low-power Multichannel Aculas-AM laser (grade II) of wave length 780 nm, output power 800 mw, and beam spot size 0.1 cm² with continuous mode was used. Eighteen acupoints were stimulated for 2 min, giving energy of 9.6 J/cm²/acupoint. The total session time was 3 min. Both groups were evaluated pre- and post-laser acupuncture intervention by recording levels of asthma control, pulmonary function, and EBC nitric oxide. In the case (laser) group, 91.7 % of patients experienced an improvement in the level of asthma control versus 25 % in the control group (p < 0.001). This was associated with a significant decrease of the breath condensate FENO concentration (p < 0.001) and significant increase of spirometry parameters (p < 0.001) in the case (laser) group. Application of laser acupuncture treatment given with conventional therapy can effectively improve bronchial asthma more than prescription of medications alone could.

Beyond anti-microbial properties: The role of cathelicidin in allergic rhinitis

BACKGROUND

Cathelicidin, an anti-microbial peptide, is a component of the innate immune system. Cathelicidin has anti-microbial, anti-inflammatory and immunoregulatory functions. Knowledge about the role of the innate immune system in the pathogenesis of allergic diseases has expanded in recent years. We measured levels of the LL-37 peptide in the nasal fluids of children with allergic rhinitis (AR) and investigated the possible role of this peptide in the pathogenesis of AR.

METHODS

The study population included 46 children who were newly diagnosed with AR and not taking any medication. Thirty-three healthy control subjects were also enrolled. Nasal secretions were collected from the study and control groups using a polyurethane sponge nasal secretion collector, and nasal fluid LL-37 levels were determined using the ELISA method.

RESULTS

The levels of LL-37 in the nasal fluid of the AR patients were lower than those of the control group (median of 2.3ng/ml [minimum-maximum, 2.1-3.2] vs. 2.6ng/ml [2.1-5.4], respectively; p<0.001), and they were significantly reduced in patients with moderate/severe AR compared with those of patients with mild AR (2.2ng/ml [2.1-2.4] vs. 2.5ng/ml [2.1-3.1], respectively; p<0.001).

CONCLUSION

Our results show that children with AR have reduced nasal fluid LL-37 levels compared with healthy controls. Additionally, children with moderate/severe AR have decreased nasal fluid LL-37 levels compared with children with mild AR. These findings highlight the role of cathelicidin in the pathogenesis of AR.

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.

[Use of inflammatory markers for monitoring paediatric asthma]

The assessment of asthma control takes into account the symptoms, quality of life, lung function, and inflammatory markers. In the last few years, there has been a large increase in the number of publications related to the study of biomarkers in the management of paediatric asthma. Despite the large variety of inflammatory markers described in research studies, only a small group has shown to be useful in monitoring the disease. Induced sputum eosinophils offer the most solid evidence in assessing asthma control. Exhaled breath condensate and urinary leucotrienes could be useful in the future if there is standardisation in their procedures and interpretation of the results. Nitric oxide, basic eosinophil cationic protein, and bronchial biopsy with bronchoalveolar lavage, only appeared to be useful in a reduced group of patients.

Periostin, a novel biomarker of TH2-driven asthma

PURPOSE OF REVIEW

Asthma is a heterogeneous disease with multiple, overlapping phenotypes. Biomarkers are currently being investigated to better characterize the disease phenotypes and to identify the responders to specific targeted therapies. This review focuses on the emerging data surrounding the use of one such biomarker for T helper 2 (TH2)-driven asthma: periostin.

RECENT FINDINGS

Periostin is an extracellular matrix protein that is induced by interleukin (IL)-4 and IL-13 in airway epithelial cells and lung fibroblasts. It has proven to be an important biomarker of TH2-associated airway inflammation and a potential predictor of airway eosinophilia. It has also been shown to predict response to treatment with inhaled corticosteroids in patients with these characteristics. Furthermore, recent asthma clinical trials have established that serum periostin may have value in predicting the response to targeted therapy with biologic agents such as lebrikizumab and omalizumab.

SUMMARY

Emerging data suggest a role for periostin in refining asthma phenotypes and predicting the response to targeted therapy. Although early data are promising, further investigations are needed to confirm these findings and to identify other clinical applications in which periostin may be valuable.

Disease models of chronic inflammatory airway disease: applications and requirements for clinical trials

PURPOSE OF REVIEW

This review will discuss methodologies and applicability of key inflammatory models of respiratory disease in proof of concept or proof of efficacy clinical studies. In close relationship with these models, induced sputum and inflammatory cell counts will be addressed for phenotype-directed drug development. Additionally, important regulatory aspects regarding noninvestigational medicinal products used in bronchial challenges or clinical inflammatory models of respiratory disease will be highlighted.

RECENT FINDINGS

The recognition of an ever increasing number of phenotypes and endotypes within conditions such as asthma and chronic obstructive pulmonary disease urges phenotyping of study populations already in early clinical phases of drug development. Apart from the choice of a relevant disease model, recent studies show that especially targeted therapies need to be tested in well defined disease subsets for adequate efficacy assessment. Noninvasive biomarkers, especially sputum inflammatory cell counts, aid phenotyping and are useful outcome measures for novel, targeted therapies.

SUMMARY

Disease phenotyping becomes increasingly important for efficient and cost-effective drug development and subsequent disease management. Inflammatory models of respiratory disease combined with sputum biomarkers are important tools in this approach.

Exhaled nitric oxide and nasal tryptase are associated with wheeze, rhinitis and nasal allergy in primary school children

Rhinitis and asthma are the most common respiratory diseases in children. We assessed whether airway inflammation markers were associated with nasal allergies and self-reported symptoms of wheeze and rhinitis in 130 children 6-12 year old in an epidemiological context. Independent of sex and age, the fraction of exhaled nitric oxide (FeNO) and nasal mast cell (MC) activation (tryptase ≥ 5 ng/mL) were positively associated with wheeze, rhinitis and with nasal allergy. Nasal eosinophil cationic protein (ECP) and exhaled breath condensate (EBC) markers (pH, 8-isoprostane, interleukin-1β) were not associated with symptoms or with nasal allergy. In conclusion, FeNO and nasal tryptase reflect allergic inflammation in the respiratory system.

Predicting steroid responsiveness in patients with asthma using exhaled breath profiling

BACKGROUND

Exhaled breath contains disease-dependent volatile organic compounds (VOCs), which may serve as biomarkers distinguishing clinical phenotypes in asthma. Their measurement may be particularly beneficial in relation to treatment response.

OBJECTIVE

Our aim was to compare the performance of electronic nose (eNose) breath analysis with previously investigated techniques (sputum eosinophils, exhaled nitric oxide (FeNO) and airway hyperresponsiveness) to discriminate asthma from controls and identify steroid responsiveness in steroid-free patients. Trial registration ACTRN12613000038796.

METHODS

Twenty-five patients with mild/moderate asthma had their inhaled steroid treatment discontinued until loss of control or 28 days. They were subsequently treated with oral prednisone 30 mg/day for 14 days. Steroid responsiveness was defined as an increase of either > 12% FEV1 or > 2 doubling doses PC20 AMP. Steroid-free assessment of sputum eosinophils, FeNO and exhaled breath VOCs were used to construct algorithms predicting steroid responsiveness. Performance characteristics were compared by ROC analysis.

RESULTS

The eNose discriminated between asthma and controls (area under the curve = 0.766 ± 0.14; P = 0.002) with similar accuracy to FeNO (0.862 ± 0.12; P < 0.001) and sputum eosinophils (0.814 ± 0.15; P < 0.001). Steroid responsiveness was predicted with greater accuracy by VOC-analysis (AUC = 0.883 ± 0.16; P = 0.008) than FeNO (0.545 ± 0.28; P = 0.751) or sputum eosinophils (0.610 ± 0.29; P = 0.441).

CONCLUSIONS AND CLINICAL RELEVANCE

Breath analysis by eNose can identify asthmatic patients and may be used to predict their response to steroids with greater accuracy than sputum eosinophils or FeNO. This implies a potential role for breath analysis in the tailoring of treatment for asthma patients.

Anti-allergic effect of a Korean traditional medicine, Biyeom-Tang on mast cells and allergic rhinitis

Background

Biyeom-Tang, a medicine prescribed by oriental clinics, has been used for the treatment of the allergic rhinitis (AR). In the present study, an ethanol extract of Biyeom-Tang (EBT) was investigated for anti-allergic properties on bone-marrow derived mast cells (BMMC) and in vivo models.

Methods

The anti-allergic properties of EBT were evaluated by measuring β-Hex release and the production of prostaglandin D₂ (PGD₂) and leukotriene C₄ (LTC₄) on BMMC in vitro and PCA and OVA-induced AR models in vivo.

Results

EBT strongly inhibited a degranulation reaction in a dose dependent manner with an IC₅₀ value of 35.6 μg/ml. In addition, the generation of PGD₂ and LTC₄ was inhibited in BMMC in a concentration-dependent manner with IC₅₀ values of 7.0 μg/ml and 10.9 μg/ml, respectively. When administrated orally, EBT ameliorated the mast cell-mediated PCA reaction. In the OVA-induced AR model, the increased levels of IgE were reduced by EBT. The levels of cytokines, such as IL-4, IL-5, IL-10, and IL-13 decreased in the splenocytes of EBT-treated mice. The histological analysis shows that the infiltration of inflammatory cells increased by OVA-sensitization was also reduced.

Conclusions

Taken together, these results suggested that EBT has anti-allergic and anti-inflammatory effects in vitro and in vivo models.

Which biomarkers are effective for identifying Th2-driven inflammation in asthma?

Recognition of asthma as a heterogeneous disease revealed different potential molecular targets and urged the development of targeted, customized treatment modalities. Evidence was provided for different inflammatory subsets of asthma and more recently, further refined to T helper (Th)2-high and Th2-low subphenotypes with different responsiveness to standard and targeted pharmacotherapy. Given these differences in immunology and pathophysiology, proof of concept studies of novel treatment modalities for asthma should be performed in adequate, well-defined phenotypes. In this review, we describe both existing and novel biomarkers of Th2-inflammation in asthma that can be applied to classify asthma subphenotypes in clinical studies and for treatment monitoring.

Fibroblast growth factor-2 is a sputum remodeling biomarker of severe asthma

OBJECTIVE

Given the large phenotypic diversity of asthma, our aim was to characterize molecular profiles related to asthma severity using selected remodeling biomarkers in induced sputum.

METHODS

Induced sputum from healthy controls, patients with mild to moderate asthma and severe asthma were collected. Twelve selected biomarkers previously associated to airway remodeling such as connective tissue growth factor (CTGF), fibroblast growth factor (FGF)-2, matrix metalloproteinase (MMP)-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-12, MMP-13, procollagen type 1 and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in sputum samples using ELISA or Luminex technology. FGF-2 level was also evaluated in bronchial biopsies using immunohistochemistry.

RESULTS

Sputum of severe asthma was characterized by reduced percentage of macrophages and increased percentage of neutrophils and eosinophils. FGF-2, MMP-1 and TIMP-1 levels increased with asthma severity. Interestingly, only FGF-2 level inversely correlated with FEV1/FVC ratio. Although percentage of eosinophils correlated with asthma severity, it did not correlate with FGF-2 levels. Increased levels of FGF-2 with asthma severity were confirmed in bronchial biopsies by immunohistochemistry.

CONCLUSIONS

Level of FGF-2 in induced sputum represents a relevant remodeling biomarker of asthma severity and significantly correlates with pulmonary function. FGF-2 sputum biomarker is proposed to reveal the phenotype of asthma characterized by fixed airflow obstruction.

Airway inflammation and hypothalamic-pituitary-adrenal axis activity in asthmatic adults with depression

OBJECTIVE

To investigate the features of airway inflammation and hypothalamic-pituitary-adrenal axis (HPAA) activity in patients with asthma accompanied by depression.

METHODS

Adult asthmatics were recruited and enrolled into one of the two groups based on scores on the Hamilton Depression Rating Scale (HAMD): asthmatics with depression (HAMD score ≥8, n = 23), and asthmatics without depression (HAMD score <8, n = 41). In addition, 27 healthy individuals and 21 adults with depression only were enrolled as controls. Induced sputum and blood samples were collected for measurement of cytokines and other inflammatory factors. The diurnal rhythm profiles of salivary cortisol and other hormones were obtained for assessment of the HPAA activity.

RESULTS

For the group of asthmatics with depression, the mean HAMD score was 19.0, and for the group of asthmatics without depression, the HAMD score averaged 4.9(p < .001). Serum and sputum tumor necrosis factor alpha (TNF-α) were significantly higher in asthmatics with depression than those in the other groups (p < .05) while serum interferon-gamma (IFN-γ) was lower in asthmatics with depression than that in the other groups (p < .05). Twenty-four-hour urinary cortisol, salivary cortisol at 8 a.m. and 4 p.m. were lower in asthmatics with depression compared to other groups (p < .05).

CONCLUSIONS

As compared to healthy individuals and those with asthma or depression alone, individuals with comorbid depression and asthma showed the highest level of pro-inflammatory cytokines and the lowest level of anti-inflammatory cytokines and cortisol. These observations may serve as a valuable reference for diagnosis and clinic therapies of depression in asthmatics.

In vitro and ex vivo models of human asthma

Asthma is an inflammatory disorder of the conducting airways which undergo distinct structural and functional changes leading to non-specific bronchial hyperresponsiveness (BHR) and airflow obstruction that fluctuate over time. It is a complex disease involving multiple genetic and environmental influences whose multifactorial interactions can result in a range of asthma phenotypes. Since our understanding of these gene-gene and gene-environment interactions is very poor, this poses a major challenge to the logical development of 'models of asthma'. However, use of cells and tissues from asthmatic donors allows genetic and epigenetic influences to be evaluated and can go some way to reflect the complex interplay between genetic and environmental stimuli that occur in vivo. Current alternative approaches to in vivo animal models involve use of a plethora of systems ranging from very simple models using human cells (e.g. bronchial epithelial cells and fibroblasts) in mono- or co-culture, whole tissue explants (biopsies, muscle strips, bronchial rings) through to in vivo studies in human volunteers. Asthma research has been greatly facilitated by the introduction of fibreoptic bronchoscopy which is now a commonly used technique in the field of respiratory disease research, allowing collection of biopsy specimens, bronchial brushing samples, and bronchoalveolar lavage fluid enabling use of disease-derived cells and tissues in some of these models. Here, we will consider the merits and limitations of current models and discuss the potential of tissue engineering approaches through which we aim to advance our understanding of asthma and its treatment.

Peptidome profiling of induced sputum by mesoporous silica beads and MALDI-TOF MS for non-invasive biomarker discovery of chronic inflammatory lung diseases

Induced sputum is recognized as being of increasing importance for the diagnosis and monitoring of chronic inflammatory lung diseases. The main purpose of this study is to provide a valid approach to better fractionate and characterize the still under-estimated low-molecular weight proteome of induced sputum by using mesoporous silica beads (MSBs) SPE coupled to MALDI-TOF MS. Sputum peptides were captured from both derivatized and non-derivatized MSBs and then profiled by MALDI-TOF MS. Depending on the chemical groups present on the mesoporous surface, complex peptide mixtures were extracted from induced sputum and converted into reproducible MALDI profiles. The number of peaks detected as a function of S/N was evaluated for each mesoporous surface. More than 400 peaks with an S/N>5 were obtained in comparison to 200 peaks detected without MSBs. Additionally, as a proof-of-principle, we investigated the ability of this platform to discriminate between the "sputome" of patients with asthma and chronic obstructive pulmonary disease, and between these groups and those of healthy control subjects. Six m/z peaks emerged as potential diagnostic peptidic patterns able to differentiate these inflammatory airway diseases in the sputome range. Human α-defensins (human neutrophil peptide (HNP)1, HNP2, HNP3) and three C-terminal amidated peptides, one of which is phosphorylated on serine, were identified by MALDI-TOF/TOF MS. These findings may contribute to defining a high-throughput screening MS-based platform for monitoring key peptidic-biomarkers for inflammatory and chronic respiratory diseases in induced sputum samples.

Monitoring asthma status

PURPOSE

Asthma is a chronic disorder of the airways involving inflammation and airway hyper-reactivity. Clinical diagnosis and monitoring of asthma must incorporate the immunological, biochemical, and histological changes of a chronic disorder, while recognizing acute phenotypic changes in order to optimally tailor therapeutics to each individual.

RECENT FINDINGS

Articles published within the previous 18 months are summarized in this article in order to present an up to date review of the latest findings regarding the monitoring of asthma. The articles encompass a wide array of specialties from basic research and histology to clinical medicine as well as community medicine and nursing.

SUMMARY

Exciting new advancements in the monitoring of asthma continue to unfold. Potentially new diagnostic and monitoring tools are highlighted in this study. Continued investigations may enable a select few methodologies to reach clinical utility in the ongoing monitoring and treatment of patients with asthma.

Identification of novel biomarkers in seasonal allergic rhinitis by combining proteomic, multivariate and pathway analysis

Background

Glucocorticoids (GCs) play a key role in the treatment of seasonal allergic rhinitis (SAR). However, some patients show a low response to GC treatment. We hypothesized that proteins that correlated to discrimination between symptomatic high and low responders (HR and LR) to GC treatment might be regulated by GCs and therefore suitable as biomarkers for GC treatment.

Methodology/Principal Findings

We identified 953 nasal fluid proteins in symptomatic HR and LR with a LC MS/MS based-quantitative proteomics analysis and performed multivariate analysis to identify a combination of proteins that best separated symptomatic HR and LR. Pathway analysis showed that those proteins were most enriched in the acute phase response pathway. We prioritized candidate biomarkers for GC treatment based on the multivariate and pathway analysis. Next, we tested if those candidate biomarkers differed before and after GC treatment in nasal fluids from 40 patients with SAR using ELISA. Several proteins including ORM (P<0.0001), APOH (P<0.0001), FGA (P<0.01), CTSD (P<0.05) and SERPINB3 (P<0.05) differed significantly before and after GC treatment. Particularly, ORM (P<0.01), FGA (P<0.05) and APOH (P<0.01) that belonged to the acute phase response pathway decreased significantly in HR but not LR before and after GC treatment.

Conclusions/Significance

We identified several novel biomarkers for GC treatment response in SAR with combined proteomics, multivariate and pathway analysis. The analytical principles may be generally applicable to identify biomarkers in clinical studies of complex diseases.

Using biomarkers in the assessment of airways disease

A biomarker provides a window on underlying disease activity. This is helpful when the pathology, treatment response, or both are heterogeneous or when trying to interpret nonspecific respiratory symptoms in patients with comorbidities. The successful application of a biomarker result is critically dependent on the specific question being addressed and the performance characteristics of the biomarker in relation to that question in the context of pretest probabilities. Negative prediction might be the best way to use a biomarker, such as a D-dimer, pro-brain natriuretic peptide, and exhaled nitric oxide. In this review the role of biomarkers in airways disease (notably induced sputum eosinophils and exhaled nitric oxide) is considered in relation to risk stratification, identification of treatment responders, identification of a clinical phenotype, monitoring of disease, and new drug development.