Non-allergic rhinitis with eosinophilia syndrome is not associated with local production of specific IgE in nasal mucosa. Eur Arch Otorhinolaryngol. 2016;273:1469-1475. [PMID: 26342925 DOI: 10.1007/s00405-015-3769-4]

Mometasone Furoate in Non-Allergic Rhinitis: A Real-Life Italian Study

Background: In order to evaluate the efficacy of intranasal mometasone furoate in patients with non-allergic rhinitis (NAR), a real-life, observational, prospective study is performed. Methods: Thirty-one patients (age 18–64 years) receive intranasal (mometasone furoate, 200 µg b.i.d. for 15 consecutive days per month for 6 consecutive months), plus isotonic nasal saline. The cytologic pattern of local inflammation, nasal airflow, through peak nasal inspiratory flow (PNIF), quality of life (QoL), through the rhinitis quality of life questionnaire (RQLQ), the sinonasal outcome test (SNOT-22), the short-form 36-item health survey (SF-36v2), and the combined symptom medication score (CSMS), and, finally, olfactory function, through Sniffin’ sticks-16 identification test (SSIT-16), are evaluated at baseline and after treatment. Results: NARNE is the most frequent cytological pattern (48% of the total sample). The therapeutic response shows improvement in olfactory function and QoL. Conclusions: The results of this study confirm that intranasal mometasone furoate is an effective treatment for patients with NAR.

Clinical Evidence of Type 2 Inflammation in Non-allergic Rhinitis with Eosinophilia Syndrome: a Systematic Review

PURPOSE OF REVIEW

Non-allergic rhinitis (NAR) includes different subtypes, among which NAR with eosinophilia syndrome (NARES) is the most important because of severity of symptoms and the high risk of comorbidities. Its pathophysiology is still object of debate, but a crucial role of chronic eosinophilic inflammation has been recognized. The aim of this review is to critically analyze the current evidence regarding the hypothesis that NARES may be considered a type 2 inflammatory disorder.

RECENT FINDINGS

The definition and diagnostic criteria for NARES are not universally shared and adopted, thus generating difficulties in reproducing the results. At present, there is extreme heterogeneity in sampling methods and disagreement in the cut-off of local eosinophilic count to determine a diagnosis of NARES. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standard was applied to identify English-language experimental and clinical articles regarding NARES. The search was performed in April 2021. Twenty-six articles were included. Our data suggest a particular heterogeneity regarding sampling and specific cut-offs adopted for diagnosis of NARES and consensus should be reached. We suggest that eosinophil count should be reported as an absolute value for at least 10 observed rich fields in order to increase the level of standardization. Consensus among authors on this topic should be reached with particular attention to the cut-off for diagnosis. In the future, this limitation may be overcome by the identification of repeatable biomarkers to refine diagnosis and prognosis of NARES. Furthermore, our data strongly suggest that NARES have numerous similarities with clinical features of the most common type 2 diseases such as eosinophilic asthma and chronic rhinosinusitis with nasal polyps (CRSwNP): late onset, association with type 2 comorbidities, selective eosinophilic tissue infiltration, remarkable response to oral and intranasal corticosteroids, and progression in a type 2 CRSwNP.

The prevalence of non-allergic rhinitis phenotypes in the general population: A cross-sectional study

Background

Non‐allergic rhinitis (NAR) can be subdivided into several phenotypes: rhinorrhea of the elderly, rhinitis medicamentosa, smokers', occupational, hormonal, drug‐induced, gustatory, and idiopathic rhinitis. There are two pathophysiological endotypes of NAR: inflammatory and neurogenic. Phenotypes may serve as an indicator of an underlying endotype and, therefore, help to guide the treatment. The prevalence of each phenotype in the general population is currently unknown.

Methodology/Principal

Cross‐sectional questionnaire‐based study in the general population of the Netherlands.

Results

The prevalence of chronic rhinitis in the general population was 40% (N = 558, of those, 65% had NAR and 28% AR, in 7% allergy status is unknown). Individuals with NAR (N = 363) had significantly more complaints in October–February. Those with AR (N = 159) had significantly more complaints in April–August. The most common NAR phenotypes were idiopathic (39%) and rhinitis medicamentosa (14%), followed by occupational (8%), smokers' (6%), hormonal (4%), gustatory (4%), and rhinorrhea of the elderly (4%). The least prevalent phenotype was drug induced (1%). Nineteen percent of the NAR group could not be classified into any of the phenotypes.

Conclusions

This is the first study to describe the prevalences of NAR phenotypes in the general population. AR and NAR have a distinct seasonality pattern with NAR being more prevalent in autumn/winter and AR in spring/summer. Our data on the prevalence of phenotypes may help clinicians to anticipate the type of patients at their clinic and help guide a tailored treatment approach. The high prevalence of rhinitis medicamentosa is alarming, since this is a potentially preventable phenotype.

Distinct differences in analytical performance of two commercially available assays for specific IgE to egg white and house dust mite allergens

Background

Measurements of allergen-specific IgE antibodies with different manufacturers’ assays show modest or poor agreement. This study compares analytical performance of specific IgE tests for whole allergen extracts and individual allergen components of two assay systems, IMMULITE and ImmunoCAP, using human sera as well as monoclonal antibodies.

Methods

Comparisons were performed for specific IgE to house dust mite (HDM, n = 44), egg white (EW, n = 36) and the allergen components rDer p 1, rDer p 2, nGal d 1, nGal d 2 and nGal d 4 in human sera and with monoclonal mouse/human chimeric IgE antibodies specific for the same allergen components. Competitive interference with IgE measurement was investigated using allergen-specific monoclonal IgG and IgG4 antibodies.

Results

Measurements of IgE to HDM and EW in serial dilutions of human sera revealed weaker dilution linearity with IMMULITE than with ImmunoCAP. Analysis of five different monoclonal IgE antibodies with total and specific IgE assays, expected to return similar levels, gave an average specific/total IgE ratio of 0.96 (range 0.71–1.14) with ImmunoCAP and 1.89 (range 0.76–2.85) with IMMULITE, indicating overestimation of specific IgE by IMMULITE. With the EW IgE tests of both assay systems, measurements of a chimeric anti-Gal d 2 IgE antibody were unaffected by a competing mouse IgG antibody. While the same was true for measurement of a chimeric anti-Der p 1 IgE antibody using the HDM test in ImmunoCAP, a suppression of measured concentrations by up to 42% was observed in IMMULITE. Similarly, measurement of HDM-specific IgE in human sera by ImmunoCAP was unaffected by a competing monoclonal anti-Der p 2 IgG4 antibody while IMMULITE displayed a reduction of HDM-specific IgE values by up to 30%.

Conclusions

In this evaluation of analytical performance of two widely used assay systems, ImmunoCAP showed higher accuracy in quantitation of specific IgE and greater resistance against competing allergen-specific non-IgE antibodies which may arise through natural or dietary exposure, or as a result of allergen immunotherapy treatment.

Rhinitis Phenotypes

Rhinitis is an umbrella term of a group of upper airway diseases with nasal symptoms and signs with different etiologies and various clinical features or traits. It can be classified into different "phenotypes," based on these observable traits. A proper differential diagnosis is necessary to adequately manage the disease. The objective of this review is to clarify the concept of rhinitis phenotypes while analyzing the clinical features and/or traits of each in order to determine a proper differential diagnosis and appropriate treatment.

Diagnosis and treatment of non-allergic rhinitis: focus on immunologic mechanisms

INTRODUCTION

Non-allergic rhinitis (NAR) is a heterogeneous nasal disease with high global prevalence. NAR can be subclassified as nonallergic rhinitis with eosinophilia syndrome (NARES), vasomotor rhinitis (VMR), and local allergic rhinitis (LAR). Although the precise factors involved in the etiology of NAR are not clear, there is evidence that immunological factors play an important role in the pathogenesis of NAR. This review provides a comprehensive overview of the immunological and neurogenic mechanisms involved in the diagnosis and treatment of NAR.

AREAS COVERED

This review provides a comprehensive overview of the immunological basis of diagnostic and treatment strategies for NARES, VMR, and LAR. In particular, recently documented molecular and immunological mechanisms of NAR are discussed, which may help to better understand the mechanisms underlying the pathologies of the different endotypes of NAR.

EXPERT OPINION

An increasing number of studies investigating the pathogenesis of NAR suggest that the immunological mechanisms underlying the different subtypes of NAR vary greatly, and are still not fully understood to accurately diagnose these subtypes. Thus, further studies should focus on making diagnosis and treatment of NAR more precise, safe, and effective. A better understanding of the immunological mechanisms involved in NAR should help in the discovery of new diagnostic and treatment strategies.

Levels of nasal exhaled hydrogen sulfide in the general population and allergic rhinitis patients

Background

Objective measures used for the differential diagnosis and severity assessment of allergic rhinitis (AR) are still lacking. The involvement of hydrogen sulfide (H₂S) in the development of AR indicates that nasal exhaled H₂S (NeH₂S) has potential as a biomarker to be used in AR patients. This study aimed to evaluate the application value of NeH₂S measurement in the diagnosis and assessment of AR.

Methods

This study was a multi‐center cross‐sectional survey conducted in Northwestern China. Demographic information collection and rhinitis assessment were completed through questionnaires. The level of NeH₂S and serum immunoglobulin E were measured.

Results

The level of NeH₂S in general population ranged from 0 to 35 ppb, with a median value of 2 ppb. The NeH₂S levels in seasonal allergic rhinitis (SAR) patients were significantly lower than those in general population (2 [1, 2.75] vs. 2 [2, 3] ppb; p = .023), and the NeH₂S value of the SAR group tended to be lower than that of the non‐allergic rhinitis (NAR) group (2 [1, 2.75] vs. 2 [2, 3] ppb; p = .094). The subgroup of AR patients with symptoms lasting longer than 2 weeks per month had a lower NeH₂S level compared with the subgroup of patients with symptoms lasting less than 2 weeks per month (2 [1, 2] vs. 2 [2, 3] ppb; p = .015).

Conclusion

This study described the distribution range of NeH₂S levels in the general population. Further study with larger sample size was needed to clarify the relationship between NeH₂S level and AR.

Nasal IgE in subjects with allergic and non-allergic rhinitis

Purpose

The prevalence of "ocal allergic rhinitis" within individuals suffering from perennial rhinitis remains uncertain, and patients usually are diagnosed with non-allergic rhinitis. The aim of this study was to evaluate the prevalence of a potential "local allergic rhinitis" in subjects suffering from non-allergic rhinitis in a non-selected group of young students.

Methods

131 students (age 25.0 ± 5.1 years) with a possible allergic rhinitis and 25 non-allergic controls without rhinitis symptoms (age 22.0 ± 2.0 years) were recruited by public postings. 97 of 131 students with rhinitis were tested positive (≥3 mm) to prick testing with 17 frequent allergens at visit 1. Twenty-four 24 subjects with a house dust mite allergy, 21 subjects with a non-allergic rhinitis, and 18 non-allergic controls were further investigated at visit 2. Blood samples were taken, and nasal secretion was examined. In addition, all groups performed a nasal provocation test with house dust mite (HDM).

Results

In serum and nasal secretion, total IgE and house dust mite specific IgE significantly differed between HDM positive subjects and controls. However, no differences between non-allergic subjects and control subjects were quantifiable. Neither a nasal provocation test nor a nasal IgE to HDM allergens showed a measurable positive response in any of the non-allergic rhinitis subjects as well as the healthy controls, whilst being positive in 13 subjects with HDM allergy.

Conclusions

Nasal IgE is present in subjects with HDM allergy, but not in non-allergic rhinitis. In the investigated non-selected population, exclusive local production of IgE is absent. By implication, therefore, our findings challenge the emerging concept of local allergic rhinitis.Study identifier at ClinicalTrials.gov: NCT02810535.

IgE antibody repertoire in nasal secretions of children and adults with seasonal allergic rhinitis: A molecular analysis

BACKGROUND

There is growing interest both in testing IgE in nasal secretions (NS) and in molecular diagnosis of seasonal allergic rhinitis (SAR). Yet, the reliability of nasal IgE detection with the newest molecular assays has never been assessed in a large cohort of pollen allergic patients.

OBJECTIVE

To investigate with microarray technology and compare the repertoires of specific IgE (sIgE) antibodies in NS and sera of a large population of children and adults with SAR.

METHODS

Nasal secretions were collected with an absorbent device (Merocel 2000^® , Medtronic) and a minimal dilution procedure from 90 children and 71 adults with SAR. Total IgE (tIgE) (ImmunoCAP, Thermo Fisher Scientific (TFS)) and sIgE antibodies against 112 allergen molecules (ISAC-112, TFS) were measured in NS and serum.

RESULTS

Nasal sIgE was detectable in 68.3% of the patients. The detected nasal sIgE antibodies recognized airborne (88%), vegetable (10%), and animal food or other (<1%) allergen molecules. The prevalence and average levels of sIgE in NS and serum were highly interrelated at population level. A positive nasal sIgE antibody to a given molecule predicted the detection of the same antibody in the patient's serum with a specificity of 99.7% and a sensitivity of 40%.

CONCLUSIONS

The concentration of sIgE is much lower in nasal secretions than in the serum. sIgE assays with very high analytical sensitivity and sampling methods with minimal dilution will be therefore needed to validate nasal secretions as alternative to serum in testing the sIgE repertoire.

A Precision Medicine Approach to Rhinitis Evaluation and Management

PURPOSE OF REVIEW

Precision medicine (PM) represents a new paradigm in disease diagnosis, prevention, and treatment. The PM approach focuses on the characterization of different phenotypes and pathogenic pathways in order to allow the selection of specific biomarkers that will be useful in disease management. Rhinitis is a highly prevalent and heterogeneous disease, both in terms of underlying endotypes and clinical presentations. Therefore, to apply the PM principles to the various rhinitis subtypes rise as a meaningful strategy to improve evaluation and treatment.

RECENT FINDINGS

The technology of recombinant allergens has allowed molecular characterization of IgE reactivity of specific individual components of allergenic extracts. Recently published and ongoing clinical trials based on component resolved diagnosis (CRD) bring more precision to allergen immunotherapy for allergic rhinitis. Monoclonal antibodies against various cytokines involved in inflammatory allergic and nonallergic rhinitis endotypes show promissory results.

SUMMARY

Better understanding of pathogenic pathways together with an accurate phenotype classification of patients presented with rhinitis symptoms contributes to point out clinical usefulness of biomarkers and other diagnostic tools, which leads to more accurate environmental control measures, personalized pharmacologic options, and new biological therapy developments.

Current and future targeted therapies for severe asthma: Managing treatment with biologics based on phenotypes and biomarkers

Asthma is a respiratory disorder with considerable heterogeneity in aetiology, triggers, clinical characteristics and response to therapy. This diversity reflects different inflammatory pathways that can be subdivided into clinically similar categories called phenotypes, or pathogenically comparable groups called endotypes. In recent years, a great amount of research has been dedicated to the investigation and understanding of the heterogeneity of asthma pathophysiology and to the identification of treatable traits, biomarkers, mediators and therapeutic targets. Severe asthma is defined as an uncontrolled disease despite a maximal conventional therapeutic approach. While, to date, some target therapies showing improvements in lung function, asthma symptoms and a reduction of the annual rate of exacerbations in patients with severe asthma have been already approved, other treatments are currently being studied, specifically targeting Type 2 asthma. Further progress however, is still needed to tackle the molecular pathways for non-Type 2 asthma. The aim of the present narrative review is to discuss and examine the indication, mechanisms of action and therapeutic effects of currently available and emerging biologic agents for the treatment of severe asthma.

The Distinguishing Clinical Features of Nonallergic Rhinitis Patients

Background

Not all rhinitis patients are affected by an immunoglobulin E (IgE)-mediated inflammatory process. Skin and serum allergy assessments are limited in their ability to define local allergic rhinitis (LAR). Thus, patients with negative systemic allergy assessments comprise a mix of those who truly have nonallergic rhinitis (NAR) and patients with LAR.

Objective

To determine the clinical characteristics of patients with NAR.

Methods

A cross-sectional study was performed on consecutive adults with rhinitis symptoms who underwent turbinate surgery. NAR patients were defined by excluding allergy using both systemic (serum-specific IgE and/or skin prick test) and local (inferior turbinate tissue-specific IgE) tests. Allergic rhinitis (AR) patients were defined by any positive systemic or local test toward aeroallergens. The clinical characteristics studied included allergic comorbidities (asthma, eczema, allergic conjunctivitis), inhalant allergen triggers (dust, pollen, animal dander), and environmental triggers (Cincinnati Irritant Index [CII]).

Results

There were 154 participants (41.79 ± 14.78 years, 37.7% female). NAR patients (11.7%) were older (49.33 ± 15.99 vs 40.78 ± 14.38 years, P = .02), had less self-reported asthma (5.6% vs 36.3%, P < .01) and house dust inhalant trigger (38.9 vs 65.2%, P = .03) compared to AR patients. The CII score was similar for NAR and AR (31.06 ± 28.88 vs 35.49 ± 24.70, P = .61).

Conclusion

Patients who were older, without asthma, and lacked an inhalant allergy trigger were more likely to have true NAR. Environmental triggers are not distinguishing features of NAR. This may be used as a guide to identify rhinitis patients whose symptoms are truly nonallergic etiology compared to those with falsely negative systemic allergy assessment but may still need management for LAR.

Is the evidence of local allergic rhinitis growing?

PURPOSE OF REVIEW

To examine the recent advances on epidemiological studies, diagnostic approach and clinical management of local allergic rhinitis (LAR) in adults and children.

RECENT FINDINGS

Evidence about LAR is growing especially in pediatric and Asian populations. The prevalence of LAR is lower in Asian countries compared with western countries in both children and adults. LAR is considered a chronic condition and an independent rhinitis phenotype that affects up to 26.5% of nonatopic rhinitis patients. The disease rapidly progress toward the clinical worsening with associated onset of asthma and conjunctivitis, which further impairs patient's quality of life. Nasal Allergen Provocation Test is the diagnostic gold standard that can be complemented by basophil activation test and the detection of specific IgE in nasal secretions. Allergen immunotherapy induces a significant and early improvement in both clinical symptoms and quality of life in LAR patients.

SUMMARY

LAR is a common entity, with different prevalence depending on geographical locations. LAR has to be considered in the process of differential diagnosis in children and adults with rhinitis. Diagnosis of LAR is crucial in order to start an etiologic treatment such as allergen immunotherapy, which has proven to be very effective in these patients.

IgE Test in Secretions of Patients with Respiratory Allergy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Precision medicine in united airways disease: A "treatable traits" approach

United airways disease (UAD) is the concept that the upper and lower airways, which are anatomically and immunologically related, form a single organ. According to this concept, upper and lower airway diseases are frequently comorbid because they reflect manifestations of a single underlying disease at different sites of the respiratory tract. Allergic asthma-allergic rhinitis is the archetypal UAD, but emerging data indicate that UAD is a heterogeneous condition and consists of multiple phenotypes (observable clinical characteristics) and endotypes (pathobiologic mechanisms). The UAD paradigm also extends to myriad sinonasal diseases (eg, chronic rhinosinusitis with or without nasal polyps) and lower airway diseases (eg, bronchiectasis, chronic obstructive pulmonary disease). Here, we review currently known phenoendotypes of UAD and propose a "treatable traits" approach for the classification and management of UAD, wherein pathophysiological mechanisms and factors contributing to disease are identified and targeted for treatment. Treatable traits in UAD can be analyzed according to a framework comprising airway inflammation (eosinophilic, neutrophilic), impaired airway mucosal defense (impaired mucociliary clearance, antibody deficiency), and exogenous cofactors (allergic sensitizers, tobacco smoke, microbes). Appreciation of treatable traits is necessary in advancing the effort to deliver precise treatments and achieve better outcomes in patients with UAD.

Aberrant expression of miR-663 and transforming growth factor-β1 in nasal polyposis in children

The aim of the present study was to investigate the expression of microRNA (miR)-663 and its regulatory effects on the pathogenesis of nasal polyposis in children. Nasal polyp tissue, as well as serum and peripheral blood eosinophils were collected from 35 children diagnosed with nasal polypectomy between August 2013 and August 2015. As a control, the inferior nasal concha, serum and peripheral blood eosinophils were collected from 46 patients with nasal septal deviation complicated by inferior turbinate hypertrophy or patients with simple inferior turbinate hypertrophy who had undergone surgical removal of the inferior nasal concha. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to measure the expression of miR-663 and transforming growth factor-β1 (TGF-β1) in the nasal polyp tissue, serum and peripheral blood eosinophils of patients with nasal polyposis and controls. Western blotting was used to measure the expression of TGF-β1 protein in nasal tissue and eosinophils and an enzyme-linked immunosorbent assay was used to measure serum level of TGF-β1 protein. A dual luciferase reporter assay was used to determine whether TGF-β1 was a target gene of miR-663. Compared with the control group, levels of TGF-β1 mRNA and protein were significantly increased in all three types of specimens from pediatric patients with nasal polyposis (P<0.05). miR-663 expression was significantly decreased in nasal polyp tissue and peripheral blood eosinophils (P<0.05). The dual luciferase reporter assay confirmed that TGF-β1 was a target gene of miR-663. The current study suggests that the upregulation of TGF-β1 may be associated with the downregulation of miR-663 in nasal polyposis in children. miR-663 may have regulatory effects on the pathogenesis of nasal polyposis by regulating TGF-β1 and may be developed as a genetic marker of nasal polyposis in children.

[Biologics in Rhinology - Forthcoming Personalized Concepts: the Future Starts Today]

Sinunasale Erkrankungen zählen mit zu den häufigsten chronischen Erkrankungen und führen zu einer erheblichen Störung der Lebensqualität, ein komorbides Asthma ist häufig. Trotz leitliniengerechter Therapie ist anzunehmen, dass mind. 20% der Patienten ihre Erkrankungssymptome nicht adäquat kontrollieren können. Neben den etablierten chirurgischen und konservativen Therapieoptionen finden sich nun vielversprechende Therapieansätze, die bspw. mittels therapeutischer Antikörper mechanistisch gezielt in die Pathophysiologie der Erkrankungen eingreifen können. Die Auswahl der geeigneten Patienten durch geeignete Biomarker und die richtige Therapie zum richtigen Stadium der Erkrankung anbieten zu können, ist das Ziel stratifizierter Medizin und eine wichtige Perspektive für die HNO.Chronic diseases of the nose and the paranasal sinuses are most common, frequently associated with bronchial asthma, and result in substantial reduction of quality of life. Despite optimal treatment according to guidelines, approx. 20 % of the patients will report inadequate control of symptoms. Apart from well established surgical and conservative approaches in therapy new therapeutic antibodies are available that aim specifically pathophysiological targets. The optimal allocation of effective therapy for patients using appropriate biomarkers at the most suitable timepoint is the hallmark of stratified medicine and an important perspective in ENT.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Local allergic rhinitis: evolution of concepts

The discovery of an exclusive local production of IgE antibodies dates back to the 1970s, but only recently the pathophysiology of such phenomenon was deeply investigated, leading to the concept of local allergic rhinitis (LAR). Currently, LAR is defined by the occurrence, in patients with symptoms clearly suggesting allergic rhinitis but with negative results to common allergy testing, of allergen specific IgE in the nasal mucosa. Most studies investigating LAR were based on the development of rhinitis symptoms following nasal provocation test (NPT) with the suspected allergens, but such test may be performed by a number of options, none of them being as yet acknowledged and recommended in consensus document. On the other hand, also the mere detection of IgE in the nasal mucosa indicates, as for IgE measurement in blood or other tissues, allergic sensitization but cannot give the certainty of clinical allergy. Therefore, the combination of IgE detection in nasal mucosa and a positive result of NPT should be used to diagnose LAR. Recent data on the use for in vitro testing of molecular allergy diagnostics in place of whole allergen extracts suggest that this method could improve the sensitivity and specificity of laboratory tests, and an appraisal of the basophil activation test as a third level technique, to be implemented when the results of local IgE testing and NPT are uncertain, is currently ongoing.

Airborne Particulate Matter Induces Nonallergic Eosinophilic Sinonasal Inflammation in Mice

Exposure to airborne particulate matter (PM) has been linked to aggravation of respiratory symptoms, increased risk of cardiovascular disease, and all-cause mortality. Although the health effects of PM on the lower pulmonary airway have been extensively studied, little is known regarding the impact of chronic PM exposure on the upper sinonasal airway. We sought to test the impact of chronic airborne PM exposure on the upper respiratory system in vivo. Mice were subjected, by inhalation, to concentrated fine (2.5 μm) PM 6 h/d, 5 d/wk, for 16 weeks. Mean airborne fine PM concentration was 60.92 μm/m³, a concentration of fine PM lower than that reported in some major global cities. Mice were then killed and analyzed for evidence of inflammation and barrier breakdown compared with control mice. Evidence of the destructive effects of chronic airborne PM on sinonasal health in vivo, including proinflammatory cytokine release, and macrophage and neutrophil inflammatory cell accumulation was observed. A significant increase in epithelial barrier dysfunction was observed, as assessed by serum albumin accumulation in nasal airway lavage fluid, as well as decreased expression of adhesion molecules, including claudin-1 and epithelial cadherin. A significant increase in eosinophilic inflammation, including increased IL-13, eotaxin-1, and eosinophil accumulation, was also observed. Collectively, although largely observational, these studies demonstrate the destructive effects of chronic airborne PM exposure on the sinonasal airway barrier disruption and nonallergic eosinophilic inflammation in mice.

Nonallergic rhinitis and lower airway disease

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

Non-allergic rhinitis in children: Epidemiological aspects, pathological features, diagnostic methodology and clinical management

Chronic rhinitis is a very common disease, as the prevalence in the general population resulted to be 40%. Allergic rhinitis has been considered to be the most frequent form of chronic rhinitis, as non-allergic rhinitis has been estimated to account for 25%. However, several evidences suggested that non-allergic rhinitis have been underrated, especially in children. In pediatrics, the diagnostic definition of non-allergic rhinitis has been often limited to the exclusion of an allergic sensitization. Actually, local allergic rhinitis has been often misdiagnosed as well as mixed rhinitis has not been recognized in most cases. Nasal cytology is a diagnostic procedure being suitable for routine clinical practice with children and could be a very useful tool to characterize and diagnose non-allergic rhinitis, providing important clues for epidemiological analysis and clinical management.