Induction of nasal hyper-responsiveness by allergen challenge in allergic rhinitis: the role of afferent and efferent nerves

Colonisation of Irish patients with chronic obstructive pulmonary disease by Streptococcus pneumoniae and analysis of the pneumococcal vaccine coverage: a non-interventional, observational, prospective cohort study

OBJECTIVES

To characterise the pattern of colonisation and serotypes of Streptococcus pneumoniae among patients with chronic obstructive pulmonary disease (COPD) who currently receive the 23-valent pneumococcal polysaccharide vaccine (PPV-23) according to vaccination status, use of antibiotics and steroids. To investigate the prevalence of PPV-23 and 13-valent pneumococcal conjugate vaccine (PCV-13) serotypes within the study cohort.

DESIGN

A non-interventional, observational, prospective cohort study with a 12 -month follow-up period inclusive of quarterly study visits.

SETTING

Beaumont Hospital and The Royal College of Surgeons in Ireland Clinical Research Centre, Dublin, Ireland.

PARTICIPANTS

Patients with an established diagnosis of COPD attending a tertiary medical centre.

PRIMARY OUTCOME MEASURE

Colonisation rate of S. pneumoniae in patients with COPD and characterisation of serotypes of S. pneumoniae with correlation to currently available pneumococcal vaccines. Sputum and oropharyngeal swab samples were collected for the isolation of S. pneumoniae.

SECONDARY OUTCOME MEASURE

Seasonality of colonisation of S. pneumoniae and its relationship with the incidence of exacerbations of COPD.

RESULTS

S. pneumoniae was detected in 16 of 417 samples, a colonisation incident rate of 3.8% and in 11 of 133 (8%) patients at least once during the study. The majority of S. pneumoniae isolates were identified in spring and were non-vaccine serotypes for either the PPV-23 or PCV-13 (63%). The colonisation incident rate of S. pneumoniae fluctuated over the four seasons with a peak of 6.6% in spring and the lowest rate of 2.2% occurring during winter. Antibiotic use was highest during periods of low colonisation.

CONCLUSIONS

There is seasonal variation in S. pneumoniae colonisation among patients with COPD which may reflect antibiotic use in autumn and winter. The predominance of non-vaccine types suggests that PCV-13 may have limited impact among patients with COPD in Ireland who currently receive PPV-23.

TRIAL REGISTRATION NUMBER

NCT02535546; post-results.

In patients with severe uncontrolled asthma, does knowledge of adherence and inhaler technique using electronic monitoring improve clinical decision making? A protocol for a randomised controlled trial

INTRODUCTION

Many patients with asthma remain poorly controlled despite the use of inhaled corticosteroids and long-acting beta agonists. Poor control may arise from inadequate adherence, incorrect inhaler technique or because the condition is refractory. Without having an objective assessment of adherence, clinicians may inadvertently add extra medication instead of addressing adherence. This study aims to assess if incorporating objectively recorded adherence from the Inhaler Compliance Assessment (INCA) device and lung function into clinical decision making provides more cost-effective prescribing and improves outcomes.

METHODS AND ANALYSIS

This prospective, randomised, multicentre study will compare the impact of using information on adherence to influence asthma treatment. Patients with severe uncontrolled asthma will be included. Data on adherence, inhaler technique and electronically recorded peak expiratory flow rate will be used to promote adherence and guide a clinical decision protocol to guide management in the active group. The control group will receive standard inhaler and adherence education. Medications will be adjusted using a protocol based on Global Initiativefor Asthma (GINA) recommendations. The primary outcome is the between-group difference in the proportion of patients who have refractory disease and are prescribed appropriate medications at the end of 32 weeks. A co-primary outcome is the difference between groups in the rate of adherence to salmeterol/fluticasone inhaler over the last 12 weeks. Secondary outcomes include changes in symptoms, lung function, type-2 cytokine biomarkers and clinical outcomes between both groups. Cost-effectiveness and cost-utility analyses of the INCA device intervention will be performed. The economic impact of a national implementation of the INCA-SUN programme will be evaluated.

ETHICS AND DISSEMINATION

The results of the study will be published as a manuscript in peer-reviewed journals. The study has been approved by the ethics committees in the five participating hospitals.

TRIAL REGISTRATION

NCT02307669; Pre-results.

Targeting patients with asthma for omalizumab therapy: choosing the right patient to get the best value for money

The asthma syndrome has many manifestations, termed phenotypes, that arise by specific cellular and molecular mechanisms, termed endotypes. Understanding an individual's asthma phenotype helps clinicians make rational therapeutic decisions while the understanding of endotypes has led to the development of specific precision medications. Allergic asthma is an example of an asthma phenotype and omalizumab, a monoclonal antibody that neutralizes serum immunoglobulin (Ig)E, is a specific targeted treatment which was developed as a result of an understanding of the endotype of allergic asthma. Omalizumab has been widely used in clinical practice in Europe for over a decade as an add-on therapy to treat patients who have severe refractory allergic asthma. Over this period, many centres have reported their experience with omalizumab as an add-on therapy in patients with severe asthma. These 'real world' clinical effectiveness studies have confirmed the benefits, cost-effectiveness and clinical utility of this medication. Combining the outcomes of both sources of research has yielded important insights that may benefit patients with severe asthma, clinicians who treat them, as well as the funding agencies that reimburse the cost of this medication. The purpose of this review is to describe how to identify and evaluate a patient with asthma for whom treatment with omalizumab may be of clinical and cost-effective benefit. The assessment and investigations used to confirm allergic asthma, the objective assessment of adherence to asthma therapy and the expected benefits of add-on omalizumab treatment are described.

Eosinophil peroxidase activates cells by HER2 receptor engagement and β1-integrin clustering with downstream MAPK cell signaling

Eosinophils account for 1–3% of peripheral blood leukocytes and accumulate at sites of allergic inflammation, where they play a pathogenic role. Studies have shown that treatment with mepolizumab (an anti-IL-5 monoclonal antibody) is beneficial to patients with severe eosinophilic asthma, however, the mechanism of precisely how eosinophils mediate these pathogenic effects is uncertain. Eosinophils contain several cationic granule proteins, including Eosinophil Peroxidase (EPO). The main significance of this work is the discovery of EPO as a novel ligand for the HER2 receptor. Following HER2 activation, EPO induces activation of FAK and subsequent activation of β1-integrin, via inside-out signaling. This complex results in downstream activation of ERK1/2 and a sustained up regulation of both MUC4 and the HER2 receptor. These data identify a receptor for one of the eosinophil granule proteins and demonstrate a potential explanation of the proliferative effects of eosinophils.

•

Eosinophil peroxidase (EPO) is confirmed as a ligand for the HER2 receptor.

•

EPO activation of HER2 leads to activation of FAK, ERK and β1 integrin.

•

EPO induces a sustained upregulation of MUC4 and HER2.

•

Possible mechanism for the proliferative effects of eosinophils is uncovered.

Effect of Intranasal Azelastine on Substance P Release in Perennial Nonallergic Rhinitis Patients

Background

Rhinitis symptoms can be produced or augmented by neural mechanisms. Azelastine, a pharmacologic agent with potent H1-receptor blocking activity can inhibit the release of various mediators implicated in the pathogenesis of nasal hyperresponsiveness. The therapeutic benefits of topical intranasal azelastine on symptoms of perennial nonallergic rhinitis (NAR) are in part because of an impact on neural mechanisms. Assessment of changes in the concentration of substance P (SP) in nasal lavage fluid before and after saline hypertonic challenge may be a means of assessing the effect of intranasal azelastine on neuropeptide release and severity of rhinitis symptoms.

Methods

Twenty-three patients with perennial NAR (negative skin-prick tests with inhalant allergens and concentration of total IgE in the normal range) were studied. Thirteen of 23 patients were treated with intranasal azelastine 0.15% spray at a dosage of 2 sprays (137 micrograms/spray) twice daily for 10 days. The control group consisted of 10 untreated patients with rhinitis. Nasal provocation using 4.5% saline solution was after 15 minutes by lavage before and after 10 days of treatment with intranasal azelastine. The concentration of SP in nasal lavage fluid was determined by enzyme immunoassay methods.

Results

Nasal lavage fluid baseline concentrations of SP were similar in both groups. After azelastine treatment, significantly greater concentrations of SP were seen in nasal lavage fluid 15 minutes after hypertonic saline challenge in the untreated patients (56.8 ± 13.8 pg/mL) in comparison with azelastine-treated patients (44.5 ± 16.5 pg/mL; p < 0.05). Total vasomotor rhinitis symptoms scores were substantially reduced in the azelastine-treated subjects compared with the control group.

Conclusion

Azelastine intranasal spray reduces SP release into nasal lavage fluid of NAR patients immediately after hypertonic nasal saline challenge. Reduction of neuropeptide release may be an important aspect of the clinical efficacy of topical azelastine in perennial NAR patients.

Eosinophil peroxidase induces the expression and function of acid-sensing ion channel-3 in allergic rhinitis: in vitro evidence in cultured epithelial cells

BACKGROUND

Acid-sensing ion channels (ASIC) are a family of acid-activated ligand-gated cation channels. As tissue acidosis is a feature of inflammatory conditions, such as allergic rhinitis (AR), we investigated the expression and function of these channels in AR.

OBJECTIVES

The aim of the study was to assess expression and function of ASIC channels in the nasal mucosa of control and AR subjects.

METHODS

Immunohistochemical localization of ASIC receptors and functional responses to lactic acid application were investigated. In vitro studies on cultured epithelial cells were performed to assess underlying mechanisms of ASIC function.

RESULTS

Lactic acid at pH 7.03 induced a significant rise in nasal fluid secretion that was inhibited by pre-treatment with the ASIC inhibitor amiloride in AR subjects (n = 19). Quantitative PCR on cDNA isolated from nasal biopsies from control and AR subjects demonstrated that ASIC-1 was equally expressed in both populations, but ASIC-3 was significantly more highly expressed in AR (P < 0.02). Immunohistochemistry confirmed significantly higher ASIC-3 protein expression on nasal epithelial cells in AR patients than controls (P < 0.01). Immunoreactivity for EPO+ eosinophils in both nasal epithelium and submucosa was more prominent in AR compared with controls. A mechanism of induction of ASIC-3 expression relevant to AR was suggested by the finding that eosinophil peroxidase (EPO), acting via ERK1/2, induced the expression of ASIC-3 in epithelial cells. Furthermore, using a quantitative functional measure of epithelial cell secretory function in vitro, EPO increased the air-surface liquid depth via an ASIC-dependent chloride secretory pathway.

CONCLUSIONS

This data suggests a possible mechanism for the observed association of eosinophils and rhinorrhoea in AR and is manifested through enhanced ASIC-3 expression.

Role of parasympathetic nerves and muscarinic receptors in allergy and asthma

Parasympathetic nerves control the symptoms and inflammation of allergic diseases primarily by signaling through peripheral muscarinic receptors. Parasympathetic signaling targets classic effector tissues such as airway smooth muscle and secretory glands and mediates acute symptoms of allergic disease such as airway narrowing and increased mucus secretion. In addition, parasympathetic signaling modulates inflammatory cells and non-neuronal resident cell types such as fibroblasts and smooth muscle contributing to chronic allergic inflammation and tissue remodeling. Importantly, muscarinic antagonists are experiencing a rebirth for the treatment of asthma and may be useful for treating other allergic diseases.

Mechanism of sphingosine 1-phosphate- and lysophosphatidic acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells

The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

Allergic rhinitis and inflammatory airway disease: interactions within the unified airspace

BACKGROUND

Allergic rhinitis (AR), the most common chronic allergic condition in outpatient medicine, is associated with immense health care costs and socioeconomic consequences. AR's impact may be partly from interacting of respiratory conditions via allergic inflammation. This study was designed to review potential interactive mechanisms of AR and associated conditions and consider the relevance of a bidirectional "unified airway" respiratory inflammation model on diagnosis and treatment of inflammatory airway disease.

METHODS

MEDLINE was searched for pathophysiology and pathophysiological and epidemiologic links between AR and diseases of the sinuses, lungs, middle ear, and nasopharynx.

RESULTS

Allergic-related inflammatory responses or neural and systemic processes fostering inflammatory changes distant from initial allergen provocation may link AR and comorbidities. Treating AR may benefit associated respiratory tract comorbidities. Besides improving AR outcomes, treatment inhibiting eosinophil recruitment and migration, normalizing cytokine profiles, and reducing asthma-associated health care use in atopic subjects would likely ameliorate other upper airway diseases such as acute rhinosinusitis, chronic rhinosinusitis (CRS) with nasal polyposis (NP), adenoidal hypertrophy, and otitis media with effusion.

CONCLUSION

Epidemiological concordance of AR with several airway diseases conforms to a bidirectional "unified airway" respiratory inflammation model based on anatomic and histological upper and lower airway connections. Epidemiology and current understanding of inflammatory, humoral, and neural processes make links between AR and disorders including asthma, otitis media, NP, and CRS plausible. Combining AR with associated conditions increases disease burden; worsened associated illness may accompany worsened AR. AR pharmacotherapies include antihistamines, leukotriene antagonists, intranasal corticosteroids, and immunotherapy; treatments attenuating proinflammatory responses may also benefit associated conditions.

Conjunctival effects of a selective nasal pollen provocation

BACKGROUND

Several clinical and experimental observations suggest that allergen deposition in the nose may partially be responsible for the induction of conjunctival symptoms in allergic rhinitis. The aims of this study were to evaluate the induction of conjunctival symptoms by selective nasal allergen provocation and to assess the feasibility of the different tools for evaluation of conjunctival allergic inflammation.

METHODS

Grass pollen allergic subjects with rhinoconjunctivitis symptoms during the pollen season (n = 12) underwent a nasal sham and grass pollen provocation extra-seasonally. Nasal and conjunctival symptoms were scored using the Visual Analogue Scale (VAS) system at baseline, 15 min, 1 h and 24 h after provocation. In addition to Peak Nasal Inspiratory flow (PNIF) measurements, conjunctival inflammation and vascular congestion were evaluated and histamine and substance P levels in tear fluid were measured.

RESULTS

Selective nasal grass pollen provocation induced ocular pruritus, lacrimation and conjunctival vascular congestion. PNIF values correlated inversely with lacrimation (r = -0.71, P < 0.001) and ocular pruritus (r = -0.41, P < 0.05). Four out of 11 patients showed a conjunctival eosinophilic inflammation and levels of histamine (r = 0.73, P < 0.05) and substance P (r = 0.67, P = 0.05) in tear fluid correlated with conjunctival symptoms.

CONCLUSION

Selective nasal grass pollen provocation induced conjunctival inflammation, ocular pruritus and lacrimation, which correlated with histamine and substance P levels in tear fluid and inversely with the PNIF values. These data show a naso-ocular interaction in allergic rhinitis and offer objective tools for evaluation of conjunctival inflammation in allergic rhinoconjunctivitis.

[Airways inflammation evaluation. Upper and lower airways]

It is done a review of evaluation methods of the inflammation in upper airways and bronchi used for diagnosis, therapeutic approach and prognosis of pathologies like rhinosinusitis and asthma. It is also analysed methods that supply relevant information of inflammation in COPD. The chronic inflammation of the airways is associated to respiratory distress, obstruction in basal lung function tests and to bronchial and nasal hyperreactivity. Computerized tomography informs about lumen dimensions, bronchial walls thickness and pulmonary density. These changes are associated to inflammation and to remodelling of the airways. Localized inflammation in respiratory tract can be detected by modifications of systemic inflammatory markers. The direct evaluation of inflammatory airways changes are based on immune, histological and chemical analysis of lung tissue obtained by biopsies and by fluids recoil in basal conditions or after stimulation. The eosinophils are increased in biopsies and in nasal and bronchoalveolar lavage in asthma and rhinitis and can change with therapy. Proteins and mRNA expression of cellular activation mediators are also observed. The induced sputum identifies eosinophilic inflammation that is inversely associated with lung function parameters. In each respiratory cycle the air is enriched in organic volatile compounds produced by cellular breathing. FENO is the bio marker more deeply studied in asthma and its increase is well documented in this disorder. In the exhaled air condensed, reactive oxygen species, membrane mediators, cytokines, and chemokines are identified. If the non invasive evaluation of inflammation became reliable and reproducible it will be indispensable in monitoring the airways diseases.

Mechanisms and clinical implications of glucocorticosteroids in the treatment of allergic rhinitis

Allergic rhinitis is a common airway disease characterized by hypersensitivity, exudation, hypersecretion, inflammatory cell infiltration and remodelling. Intranasal glucocorticosteroids are the most effective drugs for controlling the inflammation caused by allergic rhinitis. Glucocorticosteroids exert anti-inflammatory effects through at least two pathways: the transactivation pathway and the transrepression pathway. Glucocorticosteroids also exert regulatory functions by inducing regulatory cytokines and forkhead box P3 (FoxP3(+)) regulatory T cells. Evidence suggests that intranasal glucocorticosteroids control not only nasal symptoms but also ocular symptoms. In contrast to sedating H1 receptor antagonists, intranasal glucocorticosteroids can improve impaired performance symptoms, such as daytime sleepiness, associated with allergic rhinitis. Recent studies suggest that intranasal glucocorticosteroids might also be useful for the prophylactic treatment of pollinosis; this possibility is supported by the molecular mechanism of the anti-inflammatory action of glucocorticosteroids. These findings suggest that intranasal glucocorticosteroids might be positioned as first-line drugs for the treatment of both perennial and seasonal allergic rhinitis.

Are intranasal corticosteroids all equally consistent in managing ocular symptoms of seasonal allergic rhinitis?

BACKGROUND

Nasal and ocular symptoms of allergic rhinitis (AR) are reported by >70% of patients and have a profound impact on quality of life while also incurring substantial healthcare costs. It has been suggested that intranasal corticosteroids (INS), in addition to effectively treating the nasal components of AR, are effective in treating the ocular symptoms.

OBJECTIVE

This review provides a comprehensive, updated assessment of available data in the public domain to determine the consistency of INS efficacy in treating ocular AR symptoms.

METHODS

MEDLINE and EMBASE searches, and research of governmental and regulatory institution sources identified 35 randomised, placebo-controlled trials of INS and seasonal AR (SAR) published between 1990 and May 2009 that specifically contained ocular efficacy as part of the study analyses.

RESULTS

Examination of these studies reveals substantial inconsistency of effect of some INS across, and even within, trials, casting doubt on the suggestion that ocular efficacy is a class effect of INS. Conflicting, inconsistent or even negative effects were observed for most INS examined including mometasone furoate and fluticasone propionate. Only fluticasone furoate nasal spray, in addition to established efficacy in treating nasal symptoms, demonstrated a consistent positive effect on ocular symptoms of SAR compared with placebo in a large number of patients across all of its prospective studies. Moreover, these results were consistent across different allergy seasons, including grass, ragweed, and mountain cedar seasons, and different geographical locations throughout Europe and the USA.

CONCLUSION

While additional prospective head-to-head clinical trials comparing the efficacy of INS in treating ocular symptoms of AR are needed to fully elucidate the benefits of one INS compared with another, data available to date suggest that not all INS are equally consistent in managing ocular symptoms of SAR. Fluticasone furoate is currently the most consistent.

Nasal ocular reflexes and eye symptoms in patients with allergic rhinitis

BACKGROUND

Allergic patients often complain of eye symptoms during the allergy season. A possible mechanism for these eye symptoms is a nasal ocular reflex.

OBJECTIVE

To demonstrate eye symptoms after nasal allergen challenge.

METHODS

In a double-blind, placebo-controlled, crossover, clinical trial, 20 patients with seasonal allergic rhinitis were challenged in 1 nostril with antigen, and the response was monitored in both nostrils and in both eyes. Symptoms were recorded. Filter paper disks (intranasally) and Schirmer strips (intraocularly) were used for collecting secretions, which were subsequently eluted for the measurement of histamine and albumin levels. Patients were treated once topically at the site of challenge with azelastine or placebo.

RESULTS

After placebo treatment, ipsilateral nasal challenge caused nasal symptoms and an increase in secretion weights; both were blocked by treatment with azelastine. Histamine and albumin levels increased only at the site of nasal challenge. Azelastine pretreatment inhibited the increase in albumin but not histamine levels. Symptoms of itchy and watery eyes increased significantly compared with symptoms with sham challenge after nasal allergen and were blocked by azelastine use. Ocular secretion weights increased bilaterally after placebo use and were not inhibited by azelastine use.

CONCLUSIONS

Nasal allergen challenge releases histamine at the site of the challenge, which probably initiates a nasonasal and a nasal ocular reflex. This reflex is reduced by an H1-receptor antagonist applied at the site of the challenge. The eye symptoms associated with allergic rhinitis probably arise, in part, from a naso-ocular reflex.

Contribution of allergen-specific and nonspecific nasal responses to early-phase and late-phase nasal responses

BACKGROUND

The relative contributions of the allergen-specific early-phase nasal response and nonspecific nasal response and mast cells to the pathophysiology of allergic rhinitis are not well defined.

OBJECTIVES

To determine the contributions of specific reactivity, nonspecific reactivity, and mast cells to the development of early-phase and late-phase responses using a mouse model of allergic rhinitis.

METHODS

Sensitized wild-type and FcvarepsilonRI-deficient (FcvarepsilonRI-/-) mice were exposed to allergen for 3, 5, or 12 days. As indicators of nasal reactivity, respiratory frequency and nasal resistance were monitored.

RESULTS

Sensitized mice exposed to 3 days of nasal allergen challenge showed a nonspecific early-phase response. As the number of allergen exposures increased, there was progressive diminution in nonspecific responses with increased allergen-specific early-phase responses and a late-phase response. Sensitized FcvarepsilonRI-/- mice did not develop nonspecific nasal responses or late-phase responses, but transfer of in vitro-differentiated wild-type mast cells into FcvarepsilonRI-/- mice restored nonspecific early-phase nasal responses but not the late-phase response.

CONCLUSION

These data identify the nonspecific nasal response as a major contributor to the early-phase response, especially during initial allergen exposure, and is dependent on mast cells. Increasing allergen exposure results in increasing allergen-specific responses, converting the nonspecific early-phase response to a late-phase response that is allergen-specific and mast cell-independent.

Neural aspects of allergic rhinitis

PURPOSE OF REVIEW

Recent advances have helped to clarify the role of nerves in allergic rhinitis.

RECENT FINDINGS

Mast cell histamine release activates histamine H1 receptors on a subset of nonmyelinated Type C afferent trigeminal neurons to convey the sensation of itch. The itch nerves may be distinct from those responsible for burning pain and the dull ache of congestion. Activation of brain stem centers leads to cognition of nasal pruritus, generation of the systemic sneeze reflex and recruitment of local nasal parasympathetic reflexes. These cholinergic reflexes stimulate M3 muscarinic receptors on the submucosal glands to cause exocytosis and the thick mucous discharge of allergic rhinitis. The importance of these neural pathways is demonstrated by the benefits of antihistamines to block itch and sneeze, and anticholinergic drugs to block glandular secretion. One open question remains the role of mediators of allergic inflammation on the sensitivity and reactivity of afferent neurons and these secretory reflexes.

SUMMARY

The neurology of the nose helps to explain the sensations encountered in allergic rhinitis and opens new frontiers for drug discovery.

Nasonasal reflexes, the nasal cycle, and sneeze

The nasal mucosa is a complex tissue that interacts with its environment and effects local and systemic changes. Receptors in the nose receive signals from stimuli, and respond locally through afferent, nociceptive, type C neurons to elicit nasonasal reflex responses mediated via cholinergic neurons. This efferent limb leads to responses in the nose (eg, rhinorrhea, glandular hyperplasia, hypersecretion with mucosal swelling). Anticholinergic agents appear useful against this limb for symptomatic relief of a "runny nose." Chronic exposure to allergens can lead to hyperresponsiveness of the nasal mucosa. As a result, receptors upregulate specific ion channels to increase the sensitivity and potency of their reflex response. Nasal stimuli also affect distant parts of the body. Nerves in the sinus mucosa cause vasodilation; the lacrimal glands can be stimulated by nasal afferent triggers. Even the cardiopulmonary system can be affected via the trigeminal chemosensory system, where sensed irritants can lead to changes in tidal volume, respiratory rate, and blink frequency. The sneeze is an airway defense mechanism that removes irritants from the nasal epithelial surface. It is generally benign, but can lead to problems in certain circumstances. The afferent pathway involves histamine-mediated depolarization of H1 receptor-bearing type C trigeminal neurons and a complex coordination of reactions to effect a response.

The Allergic Rhinitis and its Impact on Asthma system: a new classification of allergic rhinitis and nasal responsiveness

OBJECTIVES AND HYPOTHESIS

Allergic rhinitis has traditionally been classified into seasonal and perennial rhinitis. However, many subjects with dual sensitisation do not fit neatly into either category. Recently, the Allergic Rhinitis and its Impact on Asthma workshop has proposed a new allergic rhinitis classification, into intermittent and persistent forms. The purpose of the present study was to investigate whether the symptomatic and secretory responsiveness of allergic rhinitis sufferers correlated well with the Allergic Rhinitis and its Impact on Asthma classification, compared with the traditional classification.

STUDY DESIGN

Experimental study.

METHODS

Forty subjects with allergic rhinitis and 13 normal controls underwent a unilateral nasal bradykinin challenge protocol. Symptom scores were recorded and secretion weights measured bilaterally using filter paper disks. The symptomatic and secretory responses of allergic subjects were analysed according to both the traditional and the Allergic Rhinitis and its Impact on Asthma classifications, and the two systems were compared.

RESULTS

For both classification systems, the two groups of allergic subjects were clearly demarcated by secretory responses. However, after classification according to the traditional system, there was a lack of clear demarcation between the groups as regards symptomatic response, whereas clear demarcation of symptomatic responses was seen after using the Allergic Rhinitis and its Impact on Asthma classification.

CONCLUSIONS

In allergic rhinitis subjects, the degree of nasal responsiveness was closely related to their Allergic Rhinitis and its Impact on Asthma classification. Furthermore, this classification was not compromised by the inclusion of subjects with dual sensitisation. Thus, the Allergic Rhinitis and its Impact on Asthma classification may have advantages for future research studies on allergic rhinitis.

Subjects with non-allergic non-infectious perennial rhinitis do not show nasal hyper-responsiveness to bradykinin

Symptoms in non-allergic non-infectious perennial rhinitis (NANIPER) are characteristically trigged by non-specific irritants. Hyper-responsiveness to cold dry air has been demonstrated in NANIPER. Bradykinin is a peptide involved in allergic inflammation. Neurally mediated hyper-responsiveness to bradykinin has been demonstrated in allergic rhinitis. The purpose of the present study was to investigate whether hyper-responsiveness to bradykinin is present in NANIPER. Normal subjects (n = 13) and subjects with NANIPER (n = 10) were subjected to a nasal bradykinin challenge protocol. Secretory responses were measured using filter paper disks, and congestive responses measured using acoustic rhinometry. Compared to normal subjects, with NANIPER had a greater secretory response to control challenge with Hartman's solution. On the other hand, the normal ipsilateral secretory and congestive response to bradykinin was absent in NANIPER. Subjects with NANIPER did not demonstrate any evidence of reflex responses to bradykinin, and no evidence of nasal hyper-responsiveness to bradykinin. Hyper-responsiveness to bradykinin is absent in NANIPER. These results suggest that autonomic hyporesponsiveness rather than neural hyper-responsiveness may be an important factor in the etiology of NANIPER.