Measuring nasal nitric oxide in allergic rhinitis patients

Nasal nitric oxide measurement in allergic rhinitis and non-allergic rhinitis: a meta-analysis

The goal of this meta-analysis was to study nasal nitric oxide (nNO) measurements in allergic rhinitis (AR) and non-allergic rhinitis (non-AR). The protocol was registered with PROSPERO (no: CRD4202124828). Electronic databases from PubMed, Google Scholar, Scopus, Web of Science, and Cochrane were all thoroughly searched and studies were chosen based on the qualifying requirements. The quality of the studies was evaluated by Joanna Briggs Institute evaluation tools, and publication bias using funnel plots. The meta-analysis included 18 studies, whereas the systematic review included 20 studies, totaling 3097 participants (1581 AR, 458 non-AR, and 1058 healthy/control). Patients with AR had significantly greater nNO levels than the control group, although this did not change significantly before or after treatment. AR patients had significantly greater nNO levels than non-AR patients, but there was no significant difference between non-AR patients and healthy controls. Nineteen of the studies were of high quality and the remaining one was of moderate quality. nNO measurement has a promising role in the management of AR and non-AR patients, but more investigations are needed to document clinical benefits.

Nasal Nitric Oxide in Children: A Review of Current Outreach in Pediatric Respiratory Medicine

Nasal nitric oxide (nNO) is a gas synthesized by the inducible and constitutive NO synthase (NOS) enzyme in the airway cells of the nasal mucosa. Like lung nitric oxide, it is thought to be associated with airway inflammation in various respiratory diseases in children. The aim of our review was to investigate the current state of use of nNO measurement in children. A comprehensive search was conducted using the Web of Science and PubMed databases specifically targeting publications in the English language, with the following keywords: nasal NO, children, allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, primary ciliary dyskinesia (PCD), and cystic fibrosis (CF). We describe the use of nNO in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF based on the latest literature. nNO is a noninvasive, clinically applicable test for use in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF. It can be used as a complementary method in the diagnosis of these respiratory diseases and as a monitoring method for the treatment of allergic rhinitis and acute and chronic rhinosinusitis.

Clinical Applications of Nasal Nitric Oxide in Allergic Rhinitis: A Review of the Literature

Allergic rhinitis, a common allergic disease affecting a significant number of individuals worldwide, is observed in 25% of children and 40% of adults, with its highest occurrence between the ages of 20 and 40. Its pathogenesis, like other allergic diseases, involves innate and adaptive immune responses, characterized by immunologic hypersensitivity to environmental substances. This response is mediated by type 2 immunity. Within type 2 allergic diseases, certain molecules have been identified as clinical biomarkers that contribute to diagnosis, prognosis, and therapy monitoring. Among these biomarkers, nitric oxide has shown to play a key role in various physiological and pathological processes, including neurotransmission, immunity, inflammation, regulation of mucus and cilia, inhibition of microorganisms, and tumor cell growth. Therefore, measurement of nasal nitric oxide has been proposed as an objective method for monitoring airway obstruction and inflammation in different settings (community, hospital, rehabilitation) and in various clinical conditions, including upper airways diseases of the nose and paranasal sinuses. The purpose of this review is to analyze the potential mechanisms contributing to the production of nasal nitric oxide in allergic rhinitis and other related health issues. Additionally, this review aims to identify potential implications for future research, treatment strategies, and long-term management of symptoms.

Diagnostic value and underlying mechanism of nasal nitric oxide in eosinophilic chronic rhinosinusitis with nasal polyps

PURPOSE

Nitric oxide (NO) is an important messenger molecule widely present in the human body. However, the role of nasal NO (nNO) in eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) remain unclear. This study aimed to investigate the diagnostic value and underlying mechanism of nNO in Eos CRSwNP.

METHODS

The medical records of 84 non-Eos CRSwNP patients, 55 Eos CRSwNP patients, and 37 control subjects were retrospectively reviewed. The diagnostic value of nNO for Eos CRSwNP was assessed. The expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and tight junctions (TJs) components claudin-1, occludin, and ZO-1 was detected in the nasal polyps. Primary human nasal epithelial cells (HNECs) were co-treated with eNOS inhibitor (L-NAME) or Akt inhibitor (MK-2206), interleukin (IL)-13, and dexamethasone (Dex). The level of NO and the expression of TJs and Akt/eNOS pathways were examined.

RESULTS

The nNO levels of the CRSwNP group were significantly lower than those of the control group. Compared with the non-Eos CRSwNP group, the Eos CRSwNP group showed higher nNO level. The combination of nNO level, eosinophilic percentage, and posterior ethmoid score had a better predictive value for Eos CRSwNP (AUC = 0.855). The expression of iNOS, eNOS, and p-eNOS was higher in the CRSwNP groups than in the control group, and p-eNOS expression was higher in the Eos CRSwNP group than in the non-Eos CRSwNP group. The expression of TJs was lower in the Eos CRSwNP group than in the non-Eos CRSwNP and control group. IL-13 decreased TJ expression in HNECs, while Dex promoted Akt and eNOS phosphorylation, NO production and TJ expression. Furthermore, these effects of Dex were inhibited by L-NAME and MK-2206 in HNECs.

CONCLUSION

nNO may have a high diagnostic value in Eos CRSwNP, and Akt/eNOS pathway may promote the generation of NO to protect TJs. NO may have a potentially important role in the diagnosis and treatment of Eos CRSwNP.

Nasal Nitric Oxide as a Biomarker in the Diagnosis and Treatment of Sinonasal Inflammatory Diseases: A Review of the Literature

OBJECTIVE

To critically review the literature on nasal nitric oxide (nNO) and its current clinical and research applicability in the diagnosis and treatment of different sinonasal inflammatory diseases, including acute bacterial rhinosinusitis (ABRS), allergic rhinitis (AR), and chronic rhinosinusitis (CRS).

METHODS

A search of the PubMed database was conducted to include articles on nNO and sinonasal diseases from January 2003 to January 2020. All article titles and abstracts were reviewed to assess their relevance to nNO and ABRS, AR, or CRS. After selection of the manuscripts, full-text reviews were performed to synthesize current understandings of nNO and its applications to the various sinonasal inflammatory diseases.

RESULTS

A total of 79 relevant studies from an initial 559 articles were identified using our focused search and review criteria. nNO has been consistently shown to be decreased in ABRS and CRS, especially in cases with nasal polyps. While AR is associated with elevations in nNO, nNO levels have also been found to be lower in AR cases with higher symptom severity. The obstruction of the paranasal sinuses is speculated to be an important variable in the relationship between nNO and the sinonasal diseases. Treatment of these diseases appears to affect nNO through the reduction of inflammatory disease burden and also mitigation of sinus obstruction.

CONCLUSION

nNO has been of increasing interest to researchers and clinicians over the last decade. The most compelling data for nNO as a clinical tool involve CRS. nNO can be used as a marker of ostiomeatal complex patency. Variations in measurement techniques and technology continue to impede standardized interpretation and implementation of nNO as a biomarker for sinonasal inflammatory diseases.

Diagnostic Value and Clinical Application of Nasal Fractional Exhaled Nitric Oxide in Subjects with Allergic Rhinitis

Purpose

Nitric oxide (NO) is a potential marker in the diagnosis and monitoring of treatment for the management of patients with allergic rhinitis (AR). The study aimed to determine the value of nasal fractional exhaled nitric oxide (FeNO) in the diagnosis and treatment response of AR patients.

Methods

The participants were divided into control and allergic rhinitis groups based on the clinical symptoms and skin prick tests. The AR group was treated with intranasal corticosteroid after the diagnosis. The nasal fractional exhaled nitric oxide (FENO) levels were compared between control and AR groups. In the AR group, the visual analogue scale (VAS), Nasal Obstruction Symptoms Evaluation (NOSE) questionnaire, and nasal fractional exhaled nitric oxide (FeNO) were assessed pre- and post-treatment.

Results

One hundred ten adults were enrolled. The nasal FeNO level was significantly higher in AR compared to control ( p < 0.001). Both the subjective (VAS and NOSE), both ( p  < 0.01) and objective (nasal FeNO, p < 0.001) assessments showed significant different pre- and post-treatment. The threshold level of nasal FeNO in the diagnosis of AR was 390.0 ppb (sensitivity of 73% and specificity of 80%) based on the receiver operator characteristic curve.

Conclusion

Nasal FeNO level is significantly higher in AR compared to control group with significant difference pre- and post-treatment. The findings suggest nasal FeNO can serve as an adjunct diagnostic tool together with the monitoring of treatment response in AR.

Nasal nitric oxide testing for allergic rhinitis patients: Systematic review and meta-analysis

BACKGROUND

Nasal nitric oxide (nNO) levels in allergic rhinitis (AR), healthy people or nonallergic rhinitis (NAR) have shown contradicting results in previous studies. By meta-analysis, we reviewed studies that measured nNO in AR patients to assess nNO's ability to discriminate AR from healthy people or NAR.

METHODS

We systematically searched PubMed, Cochrane, Embase, Ovid, Web of Science, Wanfang Data, CNKI until December 15, 2020. Differences were expressed as standardized mean differences (SMD) with 95% confidence interval (CI), by random-effects method.

RESULTS

A total of 10 original studies with 561 AR patients, 327 healthy controls, 123 NAR patients were included in the narrative synthesis and 9 studies in the meta-analysis. nNO in AR was significantly increased compared with healthy controls (SMD: 0.989; 95% CI: 0.402, 1.576; p = .001) or NAR (SMD: 0.680; 95% CI: 0.101, 1.259; p = 0.021). However, subgroup analysis based on measuring process and patient characteristics showed that no significant differences were detected in nNO between AR patients with nasal polyps or sinusitis or marked ostial obstruction and healthy controls.

CONCLUSIONS

nNO is a potential indicator for recognizing AR. Nasal polyps, sinusitis and marked ostial obstruction should be considered before nNO is applied to detect AR.

The roles of nasal nitric oxide in diagnosis and endotypes of chronic rhinosinusitis with nasal polyps

Background

Chronic rhinosinusitis with polyps (CRSwNP) is a global health concern. Nasal nitric oxide (nNO), a clinical biomarker, have been studied to assess the presence of airway mucosal inflammation. This study aimed to clarify the roles of nNO in diagnosis and endotypes of CRSwNP.

Methods

Eighty-two CRSwNP patients and thirty healthy volunteers were recruited for this study. The patients were classified into eosinophilic CRSwNP (Eos CRSwNP) and non⁃eosinophilic CRSwNP (Non-Eos CRSwNP) endotypes by tissue eosinophil percentage. nNO levels were measured with an electrochemical sensor-based device. nNO levels and clinical factors were compared among the groups. Receiver-operating characteristic (ROC) curve and logistic regression analyses were performed to evaluate the predictive ability of the nNO for diagnosis and endotypes of CRSwNP.

Results

Eos CRSwNP patients(143.9 ± 106.2, ppb) had lower nNO levels than Non-Eos CRSwNP(228.3 ± 109.2, ppb, p = 0.013) and healthy subjects(366.5 ± 88, ppb, p < 0.0001). Patients with atopy exhibited significantly higher levers of nNO compared with patients without atopy (p < 0.05). For Eos CRSwNP diagnosis, nNO had high predictive value for Eos CRSwNP (AUC: 0.939; sensitivity: 76.74%; specificity: 96.67%; cut-off value: 231 ppb, p < 0.001). Furthermore, nNO levels were associated with CRSwNP endotypes (odds ratio: 1.010; 95% confidence interval: 1.003, 1.016%; p = 0.002). When the nNO concentration was 158 ppb, we could discriminate Eos CRSwNP from Non-Eos CRSwNP (AUC = 0.710, sensitivity: 76.92%; specificity, 60.47%, P = 0.001). After it was combinated by nNO, peripheral blood eosinophil count (PEAC) and VAS score, the AUC was increased to 0.894 (95%CI = 0.807 to 0.951, p < 0.0001, sensitivity:76.74%, specificity: 89.74%).

Conclusions

nNO may have potential for non-invasive diagnosis and endotype of CRSwNP. nNO combined with PEAC and VAS score may be a good diagnostic tool for endotyps of Eos CRSwNP. However, the atopic status of the patients influenced the levels of nNO.

Clinical application of nasal nitric oxide measurement in allergic rhinitis: A systematic review and meta-analysis

BACKGROUND

Nasal nitric oxide (nNO) is considered a biomarker of nasal inflammation.

OBJECTIVE

To perform a systematic review with meta-analysis and meta-regressions on the association between nNO levels and allergic rhinitis (AR).

METHODS

PubMed, Web of Science, Scopus, and EMBASE databases were systematically searched. Differences between cases and controls were expressed as standardized mean differences (SMD) with 95% confidence intervals (CI).

RESULTS

Overall, 39 articles were included: 30 containing data on nNO measured by nasal aspiration (1881 patients with AR and 1337 controls) and 12 assessing nNO by nasal exhalation (525 patients with AR and 350 controls). Compared with controls, AR presented significantly higher nNO values both during nasal aspiration (SMD, 1.309; 95% CI, 0.841-1.777; P < .001) and nasal exhalation (SMD, 0.708; 95% CI, 0.303-1.114; P = .001). Sensitivity and subgroup analyses confirmed that the results for the evaluated outcomes were not affected by the presence of clinical confounding factors (asthma, nasal polyps, inhaled corticosteroids, smoking history), this being valid for both perennial and seasonal diseases during exposure to allergens. For the aspiration method, meta-regressions indicated that older age and a better pulmonary function were associated with a lower difference in nNO levels between patients with AR and controls, whereas an increasing aspiration flow was associated with a high effect size.

CONCLUSION

nNO levels are higher in AR, particularly when using high aspiration flows and in younger patients, who often perceive this condition as a source of disability. Further studies are needed to evaluate the usefulness of this biomarker for monitoring airway disorders and optimizing strategies in different settings (community, hospital, rehabilitation).

The effect of medical treatment on nasal exhaled nitric oxide (NO) in patients with persistent allergic rhinitis: A randomized control study

PURPOSE

This study aimed to evaluate the role of nasal nitric oxide (NO) in the management of patients with persistent allergic rhinitis (PER).

METHODS

It was a randomized and comparative study. The study subjects were classified as controls (healthy subjects) or patients with PER based on defined criteria. All clinical, functional and biological data were collected for analyzing. Nasal fractional exhaled nitric oxide (FENO) was measured by electroluminescence device. Patients with PER were randomized for treatment with antihistamine (ATH) combined with leukotriene receptor antagonists (LRA) or only with intranasal steroids (INS).

RESULTS

During two years, 501 subjects were included: 234 control subjects and 267 patients with PER. The levels of nasal NO, total IgE, blood eosinophil counts, and apnea-hypopnea index (AHI) in patients with PER were higher than controls (P < 0.001; P < 0.05; P < 0.05; P < 0.01; respectively). There were statistically significant correlations between nasal NO, nasal peak flows, total IgE, and blood eosinophil counts in patients with PER (R = -0.687 and P = 0.0012; R = -0.643 and P = 0.0018; R = 0.432 and P = 0.0024; R = 0.445 and P = 0.002; respectively). After 6 months of treatment, patients treated with INS had greater improvement of clinical symptoms and reduction of nasal NO values than patients treated with ATH + LRA (985 ± 253 vs. 732 ± 298 ppb; P < 0.05).

CONCLUSION

Nasal NO measurement is a useful tool for the follow-up of patients with PER. It also helps clinicians to estimate the level of response to treatment in patients with PER.

Nasal nitric oxide in upper airways in children with asthma and allergic rhinitis

PURPOSE

The aim of this study is to compare levels of nasal nitric oxide (nNO) in pediatric patients with respiratory diseases.

MATERIALS AND METHODS

nNO was measured by an electrochemical analyzer in 179 patients aged 7-15 with asthma, allergic rhinitis or with asthma and allergic rhinitis and in healthy children recruited from a local allergology clinic. Correlations between nNO levels and patient clinical parameters were assessed.

RESULTS

nNO was significantly higher in patients with allergic rhinitis (2316.3 ± 442.33 ppb, p < 0.001) as well as with asthma and allergic rhinitis (2399.9 ± 446.73 ppb, p < 0.001) compared to asthmatic and healthy children (1066.4 ± 416.75; 836.2 ± 333.47 ppb, respectively). A receiver operating characteristic curve analysis revealed that a cut-off value of 1545 ppb nNO and 1459 ppb nNO has sensitivity of 100% and specificity of 100% in distinguishing allergic rhinitis and combined asthma and allergic rhinitis from healthy subjects. A positive correlation between nNO and age and height was determined only in groups of healthy controls. We found no association between nNO level and clinical parameters including percent of eosinophils and total IgE.

CONCLUSION

Levels of nNO are currently measured by different analyzers and with different methods, so assessment of nNO is in need of standardization improvement to become a more reliable tool. However, because it is cheap, painless and fast, it may be helpful in combination with recognition of clinical symptoms and typical diagnostic methods, especially in estimation of inflammation.

Clinical Utility Of The Exhaled Nitric Oxide (NO) Measurement With Portable Devices In The Management Of Allergic Airway Inflammation And Asthma

Nitric oxide (NO) is a potential bioactive gas produced continuously and constantly in the airways of healthy subjects. In allergic airway inflammation, the level of exhaled NO is usually increased and mediated by inducible nitric oxide synthase (iNOS) enzyme presenting in the epithelium and different inflammatory cells. The measurement of NO concentration in the airway is possible with portable devices which use an electroluminescence technique. In subjects with upper airway with allergic inflammation such as in allergic rhinitis, the measurement of nasal NO (nNO) may help to diagnose and manage the disease. In the lower airway, increased fractional exhaled NO (FENO) reflects directly the inflammatory process that occurs in the airways that are typically seen in asthma. It has been shown that there is a strong correlation between FENO levels and increased activity of airway inflammation mediated by immuno-allergic cells and mediators. Thus, FENO has higher specificity and sensitivity than other methods in diagnosing the severity of inflammation in asthmatic patients. Moreover, the correlation between increased FENO levels and a high risk of bronchial hyperresponsiveness has also been demonstrated. FENO is also a relevant biomarker to evaluate asthma status due to the change of its values occurring earlier than clinical manifestations and spirometry parameters. In addition, the measurement of FENO with portable devices helps to support the diagnosis of asthma, to follow-up the control of asthma and to personalize asthmatic patients for target treatment with biologic therapy. Therefore, measuring FENO with portable devices in the diagnosis and treatment of allergic airway inflammation, especially in asthma, is one of the most essential applications of NO biomarkers in exhaled breath.

Effects of Low-Level Laser Irradiation in a Mouse Model of Allergic Rhinitis

BACKGROUND AND OBJECTIVES

To evaluate the antiallergic effect of low-level laser irradiation (LLLI) at 650 nm in a mouse model of allergic rhinitis (AR), and to examine the underlying mechanisms.

STUDY DESIGN/MATERIALS AND METHODS

BALB/c mice were sensitized with ovalbumin (OVA) and alum and challenged intranasally with OVA. Straight- and diffusion-type LLLI were applied directly into the intranasal cavity of the mice once daily for 10 days (650 nm, 5 mW, 15 min/day) and multiple allergic parameters were evaluated.

RESULTS

LLLI reduced allergic symptoms, such as rubbing and sneezing, and suppressed the serum total immunoglobulin E (IgE), OVA-specific IgE, and OVA-specific IgG1 levels. Diffusion-type LLLI significantly reduced eosinophil infiltration of nasal mucosa and lymph nodes (LNs). LLLI reduced the expression of interleukin-4 (IL-4) and IL-17 in cervical LN and splenocyte culture supernatant, as well as their messenger RNA levels in nasal mucosa. However, the expression of interferonγ (IFN-γ) and IL-6 was unaffected by LLLI. The levels of reactive oxygen species (ROS) and nitric oxide (NO) in LN cells and the nasal mucosa, which were increased in the AR group, were reduced by LLLI, suggesting involvement of ROS and NO within their mechanism.

CONCLUSIONS

LLLI exerted an antiallergic effect by decreasing local and systemic IL-4, IL-17, and IgE levels, as well as eosinophilic infiltration into the nasal mucosa, in a mouse model of AR by modulating ROS and NO levels. Diffusion-type LLLI exhibited greater efficacy against AR than straight-type LLLI. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Nasal nitric oxide is a useful biomarker for acute unilateral maxillary sinusitis in pediatric allergic rhinitis: A prospective observational cohort study

Background

Nasal nitric oxide (nNO) could be a biomarker for nasal passage inflammation and sinus ostial patency. We have aimed to investigate the nNO concentration and the effect of antibiotic therapy in children with perennial allergic rhinitis (PAR) children with/without acute bacterial sinusitis.

Methods

We enrolled a cohort of 90 and 31 children with PAR, without and with acute unilateral maxillary sinusitis, and 79 normal children. Acute bacterial maxillary sinusitis was diagnosed based on clinical signs and symptoms, radiographic examination and nasal fibroendoscopy. Rhinitis control assessment test (RCAT), rhinomanometry, nNO and fractional exhaled NO (FENO) measurements were performed before and 2 weeks after antibiotic therapy.

Results

We found significantly higher mean nNO levels, FENO values, and total nasal resistance in children with PAR than in normal children (p ​< ​0.05). Acute unilateral maxillary sinusitis was associated with lower lesion-side nNO levels, higher FENO values, total nasal resistance, and poor RCAT scores (p ​< ​0.05). In multivariate analysis, age, IgE, and acute maxillary sinusitis were significant factors influencing nNO levels in children with PAR. The lesion-side nNO levels, FENO values, total nasal resistance, and RCAT scores were reversed after antibiotic therapy (p ​< ​0.05). The lesion-side nNO levels were significantly correlated to nasal obstructive scores (r ​= ​0.59, p ​< ​0.05) and expiratory nasal resistance (r ​= ​-0.54, p ​< ​0.05) in the acute maxillary sinusitis. A cut-off nNO value of 538 ​ppb showed 100% sensitivity and 94.9% specificity, to predict PAR from normal children. An nNO value of 462 ​ppb showed 100% sensitivity and 100% specificity to discriminate between the lesion-side and the unaffected sinus-side in PAR children with acute unilateral maxillary sinusitis.

Conclusions

We conclude that the obstruction of NO from the sinus into the nasal passage is the likely explanation for the decreased lesion-side nNO levels in acute unilateral maxillary sinusitis. nNO is a non-invasive biomarker with high sensitivity to diagnose and monitor treatment responses of PAR patients with acute rhinosinusitis. Both nNO and FENO levels return to baseline following antibiotic therapy, supporting the "one airway one disease" concept.

Nasal Nitric Oxide Is Correlated With Nasal Patency and Nasal Symptoms

PURPOSE

Nitric oxide (NO) is an important endogenous mediator in both upper and lower respiratory systems. The purpose of the present study was to extract nasal NO (nNO) normal range of Chinese adults and the internal influencing factors. The differences in nNO levels between rhinitis and asymptomatic atopic subjects, and the diagnostic value of nNO in allergic rhinitis (AR) were further investigated.

METHODS

One thousand adults were recruited from the general public. Participants were divided into different subgroups according to the questionnaires and skin prick tests. In all of these subjects, nNO, fractional exhaled NO (FeNO) and nasal airflow resistance were measured. The normal ranges of nNO and FeNO, the differences between subgroups, and the correlations between NO (nNO and FeNO) and other internal factors were analyzed.

RESULTS

Both nNO and FeNO levels were significantly higher in AR patients than in healthy and asymptomatic atopic subjects. The nNO levels were significantly lower in asymptomatic atopic subjects than in normal adults. FeNO levels were significantly higher in non-AR patients than in the healthy and asymptomatic atopic adults. The cutoff value of nNO for the diagnosis of AR was 117.5 ppb (sensitivity, 50.9%; specificity, 63.9%). The nNO levels were correlated with FeNO levels, total nasal resistance measured at 75Pa, nasal volume within 0-7 cm from the anterior nares (V_0-7cm) and nasal symptom visual analogue scale (VAS) scores, while the FeNO levels were correlated with age, height, weight, body surface area, nasal volume of V_0-7cm and the nasal symptom VAS score.

CONCLUSIONS

The nNO level can be significantly different between healthy and AR patients and may be significantly correlated with nasal symptoms and nasal patency of rhinitis patients. However, the clinical value of nNO is still in the exploration stage.

Specificity and reproducibility of nasal biomarkers in patients with allergic rhinitis after allergen challenge chamber exposure

BACKGROUND

Allergic rhinitis is an inflammatory disease that causes cellular influx and mediator release in the nose. These inflammatory changes might be used as nasal biomarkers to assess the efficacy of novel anti-allergic treatments.

OBJECTIVE

To assess the specificity and reproducibility of nasal biomarkers in patients with allergic rhinitis after grass pollen exposure in an allergen challenge chamber.

METHODS

In a monocenter pilot study, 15 patients with allergic rhinitis and 19 healthy individuals underwent two 4-hour Dactylis glomerate pollen challenges in the challenge chamber with an interval of 21 days. Before challenge, on exit, and after 2 and 22 hours, a nasal lavage was performed and nasal secretions were collected on filter paper to determine a wide panel of cells and mediators. Furthermore, total nasal symptom score, nasal flow, and nasal nitric oxide were measured.

RESULTS

Pollen exposure significantly increased eosinophil, interleukin (IL) 5, IL-6, IL-13, and macrophage inflammatory protein 1β levels in allergic patients but not in healthy individuals. The effect could be reproduced for eosinophils, IL-5, IL-6, and macrophage inflammatory protein 1β after the second allergen challenge. By contrast, the IL-13 levels were higher and eotaxin levels first increased after repetitive allergen challenge. There was no correlation between total nasal symptom score and elevated cell or cytokine levels. Nasal nitric oxide levels were nonspecifically elevated in both patients with allergy and healthy controls.

CONCLUSION

A subset of cellular and soluble biomarkers in nasal lavage and secretion reveals specificity and reproducibility in patients with allergic rhinitis. These can be used to measure the immunologic efficacy of antiallergic treatments in an allergen challenge chamber. Carryover effects attributable to priming must be considered when designing cross-over studies.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00297843.

Study of nasal exhaled nitric oxide levels in diagnosis of allergic rhinitis in subjects with and without asthma

Background

The measure of fractional exhaled nitric oxide (FENO) in the airways is a useful tool to guide the diagnosis and titration of inhaled corticosteroids in patients with asthma. However, its role in diagnosis of allergic rhinitis (AR), especially in subjects with asthma, is not well established.

Objective

To study the cutoff of nasal FENO in the diagnosis of subjects with AR and AR-asthma compared to age-matched subjects without AR or asthma and its correlations with the clinical and functional characteristics.

Methods

The study was cross sectional and descriptive. Subjects were grouped into control subjects, AR, and AR-asthma, based on the inclusion criteria. Exhaled NO (nasal FENO, bronchial FENO, and alveolar concentration of NO) was measured by multiple flow electro-luminescence device.

Results

Six hundred twenty-eight subjects were included: 217 control subjects (children: n=98, 10±4 years; adults: n=119, 50±16 years), 168 subjects with AR (children: n=54, 10±3 years; adults: n=114, 49±15 years), and 243 subjects with AR-asthma (children: n=115, 10±3 years; adults: n=128, 51±14 years). Nasal peak inspiratory flow and peak expiratory flow were lower in subjects with AR and AR-asthma than in control subjects (P<0.01 and P<0.01; and P<0.05 and P<0.01, respectively). Nasal FENO levels were significantly higher in subjects with AR and AR-asthma than in control subjects (1614±629 and 1686±614 ppb vs 582±161 ppb; P<0.001 and P<0.001, respectively). In subjects with AR non-asthma, the cutoffs of nasal FENO for those diagnosed with AR were 775 ppb in children, 799 ppb in adults, and 799 in the general population (sensitivity: 92.68%, 92.63%, and 92.65%, respectively; specificity: 91.67%, 95.00%, and 96.87%, respectively). In subjects with AR-asthma, the cutoffs of nasal FENO were higher, especially in asthma children (1458 ppb; sensitivity: 72.97% and specificity: 95.83%).

Conclusion

Nasal FENO measurement is a useful technique for the diagnosis of AR in subjects with and without asthma.