Nasal allergen deposition leads to conjunctival mast cell degranulation in allergic rhinoconjunctivitis

Rare presence and function of neuroendocrine cells in the nasal mucosa

There is growing evidence that neurogenic inflammation contributes to the pathophysiology of upper airway diseases, with nasal hyperreactivity (NHR) being a key symptom. The rare neuroendocrine cells (NECs) in the epithelium have been linked to the pathophysiology of bronchial and intestinal hyperreactivity, however their presence in the nasal mucosa and their potential role in NHR remains unclear. Therefore, we studied the presence of NECs in the nasal epithelium of controls, allergic rhinitis patients and chronic rhinosinusitis with nasal polyps patients, and their link to NHR. The expression of typical NECs markers, CHGA, ASCL1 and CGRP, were evaluated on gene and protein level in human samples using real-time quantitative PCR (RT-qPCR), western blot, immunohistochemistry fluorescence staining, RNA scope assay, flow cytometry and single cell RNA-sequencing. Furthermore, the change in peak nasal inspiratory flow after cold dry air provocation and visual analogue scale scores were used to evaluate NHR or disease severity, respectively. Limited gene expression of the NECs markers CHGA and ASCL1 was measured in patients with upper airway diseases and controls. Gene expression of these markers did not correlate with NHR severity nor disease severity. In vitro, CHGA and ASCL1 expression was also evaluated in primary nasal epithelial cell cultures from patients with upper airway disease and controls using RT-qPCR and western blot. Both on gene and protein level only limited CHGA and ASCL1 expression was found. Additionally, NECs were studied in nasal biopsies of patients with upper airway diseases and controls using immunohistochemistry fluorescence staining, RNA scope and flow cytometry. Unlike in ileum samples, CHGA could not be detected in nasal biopsies of patients with upper airway diseases and control subjects. Lastly, single cell RNA-sequencing of upper airway tissue could not identify a NEC cluster. In summary, in contrast to the bronchi and gut, there is only limited evidence for the presence of NECs in the nasal mucosa, and without correlation with NHR, thereby questioning the relevance of NECs in upper airway pathology.

Tear cytokine levels in allergic rhinitis without ocular symptoms

OBJECTIVE

To compare cytokine levels in the pre-corneal tear film between patients with allergic rhinitis, allergic rhinoconjunctivitis and the normal population.

DESIGN

A comparative cross sectional study.

PARTICIPANTS

Patients were divided into Group 1 (allergic rhinitis without conjunctivitis), Group 2 (allergic rhinoconjunctivitis), and Group 3 (normal population).

METHODS

A comparative cross-sectional study was conducted. Patients were divided into; Group 1 (allergic rhinitis without conjunctivitis), Group 2 (allergic rhinoconjunctivitis), and Group 3 (normal controls). Tears were collected using Schirmer strips and cytokine analysis performed using enzyme linked immunosorbent assay.

RESULTS

There were a total of 68 subjects. Median values of cytokines in the allergic rhinitis group were as follows; TNFa (45.34 pg/ml), IL-4 (61.91 pg/ml), IL-5 (8.92 pg/ml), IL-6 (538.37 pg/ml) and IL-8 (1438.72 pg/ml). Cytokine levels in the group with allergic rhinoconjunctivitis were approximately two-fold higher than in the group with allergic rhinitis only. The median cytokine level in the control group was lowest. A significant inter-group difference was observed for TNF-alpha, IL-4, IL-6 and IL-8 levels, with allergic rhinoconjunctivitis patients demonstrating significantly elevated cytokines compared to those with allergic rhinitis only (p<0.001). These four cytokines were also significantly higher in those with allergic rhinitis than in controls (p<0.005). Although the group with allergic rhinoconjunctivitis had the highest levels of IL-5, no statistically significant inter-group difference was noted (p=0.479).

CONCLUSION

This study demonstrated the presence of raised tear film inflammatory cytokines even in allergic rhinitis patients without ocular symptoms. These patients may be at increased risk of developing allergic conjunctivitis. These findings not only substantiate the immunological theory of the naso-ocular reflex, but have clinical and therapeutic implications for the holistic management of allergic rhinitis and conjunctivitis.

MP29-02 reduces nasal hyperreactivity and nasal mediators in patients with house dust mite-allergic rhinitis

BACKGROUND

Nasal hyperreactivity (NHR) is an important clinical feature of allergic rhinitis (AR). The efficacy of MP29-02 (azelastine hydrochloride (AZE) and fluticasone propionate [FP]) nasal spray on local inflammatory mediators and NHR in AR is unknown. We tested if MP29-02 decreases inflammatory mediators and NHR in AR and if this effect is due to restoration of nasal epithelial barrier function.

METHODS

A 4-week double-blinded placebo-controlled trial with MP29-02 treatment was conducted in 28 patients with house dust mite (HDM) AR. The presence of NHR was evaluated by measuring reduction in nasal flow upon cold dry air exposure. The effects of AZE ± FP on barrier integrity and airway inflammation were studied in a murine model of HDM-induced NHR and on reduced activation of murine sensory neurons and human mast cells.

RESULTS

MP29-02 but not placebo reduced NHR (P < .0001 vs P = .21), levels of substance P (P = .026 vs P = .941), and β-hexosaminidase (P = .036 vs P = .632) in human nasal secretions. In wild-type C57BL6 mice, the reduction in β-hexosaminidase levels (P < .0001) by AZE + FP treatment upon HDM challenge was found in parallel with a decreased transmucosal passage (P = .0012) and completely reversed eosinophilic inflammation (P = .0013). In vitro, repeated applications of AZE + FP desensitized sensory neurons expressing the transient receptor potential channels TRPA1 and TRPV1. AZE + FP reduced MC degranulation to the same extent as AZE alone.

CONCLUSION

MP29-02 treatment reduces inflammatory mediators and NHR in AR. The effects of AZE + FP on MC degranulation, nasal epithelial barrier integrity, and TRP channels provide novel insights into the pathophysiology of allergic rhinitis.

Model for Studying Anti- Allergic Drugs for Allergic Conjunctivitis in Animals

Allergic conjunctivitis (AC), which is characterized by ocular itching, hyperemia, and edema, deteriorates quality of life. In this study, effects of anti-allergic drugs were evaluated by assessing eye-scratching behavior, the number of eosinophils in conjunctiva epithelial tissues, and concentrations of chemical mediators in the tears of the guinea pig model of ovalbumin (OA)-induced AC.

The immediate effect of facial candling on inflammatory mediators, substance P, symptoms severity, and quality of life in allergic rhinitis patients: Study protocol for a randomized controlled trial

INTRODUCTION

Asian countries have a variety of ethnic groups and culture that provide their own traditional treatment in health care. Facial candling appears to be one of the popular traditional treatments in Southeast Asian. The complementary medicine practitioners promote that the facial candling treatment would help in reducing the symptoms of allergic rhinitis and other problems related to sinus. Due to the lack of evidence available, the effectiveness of this treatment method and its mechanism, however, remains unknown. The objective of this research is therefore to study impact of facial candling on inflammatory mediators, substance P (SP), symptoms severity, and quality of life (QoL) in allergic rhinitis patients.

METHOD AND ANALYSIS

A randomized, nonblinded, controlled trial will be carried out by recruiting a total of 66 eligible allergic rhinitis patients who fulfill the inclusion criteria from a university health center. The subjects will be randomly assigned into 2 groups: intervention group receiving facial candling treatment and control group (no treatment given). Samples of blood and nasal mucus will be collected right before and after intervention. Samples collected will be analyzed. The primary outcomes are the changes in the level of SP in both blood and mucus samples between both groups. The secondary outcomes include the levels of inflammatory mediators (ie, tumor necrosis factor alpha, interleukin (IL)-3, IL-5, IL-6, IL-10, and IL-13) and the severity of allergic rhinitis symptoms as measured by a visual analogous scale and QoL using the Rhinitis Quality of Life Questionnaire (RQLQ).

ETHICAL AND TRIAL REGISTRATION

The study protocols are approved from the Ethical and Research Committee of the Universiti Teknologi MARA (REC/113/15). The trial is registered under the Australia New Zealand Clinical Trial Registry (ACTRN12616000299404). The trial was registered on 03/07/2016 and the first patient was enrolled on 10/12/2016.

CONCLUSION

Facial candling is one of the unique treatments using candles to reduce the severity of symptoms and inflammation. This is the first ever study conducted on facial candling that will give rise to new knowledge underlying the effects of facial candling on severity of symptoms and inflammation relief mechanism mediated by substance P and inflammatory mediators.

Nasal provocation test is useful for discriminating allergic, nonallergic, and local allergic rhinitis

BACKGROUND

No standard study protocol or diagnostic criteria based on nasal provocation test (NPT) and acoustic rhinometry (AR) results are available for allergic rhinitis.

OBJECTIVE

We aimed to evaluate the usefulness of NPT plus AR for the differential diagnosis of local allergic rhinitis (LAR), allergic, and nonallergic rhinitis.

METHODS

The medical records and skin-prick test (SPT) and NPT results of 262 patients with symptoms of chronic rhinitis were reviewed. Patients were allocated to one of three groups, that is, group A [n = 110, negative SPT result for Dermatophagoides pteronyssinus (DP)], group B (n = 53, weakly positive result), or group C (n = 99, strongly positive result).

RESULTS

Twelve patients had a negative SPT result and provoked response in NPT [≥29% decrease of minimal cross-sectional area (MCA) after DP challenge] were diagnosed to have LAR. After DP challenge, group C showed significant aggravation of nasal symptoms and a greater decrease in acoustic parameters than groups A and B (p < 0.01). In patients with a more than or equal to 2 visual analog scale (VAS) increase in nasal obstruction (NO) after DP challenge, the criterion "a change of total nasal symptom score (TNSS) of more than or equal to 6.5" had 90.6% sensitivity and 77.4% specificity for the diagnosis of allergic rhinitis, whereas the diagnostic criterion "a total nasal volume (TNV) change at 30 minutes after DP challenge of more than or equal to 27.6%" had 73.4% sensitivity and 58.1% specificity.

CONCLUSION

NPT with AR could be a useful tool for the differential diagnosis of allergic, nonallergic, and local allergic rhinitis.

Nasal and ocular responses after specific and nonspecific nasal challenges in seasonal allergic rhinitis

BACKGROUND

Different nasal challenges induce neural and immune response leading to nasal and ocular symptoms in patients with seasonal allergic rhinitis (SAR). The release of neural mediators from nasal mucosa and conjunctiva after no-specific challenges in patients with SAR remains unknown.

OBJECTIVES

To compare the release of mediators from the nose and conjunctiva with symptoms after different nasal challenges in patients with SAR.

METHODS

Three types of consecutive nasal challenges were performed outside the pollen season in 25 patients with SAR. Challenges consisted of 500 biological units (BU) of allergen, 80 μg of histamine, and 1 mL of 2% hypertonic saline per nostril, within 24-hour and 72-hour intervals, respectively. Before and 15 minutes after challenges, evaluation of symptoms was performed with a visual analog scale. Concentrations of tryptase, eosinophil cationic protein in nasal lavages after 15 minutes, and substance P in tears after 5 minutes were measured with enzyme immunoassays.

RESULTS

Concentrations of substance P in tears were significantly higher after nonspecific challenges. Substance P concentration in tears significantly correlated with eye itchiness after histamine and hypertonic saline and with tearing after allergen. Ocular symptoms correlated significantly with tryptase concentration in nasal lavage collected 15 minutes after allergen challenge. There is a significant correlation in tear volume comparing different nasal challenges.

CONCLUSIONS

Nasal challenges with allergen, histamine, or irritants outside the pollen season induce a significant increase in nasal and ocular symptoms in patients with SAR. Interaction of the early-phase response and neurogenic inflammation define the pattern and severity of eye symptoms.