Local Effect of Neurotrophin-3 in Neuronal Inflammation of Allergic Rhinitis: Preliminary Report

The role of nociceptive neurons in allergic rhinitis

Allergic rhinitis (AR) is a chronic, non-infectious condition affecting the nasal mucosa, primarily mediated mainly by IgE. Recent studies reveal that AR is intricately associated not only with type 2 immunity but also with neuroimmunity. Nociceptive neurons, a subset of primary sensory neurons, are pivotal in detecting external nociceptive stimuli and modulating immune responses. This review examines nociceptive neuron receptors and elucidates how neuropeptides released by these neurons impact the immune system. Additionally, we summarize the role of immune cells and inflammatory mediators on nociceptive neurons. A comprehensive understanding of the dynamic interplay between nociceptive neurons and the immune system augments our understanding of the neuroimmune mechanisms underlying AR, thereby opening novel avenues for AR treatment modalities.

Neurotrophins: Neuroimmune Interactions in Human Atopic Diseases

Allergic diseases are accompanied by a variety of symptoms such as pruritus, coughing, sneezing, and watery eyes, which can result in severe physiological and even psychological impairments. The exact mechanisms of these conditions are not yet completely understood. However, recent studies demonstrated a high relevance of neurotrophins in allergic inflammation, as they induce cytokine release, mediate interaction between immune cells and neurons, and exhibit different expression levels in health and disease. In this review, we aim to give an overview of the current state of knowledge concerning the role of neurotrophins in atopic disorders such as atopic dermatitis, allergic asthma, and allergic rhinitis.

Neuroinflammatory Gene Expression Pattern Is Similar between Allergic Rhinitis and Atopic Dermatitis but Distinct from Atopic Asthma

Methods

In the study, we included 86 children diagnosed with atopic asthma (n = 25), allergic rhinitis (n = 20), and atopic dermatitis (n = 20) and healthy control subjects (n = 21) of Caucasian origin from the Polish population. The blood leukocyte expression of 31 genes involved in neuroinflammatory response (neurotrophins, their receptors, neuropeptides, and histamine signaling pathway) was analysed using TaqMan low-density arrays. The relative expression of selected proteins from plasma was done using TaqMan Protein Assays. Statistical analysis was done using Statistica.

Results

Blood expression of 31 genes related to neuroimmune interactions showed significant increase in both allergic diseases, allergic rhinitis and atopic dermatitis, in comparison to the control group. We found 12 genes significantly increased in allergic rhinitis and 9 genes in which the expression was elevated in atopic dermatitis. Moreover, 9 genes with changed expression in atopic dermatitis overlapped with those in allergic rhinitis. Atopic asthma showed 5 genes with altered expression. The peripheral expression of neuroinflammatory genes in the human study was verified in target tissues (nasal epithelium and skin) in a rat model of allergic inflammation.

Conclusions

A common pattern of neuroinflammatory gene expression between allergic rhinitis and atopic dermatitis may reflect similar changes in sensory nerve function during chronic allergic inflammation.

Is There any Possible Role of Neurotrophin 3 in the Pathogenesis of Antrochoanal Polyp?

Objective:

Antrochoanal polyp (ACP) is a benign soft tissue lesion arising from the inner wall of the maxillary sinus that extends into the nasal cavity and choana. Although it was first explained by Killian in 1906, the underlying pathogenesis has not been yet fully understood. Neurotrophins have been demonstrated to have a possible role in the pathogenesis of allergic rhinitis, idiopathic rhinitis and nasal polyps. To date any study has not investigated the function of neuronal inflammation and neurotrophins in the development of ACP. The objective of this study was to investigate the possible effect of neurotrophin-3 (NT-3) in ACP pathogenesis.

Method:

Twenty adult patients with ACP who underwent endoscopic sinus surgery in our department were included in the study group. The control group included 15 patients with concha bullosa of middle concha who underwent lateral excisional surgery. Nasal tissue NT-3 staining scores were evaluated using immunohistochemical methods. Blood NT-3 levels of both groups were evaluated by enzyme-linked immunosorbent assay (ELISA).

Results:

There were no statistically significant differences between these two groups regarding tissue NT-3 staining scores (p=0.843) and blood NT-3 levels (p=0.463). In addition, no statistically significant correlation has been observed between tissue NT-3 staining scores and blood NT-3 levels in both ACP (p=0.578) and control (p=0.359) group patients.

Conclusion:

NT-3-related neuronal inflammation does not seem to have any role in ACP pathogenesis.

Is there any effect of neurotrophin-3 on the pathogenesis of non-allergic nasal polyps?

BACKGROUND

Although the role of neurotrophins such as nerve growth factor and brain-derived neurotrophic factor in nasal polyps development has been studied, the contribution of neurotrophin-3 has not been evaluated yet. This study aimed to investigate the possible role of neurotrophin-3 in nasal polyps pathogenesis.

METHODS

The study group comprised 70 non-allergic nasal polyps patients and the control group consisted of 53 patients with middle turbinate concha bullosa. Specimens were taken, during surgery, from the ethmoid sinus nasal polyps in the nasal polyps group and from the lateral part of the middle turbinate concha bullosa in the control group. Tissue and serum levels of neurotrophin-3 were assessed by immunohistochemistry and enzyme-linked immunosorbent assay, respectively.

RESULTS

Nasal polyps patients had higher tissue neurotrophin-3 scores (p < 0.001). There was no statistically significant difference between groups regarding serum neurotrophin-3 levels (p = 0.417). Tissue neurotrophin-3 staining scores in the nasal polyps group had no statistically significant correlation with Lund-Mackay scores (p = 0.792).

CONCLUSION

Neurotrophin-3 may have a local effect in nasal polyps pathogenesis, without joining systemic circulation.

Eosinophil Chemokines and Clara Cell Protein 16 Production in Nasal Mucosa of Patients with Persistent Allergic Rhinitis

Objective

Eotaxin-2 and regulated on activation normal T cell expressed and secreted (RANTES) are involved in the eosinophil trafficking in patients with persistent allergic rhinitis (PAR). Clara cell protein 16 (CC16) is an anti-inflammatory protein mainly produced by the epithelial non-ciliated Clara cells. The aim of this study was to investigate the production of CC16 and chemokines eotaxin-2 and RANTES in nasal mucosa of patients with PAR.

Materials and Methods

Twenty-one PAR patients and 20 healthy participants were included. CC16, eotaxin-2, and RANTES concentrations were measured in nasal secretions. PAR patients were administered fluticasone furoate nasal spray (220 μg daily for 14 days). We performed nasal cytology, symptom score assessment, and inflammatory mediator detection before and after the therapy.

Results

The level of CC16 in patients with PAR was lower than in the healthy subjects (p=0.023). The eosinophil counts and local concentrations of eotaxin-2 and RANTES were higher in patients with PAR in comparison with controls (p=0.008, p=0.001, p=0.031, respectively). We also found a negative correlation between the CC16 and eotaxin-2 levels in nasal secretions of PAR patients (r=-0.492, p=0.023). After corticosteroid therapy, the patients with PAR had lower nasal symptoms, eosinophil counts, eotaxin-2, and RANTES levels and higher levels of CC16 (p<0.001 for all parameters).

Conclusion

Our results suggest the presence of a negative correlation in production of CC16 and eotaxin-2 in nasal mucosa of patients with PAR. Intranasal corticosteroids have a suppressive effect on mucosal eosinophilic inflammation and a stimulating effect on local CC16 production.

Botulinum Toxin for Rhinitis

PURPOSE OF REVIEW

Rhinitis is a common clinical entity. Besides nasal obstruction, itching, and sneezing, one of the most important symptoms of rhinitis is nasal hypersecretion produced by nasal glands and exudate from the nasal vascular bed. Allergic rhinitis is an IgE-mediated inflammatory reaction of nasal mucosa after exposure to environmental allergens. Idiopathic rhinitis describes rhinitis symptoms that occur after non-allergic, noninfectious irritants. Specific allergen avoidance, topical nasal decongestants, nasal corticosteroids, immunotherapy, and sinonasal surgery are the main treatment options. Because the current treatment modalities are not enough for reducing rhinorrhea in some patients, novel treatment options are required to solve this problem.

RECENT FINDINGS

Botulinum toxin is an exotoxin generated by Clostridium botulinum. It disturbs the signal transmission at the neuromuscular and neuroglandular junction by inhibiting the acetylcholine release from the presynaptic nerve terminal. It has been widely used in neuromuscular, hypersecretory, and autonomic nerve system disorders. There have been a lot of published articles concerning the effect of this toxin on rhinitis symptoms. Based on the results of these reports, intranasal botulinum toxin A administration appears to be a safe and effective treatment method for decreasing rhinitis symptoms in rhinitis patients with a long-lasting effect. Botulinum toxin type A will be a good treatment option for the chronic rhinitis patients who are resistant to other treatment methods.

Effects of Fluticasone Furoate Nasal Spray on Parameters of Eosinophilic Inflammation in Patients With Nasal Polyposis and Perennial Allergic Rhinitis

OBJECTIVES

Regulated on activation normal T cell expressed and secreted (RANTES) and eotaxin-2 have been postulated to be responsible for eosinophilia in chronically inflamed nasal mucosa. This study evaluated mucosal production of RANTES and eotaxin-2 in patients with perennial allergic rhinitis (PAR) and nonallergic and allergic form of chronic rhinosinusitis with nasal polyps (CRSwNP) before and after nasal corticosteroid treatment.

METHODS

Twenty patients with PAR, 20 nonallergic and 20 allergic CRSwNP patients, and 20 healthy controls were included. The RANTES and eotaxin-2 levels were measured in nasal secretion samples. The patients with chronic inflammation were treated with fluticasone furoate nasal spray for 2 weeks. Cytological examination and measurement of RANTES and eotaxin-2 in nasal fluid were performed before and after the treatment.

RESULTS

The levels of RANTES were higher in patients with PAR ( P < .05) and nonallergic ( P < .01) and allergic CRSwNP patients ( P < .001) compared to controls. Eotaxin-2 levels were higher in all 3 inflammation groups compared to healthy subjects ( P < .001). After the treatment, we found a significant decrease of RANTES and eotaxin-2 concentrations ( P < .001) in all 3 groups of patients.

CONCLUSION

The levels of RANTES and eotaxin-2 in nasal fluid could be reliable markers for assessing corticosteroid administration outcomes.