Allergic Rhinitis Augments the Response to a Bacterial Sinus Infection in Mice: A Review of an Animal Model

Immune responses in the injured olfactory and gustatory systems: a role in olfactory receptor neuron and taste bud regeneration?

Sensory cells that specialize in transducing olfactory and gustatory stimuli are renewed throughout life and can regenerate after injury unlike their counterparts in the mammalian retina and auditory epithelium. This uncommon capacity for regeneration offers an opportunity to understand mechanisms that promote the recovery of sensory function after taste and smell loss. Immune responses appear to influence degeneration and later regeneration of olfactory sensory neurons and taste receptor cells. Here we review surgical, chemical, and inflammatory injury models and evidence that immune responses promote or deter chemosensory cell regeneration. Macrophage and neutrophil responses to chemosensory receptor injury have been the most widely studied without consensus on their net effects on regeneration. We discuss possible technical and biological reasons for the discrepancy, such as the difference between peripheral and central structures, and suggest directions for progress in understanding immune regulation of chemosensory regeneration. Our mechanistic understanding of immune-chemosensory cell interactions must be expanded before therapies can be developed for recovering the sensation of taste and smell after head injury from traumatic nerve damage and infection. Chemosensory loss leads to decreased quality of life, depression, nutritional challenges, and exposure to environmental dangers highlighting the need for further studies in this area.

[Optimization of treatment of patients with acute bacterial rhinosinusitis with relating allergic rhinitis]

The article considers the problem of acute rhinosinusitis and its multifactorial relationship with allergic rhinitis. Data on a higher incidence of acute rhinosinusitis in patients with an allergic background is given, which is primarily associated with a deterioration in the state of the respiratory tract mucous membrane barrier function. It is shown that local allergic inflammation causes a more severe course of acute rhinosinusitis. A review of the combined course of these pathological processes is carried out and options for their treatment are considered. A study of the clinical use of the complex preparation Frinosol is described, which, thanks to the combination of a nasal decongestant and an antihistamine in its composition, effectively alleviates the symptoms of acute rhinosinusitis in patients with allergic rhinitis. It has been shown that the use of Frinosol in the complex treatment of adult patients with acute bacterial rhinosinusitis, combined with allergic rhinitis is safe and effective.

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.

Characterization of a novel high-dose ovalbumin-induced murine model of allergic sinonasal inflammation

BACKGROUND

Few efficacious topical therapies exist for chronic rhinosinusitis (CRS). The lack of a reproducible mouse model of CRS limits the pilot testing of potential novel anti-inflammatory therapies. Although the ovalbumin-induced mouse model of sinonasal inflammation is commonly used, it is difficult to reproduce and can generate variable histologic results. In this study, we explore a variation of this model in different strains of mice and explore various inflammatory cytokines as reproducible molecular markers of inflammation.

METHODS

Allergic sinonasal inflammation was generated in BALB/c and C57BL/6 mice using intraperitoneal high-dose injections of ovalbumin (Ova; Sigma Chemical Co.) followed by 10 days of high-dose intranasal sensitization. Real-time polymerase chain reaction (RT-PCR) for eotaxin, interleukin 4 (IL-4), and IL-13 were measured from sinonasal mucosa. We also pilot tested a known topical budesonide to characterize the anti-inflammatory response. Histological sections were analyzed for epithelial thickness and eosinophilia.

RESULTS

Both BALB/c and C57BL/6 mice consistently showed increases in T helper 2 (Th2) cytokines after sensitization with high-dose Ova (p < 0.0001) when compared to controls. There were also significant increases in epithelial thickening in Ova-sensitized mice and eosinophilia in both BALB/c and C57BL/6 strains. In addition, topical budesonide significantly reduced anti-inflammatory cytokines, eosinophilia, and epithelial thickness.

CONCLUSION

Our variation of the ovalbumin-induced mouse model of sinonasal inflammation in both BALB/c and C57BL/6 mice provides an efficacious model for testing potential topical anti-inflammatory therapies for CRS. The utilization of sinonasal mucosal Th2 cytokines along with histologic markers provides a consistent and quantifiable marker of inflammation in assessing the efficacy of candidate drugs.

Detection of bacteria in middle ear effusions based on the presence of allergy: does allergy augment bacterial infection in the middle ear?

Background

Bacterial infection, Eustachian tube dysfunction, allergies, and immunologic factors are major causes of otitis media with effusion (OME). However, the exact pathogenesis of OME is still unclear. This study evaluated whether allergy influences bacterial growth in middle ear effusions.

Materials

Fifty-four samples were obtained from OME patients 3–10 years of age who underwent ventilation tube insertion and were divided into two groups based on the presence of allergy as determined using the multiple allergosorbent test (MAST). Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis bacterial DNA in the middle ear effusions was analyzed using polymerase chain reaction. Overall detection rates and those for each species were compared between the two groups.

Results

Of the 54 middle ear effusion samples, 38 (70.4 %) contained bacterial DNA and 14 (36.8 %) of these contained DNA from multiple species. S. pneumoniae was detected in 27 samples (50 %), H. influenzae in 17 samples (31.4 %), and M. catarrhalis in 9 samples (16.6 %). There was no significant difference in the bacterial detection rates between the middle ear effusions of the MAST-positive and MAST-negative groups.

Conclusion

The rate of bacteria detection in middle ear effusions did not differ between allergic and non-allergic children.

Is chronic rhinosinusitis related to allergic rhinitis in adults and children? Applying epidemiological guidelines for causation

The relationship between allergic rhinitis and chronic rhinosinusitis has been assessed in a number of observational and experimental studies. In this review, we attempt their synthesis and evaluation using the modified Bradford Hill guidelines for causation. Although there is no proof of causation, especially in the pediatric literature, an evaluation of underlying allergies is recommended at least as an initial measure of symptoms relief.

Spontaneous eosinophilic nasal inflammation in a genetically-mutant mouse: comparative study with an allergic inflammation model

BACKGROUND

Eosinophilic inflammation is a hallmark of chronic rhinosinusitis with nasal polyps. To model this disease process experimentally, nasal sensitization of mice with ovalbumin or aspergillus has been described. Here, we describe a genetically mutant mouse that develops robust spontaneous nasal eosinophilic inflammation. These mice lack the enzyme SHP-1 that down-regulates the IL-4Rα/stat6 signaling pathway. We compared nasal inflammation and inflammatory mediators in SHP-1 deficient mice (mev) and an ovalbumin-induced nasal allergy model.

METHODS

A novel technique of trans-pharyngeal nasal lavage was developed to obtain samples of inflammatory cells from the nasal passages of allergic and mev mice. Total and differential cell counts were performed on cytospin preparations. Expression of tissue mRNA for IL-4, IL-13, and mouse beta-defensin-1 (MBD-1) was determined by quantitative PCR. Eotaxin in the lavage fluid was assessed by ELISA.

RESULTS

Allergic and mev mice had increased total cells and eosinophils compared with controls. Expression of IL-4 was similarly increased in both allergic and mev mice, but expression of IL-13 and eotaxin was significantly greater in the allergic mice than mev mice. Eotaxin was significantly up-regulated in both allergic rhinitis and mev mice. In both models of eosinophilic inflammation, down-regulation of the innate immune marker MBD-1 was observed.

CONCLUSIONS

The mev mice display spontaneous chronic nasal eosinophilic inflammation with potential utility for chronic rhinosinusitis with nasal polyps research. The eosinophilic infiltrate is more robust in the mev mice than allergic mice, but Th2 cytokine expression is not as pronounced. Decreased MBD-1 expression in both models supports the concept that Th2-cytokines down-regulate sinonasal innate immunity in humans, and suggests a role for mouse models in investigating the interaction between adaptive and innate immunity in the sinonasal mucosa.