Pathophysiology of and potential new therapies for allergic rhinitis

Prognostic Role of Neutrophil to Lymphocyte Ratio in Allergic Rhinitis: A Systematic Review and Meta-analysis

One of the crucial triggers of allergic diseases is an inflammatory reaction and neutrophil to lymphocyte ratio (NLR) is one of the systemic inflammation biomarkers. Our review aimed to evaluate role of NLR in predicting severity and comorbidities of allergic rhinitis (AR). We systematically searched Scopus, Web of Science, and PubMed to find relevant studies. Standardized mean difference (SMD) with a 95% confidence interval (CI) was reported. Due to the high levels of heterogeneity, the random-effects model was used to generate pooled effects. Eleven articles were included in the systematic review, among which ten were included in meta-analysis including 1122 healthy controls and 1423 patients with AR. We found that patients with AR had a significantly higher level of NLR than healthy controls (SMD = 0.19, 95%CI = 0.03-0.36, P = 0.03). In addition, patients with moderate to severe AR had significantly higher levels of NLR compared to those with mild AR (SMD = 0.41, 95%CI = 0.20-0.63, P < 0.001). Interestingly, it was found that NLR could associate with some comorbidities of AR, like asthma. Our results confirmed that NLR could assist clinicians in predicting the severity and comorbidities of AR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04148-8.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Osteopontin mediated eosinophils activation by group II innate lymphoid cells

Background

Osteopontin (OPN) can regulate Th2 inflammation in allergic rhinitis (AR). A recent study suggested that group II innate lymphoid cells (ILC2s) were very important for airway inflammation. But the role of OPN in ILC2s regulation is not explored.

Methods

Purified ILC2s were stimulated by human recombinant OPN. The expression of GATA3 and RORα was assayed using real-time polymerase chain reaction (PCR) and enzyme linked immunosorbent assay. MiR-181a was transfected into eosinophils to test the OPN production. The protein concentrations of interleukin (IL)-5 and IL-13 were examined using ELISA. Purified eosinophils and ILC2s were cocultured and stimulated by OPN and the activation of eosinophils was detected by ELISA.

Results

After OPN stimulation, the ILC2s proliferation, the mRNA levels of GATA3 and RORα, the protein of GATA3, RORα, IL-5 and IL-13 expression were up-regulated significantly in a dose dependent manner. Eosinophils cultured alone transfected with miR-181a mimics produced less OPN protein compared with eosinophils transfected with miR-control, whereas OPN production was significantly promoted when miR-181a inhibitor was transfected. In the eosinophils and ILC2s coculture system, eosinophil cationic protein (ECP) production induced by OPN or IL-33 were significantly higher than ECP production in eosinophils culture system. OPN presented similar potency with IL-33 in the activation of eosinophils. When anti-IL-5 antibody was added, the production of ECP was significantly inhibited.

Conclusions

Our data for the first time provided new evidence that OPN played important roles in innate immunity of AR by regulation of ILC2s and the interaction between ILC2s and eosinophils.

Efficacy of Vitamin D Supplementation in Allergic Rhinitis

Allergic Rhinitis is one of the most commonly recognised rhinitis globally. Though its not a life threatening entity but it is associated with severe impairment of quality of life along with substantial financial burden on patient. There has been a substantial rise in number of patients of allergic rhinitis over years and researchers worldwide have also found low levels of vitamin D in patients of allergic rhinitis. It is a randomised control trial with 87 subjects divided into two groups. Pre-treatment total nasal symptom score (TNSS) were recorded for these patients. The Group A was given intranasal steroidal spray while Group B was given vitamin D supplementation along with intranasal steroidal spray. Post treatment TNSS scores and rhinitis control assessment test scores were calculated and analysed. 38 patients had severe Vit D deficiency with average TNSS score as 11.3 while 49 patients had insufficient Vit D levels with average TNSS as 8.6. The pre-treatment TNSS score in Group A was 12.5 ± 2.68 while post-treatment score was 8.98 ± 1.009 with difference in both scores of Group A as 3.52. The pre-treatment TNSS score in Group B (fluticasone spay with Vit D) was 11.64 ± 3.09 while post-treatment score was 6.3 ± 1.45 with difference in both scores of Group A as 5.34. The post treatment RCAT in Group A and Group B was 19.72 ± 2.84 and 28.2 ± 1.53 respectively with difference between two groups as 8.48. Though Intranasal steroidal sprays are the first line of management of allergic rhinitis however vitamin D supplementation can have a role in better relief of symptoms when used in conjunction. More multi-institutional studies are encouraged to confirm the validity of results before it can be incorporated in standard treatment guidelines.

PM2.5 exposure exacerbates allergic rhinitis in mice by increasing DNA methylation in the IFN-γ gene promoter in CD4+T cells via the ERK-DNMT pathway

Allergic rhinitis (AR) is a common chronic inflammatory disease that has a significant impact on the quality of life of patients. Our previous study suggested that PM2.5 might affect pediatric AR through epigenetic regulation, but the underlying mechanisms remained unclear. In this study, an experimental murine AR model was created, and the nasal symptoms, pathological changes, the DNA methylation level of the IFN-γ gene promoter and activation of the ERK-DNMT pathway were evaluated after treatment with PM2.5. Our results showed that PM2.5 exposure led to more severe symptoms of AR in mice. In addition, PM2.5 exposure significantly decreased the percentage of Th1 T cells in the AR group, and this change was correlated with increased DNA methylation of the IFN-γ gene promoter in CD4 + T cells (r=-0.916, p = 0.029). In addition, PM2.5 exposure increased the activation of the ERK-DNMT pathway in CD4+ T cells, and inhibiting this effect rescued the polarization of the Th1/Th2 balance toward Th2, thereby decreasing the risk of AR. Our findings demonstrate that PM2.5 exposure could exacerbate AR by increasing the DNA methylation of the IFN-γ gene promoter in CD4 + T cells via the ERK-DNMT pathway, and these effects were rescued when the ERK-DNMT pathway was inhibited.

Recent Advances in Experimental Allergy

Atopic disorders are on the rise and pose a great burden on society. A better understanding of the underlying mechanisms is required for the development of improved or novel therapeutic strategies. Here we aim to highlight recent advances in experimental allergy, with a particular focus on proposed treatment alternatives for airway disorders, atopic dermatitis, and food allergy. Furthermore, we discuss recent work focusing on molecular and cellular mechanisms that might offer candidates for future preventive or therapeutic intervention.

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.

The role of vitamin D in allergic rhinitis

Recent studies suggest that vitamin D is related to allergic rhinitis (AR). In this review, we first discuss the physiology and metabolism of vitamin D, then we review the function of vitamin D in the immune system, and above all, we highlight the current research regarding the role of vitamin D in AR. Finally, we find that there are both experimental and clinical studies showing that vitamin D is associated with AR, although the results are not consistent and even conflicting. Evidences from those clinical studies show a slightly tendency that serum vitamin D level might be inversely associated with the risk of AR. Meanwhile, it seems that gender and age may influence the relationship between vitamin D and AR. However, because of the heterogeneity in defining AR, differences in study design and so on, all these findings need to be confirmed by further studies. Additional clinical studies as well as experimental research are needed to better understand how vitamin D influences AR.

Inhibitory Effect of Pycnogenol® on Airway Inflammation in Ovalbumin-Induced Allergic Rhinitis

BACKGROUND

The supplement Pycnogenol® (PYC) has been used for the treatment of several chronic diseases including allergic rhinitis (AR). However, the in vivo effects on allergic inflammation have not been identified to date.

AIMS

To investigate the treatment results of PYC on allergic inflammation in a rat model of allergic rhinitis.

STUDY DESIGN

Animal experimentation.

METHODS

Allergic rhinitis was stimulated in 42 rats by intraperitoneal sensitization and intranasal challenge with Ovalbumin. The animals were divided into six subgroups: healthy controls, AR group, AR group treated with corticosteroid (dexamethasone 1 mg/kg; CS+AR), healthy rats group that were given only PYC of 10 mg/kg (PYC10), AR group treated with PYC of 3mg/kg (PYC3+AR), and AR group treated with PYC of 10 mg/kg (PYC10+AR). Interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-10 (IL-10), and OVA-specific immunoglobulin E (Ig-E) levels of serum were measured. Histopathological changes in nasal mucosa and expression of tumor necrosis factor-α (TNF-α) and IL-1β were evaluated.

RESULTS

The levels of the IL-4 were significantly decreased in the PYC3+AR, PYC10+AR and CS+AR groups compared with the AR group (p=0.002, p<0.001, p=0.006). The production of the IFN-γ was significantly decreased in the PYC3+AR and PYC10+AR groups compared with the AR group (p=0.013, p=0.001). The administration of PYC to allergic rats suppressed the elevated IL-10 production, especially in the PYC3+AR group (p=0.006). Mucosal edema was significantly decreased respectively after treatment at dose 3 mg/kg and 10 mg/kg PYC (both, p<0.001). The mucosal expression of TNF-α has significantly decreased in the PYC3+AR and PYC10+AR groups (p=0.005, p<0.001), while the IL-1β expression significantly decreased in the CS+AR, PYC3+AR, and PYC10+AR groups (p<0.001, p=0.003, p=0.001).

CONCLUSION

PYC has multiple suppressive effects on allergic response. Thus, PYC may be used as a supplementary agent in allergic response.

Allergic rhinitis is associated with open-angle glaucoma: a population-based case-control study

BACKGROUND

Despite many reports linking allergic rhinitis (AR) to problems of the eye, the relationship between AR and open-angle glaucoma (OAG) has not been studied. The purpose of this epidemiology study was to provide an estimation of the association of OAG with AR by using a population-based data set in Taiwan.

METHODS

We retrieved our study sample for this case-control study from the Longitudinal Health Insurance Database 2000. We extracted 7063 subjects with OAG as cases and 21,189 matched controls (three controls per case). We used conditional logistic regression analyses to calculate the odds ratio (OR) and corresponding 95% confidence interval (CI) to describe the association between OAG and having previously been diagnosed with AR.

RESULTS

A chi-squared test showed that there was a significant difference in the prevalence of prior AR between cases and controls (28.8% versus 22.3%; p < 0.001). A conditional logistic regression analysis suggested that the OR of having previously been diagnosed with AR for cases was 1.40 (95% CI, 1.31∼1.48; p < 0.001) compared with controls after adjusting for monthly income, geographic region, urbanization level, hypertension, diabetes, asthma, coronary heart disease, hyperlipidemia, and hypothyroidism. It also revealed that OAG was consistently and significantly associated with prior AR across all age groups. In particular, subjects aged 50∼59 years had the highest OR for prior AR among cases compared with controls (OR, 1.77; 95% CI, 1.53∼2.06; p < 0.001).

CONCLUSION

This outcome research found that there was an association between AR and OAG.

Asthma and risk of lethal prostate cancer in the Health Professionals Follow-Up Study

Inflammation, and more generally, the immune response are thought to influence the development of prostate cancer. To determine the components of the immune response that are potentially contributory, we prospectively evaluated the association of immune-mediated conditions, asthma and hayfever, with lethal prostate cancer risk in the Health Professionals Follow-up Study. We included 47,880 men aged 40-75 years with no prior cancer diagnosis. On the baseline questionnaire in 1986, the men reported diagnoses of asthma and hayfever and year of onset. On the follow-up questionnaires, they reported new asthma and prostate cancer diagnoses. We used Cox proportional hazards regression to estimate relative risks (RRs). In total, 9.2% reported ever having been diagnosed with asthma. In all, 25.3% reported a hayfever diagnosis at baseline. During 995,176 person-years of follow-up by 2012, we confirmed 798 lethal prostate cancer cases (diagnosed with distant metastases, progressed to distant metastasis or died of prostate cancer [N = 625]). Ever having a diagnosis of asthma was inversely associated with risk of lethal (RR = 0.71, 95% confidence interval [CI] = 0.51-1.00) and fatal (RR = 0.64, 95% CI = 0.42-0.96) disease. Hayfever with onset in the distant past was possibly weakly positively associated with risk of lethal (RR = 1.10, 95% CI = 0.92-1.33) and fatal (RR = 1.12, 95% CI = 0.91-1.37) disease. Men who were ever diagnosed with asthma were less likely to develop lethal and fatal prostate cancer. Our findings may lead to testable hypotheses about specific immune profiles in the etiology of lethal prostate cancer.