Allergic Rhinitis: Pathophysiology and Treatment Focusing on Mast Cells

Serum Soluble Fibrinogen-Like Protein 2 Estimates Increased T-Helper 2 Cytokine, Elevated Disease Severity, and Unfavorable Outcomes in Allergic Rhinitis Patients

OBJECTIVE

Soluble fibrinogen-like protein 2 (sFGL2) may be involved in the pathology and progression of allergic rhinitis (AR) through regulating T-helper (Th)2 cell response. This study aimed to explore the ability of sFGL2 to estimate outcomes in AR patients.

METHODS

sFGL2 was detected in the serum sample of 119 AR patients at baseline and 20 healthy controls (HCs) after enrollment by enzyme-linked immunosorbent assay. In AR patients, disease severity was assessed at baseline as well as 4 weeks (W4) and 8 weeks (W8) after enrollment by the total nasal symptom score (TNSS).

RESULTS

sFGL2 was higher in AR patients than HCs [median (interquartile range): 100.0 (70.0-154.0) vs 47.0 (31.5-78.5) ng/mL] (P < .001). In AR patients, sFGL2 was positively correlated with TNSS score (P = .002), itching score (P = .037), sneezing score (P = .012), and interleukin (IL)-4 (P = .006) at baseline. TNSS score declined from baseline to W8 in AR patients (P < .001). To further explore the association between sFGL2 levels and treatment outcomes, we compared the sFGL2 levels between patients with TNSS scores at W4 or W8 >4 and those with TNSS scores at W4 or W8 ≤4. It was found that sFGL2 was only increased in AR patients with a TNSS score at W4 >4 versus those with a TNSS score at W4 ≤4 (P = .012).

CONCLUSION

Serum sFGL2 is increased in AR patients, and its high level estimates an increased Th2 cytokine and disease severity as well as poor outcomes.

Inhibition of mast cell activation by Jaranol-targeted Pirin ameliorates allergic responses in mouse allergic rhinitis

Jaranol, a bioactive compound derived from various traditional medicinal herbs, has demonstrated significant anti-inflammatory properties. This study investigates its effects and possible mechanisms underlying its anti-inflammatory role in mast cells, as well as ovalbumin (OVA)-induced allergic rhinitis (AR) mice model. Forty mice were randomly divided into blank, AR, dexamethasone (positive control), and Jaranol groups (10 mg/ml), with 10 mice in each group. Jaranol was found to inhibit nasal mucosal inflammation and reduce mast cell numbers in AR models. It also inhibited the secretion of several inflammatory cytokines (IFN-γ, TNF-α, IL-1β, IL-6, MCP-1, and CXCR10) from mast cells, as well as mast cell proliferation and migration. Interestingly, Pirin was differentially expressed in blank, AR, and Jaranol groups. Further studies indicated that Jaranol inhibited inflammatory cytokine secretion from mast cells by mediating Pirin and also inhibited mast cell proliferation and migration. Moreover, it inhibited mast cell function by suppressing Pirin expression. These findings suggest that Jaranol exerts its therapeutic effects by inhibiting Pirin expression in mast cells, thereby reducing inflammation and histopathological changes associated with AR.

Factors associated with carditis adverse events following SARS-COV-2-19 vaccination

The study aimed to delve into the incidence and risk factors associated with myocarditis and pericarditis following SARS-COV-2-19 vaccination, addressing a notable gap in understanding the safety profile of vaccinations. Through meticulous data selection from the National Health Insurance System (NHIS) database of Korea, the researchers employed both a case-crossover study and a nested case-control design to analyze temporal patterns and risk factors related to carditis occurrences post-immunization. Key findings revealed a significant association between SARS-COV-2-19 vaccination and the occurrence of carditis, with a strong temporal correlation observed within 10 days post-vaccination. Noteworthy factors contributing to carditis risk included the duration between vaccination and carditis, specific comorbidities and medication use. The study concluded by recommending an extended post-vaccination surveillance duration of at least 10 days and underscored the importance of considering individual medical histories and concurrent medication use in assessing vaccine-induced carditis risk. This study might contribute to understanding vaccine safety profiles and emphasizes the significance of comprehensive post-vaccination monitoring protocols.

Association between pollinosis and obstructive sleep apnea hypopnea syndrome in the US population: evidence from the NHANES database 2005-2018

BACKGROUND

Rhinobyon and inflammation associated with pollinosis may elevate the risk of obstructive sleep apnea hypopnea syndrome (OSAHS). However, the exact nature of this association remains unclear, particularly in large-scale populations. This study aimed to examine the relationship between pollinosis and OSAHS using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

Data from the NHANES spanning 2005 to 2018 were analyzed. Three multivariate generalized linear models (GLMs) were employed to explore the relationship between pollinosis and OSAHS: one unadjusted model, one minimally adjusted model, and one fully adjusted model. Stratified analyses were conducted to assess the impact of pollinosis and other covariates on OSAHS. Additionally, the study incorporated K-Nearest Neighbors (KNN) and smoothed curves to refine the analysis.

RESULTS

The study identified significant demographic differences between groups in factors such as pollinosis, age, gender, weight (WT), body mass index (BMI), waist circumference (WC), protein, and fat. In three adjusted models, a consistent association was observed between pollinosis and OSAHS. Specifically, Model 1 showed an odds ratio (OR) of 1.31 [95% confidence interval (CI): 1.16-1.48, P < 0.001], Model 2 revealed an OR of 1.35 (95% CI: 1.19-1.54, P < 0.001), and Model 3 indicated an OR of 1.29 (95% CI: 1.10-1.50, P = 0.002), suggesting that the relationship between pollinosis and OSAHS remained robust despite the inclusion of other covariates. Risk stratification confirmed that pollinosis was a risk factor for OSAHS (OR = 1.28, 95% CI: 1.10-1.50, P = 0.002). The KNN model further supported the utility of pollinosis as a diagnostic marker for OSAHS. Smoothing curves also demonstrated a positive correlation between pollinosis prevalence and OSAHS incidence.

CONCLUSION

This study established pollinosis as a risk factor for OSAHS, emphasizing the need for vigilance in monitoring and managing OSAHS in individuals with pollinosis risk.

Effect of eucalyptus oil on symptoms of allergic rhinitis: a systematic review

Objective

This study was conducted in order to view the effect of eucalyptus oil in the treatment of allergic rhinitis by reducing allergic symptoms.

Data sources

Databases including PubMed, The Cochrane Library, PLOS ONE and JSTOR were searched for articles from inception to 31st December, 2023.

Study Selections

The criteria for selection involved clinical trials in English with full text, having patients of allergic rhinitis. Screening and selection were done according to PRISMA guidelines after registration of protocol on PROSPERO (CRD42024498763).

Results

Out of 1772 studies searched only 3 clinical trials were included. Eucalyptus oil reduced allergic symptoms evaluated using RQLQ placebo (MD -0.40; 95% CI [-0.68, -0.12], p = 0.005) and total nasal symptom score (MD -3.86; 95% CI [-8.06, 0.34], p = 0.07). Nasal itching length exanthema and heart burn were the most common adverse effects.

Conclusion

This review showed that eucalyptus oil was beneficial in reducing the symptoms of allergic rhinitis and improving the quality of life thus providing a way for future studies to establish its dose and duration for the management of allergic rhinitis.

Mast Cells in Allergic and Non-Allergic Upper Airways Diseases: Sentinel in the Watchtower

Mast cells are immune system cells with the most disparate functions, but are also among the least understood. Mast cells are implicated in several known pathological processes, tissue homeostasis, and wound repair. However, they owe their notoriety to allergic diseases, of which they represent the effector cell par excellence. In both allergic and not upper airway pathologies, mast cells play a key role. Exploring the mechanisms through which these cells carry out their physiological and pathological function may help us give a new perspective on existing therapies and identify new ones. A focus will be placed on non-allergic rhinitis, a poorly recognized and often neglected condition with complex management, where the role of the mast cell is crucial in the pathogenetic, clinical, and prognostic aspects.

Decongestant Effect of "Coldamaris Akut", a Carrageenan- and Sorbitol-Containing Nasal Spray in Seasonal Allergic Rhinitis

Purpose

This study aimed to develop a hyperosmolar, barrier-forming nasal spray based on carrageenan and sorbitol, and to demonstrate its decongestant effect in the context of allergic rhinitis (AR).

Methods

The efficacy of the nasal spray components was tested in vitro by barrier function, virus replication inhibition, and water absorption assays. The decongestant effectiveness was assessed in a randomized, controlled, crossover environmental chamber trial, where participants with a history of seasonal grass pollen AR were exposed to grass pollen allergens under controlled conditions. Forty-one adults were randomized to receive either carrageenan- and sorbitol-containing nasal spray (CS) or saline solution (SS). After 1 week, participants repeated the exposure with the treatment they had not received before. The primary efficacy endpoint was the mean change in nasal congestion symptom score (NCSS). Secondary efficacy endpoints were nasal airflow, nasal secretion, total nasal symptom score (TNSS), total ocular symptom score (TOSS) and total respiratory symptom score (TRSS).

Results

Preclinical assays demonstrated barrier-building, virus-blocking, and water-withdrawing properties of the CS components. In the clinical study, there was no significant difference in mean NCSS change from pre- to post-treatment between CS and SS. However, nasal airflow increased over time after treatment with CS, while it declined after SS, leading to a growing difference in airflow between CS and SS (p = 0.04 at 6:00 h). Mean nasal secretion over 2-6 h was reduced by ~25% after CS (p = 0.003) compared to pre-treatment, while it was reduced by only ~16% after SS (p = 0.137). No significant differences in TNSS, TOSS and TRSS were observed between CS and SS.

Conclusion

CS improves nasal airflow and reduces nasal secretion in adults with AR. We propose CS as a safe and effective adjuvant to baseline pharmacological treatments.

Trial Registration

NCT04532762.

Camel Whey Protein and Baicalein Suppressed Mast Cell Degranulation in Mice Models of IgE- and Non-IgE-Mediated Anaphylaxes: Potential Mechanisms on Downstream Cell Signaling of Mast Cells

INTRODUCTION

Novel treatments are being researched to develop more safe and effective protective medications for anaphylaxis. Camel whey protein (CWP) and baicalein (BAC, one of the major flavones) have multiple beneficial properties including anti-inflammatory and antioxidant activities.

METHODS

The current study investigated/compared the therapeutic protection of repeated intragastric administration of CWP (100 mg/kg body weight, as an animal extract) and BAC (10 mg/kg body weight, as a plant extract), before the challenge with ovalbumin (OVA) or receiving the compound 48/80 (C48/80), against mice models for IgE-independent and dependent anaphylaxes. Besides, their effects on mast cells (MCs) downstream cell signaling were explored.

RESULTS

The results revealed that CWP and BAC reduced the mortality rate, as compared with a MCs stabilizer "sulfasalazine (SSZ, 100 mg/kg body weight, intraperitoneally)," in both mice models. Furthermore, they prevented the MCs degranulation and significantly reduced (p < .05) lung tissue levels of cell signaling (p-AKT, p-ERK, and p-IκBα). Additionally, they decreased histamine, tryptase, leukotriene C4, prostaglandin D2, interleukin (IL)-4, and IL-10 levels in broncho-alveolar and peritoneal lavages in systemic anaphylaxis mice models. They also restored the stabilization of peritoneal MCs membrane in inverted light microscopy results accompanied by amelioration of the lung histology.

DISCUSSION

The present study provided evidence for the protective therapeutic effect of CWP and BAC against anaphylaxis. As a result, CWP and BAC may be used as preventative supplemented regimens for both non-vegetarian and vegetarian consumers to treat allergy through downregulation of MCs signal transduction pathways, and hence controlling the production of inflammatory mediators.

The Role of Neuro-Immune Interactions in the Pathology and Pathogenesis of Allergic Rhinitis

BACKGROUND

Allergic rhinitis (AR) is a non-infectious inflammatory disease of the nasal mucosa mediated by IgE and involving a variety of immune cells such as mast cells. In previous studies, AR was considered as an isolated disease of the immune system. However, recent studies have found that the nervous system is closely related to the development of AR. Bidirectional communication between the nervous and immune systems plays an important role in AR.

SUMMARY

The nervous system and immune system depend on the anatomical relationship between nerve fibers and immune cells, as well as various neurotransmitters, cytokines, inflammatory mediators, etc. to produce bidirectional connections, which affect the development of AR.

KEY MESSAGES

This article reviews the impact of neuro-immune interactions in AR on the development of AR, including neuro-immune cell units.

The Role of WNT3A Protein and Gene Variants in Allergic Rhinitis: A Case-Control Study

Allergic rhinitis (AR) is a prevalent inflammatory disorder of the upper respiratory tract, driven by allergen exposure. Understanding mechanisms and identifying biomarkers for AR could significantly impact diagnosis and treatment. This study aimed to investigate the association between serum Wingless-Type MMTV Integration Site Family, Member 3A (WNT3A) protein levels, WNT3A polymorphisms, and AR. A cohort of 92 AR patients and 86 healthy controls was recruited. Serum WNT3A levels were measured by enzyme-linked immunosorbent assay (ELISA). WNT3A gene polymorphisms (rs752107 and rs3121310) were analyzed using Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) method. The study revealed significantly higher serum WNT3A levels in AR patients compared to controls (p < 0.0001). The impact of WNT3A in the differential diagnosis of AR was determined to be moderate, with an area under the curve (AUC) value of 0.67 (95% Confidence Interval: 0.59-0.75) based on the receiver operating characteristic (ROC) curve analysis. The rs3121310 polymorphism showed a significant association with the GA genotype more prevalent in controls (p < 0.05). However, no significant relationship was observed between rs3121310 genotypes and clinical parameters of the patients. These findings suggest a role for WNT3A in AR pathogenesis, given the elevated serum levels in patients. Larger cohort studies are needed to validate these findings and explore serum WNT3A levels as a biomarker for AR diagnosis and treatment monitoring.

Astragalus membranaceus, Nigella sativa, and Perilla frutescens as Immunomodulators-Molecular Mechanisms and Clinical Effectiveness in Allergic Diseases

Plants are the source of numerous remedies in modern medicine, and some of them have been studied due to their potential immunomodulatory activity. Astragalus membranaceus Fisch. ex Bunge (A. membranaceus), Nigella sativa L. (N. sativa), and Perilla frutescens (L.) Britton (P. frutescens) are plant species used in traditional medicine for the treatment of various diseases. Their potential to act as immunomodulatory, anti-inflammatory, and anti-allergic agents makes them interesting for investigating their clinical potential in alleviating the symptoms of allergic diseases. Allergy affects a large number of people; according to some sources more than 30% of the world population suffer from some type of allergic reaction, with pollen allergy as the most common type. Treatment is usually pharmacological and may not be completely effective or have side effects. Thus, we are seeking traditional medicine, mostly medicinal plants, with promising potential for alleviating allergy symptoms. A literature overview was conducted employing databases such as Scopus, PubMed, Web of Science, Springer, and Google Scholar. This manuscript summarizes recent in vivo preclinical and clinical studies on three species with immunomodulatory activity, provides a comparison of their anti-allergic effects, and underlines the potential of their application in clinical practice. The obtained results confirmed their efficacy in the in vivo and clinical studies, but also emphasize the problem of phytochemical characterization of the species and difference between tested doses. More clinical trials with standardized protocols (defined active molecules, dosage, side effects) are required to obtain safe and effective herbal drugs.

Integrating 16S rRNA Sequencing, Microflora Metabolism, and Network Pharmacology to Investigate the Mechanism of SBL in Alleviating HDM-Induced Allergic Rhinitis

Allergic rhinitis (AR) is a series of allergic reactions to allergens in the nasal mucosa and is one of the most common allergic diseases that affect both children and adults. Shi-Bi-Lin (SBL) is the modified formula of Cang Er Zi San (CEZS), a traditional Chinese herbal formula used for treating AR. Our study aims to elucidate the anti-inflammatory effects and mechanisms of SBL in house dust mite-induced AR by regulating gut microflora metabolism. In vivo studies showed that nasal allergies and the infiltration of inflammatory cells in the nasal epithelium were significantly suppressed by SBL. Moreover, SBL restored the impaired nasal epithelial barrier function with an increased tight junction protein expression and reduced the endothelial nitric oxide synthase (eNOS). Interestingly, SBL significantly reconstituted the abundance and composition of gut microbiota in AR mice; it increased the relative abundance of potentially beneficial genera and decreased the relative abundance of harmful genera. SBL also restored immune-related metabolisms, which were significantly increased and correlated with suppressing inflammatory cytokines. Furthermore, a network analysis and molecular docking indicated IL-6 was a possible target drug candidate for the SBL treatment. SBL dramatically reduced the IL-6 level in the nasal lavage fluid (NALF), suppressing the IL-6 downstream Erk1/2 and AKT/PI3K signaling pathways. In conclusion, our study integrates 16S rRNA sequencing, microflora metabolism, and network pharmacology to explain the immune mechanism of SBL in alleviating HDM-induced allergic rhinitis.

NLRP3 Inflammasome Deficiency Alleviates Inflammation and Oxidative Stress by Promoting PINK1/Parkin-Mediated Mitophagy in Allergic Rhinitis Mice and Nasal Epithelial Cells

Purpose

Accumulating evidence indicates that oxidative stress and inflammation are the pathological basis of allergic diseases. Inhibition of NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome could ameliorate allergic rhinitis (AR). Here, we explored the effects and mechanisms that underlie NLRP3 inhibition on oxidative stress and inflammation in AR.

Methods

Ovalbumin (OVA)-induced AR murine model was established using wild-type (WT) and NLRP3-deficient mice. HNEpCs were stimulated with interleukin (IL)-13 with MCC950 pretreatment or PTEN-induced putative kinase 1 (PINK1) siRNA. The indicators of oxidative stress, inflammation, apoptosis, and mitophagy were determined both in vivo and in vitro.

Results

NLRP3 knockout (KO) reduced the frequency of nasal rubbing and sneezing, the infiltration of eosinophils, the number of mast cells, and the accumulation of goblet cells in AR mice after OVA stimulation. The NLRP3 KO AR mice exhibited the increased concentrations of OVA-specific immunoglobulin E (OVA-sIgE), IL-1β, IL-4, IL-13, IL-6, TNF-α, and the upregulated level of IFN-γ. NLRP3 KO significantly inhibited oxidative stress, and also markedly decreased apoptosis in the nasal mucosa of AR mice. Moreover, evaluated protein expressions of PINK1, enzyme 3 (E3) ubiquitin ligase PRKN (Parkin), and LC3 II, decreased expression of TOM20, as well as the increased colocalization of LC3 with mitochondria were observed in NLRP3 KO AR mice. In vitro, IL-13 exposure increased the levels of NLRP3 and IL-1β. Inhibition of NLRP3 using MCC950 enhanced PINK1/Parkin-mediated mitophagy but attenuated inflammation, oxidative stress, and apoptosis. However, PINK1 knockdown abrogated mitophagy and also reversed the protective effects of MCC950 on inflammation, oxidative stress, and apoptosis in HNEpCs stimulated with IL-13.

Conclusion

Inhibition of NLRP3 inflammasome exerts the protective effects on AR by facilitating mitophagy regulated by PINK1/Parkin signaling pathway.

The emerging role of T helper 9 (Th9) cells in immunopathophysiology: A comprehensive review of their effects and responsiveness in various disease states

Th9 cells, a subset of T-helper cells producing interleukin-9 (IL-9), play a vital role in the adaptive immune response and have diverse effects in different diseases. Regulated by transcription factors like PU.1 and IRF4, and cytokines such as IL-4 and TGF-β, Th9 cells drive tissue inflammation. This review focuses on their emerging role in immunopathophysiology. Th9 cells exhibit immune-mediated cancer cell destruction, showing promise in glioma and cervical cancer treatment. However, their role in breast and lung cancer is intricate, requiring a deeper understanding of pro- and anti-tumor aspects. Th9 cells, along with IL-9, foster T cell and immune cell proliferation, contributing to autoimmune disorders. They are implicated in psoriasis, atopic dermatitis, and infections. In allergic reactions and asthma, Th9 cells fuel pro-inflammatory responses. Targeting Foxo1 may regulate innate and adaptive immune responses, alleviating disease symptoms. This comprehensive review outlines Th9 cells' evolving immunopathophysiological role, emphasizing the necessity for further research to grasp their effects and potential therapeutic applications across diseases.

Low-Level Laser Therapy for Allergic Rhinitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Allergic rhinitis (AR) is a common allergic disorder that impairs social and physical functioning as well as quality of life. It is characterized by sneezing, rhinorrhea, congestion, and itching which respond suboptimally to drug therapy. Low-level laser therapy (LLLT) has anti-inflammatory and immunosuppressive properties that have shown promise in some studies. We aimed to systematically review LLLT's effectiveness in treating AR and meta-analyze our findings.

METHODS

A systematic search of PubMed, Scopus, and Web of Science was conducted on November 24, 2023. All studies investigating LLLT on AR were included, and a pre-post meta-analysis of nasal symptoms (rhinorrhea, nasal congestion, nasal itching, and sneezing) in the LLLT-treated arm was conducted. Rhinoconjunctivitis quality of life questionnaire (RQLQ) scores before and after LLLT were also meta-analyzed alongside a pairwise meta-analysis of LLLT with placebo, acupuncture, steroids/antihistamines, and ultraviolet lasers. A random-effects model was used with a conservative pre-post correlation of 0.4 and standardized mean difference (SMD) as the effect size.

RESULTS

Sixteen studies were included in this review, and we found that nasal symptoms are alleviated post-LLLT in people with AR (SMD: -1.4, 95 CI: [-2.07 to -1.13], p value <0.001). RQLQ scores were also reduced after LLLT (SMD = -0.72, 95 CI: [-0.94 to -0.50], p value <0.001), and very few adverse events were reported. This meta-analysis, however, had significant publication bias and heterogeneity. When compared to a placebo, LLLT did not significantly improve nasal symptoms (SMD: -0.69, p value = 0.167), which might mean the post-LLLT nasal symptom alleviation is due to a placebo effect. Comparisons to other treatment modalities were too few to deduce anything meaningful, although it does appear that LLLT is less effective than UV lasers.

CONCLUSION

LLLT is most likely effective at alleviating nasal symptomology and has a low likelihood of adverse event incidence, yet more high-quality studies with larger sample sizes are needed to compare LLLT to a placebo to ensure its superiority to the placebo effect, as well as non-inferiority clinical trials to compare it to standard treatments.

Long-acting anti-inflammatory injectable DEX-Gel with sustained release and self-healing properties regulates TH1/TH2 immune balance for minimally invasive treatment of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a prevalent immune-related allergic disease, and corticosteroid nasal sprays serve as the primary treatment for this patient population. However, their short duration of efficacy and frequent administration pose challenges, leading to drug wastage and potential adverse effects. To overcome these limitations, we devised a novel approach to formulate DEX-Gel by incorporating dexamethasone (DEX) into a blend of Pluronic F127, stearic acid (SA), and polyethylene glycol 400 (PEG400) to achieve sustained-release treatment for AR.

RESULTS

Following endoscopic injection into the nasal mucosa of AR rats, DEX-Gel exhibited sustained release over a 14-day period. In vivo trials employing various assays, such as flow cytometry (FC), demonstrated that DEX-Gel not only effectively managed allergic symptoms but also significantly downregulated helper T-cells (TH) 2 and TH2-type inflammatory cytokines (e.g., interleukins 4, 5, and 13). Additionally, the TH1/TH2 cell ratio was increased.

CONCLUSION

This innovative long-acting anti-inflammatory sustained-release therapy addresses the TH1/TH2 immune imbalance, offering a promising and valuable approach for the treatment of AR and other inflammatory nasal diseases.

Mast Cells in Upper and Lower Airway Diseases: Sentinels in the Front Line

Mast cells (MCs) are fascinating cells of the innate immune system involved not only in allergic reaction but also in tissue homeostasis, response to infection, wound healing, protection against kidney injury, the effects of pollution and, in some circumstances, cancer. Indeed, exploring their role in respiratory allergic diseases would give us, perhaps, novel therapy targets. Based on this, there is currently a great demand for therapeutic regimens to enfeeble the damaging impact of MCs in these pathological conditions. Several strategies can accomplish this at different levels in response to MC activation, including targeting individual mediators released by MCs, blockade of receptors for MC-released compounds, inhibition of MC activation, limiting mast cell growth, or inducing mast cell apoptosis. The current work focuses on and summarizes the mast cells' role in pathogenesis and as a personalized treatment target in allergic rhinitis and asthma; even these supposed treatments are still at the preclinical stage.

Fungal Aeroallergens-The Impact of Climate Change

The incidence of allergic diseases worldwide is rapidly increasing, making allergies a modern pandemic. This article intends to review published reports addressing the role of fungi as causative agents in the development of various overreactivity-related diseases, mainly affecting the respiratory tract. After presenting the basic information on the mechanisms of allergic reactions, we describe the impact of fungal allergens on the development of the allergic diseases. Human activity and climate change have an impact on the spread of fungi and their plant hosts. Particular attention should be paid to microfungi, i.e., plant parasites that may be an underestimated source of new allergens.

Innate immunity and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), recently renamed as metabolic (dysfunction)-associated fatty liver disease (MAFLD), is a complex, multifactorial disease that progresses via nonalcoholic steatohepatitis (NASH) towards severe liver complications. MAFLD/NAFLD affects up to a third of the global population. It is connected with metabolic syndrome parameters and has been increasing in parallel with the rates of metabolic syndrome parameters worldwide. This disease entity exhibits a strong immune-inflammatory dimension. In MAFLD/NAFLD/NASH, a vast network of innate immune cells is mobilized that can provoke liver damage, leading to advanced fibrosis, cirrhosis and its complications, including hepatocellular carcinoma. However, our understanding of the inflammatory signals that drive the onset and progression of MAFLD/NAFLD/NASH is fragmented. Thus, further investigation is required to better understand the role of specific innate immune cell subsets in the disease, and to aid the design of innovative therapeutic agents to target MAFLD/NAFLD/NASH. In this review, we discuss current concepts regarding the role of innate immune system involvement in MAFLD/NAFLD/NASH onset and progression, along with presenting potential stress signals affecting immune tolerance that may trigger aberrant immune responses. A comprehensive understanding of the innate immune mechanisms involved in MAFLD/NAFLD/NASH pathophysiology will help the discovery of early interventions to prevent the disease, and lead to potential innovative therapeutic strategies that may limit its worldwide burden.

Nasal cytology and histology in CRSwNP: Two sides of the same coin

Knowledge of chronic rhinosinusitis with nasal polyps (CRSwNP) has increased rapidly over the past decade. However, the study of the histological features of nasal polyps has not gone hand in hand with the study of the inflammatory mechanisms underlying CRSwNP. Indeed, precisely because they are benign neoformations, nasal polyps have not attracted the attention of pathologists over the years. Nasal cytology has shown that CRSwNP, generally defined as a Type-2 disease, is characterized not only by eosinophilic but also mast cell inflammation and, in particular, the most severe forms of CRSwNP are precisely characterized by a mixed eosinophilic-mast cell inflammation. Interestingly, mast cells cannot be visualized by histology due to limitations in staining and magnification, and therefore are not commonly described in histological reports of nasal polyps. However, immunohistochemistry can highlight these latter cells and specifically this technique has recently demonstrated that mast cells are located in the lamina propria of almost all types of polyps and in the epithelial level of the most severe forms. Unfortunately, the latter technique is not commonly carried out in clinical practice by virtue of the high cost and time burden. On the other hand, nasal cytology is an easy-to-apply and economic diagnostic tool, commonly practiced in rhinological setting, which can effectively fill the gap between histology and immunohistochemistry, allowing to non-invasively establish the endotype of nasal polyps and to highlight all cytotypes, including mast cells, that cannot be visualized by the other two techniques. The recent demonstration of the close correlation between mast cell intraepithelial infiltrate and CRSwNP severity paves the way for new therapeutic possibilities aimed at reducing not only eosinophilic infiltration but also mast cell infiltration.

Changes in serum hypoxia-inducible factor-1α and erythropoietin in allergic rhinitis patients: Correlation with the Th inflammatory profile and disease comorbidities

OBJECTIVES

The balance between proinflammatory IFN-γ Th1 vs. the anti-inflammatory allergy-mediating IL-4-heralded Th2 reactions is pivotal in IgE-mediated allergic rhinitis (AR). Hypoxia-Inducible Factor (HIF)-1α is inducible by hypoxia and various cytokines. HIF-1α activates different anti-pathogen and allergic immune cells. This cross-sectional study assessed the changes in serum HIF-1α and its dependent erythropoietin (EPO) levels among hospital-characterized AR patients. Type of the immune reaction, Th1 vs. Th2, was stratified based on the calculated IL-4/IFN-γ direct ratio, after being measured using specific ELISA assays.

METHODS

147 AR patients (83 males/64 females), and age-, BMI-, and gender-matched 24 healthy controls (13 males/11 females) were sequentially enrolled at ENT Unit, Prince Muteb General Hospital, Sakaka, Saudi Arabia. Measurement of serum parameters was carried out using specific ELISA assays.

RESULTS

Contrary to the majority of previous publications, all controls and the majority of patients (n = 137/147) exhibited naive Th0 immune response. IFN-γ and HIF-1α levels were greater in controls than in patients (168.9 ± 173.9 vs 108 ± 94.5 pg/mL; p<.012) and controls had a lower IL-4/IFN-ratio (2.439 ± 0.897 vs 3.33 ± 1.19; p<.001) than patients. The HIF-1α results disagree with earlier studies. Due to the wide inter-individual variations, serum IL-4 and EPO levels in controls were non-significantly higher than patients. Lower IL-4 levels (267.3 ± 79.95 vs 353.4 ± 320.6 pg/mL; p < .01) and the ratio (2.814 ± 1.335 vs 3.431 ± 1.137; p < .05) were associated with obstructive sleep apnea. Lower ratio was also associated with inferior turbinate hypertrophy (3.051 ± 1.026 vs 3.787 ± 1.310; p < .001). EPO and IL-4 levels were lower in patients with deviated nasal septum (66.69 ± 26.81 vs 84.24 ± 61.5 pg/mL; p < .021; and 299.5 ± 137.3 vs 391.1 ± 52.780 pg/mL; p < .001, respectively). Significant correlations were found between the recorded levels and AR comorbidities.

CONCLUSION

These results confirmed a pathogenic implication for HIF-1α and IFN-γ in AR that warranted future bigger and longitudinal studies.