Allergic rhinitis and allergic sensitisation are still increasing among Danish adults

The potential application and molecular mechanisms of natural products in the treatment of allergic rhinitis: A review

BACKGROUNDS

Allergic rhinitis (AR) is a non-infectious chronic inflammation of the nasal mucosa mainly mediated by immunoglobulin E (IgE) in atopic individuals after exposure to allergens. The application of AR guideline-recommended pharmacotherapies can rapidly relieve symptoms of AR but with poor long-term efficacy, and many of these therapies have side effects. Many natural products and their derivatives have shown potential therapeutic effects on AR with fewer side effects.

OBJECTIVES

This review aims to expand understanding of the roles and mechanisms of natural compounds in the treatment of AR and to highlight the importance of utilizing natural products in the treatment of AR.

MATERIAL AND METHOD

We conducted a systematic literature search using PubMed, Web of Science, Google Scholar, and Clinical Trials. The search was performed using keywords including natural products, natural compounds, bioproducts, plant extracts, naturally derived products, natural resources, allergic rhinitis, hay fever, pollinosis, nasal allergy. Comprehensive research and compilation of existing literature were conducted.

RESULTS

This article provided a comprehensive review of the potential therapeutic effects and mechanisms of natural compounds in the treatment of AR. We emphasized that natural products primarily exert their effects by modulating signalling pathways such as NF-κB, MAPKs, STAT3/ROR-γt/Foxp3, and GATA3/T-bet, thereby inhibiting the activation and expansion of allergic inflammation. We also discussed their toxicity and clinical applications in AR therapy.

CONCLUSION

Taken together, natural products exhibit great potential in the treatment of AR. This review is also expected to facilitate the application of natural products as candidates for treating AR. Furthermore, drug discovery based on natural products has a promising prospect in AR treatment.

Genetically predicted N-methylhydroxyproline levels mediate the association between naive CD8+ T cells and allergic rhinitis: a mediation Mendelian randomization study

Background

Allergic rhinitis (AR), a prevalent chronic inflammatory condition triggered by immunoglobulin E (IgE), involves pivotal roles of immune and metabolic factors in its onset and progression. However, the intricacies and uncertainties in clinical research render current investigations into their interplay somewhat inadequate.

Objective

To elucidate the causal relationships between immune cells, metabolites, and AR, we conducted a mediation Mendelian randomization (MR) analysis.

Methods

Leveraging comprehensive publicly accessible summary-level data from genome-wide association studies (GWAS), this study employed the two-sample MR research method to investigate causal relationships among 731 immune cell phenotypes, 1400 metabolite levels, and AR. Additionally, employing the mediation MR approach, the study analyzed potential mediated effect of metabolites in the relationships between immune cells and AR. Various sensitivity analysis methods were systematically employed to ensure the robustness of the results.

Results

Following false discovery rate (FDR) correction, we identified three immune cell phenotypes as protective factors for AR: Naive CD8br %CD8br (odds ratio (OR): 0.978, 95% CI = 0.966-0.990, P = 4.5×10-4), CD3 on CD39+ activated Treg (OR: 0.947, 95% CI = 0.923-0.972, P = 3×10-5), HVEM on CD45RA- CD4+ (OR: 0.967, 95% CI = 0.948-0.986, P = 4×10-5). Additionally, three metabolite levels were identified as risk factors for AR: N-methylhydroxyproline levels (OR: 1.219, 95% CI = 1.104-1.346, P = 9×10-5), N-acetylneuraminate levels (OR: 1.133, 95% CI = 1.061-1.211, P = 1.7×10-4), 1-stearoyl-2-arachidonoyl-gpc (18:0/20:4) levels (OR: 1.058, 95% CI = 1.029-1.087, P = 5×10-5). Mediation MR analysis indicated a causal relationship between Naive CD8br %CD8br and N-methylhydroxyproline levels, acting as a protective factor (OR: 0.971, 95% CI = 0.950-0.992, P = 8.31×10-3). The mediated effect was -0.00574, accounting for 26.1% of the total effect, with a direct effect of -0.01626. Naive CD8+ T cells exert a protective effect on AR by reducing N-methylhydroxyproline levels.

Conclusion

Our study, delving into genetic information, has substantiated the intricate connection between immune cell phenotypes and metabolite levels with AR. This reveals a potential pathway to prevent the onset of AR, providing guiding directions for future clinical investigations.

Clinical practice guideline for acupuncture and moxibustion: Allergic rhinitis

Acupuncture is one of the most effective complementary therapies for allergic rhinitis (AR) and has been recommended by several clinical practice guidelines (CPGs) for AR. However, these CPGs mentioned acupuncture without making recommendations for clinical implementation and therapeutic protocols, therefore limiting the applicability of acupuncture therapies for AR. Hence, for the benefit of acupuncture practitioners around the world, the World Federation of Acupuncture-moxibustion Societies have initiated a project to develop the CPG for the use of acupuncture and moxibustion to treat AR. This CPG was developed according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, referring to the principles of the World Health Organization Handbook for Guideline Development. During the development of the CPG, the guideline development group (GDG) played an important role. The clinical questions, recommendations and therapeutic protocols were all formulated by the GDG using the modified Delphi method. The CPG contains recommendations for 15 clinical questions about the use of acupuncture and moxibustion interventions. These include one strong recommendation for the intervention based on high-quality evidence, three conditional recommendations for either the intervention or standard care, and 11 conditional recommendations for the intervention based on very low quality of evidence. The CPG also provides one filiform needle acupuncture protocol and five moxibustion protocols extracted based on the protocols presented in randomized controlled trials reviewed by the GDG. Please cite this article as: Du SH, Chen S, Wang SZ, Wang GQ, Du S, Guo W, Xie XL, Peng BH, Yang C, Zhao JP. Clinical practice guideline for acupuncture and moxibustion: Allergic rhinitis. J Integr Med. 2024; 22(3): 245-257.

Long-term health care resource and cost savings with allergy immunotherapy: REACT study results

Background

Allergy immunotherapy (AIT) can be administered as subcutaneous immunotherapy (SCIT) injections in the clinic or as sublingual immunotherapy (SLIT) tablets at home after initiation under medical supervision. To achieve long-term, sustained effects, a 3-year treatment duration is recommended.

Objective

Our aim was to assess the association of AIT (SCIT and SLIT tablets) with long-term health care resource use (HRU) and costs in subjects with allergic rhinitis.

Methods

REACT was a retrospective propensity score-matched cohort study using claims data from a German health insurance database (2007-2017), with up to 9 years of follow-up after AIT initiation. HRU and costs were evaluated for hospitalizations, ambulatory care visits, and prescriptions, in subjects who received AIT versus in matched controls with allergic rhinitis who had not received AIT, as well as for SCIT and SLIT tablets.

Results

Across all 9 years, the subjects who received AIT had a significantly lower incidence of hospitalization than the controls did. Generally, proportions of subjects with ambulatory care visits and hospitalizations were lower, and length of hospitalization was shorter, for those receiving SLIT tablets than those who received SCIT. Total costs were significantly higher with AIT versus for the controls during the treatment period (years 1 to 3), driven by prescriptions and ambulatory care visits, but they were lower in years 4 to 9. During years 1 to 3, prescription costs were generally higher for SLIT tablets than for SCIT, whereas ambulatory care costs were numerically lower. In most years, hospitalization costs were numerically lower for SLIT tablets than for SCIT.

Conclusion

Initial higher HRU and costs of AIT during the expected treatment period are offset in the long term. At-home administration of SLIT tablets may further reduce ambulatory care costs.

Dust mite component Analysis: Identifying key allergens components for effective immunotherapy in allergic rhinitis

BACKGROUND

The aim of this study was to examine the frequency of sensitization to house dust mite (HDM) components among allergic rhinitis patients receiving subcutaneous immunotherapy (SCIT), and to assess the correlation between SCIT efficacy and specific IgE (sIgE) levels for allergenic HDM components.

METHODS

Serum samples and clinical data were collected from 38 allergic rhinitis patients receiving HDM-SCIT at baseline and after 1 year of treatment. Effective treatment was defined as a therapeutic index (TI) of at least 50% after 1 year. Cytokine levels were analyzed using commercial ELISA kits, while serum total and specific IgE levels were determined by the fluoroenzymeimmunoassay technique. The ALLEOS 2000 magnetic particle chemiluminescence system was used to measure sIgE levels for Der f, Der p 1, Der p 2, Der p 10, and Der p 23.

RESULTS

Allergic rhinitis patients undergoing HDM-SCIT had a high rate of allergic sensitization to the HDM major allergens Der p (100%), Der f (100%), Der p 1 (94.74%), Der p 2 (94.74%), and Der p 23 (36.84%). Patients who responded to SCIT had higher levels of IgE for HDM components at baseline, while those with ineffective treatment showed an opposite performance, particularly for Der p 1 (P＜0.05). After 1 year of treatment, effective and ineffective patients showed opposite trends in sIgE for dust mite components (decreased in effective patients, increased in ineffective patients). HDM-SCIT led to a significant reduction in IL-2, IL-4, IL-6, and EOS% (P＜0.05). IgE for Der p, Der f, Der p 1, Der p 2, and HDM sIgE were significantly positively correlated (P < 0.001). The correlation heatmap analysis based on changes in values reveals a negative correlation between CSMS score changes and sIgE for Der f and Der p 1, and a positive correlation with IL-2, IL-10, and TNF (P < 0.05).

CONCLUSIONS

The molecular sensitization profiles during HDM-SCIT are variable and relate to treatment efficacy. Molecular diagnosis can assist allergists in identifying patients eligible for HDM-SCIT, thereby enhancing the treatment's clinical efficacy. Serum cytokine levels of IL-2, IL-4, IL-6，and EOS% may serve as useful biomarkers for monitoring HDM-SCIT efficacy.

Air Pollution and Allergic Rhinitis: Findings from a Prospective Cohort Study

To investigate the association of long-term exposure to ambient air pollution with the risk of allergic rhinitis (AR), we performed a longitudinal analysis of 379,488 participants (47.4% women) free of AR at baseline in the UK Biobank. The annual average concentrations of PM2.5, PMcoarse, PM10, NO2, and NOx were estimated by land use regression models. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). A weighted polygenic risk score was constructed. During a median follow-up period of 12.5 years, 3095 AR cases were identified. We observed significant associations between the risk of AR and PM2.5 (HR: 1.51, 95% CI: 1.27-1.79, per 5 μg/m3), PMcoarse (HR: 1.28, 95% CI: 1.06-1.55, per 5 μg/m3), PM10 (HR: 1.45, 95% CI: 1.20-1.74, per 10 μg/m3), NO2 (HR: 1.14, 95% CI: 1.09-1.19, per 10 μg/m3), and NOx (HR: 1.10, 95% CI: 1.05-1.15, per 20 μg/m3). Moreover, participants with high air pollution combined with high genetic risk showed the highest risk of AR, although no multiplicative or additive interaction was observed. In conclusion, long-term exposure to air pollutants was associated with an elevated risk of AR, particularly in high-genetic-risk populations, emphasizing the urgent need to improve air quality.

Environmental Risk Factors, Protective Factors, and Biomarkers for Allergic Rhinitis: A Systematic Umbrella Review of the Evidence

Many potential environmental risk factors, protective factors, and biomarkers of AR have been published, but so far, the strength and consistency of their evidence are unclear. We conducted a comprehensive review of environmental risk, protective factors, and biomarkers for AR to establish the evidence hierarchy. We systematically searched Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to December 31, 2022. We calculated summary effect estimate (odds ratio (OR), relative risk (RR), hazard ratio (HR), and standardized mean difference (SMD)), 95% confidence interval, random effects p value, I2 statistic, 95% prediction interval, small study effects, and excess significance biases, and stratification of the level of evidence. Methodological quality was assessed by AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). We retrieved 4478 articles, of which 43 met the inclusion criteria. The 43 eligible articles identified 31 potential environmental risk factors (10,806,206 total population, two study not reported), 11 potential environmental protective factors (823,883 total population), and 34 potential biomarkers (158,716 total population) for meta-analyses. The credibility of evidence was convincing (class I) for tic disorders (OR = 2.89, 95% CI 2.11-3.95); and highly suggestive (class II) for early-life antibiotic use (OR = 3.73, 95% CI 3.06-4.55), exposure to indoor dampness (OR = 1.49, 95% CI 1.27-1.75), acetaminophen exposure (OR = 1.54, 95% CI 1.41-1.69), childhood acid suppressant use (OR = 1.40, 95% CI 1.23-1.59), exposure to indoor mold (OR = 1.66, 95% CI 1.26-2.18), coronavirus disease 2019 (OR = 0.11, 95% CI 0.06-0.22), and prolonged breastfeeding (OR = 0.72, 95% CI 0.65-0.79). This study is registered in PROSPERO (CRD42022384320).

Efficacy and safety of self-administered acupressure on symptoms, quality of life and nasal mucosal function in patients with perennial allergic rhinitis: study protocol for a randomized controlled exploratory trial

INTRODUCTION

Allergic rhinitis is a global health problem that can potentially be managed through acupressure. Our clinical observations have identified Allergic Rhinitis Acupressure Therapeutic (ARAT) as a novel acupressure treatment acting on specific acupoints, which may enhance the effectiveness of acupressure. Therefore, we propose a three-arm randomized controlled trial will be conducted to investigate the efficacy and safety of ARAT for perennial allergic rhinitis (PAR).

METHODS/DESIGN

In this trial, eligible 111 participants diagnosed with PAR will be randomly assigned to one of three groups: the ARAT group, the non-specific acupoints group, or the blank control group. The primary outcome will be the change in the total nasal symptom score, and the secondary outcomes will include: 1) changes in the scores of the standard version of Rhinoconjunctivitis Quality of Life Questionnaire (RQLQs); 2) acoustic rhinometry and anterior rhinomanometry; 3) changes in the scores of relief medication usage; 4) incidence of adverse events. Additionally, we will measure and compare the changes in cytokine levels (IL-5, IL-13, IFN-γ, and TSLP) in nasal secretions. The RQLQs and primary outcomes will be assessed at the beginning, middle, and end stages of the treatment period, with monthly follow-ups conducted over a total of three months. The secondary outcomes and biomarkers in nasal secretions will be measured at the beginning and end of the treatment period. Any adverse events or need for rescue medication will be carefully noted and recorded.

DISCUSSION

This study may produce a new acupressure treatment prescription that is easy to learn, more targeted, and adaptable. This trial represents the first clinical investigation comparing ARAT treatment for PAR with the non-specific acupoints group and blank control group. Our data is expected to provide evidence demonstrating the safety and efficacy of ARAT for PAR patients, while also exploring the functional mechanism underlying ARAT treatment, moreover, the results offer valuable insights for healthcare professionals in managing PAR symptoms.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2300072292. Registered on June 08, 2023.

DNA methylation regulatory patterns and underlying pathways behind the co-pathogenesis of allergic rhinitis and chronic spontaneous urticaria

Background

Allergic rhinitis (AR) and chronic spontaneous urticaria (CSU) are often concurrent in patients. Changes in DNA methylation affect T cell biological processes, which may explain the occurrence and progression of comorbidity. However, downstream regulatory pathways of DNA methylation in two diseases and the underlying mechanisms have not been fully elucidated.

Methods

The GSE50101, GSE72541, GSE50222 and OEP002482 were mined for the identification of differentially expressed genes (DEGs) or co-expressed genes and differentially methylated genes (DMGs) in AR and CSU patients. We applied GO analysis and consensus clustering to study the potential functions and signal pathways of selected genes in two diseases. GSVA and logistic regression analysis were used to find the regulatory pathway between DNA methylation and activation patterns of CD4+ T cells. Besides, we used the Illumina 850k chip to detect DNA methylation expression profiles and recognize the differentially methylated CpG positions (DMPs) on corresponding genes. Finally, we annotated the biological process of these genes using GO and KEGG pathway analysis.

Result

The AR-related DEGs were found closely related to the differentiation and activation of CD4+ T cells. The DEGs or co-expressed genes of CD4+ T cells in AR and CSU patients were also clustered using GO and KEGG analysis and we got 57 co-regulatory pathways. Furthermore, logistic regression analysis showed that the regulation of cellular component size was closely related to the activation of CD4+ T cells regulated by DNA methylation. We got self-tested data using the Illumina 850k chip and identified 98 CpGs that were differentially methylated in patients. Finally, we mapped the DMPs to 15 genes and found that they were mainly enriched in the same CD4+T cell regulating pathway.

Conclusion

Our study indicated that DNA methylation affected by pollen participated in the activation patterns of CD4 + T cells, providing a novel direction for the symptomatic treatment of the co-occurrence of AR and CSU.

High baseline prevalence of atopic comorbidities and medication use in children treated with allergy immunotherapy in the REAl-world effeCtiveness in allergy immunoTherapy (REACT) study

Background

Respiratory allergy, commonly manifesting as allergic rhinitis (AR) and asthma, is a chronic progressive disease that frequently starts in childhood. Allergy immunotherapy (AIT) is the only causal treatment for respiratory allergy with the potential to modify the underlying cause of allergy and, ultimately, prevent disease progression. This analysis aimed to determine if AIT is received sufficiently early to halt the progression of allergic disease, by characterizing the burden and progression of disease in children prior to AIT initiation in real-life clinical practice.

Methods

The REAl-world effeCtiveness in allergy immunoTherapy (REACT) study was a large retrospective cohort study using German claims data between 2007 and 2017. Characteristics of two pre-defined AIT age cohorts from the REACT study - children (aged <18 years) and adults (aged ≥18 years) - were evaluated during the 1-year period before the first AIT prescription. For comparison, a control group of all subjects with a confirmed diagnosis of AR and without prescriptions for AIT was included. Burden of disease was assessed using diagnostic codes for atopic comorbidities [e.g., atopic dermatitis (AD), asthma, and acute allergic conjunctivitis] and non-atopic comorbidities (e.g., migraine, headache); medication use, recorded as prescriptions for symptom-relieving AR medication and reliever/controller medication for asthma, was also assessed. Data were analyzed descriptively, using summary statistics.

Results

Both children (n = 11,036) and adults (n = 30,037) showed a higher prevalence of atopic comorbidities and a greater drug burden prior to AIT initiation compared to AR patients not treated with AIT (n = 1,003,332). In the two age-specific AIT cohorts, children consistently showed the highest prevalence of atopic comorbidities compared to adults (AIT children, AIT adults - asthma: 41.4%, 34.5%; AD: 19.9%, 10.2%; acute allergic conjunctivitis: 13.6%, 10.2%). Generally, prescriptions per year for symptom-relieving AR and asthma treatments were also higher for children initiating AIT vs. adults (AIT children, AIT adults - AR prescriptions per subject: 1.72, 0.73; asthma prescriptions per subject: 1.42, 0.79).

Conclusions

Children with AR who are offered AIT in real-life show considerable disease burden prior to initiation. As AIT may alleviate the burden and halt the progression of allergic disease, considering AIT earlier in the disease course may be warranted.

A review of recent advances in exosomes and allergic rhinitis

Allergic rhinitis is a chronic inflammatory disease of nasal mucosa caused by the presence of IgE after exposure to allergens, characterized by nasal irritation, hypersecretion of the nasal passages and sneezing, which frequently occurs in children and adolescents. There has been an increase in allergic rhinitis over the past few years due to air pollution. Exosomes have been discovered to be nano-sized vesicles, which contain a wide range of substances, including proteins and nucleic acids, numerous studies indicates that exosomes play a vital role in cells communication. Recently there have been more and more studies exploring the role of exosomes in allergic rhinitis. Therefore, here we will present a comprehensive review of the research on exosomes and their role in allergic rhinitis for the purpose of providing new understanding of potential value of exosomes applied to the treatment of allergic rhinitis.

Filiform needle acupuncture for allergic rhinitis: A systematic review and meta-analysis

BACKGROUND

Filiform needle acupuncture (FNA), the most classical and widely applied acupuncture method based on traditional Chinese medicine theory, has shown a promising effect in the treatment of allergic rhinitis (AR).

OBJECTIVE

To evaluate the efficacy, safety, cost-effectiveness, and patient preference of FNA in the treatment of AR by comparing FNA with sham acupuncture, no treatment, and conventional medication.

SEARCH STRATEGY

Eight electronic databases were systematically searched from inception to October 14, 2021. Additional studies were acquired from clinical trial registration platforms and reference lists.

INCLUSION CRITERIA

Randomized controlled trials were included if they compared FNA with either sham acupuncture, no treatment or conventional medication for AR.

DATA EXTRACTION AND ANALYSIS

Two researchers extracted data independently of each other using a predesigned data acquisition form, and results were cross-checked after completion. The primary outcome was symptom score (Total Nasal Symptom Score or Visual Analogue Scale), and the secondary outcomes were the AR control questionnaire, quality of life (QoL) score (Different versions of Rhinoconjunctivitis Quality of Life Questionnaire), medication score (use of rescue medication), mental health score, total IgE, adverse event rate, clinical economic indicators, and patient satisfaction score. Standardized mean difference (SMD) or mean difference (MD) with 95% confidence interval was used to calculate the effect size for continuous data, while risk ratio with 95% CI was used for dichotomous data.

RESULTS

Thirty studies were included in this review. Compared with sham acupuncture, FNA significantly reduced the symptom score (SMD: -0.29 [-0.43, -0.15]), AR's impact on QoL (SMD: -0.23 [-0.37, -0.08]) and medication score (SMD: -0.3 [-0.49, -0.11]). Compared with no treatment, FNA dramatically reduced the symptom score (SMD: -0.8 [-1.2, -0.39]) and AR's impact on QoL (SMD: -0.82 [-1.13, -0.52]). There were no increased rates of adverse events with FNA compared to sham acupuncture and no treatment. FNA increased patient satisfaction and may be cost-effective. Most pieces of evidence from the above two comparisons were of high confidence. Moreover, FNA significantly outperformed conventional medication in reducing the symptom score (SMD: -0.48 [-0.85, -0.1]) and displayed a lower rate of adverse events, but the quality of evidence was very low.

CONCLUSION

FNA is an effective and safe intervention for AR and can help with symptom relief, QoL improvement, reducing medication usage, and increasing patient satisfaction. Further studies are needed to verify its cost-effectiveness and superiority over conventional medication and the best therapeutic strategies.

Allergic rhinitis in Chinese young adults from the Singapore/Malaysia cross-sectional genetics epidemiology study (SMCGES) cohort: Prevalence, patterns, and epidemiology of allergic rhinitis

Background

Allergic rhinitis (AR) is characterized by the occurrence of at least 2 symptoms of nasal itching, nasal blockage, rhinorrhea, and sneezing, when not afflicted with a cold or flu, with defined atopic sensitization demonstrated by skin prick test or specific IgE responses. Besides the detriment to standard of living and economic burden of AR, both multicentre and single-cohort studies have observed an increase in AR prevalence in Asia over time.

Methods

In total, 12 872 individuals, with mean age 22.1 years (SD = 4.8), were recruited from universities in Singapore and Malaysia. Each participant provided epidemiological data based on an investigator-administered questionnaire adapted from the validated International Study of Allergies and Asthma in Childhood (ISAAC) protocol, and atopy status was determined using a skin prick test (SPT) performed by qualified staff. AR was diagnosed according to Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines and a positive SPT result.

Results

Sensitization (determined by SPT) to either Blomia tropicalis or Dermatophagoides pteronyssinus was prevalent in 66.5% of the cohort. Current rhinitis (manifesting ≥2 rhinitis symptoms, within the past 12 months) was observed in 48.9% of our population, while AR, which included atopy status, was estimated at 39.4%. Sneezing and rhinorrhea were the most common symptoms among AR cases. AR prevalence decreased with increasing age (OR: 0.979; 95% CI: 0.969-0.989), while male gender (OR: 2.053; 95% CI: 1.839-2.294), and a parental history of allergic diseases (OR: 2.750; 95% CI: 2.284-3.316) were significant risk factors for AR. Upon adjustment for age, gender, and parental history, housing type (OR: 0.632; 95% CI: 0.543-0.736) and income level (>$6000 vs <$2000; OR: 2.461; 95% CI: 2.058-2.947) remained as significant risk factors for AR, while ever having kept a pet (OR: 1.167; 95% CI: 1.025-1.328) emerged as a risk factor. Conflicting results were obtained for indicators of sedentary lifestyle: frequent physical activity (OR: 1.394; 95% CI: 1.150-1.694) and increased duration spent using the TV/computer (OR: 1.224; 95% CI: 1.006-1.489) both increased the risk of AR. Lastly, we used the Quality of Diet based on Glycaemic Index Score (QDGIS) to assess the Glycaemic Index (GI) level of overall diet. We identified lower GI level of overall diet as a protective factor against AR manifestation (OR: 0.682; 95% CI: 0.577-0.807).

Conclusion

While the previously established non-modifiable risk factors for AR were present in our study population, the identification of modifiable risk factors, such as TV/computer usage, and dietary habits, opens a new area for research, both in the areas of gene-environment interaction, and management of AR.

Population-based epidemiology: The Glostrup Population Studies 1964–2021

The Glostrup Population Studies are population-based cohorts undertaken in the south-western part of Greater Copenhagen since 1964. The participants were randomly selected from the adult general population. The first cohort was established to assess cardiovascular risk factors and, since, the objectives have been broadened to describe and analyse the health of the general population. The studies are health-examination studies with clinical and biochemical data in addition to data from self-administered questionnaires and, in some studies, interviews. Fasting blood and urine samples were collected and stored in our biobank for further studies. Several of the cohorts were performed according to standardized methods in international consortia, hence data have been pooled with other, both Danish and international, cohorts. To date more than 30,000 individuals, both men and women, aged 15–85 years, have participated in The Glostrup Population Studies and participants have been re-examined up to eight times. The data can be used for disease-specific epidemiology, social epidemiology, genetic epidemiology, ageing, lifestyle and health interventions nested within the cohorts. The Glostrup Population Studies represent a great resource; the possibility of merging the different cohorts enables large datasets, as well as trends over time. Furthermore, the long follow-up in both the national registers and with follow-up examinations is unique. The purpose of this commentary is to inform about The Glostrup Population Studies and to invite collaborations to continue utilizing this great resource to combat current and future challenges within health promotion and disease prevention.

Specific aeroallergen sensitization associated with current rhinitis among adults in southwestern Saudi Arabia

Data about allergic sensitization to rhinitis among adults are limited. The objectives were to explore the prevalence of current rhinitis (CR) and associated specific allergen sensitizations in southwestern Saudi Arabia. A cross-sectional study was conducted on 969 adults in southwestern regions of Saudi Arabia, namely Aseer, Jazan, and Al Baha. From each region, 5 primary health care centers were chosen. The validated Arabic Version of the International Study of Asthma and Allergies in Childhood questionnaire was used. Total immunoglobulin E (IgE) enzyme-linked immunosorbent assay, cytokine enzyme-linked immunosorbent assay (interleukin [IL]-4, IL-10, IL-13, and interferon-γ), aeroallergen-specific IgE immunoassay (a panel of 30 common aeroallergens; 9 indoor and 21 outdoors), and eosinophilic count were assessed. A prevalence of CR of 35.8% (95% confidence interval: 32.8%-38.9%) was found. Regarding outdoor aeroallergens, Mesquite-positive IgE antibodies were higher among CR adults (odds ratio = 1.52, 95% confidence interval: 1.02-2.21) compared to those without CR. The same significant pattern was found with Chenopodium, Ragweed, Pigweed, Russian thistle, Bermuda grass, Timothy grass, and Rye. All indoor aeroallergens were not significantly associated with CR. Total IgE and eosinophil count were significantly higher among adults with CR. In conclusion, CR in southwestern regions of Saudi Arabia is common and of significant public health importance. Aeroallergens that associate with adult sensitization to CR tend to be of the outdoor variety particularly the herbaceous grass and their pollens. The magnitude of CR and its association with exposure to outdoor aeroallergens should be taken into account by health policy decision makers, clinicians, and medical practitioners when diagnosing and treating related conditions.

Efficacy and Safety of Modified Yupingfeng Nasal Spray in Controlling the Recurrence of Persistent and Moderate-Severe Allergic Rhinitis: Study Protocol for a Multicenter, Open-Label, Randomized, and Parallel-Arm Trial

Background. Recurrent episode of allergic rhinitis (AR) is one of the leading illnesses that affects patients. However, there is little research evidence to support pharmacotherapy for AR recurrence. Therefore, this study was designed to explore the efficacy of pharmacotherapy in the control of the recurrence of AR. Methods. In this study, a multicenter, open-label, randomized, and parallel-arm trial will be conducted at three study centers. A total of 190 subjects aged 18–65 with persistent and moderate-severe AR (Qi deficiency and blood stasis syndrome) will be randomly assigned to receive the modified Yupingfeng nasal spray or mometasone furoate aqueous nasal spray. When subjects’ rhinitis control assessment test (RCAT) score is >21 for two weeks, they will stop taking the medication and enter the follow-up. Once a relapse occurs, the time point will be recorded, and the follow-up stops. The primary outcome is the six-month recurrence rate of AR after intervention withdrawal. The secondary outcomes are the one-month recurrence rate of AR, the RCAT score, the duration of follow-up, the duration of medication, the nasal endoscopic results, and questionnaires to evaluate symptoms, signs, and quality of life. The mechanism outcomes include some indicators that may be associated with AR recurrence. In addition, electrocardiograms and other safety indicators will be applied to evaluate the drug’s safety. Discussion. This is the first study to explore the efficacy of traditional Chinese medicine nasal spray on AR from the perspective of controlling recurrence. The results of this trial may provide valuable clinical evidence for controlling the recurrence of this disease by pharmacotherapy. Trial Registration. This study was registered with registration number ChiCTR2100047053 (Chinese Clinical Trial Registry, https://www.chictr.org.cn/showproj.aspx?proj=127432 on June 7, 2021).

Regulatory effects of miRNA-126 on Th cell differentiation and cytokine expression in allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a common disease worldwide. Imbalances in T helper (Th) cell differentiation and the dysregulation of related cytokines form the immunological basis of AR. miR-126 may play an important regulatory role in AR as a new marker and predictor of the disease. Therefore, the aim of this study was to explore the regulatory effects of miR-126 on Th cell differentiation and cytokine expression in AR.

METHODS

T lymphocytes and rat models were transfected with a miR-126 mimic and an inhibitor. The expression of miR-126 and Th cell-related cytokines was detected by RT-qPCR and western blotting. The serum IgE levels were detected using ELISA. In the nasal mucosa, pathological changes were observed by HE staining, protein expression was detected by immunohistochemistry, and the differentiation ratio of Th cell subsets was detected by flow cytometry.

RESULTS

During the occurrence and development of AR, the expression of miR-126 and the IgE levels were increased in the AR group. The number of Treg cell subsets decreased in the AR rats, increased after the miR-126 agomir intervention and decreased after miR-126 antagomir intervention. The number of Th1 and Th2 cell subsets increased in the AR rats, decreased after miR-126 agomir intervention and increased after the miR-126 antagomir intervention.

CONCLUSION

We propose that miR-126 may be involved in the pathogenesis of AR by positively regulating the expression of Treg cytokines and negatively regulating the expression of the Th1 and Th2 cytokines.

YouTube as a source of (mis)information on allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a very common chronic condition that affects nearly one-quarter of the adult population worldwide. The optimal management of AR includes useful information on the several aspects of the condition. Social media and online platforms are increasingly being used to obtain health related information.

OBJECTIVE

The study aimed to examine and evaluate the popularity and usefulness of YouTube videos on allergic rhinitis.

METHODS

Out of 225 screened videos, 86 met the inclusion criteria. A scoring scheme was designed to evaluate and rate the content of the extracted data. Data on views, likes, dislikes, and comments were extracted, and data on source of uploader, duration and content quality were recorded.

RESULTS

43% of the videos were classified as useful, 36 % as misleading, and 21 % as neither useful nor misleading. Although professional health care providers uploaded two-thirds of the videos, they accounted for only 24.4% of the total videos. Videos uploaded by TV shows and YouTube channels had by far the most user interaction, accounting for 66.9% of the total likes, 66.8 % of the total dislikes, and 54.0 % of the total comments. This source alone accounted for 23.4% of the total views, but for 48% of the total misleading videos.

CONCLUSION

The usefulness of YouTube videos on allergic rhinitis is varying and less than half of the videos provided useful information. If the proper conditions are met, selected YouTube videos on allergic rhinitis can be used as a source of information for patient education.

Airway Microbiome and Serum Metabolomics Analysis Identify Differential Candidate Biomarkers in Allergic Rhinitis

Allergic rhinitis (AR) is a common heterogeneous chronic disease with a high prevalence and a complex pathogenesis influenced by numerous factors, involving a combination of genetic and environmental factors. To gain insight into the pathogenesis of AR and to identity diagnostic biomarkers, we combined systems biology approach to analyze microbiome and serum composition. We collected inferior turbinate swabs and serum samples to study the microbiome and serum metabolome of 28 patients with allergic rhinitis and 15 healthy individuals. We sequenced the V3 and V4 regions of the 16S rDNA gene from the upper respiratory samples. Metabolomics was used to examine serum samples. Finally, we combined differential microbiota and differential metabolites to find potential biomarkers. We found no significant differences in diversity between the disease and control groups, but changes in the structure of the microbiota. Compared to the HC group, the AR group showed a significantly higher abundance of 1 phylum (Actinobacteria) and 7 genera (Klebsiella, Prevotella and Staphylococcus, etc.) and a significantly lower abundance of 1 genus (Pelomonas). Serum metabolomics revealed 26 different metabolites (Prostaglandin D2, 20-Hydroxy-leukotriene B4 and Linoleic acid, etc.) and 16 disrupted metabolic pathways (Linoleic acid metabolism, Arachidonic acid metabolism and Tryptophan metabolism, etc.). The combined respiratory microbiome and serum metabolomics datasets showed a degree of correlation reflecting the influence of the microbiome on metabolic activity. Our results show that microbiome and metabolomics analyses provide important candidate biomarkers, and in particular, differential genera in the microbiome have also been validated by random forest prediction models. Differential microbes and differential metabolites have the potential to be used as biomarkers for the diagnosis of allergic rhinitis.

Time-dependent dual beneficial modulation of interferon-γ, interleukin 5, and Treg cytokines in asthma patient peripheral blood mononuclear cells by ganoderic acid B

Th2 cytokines play a dominant role in the pathogenesis of allergic asthma. Interferon gamma (IFN-γ), a Th1 cytokine, links to therapeutic mechanisms of allergic asthma. Interleukin (IL)-10, a regulatory cytokine, is involved in the induction of immune tolerance. We previously demonstrated that Anti-Asthma Simplified Herbal Medicine Intervention (ASHMI) suppressed Th2 and increased IFN-γ in patients with asthma and in animal models, but its bioactive compound is unknown. Ganoderic acid beta (GAB) was isolated from Ganoderma lucidum (one herb in ASHMI). Human peripheral blood mononuclear cells (PBMCs) from adult patients with asthma were cultured with GAB or dexamethasone (Dex) in the presence of environmental allergens. The cytokine levels of IL-10, IFN-γ, IL-5, transcription factors T-bet, Foxp-3, and GATA3 were measured. Following 3-day culture, GAB, but not Dex, significantly increased IL-10 and IFN-γ levels by allergic patients' PBMCs. Following 6-day treatment, GAB inhibited IL-5 production, but IL-10 and IFN-γ remained high. Dex suppressed production of all three cytokines. GAB suppressed GATA3 and maintained Foxp-3 and T-bet gene expression, while Dex significantly suppressed GATA3 and T-bet expression. GAB simultaneously increased IL-10, IFN-γ associated with induction of T-bet and Foxp3, while suppressing IL-5, which was associated with suppression of GATA3, demonstrating unique beneficial cytokine modulatory effect, which distinguishes from Dex's overall suppression.

Advances and highlights in allergic rhinitis

Allergic rhinitis (AR) is a growing public health, medical and economic problem worldwide. The current review describes the major discoveries related to AR during the past 2 years, including risk factors for the prevalence of AR, the corresponding diagnostic strategy, precise underlying immunological mechanisms, and efficient therapies for AR during the ongoing global "coronavirus disease 2019" (COVID-19) pandemic. The review further attempts to highlight future research perspectives. Increasing evidence suggests that environmental exposures, climate changes, and lifestyle are important risk factors for AR. Consequently, detailed investigation of the exposome and the connection between environmental exposures and health in the future should provide better risk profiles instead of single predictors, and also help mitigate adverse health outcomes in allergic diseases. Although patients with dual AR, a newly defined AR phenotype, display perennial and seasonal allergens-related nasal symptoms, they are only allergic to seasonal allergens, indicating the importance of measuring inflammation at the local sites. Herein, we suggest that a combination of precise diagnosis in local sites and traditional diagnostic methods may enhance the precision medicine-based approach for management of AR; however, this awaits further investigations. Apart from traditional treatments, social distancing, washing hands, and disinfection are also required to better manage AR patients in the ongoing global COVID-19 pandemic. Despite recent advances in understanding the immune mechanisms underlying the effects of allergen immunotherapy (AIT), further understanding changes of cell profiles after AIT and accurately evaluate the efficacy of AIT are required.

A systematic review of the effects of temperature and precipitation on pollen concentrations and season timing, and implications for human health

Climate and weather directly impact plant phenology, affecting airborne pollen. The objective of this systematic review is to examine the impacts of meteorological variables on airborne pollen concentrations and pollen season timing. Using PRISMA methodology, we reviewed literature that assessed whether there was a relationship between local temperature and precipitation and measured airborne pollen. The search strategy included terms related to pollen, trends or measurements, and season timing. For inclusion, studies must have conducted a correlation analysis of at least 5 years of airborne pollen data to local meteorological data and report quantitative results. Data from peer-reviewed articles were extracted on the correlations between seven pollen indicators (main pollen season start date, end date, peak date, and length, annual pollen integral, average daily pollen concentration, and peak pollen concentration), and two meteorological variables (temperature and precipitation). Ninety-three articles were included in the analysis out of 9,679 articles screened. Overall, warmer temperatures correlated with earlier and longer pollen seasons and higher pollen concentrations. Precipitation had varying effects on pollen concentration and pollen season timing indicators. Increased precipitation may have a short-term effect causing low pollen concentrations potentially due to "wash out" effect. Long-term effects of precipitation varied for trees and weeds and had a positive correlation with grass pollen levels. With increases in temperature due to climate change, pollen seasons for some taxa in some regions may start earlier, last longer, and be more intense, which may be associated with adverse health impacts, as pollen exposure has well-known health effects in sensitized individuals.

A Childhood Farm Environment Protects from Allergic Sensitization until Middle Age but Not from New-Onset Sensitization in Adulthood: A 15 Year Longitudinal Study

Data are insufficient on the protective effect of a farm environment in childhood regarding sensitization in middle age and new-onset sensitization in adulthood. A skin prick test (SPT) and questionnaire data from the Northern Finland Birth Cohort 1966 study (NFBC66) were used to investigate sensitization at age 46 years related to childhood living environment. A subpopulation of 3409 participants was analyzed to study factors related to new-onset sensitization between ages of 31 and 46 years. Data on complete SPTs were available for 5373 cohort members at age 46. Professional farming by parents (odds ratio (OR) 0.54; 95% confidence interval (CI) 0.43–0.68) and keeping of farm animals (OR 0.53; 95% CI 0.43–0.66) in infancy were associated with a lower risk of sensitization at age 46. Sensitization (OR 0.58; 95% CI 0.47–0.72) and polysensitization (OR 0.43; 95% CI 0.32–0.57) were less common in those who lived in a rural area in infancy compared to a city area. The childhood living environment had no effect on new-onset sensitization between ages 31 and 46. We conclude that living on a farm or in a rural environment in childhood had a protective effect on sensitization even in middle age, but these factors did not protect from new-onset sensitization in adults.

The Association of Low Vitamin K Status with Mortality in a Cohort of 138 Hospitalized Patients with COVID-19

It has recently been hypothesized that vitamin K could play a role in COVID-19. We aimed to test the hypotheses that low vitamin K status is a common characteristic of patients hospitalized with COVID-19 compared to population controls and that low vitamin K status predicts mortality in COVID-19 patients. In a cohort of 138 COVID-19 patients and 138 population controls, we measured plasma dephosphorylated-uncarboxylated Matrix Gla Protein (dp-ucMGP), which reflects the functional vitamin K status in peripheral tissue. Forty-three patients died within 90 days from admission. In patients, levels of dp-ucMGP differed significantly between survivors (mean 877; 95% CI: 778; 995) and non-survivors (mean 1445; 95% CI: 1148; 1820). Furthermore, levels of dp-ucMGP (pmol/L) were considerably higher in patients (mean 1022; 95% CI: 912; 1151) compared to controls (mean 509; 95% CI: 485; 540). Cox regression survival analysis showed that increasing levels of dp-ucMGP (reflecting low vitamin K status) were associated with higher mortality risk (sex- and age-adjusted hazard ratio per doubling of dp-ucMGP was 1.49, 95% CI: 1.03; 2.24). The association attenuated and became statistically insignificant after adjustment for co-morbidities (sex, age, CVD, diabetes, BMI, and eGFR adjusted hazard ratio per doubling of dp-ucMGP was 1.22, 95% CI: 0.82; 1.80). In conclusion, we found that low vitamin K status was associated with mortality in patients with COVID-19 in sex- and age-adjusted analyses, but not in analyses additionally adjusted for co-morbidities. Randomized clinical trials would be needed to clarify a potential role, if any, of vitamin K in the course of COVID-19.

Towards a new epidemiological definition of chronic rhinitis: prevalence of nasal complaints in the general population

BACKGROUND

Chronic rhinitis (CR) is currently defined as the presence of at least two nasal symptoms for at least 1 hour per day for more than 12 weeks per year. Such definition lacks evidence-based foundation. CR patients are often divided into "runners" and "blockers", although the evidence supporting such subdivision is limited. The aim of the study was to define CR, to estimate its prevalence and the proportion of "runners" and "blockers".

METHODS

Cross-sectional, questionnaire-based study in a random sample of participants representing the general population of the Netherlands.

RESULTS

The questionnaire was sent to 5000 residents of the Netherlands; the response rate was 27%. CR was defined as at least 1 nasal complaint present for more than 3 weeks per year. The prevalence of CR in the general population was 40%. Participants who would have been excluded by the former CR definition were shown to have a significantly higher VAS compared to the controls. The larger part of CR group was represented by non-allergic rhinitis (NAR): 70% vs 30%. There were 25% "Blockers" and 22% "Runners" in the CR group, whereas more than a half of the CR group could be classified in neither of these subgroups.

CONCLUSION

Based on our data, we suggest that the current definition of CR should be revised and propose a new definition: at least one nasal complaint present for at least 3 weeks per year; although future studies are needed to further validate the proposed definition.

Sensitization against Fungi in Patients with Airway Allergies over 20 Years in Germany

BACKGROUND

Fungal spores are ubiquitous allergens. Severe forms of asthma are particularly highly associated with fungal sensitization. National and international asthma guidelines recommend the implementation of allergen immunotherapy if indicated. Thus, detection and treatment of relevant allergies are key components of primary care of these patients.

OBJECTIVES

The aims of the study were (i) to investigate trends in the prevalence of sensitization to twelve fungi in central Germany over the last 20 years and (ii) to dissect specific sensitization patterns among the 3 most important fungi: Aspergillus, Alternaria, and Cladosporium.

METHODS

This single-center study evaluated skin prick test (SPT) results of 3,358 patients with suspected airway allergies over a period of 20 years (1998-2017).

RESULTS

While 19.2% of all study patients had positive test results to at least 1 of the 3 fungi (Alternaria, Aspergillus, or Cladosporium) in the first study decade, this rate increased to 22.5% in the second decade. Slight increases in sensitization rates to almost all fungi were observed over the 20-year period. In the last decade, polysensitization to Alternaria, Aspergillus, and Cladosporium increased significantly. Sensitization to fungi is age-dependent and peaks in the age-group of 21-40 years during the second decade.

CONCLUSION

Fungi are relevant allergens for perennial and seasonal allergy symptoms. We currently recommend including Aspergillus, Alternaria, and Cladosporium in the standard series of SPTs for airway allergies.

A Real-Life One-Year Non-Interventional Study Assessing Safety, Tolerability, and Treatment Outcome of the SQ HDM SLIT-Tablet (Acarizax®) in House Dust Mite Allergic Rhinitis With or Without Asthma

Introduction

The aim of this study was to investigate the safety profile, tolerability, and outcome of the SQ^® house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet after 1 year of treatment in clinical practice among adults with HDM-related allergic rhinitis (AR) ± allergic asthma (AA).

Methods

In a non-interventional multicenter, observational study, patients were followed at 3 visits for 1 year. Adverse events (AE) were recorded at all visits. Patients graded their allergic symptoms as none, mild, moderate, or severe, and recorded AR and AA medication use. Asthma symptom control was assessed according to the Global Initiative for Asthma (GINA).

Results

One hundred and ninety-eight patients were included; 115 (58%) had AR without asthma and 83 (42%) had both AR and AA. One hundred and sixty-six (84%) patients completed the study. Eighty percent of patients experienced an AE: 151 (75%) AEs were mild, 42 (21%) moderate, and 4 (2%) severe. Three patients (1.5%) reported four events that were considered serious (SAEs). One SAE was considered possibly treatment-related. No anaphylactic reactions occurred. The proportion of patients experiencing allergy symptom reductions by at least one step were 75% (nasal), 62% (eye), 16% (skin), and 13% (other symptoms); 75% of patients with AA experienced a decrease of at least one step in bronchial symptoms. AR medication and inhaled corticosteroids were statistically significant reduced.

Conclusion

The SQ HDM SLIT-tablet was safe and well tolerated; the type, frequency, and severity of AEs resembled what RCTs have previously demonstrated. As explorative endpoints, statistically significant reductions in AR and AA symptoms and medication use were seen along with improved asthma control after 1 year of treatment, implying that clinically meaningful changes were seen after 1 year of treatment with the SQ HDM SLIT-tablet.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00150-z.

Advances and novel developments in allergic rhinitis

Allergic rhinitis (AR) is an upper airway disease with high prevalence in the world, and therefore needs to be thoroughly investigated and treated accordingly. Although the mechanisms underlying the pathology and treatment of AR have been widely studied, many aspects of AR are still unclear and warrant further investigations. The purpose of the present review was therefore to report recently published papers, which highlight the novel mechanisms and treatments of AR. These include role of environment, important proteins and cells, and some other factors in the pathogenesis of AR; as well as the role of immunotherapy and biologics in the treatment of AR.

Can we identify allergic rhinitis from administrative data: A validation study

BACKGROUND

Important insights on, for example, prevalence, disease progression, and treatment of allergic rhinitis can be obtained from large-scale database studies if researchers are able to identify allergic individuals. We aimed to assess the validity of 13 different algorithms based on Danish nationwide prescription and/or hospital data to identify adults with allergic rhinitis.

METHODS

Our primary gold standard of allergic rhinitis was a positive serum specific IgE (≥0.35) and self-reported nasal symptoms retrieved from two general health examination studies conducted in Danish adults (18-69 years) during 2006 to 2008 (n = 3416) and 2012 to 2015 (n = 7237). The secondary gold standard of allergic rhinitis was self-reported physician diagnosis. We calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value, and corresponding 95% confidence intervals (95% CI) for each register-based algorithm in the two time periods.

RESULTS

Sensitivity (≤0.40) was low for all algorithms irrespective of definition of allergic rhinitis (gold standard) or time period. The highest PPVs were obtained for algorithms requiring both antihistamines and intranasal corticosteroids; yielding a PPV of 0.69 (0.62-0.75) and a corresponding sensitivity of 0.10 (0.09-0.12) for the primary gold standard of allergic rhinitis in 2012 to 2015.

CONCLUSION

Algorithms based on both antihistamines and intranasal corticosteroids yielded the highest PPVs. However, the PPVs were still moderate and came at the expense of low sensitivity when applying the strict primary gold standard (sIgE and nasal symptom).

AllergoOncology: ultra-low IgE, a potential novel biomarker in cancer-a Position Paper of the European Academy of Allergy and Clinical Immunology (EAACI)

Elevated serum IgE levels are associated with allergic disorders, parasitosis and specific immunologic abnormalities. In addition, epidemiological and mechanistic evidence indicates an association between IgE-mediated immune surveillance and protection from tumour growth. Intriguingly, recent studies reveal a correlation between IgE deficiency and increased malignancy risk. This is the first review discussing IgE levels and links to pathological conditions, with special focus on the potential clinical significance of ultra-low serum IgE levels and risk of malignancy. In this Position Paper we discuss: (a) the utility of measuring total IgE levels in the management of allergies, parasitosis, and immunodeficiencies, (b) factors that may influence serum IgE levels, (c) IgE as a marker of different disorders, and d) the relationship between ultra-low IgE levels and malignancy susceptibility. While elevated serum IgE is generally associated with allergic/atopic conditions, very low or absent IgE may hamper anti-tumour surveillance, indicating the importance of a balanced IgE-mediated immune function. Ultra-low IgE may prove to be an unexpected biomarker for cancer risk. Nevertheless, given the early stage of investigations conducted mostly in patients with diseases that influence IgE levels, in-depth mechanistic studies and stratification of malignancy risk based on associated demographic, immunological and clinical co-factors are warranted.