Household pet exposure, allergic sensitization, and rhinitis in the U.S. population

V Brazilian Consensus on Rhinitis - 2024

Since we published the "IV Brazilian Consensus on Rhinitis", in2017, several advances have been achieved and have enabled a further understanding of the different aspects of "Rhinitis". This new guideline, developed jointly by ASBAI, SBP and SBORL, represents a relevant milestone in the updated and integrated management of the different forms of the disease, and it aims to unify evidence-based approaches to improve the diagnosis and treatment of this common and often underestimated condition. The document covers a wide range of topics, including clear definitions of the different phenotypes and endotypes of rhinitis, risk factors, updated diagnostic criteria, and recommended methods for clinical and laboratory investigation. We stress the importance of detailed clinical history and objective assessment, as well as tools for control and assessing severity tools an accurate diagnostic approach to the disease. Regarding treatment, it emphasizes the treatment customization, considering the severity of symptoms, the presence of comorbidities and the impact on the patient's quality of life. We discuss different drug treatment, in addition to non-pharmacological measures, such as environmental control and specific immunotherapy; and the possible role of immunobiological agents. Furthermore, the consensus addresses issues related to patient education, prevention and management of special situations, such as rhinitis in children, in pregnant women and in the elderly. In short, the "V Brazilian Consensus on Rhinitis" represents a comprehensive and updated guide for healthcare professionals involved in the diagnosis and management of rhinitis, aiming to improve patients' quality of life through an integrated and evidence-based approach.

Changes in Prevalence of IgE Sensitization and Allergenic Exposition over a 10-Year Period in a Tropical Region

INTRODUCTION

Multiple antigen environmental sources have been identified as possible causes of allergies, but few studies have evaluated changes in the sensitization profiles over time. The aim of this study was to evaluate the changes in IgE sensitization and exposure to dust mites, cats, dogs, and cockroaches over a 10-year period.

METHODS

During a period of 10 years among patients with asthma, rhinitis and/or atopic dermatitis, we evaluated the annual frequency of atopy to Dermatophagoides farinae, Dermatophagoides pteronyssinus, Blomia tropicalis, Canis familiaris, Felis domesticus and cockroaches (Periplaneta americana and Blatella germanica). Exposure to sources was also assessed using questionnaires (Pets) or direct counts (House dust mites and cockroaches). The association between some risk factors and the prevalence of atopy was explored.

RESULTS

A total of 6,000 records were included. Among the patients, 82% had IgE sensitization to at least one of the six allergenic sources. Sensitization to Dermatophagoides spp. was the most frequent (>78%). Exposure and sensitization in the first decade of life to Dermatophagoides spp. seem to determine the molecular spreading to other allergenic sources. Exposure to Blomia tropical increases significantly over time (year 2015; 38% vs. year 2022; 51%, p 0.03). Exposure to dogs was higher than with cats but association between atopy and exposure was stronger with cats (OR 27.4, 95% CI: 22.3-33.6, p < 0.01).

CONCLUSION

Exposure and sensitization in the first decade of life to Dermatophagoides spp. determine the molecular spreading of IgE antibodies to other allergenic sources. Household exposure to dogs and cats seems to be important for the subsequent development of atopy. Sensitization to B. tropicalis and cockroach appears to be mostly from cross-reactivity rather than direct exposure.

m6A mRNA methylation-mediated MAPK signaling modulates the nasal mucosa inflammatory response in allergic rhinitis

Background

Allergic rhinitis (AR) is a complex disease in which gene-environment interactions contribute to its pathogenesis. Epigenetic modifications, such as N6-methyladenosine (m6A) modification of mRNA, play important roles in regulating gene expression in multiple physiological and pathological processes. However, the function of m6A modification in AR and the inflammatory response is poorly understood.

Methods

We used the ovalbumin (OVA) and aluminum hydroxide to induce an AR mouse model. Nasal symptoms, histopathology, and serum cytokines were examined. We performed combined m6A and RNA sequencing to analyze changes in m6A modification profiles. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and methylated RNA immunoprecipitation sequencing qPCR (MeRIP-qPCR) were used to verify differential methylation of mRNAs and the m6A methylation level. Knockdown or inhibition of Alkbh5 in nasal mucosa of mice was mediated by lentiviral infection or IOX1 treatment.

Results

We showed that m6A was enriched in a group of genes involved in MAPK signaling pathway. Moreover, we identified a MAPK pathway involving Map3k8, Erk2, and Nfκb1 that may play a role in the disrupted inflammatory response associated with nasal inflammation. The m6A eraser, Alkbh5, was highly expressed in the nasal mucosa of AR model mice. Furthermore, knockdown of Alkbh5 expression by lentiviral infection resulted in high MAPK pathway activity and a significant nasal mucosa inflammatory response. Our findings indicate that ALKBH5-mediated m6A dysregulation likely contributes to a nasal inflammatory response via the MAPK pathway.

Conclusion

Together, our data show that m6A dysregulation mediated by ALKBH5, is likely to contribute to inflammation of the nasal mucosa via the MAPK signaling pathway, suggesting that ALKBH5 is a potential biomarker for AR treatment.

Exposure to household dust, allergens, and endotoxin and allergy-related outcomes alternation in the general U.S. population

It has been widely reported that the general population was at an increased risk of allergy diseases, which probably be related with household allergens exposure. However, the difference of local and systemic allergic reactions exposure to allergens has not been reported in the general population previously. The data of 1094 U.S. adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 data bank were analyzed. Dust, allergens (Bia g 1, Bia g 2, Can f 1, Feld 1, Derp 1, Mus m 1, Rat n 1, Alternaria alternate, and Aspergillus fumigatus), and endotoxin, were measured to estimate sensitizing source exposure. And allergy-related outcomes indicators including hay fever, sneezing, allergic rhinitis (AR), immunoglobulin E (IgE), and allergic sensitization, were evaluzted to estimate local and systemic allergic reactions. Multiple linear regression and logistic regression models were used to examine the associations of sensitizer and allergy-related outcomes. The mean or median concentration of dust and endotoxin were 0.66 g and 12.98 EU/mg dust. The Derp 1, Mus m 1, Rat n 1, Alternaria alternate, and Aspergillus fumigatus were the main allergens in the dust, with the concentrations of 30.66 ng/g dust, 30.73 ng/g dust, 5.94 ng/g dust, 5.20 ng/g dust, and 207.68 μg/g dust, respectively. The prevalence of AR was 34.2% among the general population. After controlling for sociodemographic factors, we found that the allergens, such as Can f 1 and Feld 1, were positively associated with AR. The prevalence of allergic sensitization was about 20%. Dust and endotoxin were found positively associated with allergic sensitization, while Bia g 2, Rat n 1, Alternaria alternate, and Aspergillus fumigatus were inversely associated with that. Dust and endotoxin probably be associated with higher risk of local allergic reactions, while some allergens, such as Bia g 2, Rat n 1, Alternaria alternate, and Aspergillus fumigatus probably be associated with lower risk of systemic allergic reactions.

Shukri N, Wong KK, Mohd Ashari NS. Zonula occludens-1 expression is reduced in nasal epithelial cells of allergic rhinitis patients

Allergic rhinitis (AR) is a common allergic disease characterized by disruption of nasal epithelial barrier. In this study, we investigated the mRNA expression of zonula occludens-1 (ZO-1), ZO-2 and ZO-3 and histone deacetylase 1 (HDAC1) and HDAC2 in AR patients compared to healthy controls. RNA samples were extracted from nasal epithelial cells of house dust mites (HDMs)-sensitized AR patients and healthy controls (n = 28 in each group). The RNAs were reverse transcribed into cDNAs for measurement of ZO-1, ZO-2, ZO-3, HDAC1 and HDAC2 expression levels by quantitative PCR. The mRNA expression of ZO-1 was significantly decreased in AR patients compared to healthy controls (p = 0.010). No significant difference was observed in the expression levels of ZO-2, ZO-3, HDAC1 and HDAC2 in AR patients compared to healthy controls. We found significant associations of higher HDAC2 levels in AR patients with lower frequency of changing bedsheet (p = 0.043) and with AR patients sensitized to Dermatophagoides farinae (p = 0.041). Higher expression of ZO-2 was observed in AR patients who had pets (p = 0.007). In conclusion, our data indicated that ZO-1 expression was lower in AR patients contributing to decreased integrity of nasal epithelial barrier integrity, and HDAC2 may be involved in the pathogenesis of the disease.

Increase in Indoor Inhalant Allergen Sensitivity During the COVID-19 Pandemic in South China: A Cross-Sectional Study from 2017 to 2020

Purpose

Public health measures during COVID-19 have led to an unprecedented change in social lifestyle which might have an impact on the allergen sensitization in population. We sought to explore the prevalence patterns of serum inhalant and food allergen-specific IgE (sIgE) sensitization and serum total immunoglobulin E (tIgE) level among patients with clinical symptoms of suspected allergic diseases before and during the COVID-19 pandemic in south China.

Patients and Methods

A large epidemiology study was conducted on the prevalence patterns of sIgE sensitization and serum tIgE level among 13,715 patients with allergic symptoms in south China from 2017 to 2020. Chi-square test and Fisher exact test were used to test statistical significance of allergen sensitization difference among years. Logistic regression was performed to assess the magnitudes of the differences among years by adjusted odds ratios and 95% confidence intervals.

Results

The number of hospital visits for patients with suspected allergy symptoms decreased during COVID-19. The positive rates of indoor inhalant allergens (house dust mites, German cockroach, dog dander) and tIgE increased significantly in 2020, while no significant differences were found in food allergens (egg white, milk, soya bean, shrimp) before and during the COVID-19 pandemic. The odds of sIgE positives in indoor inhalant allergens and tIgE positive for 2017 and 2020 were all larger than 1.00. After grouping by age and gender, there were significant differences in the positive rates of indoor inhalant allergens and tIgE when comparing 2020 with 2017.

Conclusion

The prevalence of sensitization increased significantly to indoor inhalant allergens but not to food allergens in south China during the COVID-19 pandemic.

The Role of Environmental Risk Factors on the Development of Childhood Allergic Rhinitis

Environmental factors play an important role in the development and exacerbation of allergic rhinitis (AR) in childhood. Indoor air pollution, such as house dust mites and secondhand smoke, can significantly increase the onset of AR, while pet dander may affect the exacerbation of AR symptoms in children. Furthermore, traffic related air pollution and pollen are outdoor air pollutants that can affect immune competency and airway responsiveness, increasing the risk of AR in children. Climate change has increased AR in children, as growth patterns of allergenic species have changed, resulting in longer pollen seasons. More extreme and frequent weather events also contribute to the deterioration of indoor air quality due to climate change. Additionally, viruses provoke respiratory tract infections, worsening the symptoms of AR, while viral infections alter the immune system. Although viruses and pollution influence development and exacerbation of AR, a variety of treatment and prevention options are available for AR patients. The protective influence of vegetation (greenness) is heavily associated with air pollution mitigation, relieving AR exacerbations, while the use of air filters can reduce allergic triggers. Oral antihistamines and intranasal corticosteroids are common pharmacotherapy for AR symptoms. In this review, we discuss the environmental risk factors for AR and summarize treatment strategies for preventing and managing AR in children.

Factors related to disagreement between self-reported versus objective measurement of allergen sensitization at a tertiary pediatric center in Beijing, China

BACKGROUND

The objectives of present study were to examine the level of disagreement between self-reported and objective measurement of sensitization to common inhalant allergens, and to explore the potential risk factors that might contribute to this discrepancy.

METHODS

A total of 215 children were enrolled from pediatric clinics at a tertiary pediatric center in Beijing, China. A survey questionnaires regarding self-perceived sensitization was completed by participants' parents/caregiver, meanwhile, skin prick testing(SPT) was performed as objective assessment of sensitization. Extent of agreement between self-reported versus SPT-measured sensitization to individual allergen was calculated using Cohen's kappa (κ) coefficient. Multivariable regression analyses were used to determine the factors associated with discrepancy between self-reported and objective measurement of sensitization.

RESULTS

119(55.3%) patients have reported to be sensitized to at least one of inhalant allergen, whereas 167(77.7%) patients had a positive skin testing response. Agreement between self-perceived and actual aeroallergen sensitization was moderate for mites(κ = 0.518) and grass pollen mix(κ = 0.451), moreover, fair agreement was observed for mold(κ = 0.316) and cockroach(κ = 0.297), respectively. There was a least agreement between perceived and actual sensitization observed for pet dander, with a kappa coefficient of 0.005. Subjects' age, atopy history, ownership of pet may increase the risk of disagreement, moreover, background factors of informant, like: age, education level, and the relationship with enrolled subjects, were linked to the incidence of disagreement between self-reported sensitization in comparison with SPT results.

CONCLUSION

Questionnaire-based self-assessment is easy way to collect clinical information on allergen sensitization; however, the accuracy of questionnaire-derived information is more likely to be influenced by respondent's background factors. The information from the questionnaire report is considered to be more reliable when in combination with objective assessment of sensitization, including blood IgE testing and SPT.

Atopic Patients Who Fulfilled Rome III Criteria for Irritable Bowel Syndrome Had Higher Animal Danders Sensitization

Background/Aims

The relationship between animal exposure and irritable bowel syndrome (IBS) is debated. Epidemiological studies have shown that atopy is more prevalent in IBS patients and vice versa. We set out to examine the association between animal danders sensitization and IBS-like symptoms in atopic patients.

Methods

We recruited 69 consecutive atopic patients from the allergy clinic of a tertiary hospital. Subjects completed validated bowel questionnaires, underwent skin prick test, blood was collected for serum total immunoglobulin E, and ImmunoCAP immune solid-phase allergen chip (ISAC) IgE multiplex assay.

Results

Twenty-eight (41.0%) atopic patients fulfilled the Rome III IBS criteria (atopy-IBS). There were no differences in gender, age, pet ownership, total serum IgE, or food allergen sensitization between atopy-IBS group and atopy-non-IBS group. We found that atopy-IBS group had significantly higher number of positive skin prick test for cat dander (64.3% vs 24.4%, P < 0.001), dog dander (64.3% vs 41.5%, P = 0.015) and weed pollens (32.1% vs 14.6%, P = 0.050) compared to atopy-non-IBS group. Out of 112 components from 51 allergen sources (both aeroallergen and food allergens), only Fel d1 (a major cat dander antigen) IgE is significantly higher in atopy-IBS group than atopy-non-IBS group (21.4% vs 2.4%, P = 0.029). Majority of atopy-IBS patients had mixed-type IBS.

Conclusions

We demonstrated an association between animal danders sensitization, in particular cat dander sensitization, and IBS-like symptoms in atopic patients. Future studies are needed to explore the relationship between aeroallergen and functional gastrointestinal disorders. Sensitization may be related to the pathophysiology of IBS or it could be that we are missing aeroallergen-induced gut allergy.

Nasal Provocation Test with Cat and Dog Extracts: Results according to Molecular Components

Background

IgE sensitization (atopy) to pets is commonly evaluated using pet dander extracts. However, the diagnosis by components seems to be more adequate to evaluate the clinical relevance (allergy) of sIgE sensitization.

Objective

To study the association between IgE sensitization to pet allergen components and clinical symptoms. Methodology. Dander extracts and sIgE levels to pet components (Can f 1, Can f 2, Can f 3, Can f 5, Fel d 1, Fel 2, and Fel 4) were measured in a rhinitis group (n = 101) and a control group (n = 101) and a control group (.

Results

Dog (34.6% vs. 23.5%) and cat dander (26.7% vs. 8.8%, p = 0.05) IgE sensitization was frequent among rhinitis and no-rhinitis subjects, and it was similar to dog (29.7% vs. 20.5%) and cat (18.8% vs. 8.8%) components. Polysensitization for dog (3.1, 95% CI: 1.5 to 6.1, p = 0.05) IgE sensitization was frequent among rhinitis and no-rhinitis subjects, and it was similar to dog (29.7% vs. 20.5%) and cat (18.8% vs. 8.8%) components. Polysensitization for dog (3.1, 95% CI: 1.5 to 6.1, p = 0.05) IgE sensitization was frequent among rhinitis and no-rhinitis subjects, and it was similar to dog (29.7% vs. 20.5%) and cat (18.8% vs. 8.8%) components. Polysensitization for dog (3.1, 95% CI: 1.5 to 6.1.

Conclusions

Sensitization to pet dander extract identifies atopic patients, but its utility to predict clinical relevance is poor. Allergenic components could help to define the clinical relevance of sensitization to furry animals and could reduce the need for provocation test.

Sampling Devices for Indoor Allergen Exposure: Pros and Cons

PURPOSE OF REVIEW

To review current indoor allergen sampling devices, including devices to measure allergen in reservoir and airborne dust, and personal sampling devices, with attention to sampling rationale and major indoor allergen size and characteristics.

RECENT FINDINGS

While reservoir dust vacuuming samples and airborne dust volumetric air sampling remain popular techniques, recent literature describes sampling using furnace filters and ion-charging devices, both which help to eliminate the need for trained staff; however, variable correlation with reservoir dust and volumetric air sampling has been described. Personal sampling devices include intra-nasal samples and personal volumetric air samples. While these devices may offer better estimates of breathable allergens, they are worn for short periods of time and can be cumbersome. Reservoir dust sampling is inexpensive and is possible for families to perform. Airborne dust sampling can be more expensive and may better quantify cat, dog, and mouse allergen exposure. Personal sampling devices may offer a better representation of breathable air.

Bedroom Allergen Exposure Beyond House Dust Mites

PURPOSE OF REVIEW

The review provides insight into recent findings on bedroom allergen exposures, primarily focusing on pet, pest, and fungal exposures.

RECENT FINDINGS

Large-scale studies and improved exposure assessment technologies, including measurement of airborne allergens and of multiple allergens simultaneously, have extended our understanding of indoor allergen exposures and their impact on allergic disease. Practical, streamlined methods for exposure reduction have shown promise in some settings, and potential protective effects of early-life exposures have been further elucidated through the investigation of specific bacterial taxa. Advances in molecular allergology have yielded novel data on sensitization profiles and cross-reactivity. The role of indoor allergen exposures in allergic disease is complex and remains incompletely understood. Advancing our knowledge of various co-exposures, including the environmental and host microbiome, that interact with allergens in early life will be crucial for the development of efficacious interventions to reduce the substantial economic and social burden of allergic diseases including asthma.