The genes and the environment in nasal allergy

Two-stage association study of mitochondrial DNA variants in allergic rhinitis

BACKGROUND

Correlations between mitochondrial DNA (mtDNA) and allergic rhinitis (AR) have not been reported before. This study aimed to better understand the mitochondrial genome profile with AR and to investigate the associations between AR in China and the mitochondrial genome at a single variant and gene level.

METHODS

Mitochondrial sequencing was conducted on a total of 134 unrelated individual subjects (68 patients with AR, 66 healthy controls) at discovery stage. Heteroplasmy was analyzed using the Mann-Whitney U test. Sequence kernel association tests (SKAT) were conducted to study the association between mitochondrial genes and AR. Single-variant analysis was performed using logistic regression analysis and further validated in 120 subjects (69 patients with AR, 51 healthy controls). Candidate genes were further explored based on differences in mRNA and protein abundance in nasal mucosal tissue.

RESULTS

In the discovery stage, 886 variants, including 836 SNV and 50 indels, were identified with mitochondrial sequencing. No statistically significant differences were identified for the mitochondrial heteroplasmy or SKAT analysis between these two groups after applying a Boferroni correction. One nonsynonymous variants, rs3135028 (MT8584.G/A) in ATP6, was related to a reduced risk of AR in both the discovery and validation cohorts. Furthermore, mRNA levels of MT-ATP6 in nasal mucosal tissue were significantly lower in AR individuals than in controls (P < 0.05).

CONCLUSIONS

In a two-stage analysis of associations between AR and mtDNA variations, mitochondrial gene maps of Chinese patients with AR indicated that the ATP6 gene was probably associated with AR at the single-variant level.

Self-Reported Allergic Rhinitis Prevalence and Risk Factors in Employees of the China National Railway

BACKGROUND: Allergic rhinitis (AR) is a common allergic disease globally and its prevalence is increasing year by year. This study aimed to analyze the prevalence and risk factors of self-reported AR among the Chinese National Railway train crew in the China Railway Beijing Group.METHODS: This prospective questionnaire study surveyed 1511 randomly recruited train crewmembers from 20 cities in the China National Railway network, and 494 reported having AR. A structured questionnaire was tailored, designed, and delivered electronically to all subjects. Prevalence of and risk factors for AR were analyzed based on self-reported results.RESULTS: The prevalence of self-reported AR among train crewmembers was 32.6%. Among respondents, 86.03% worked in passenger cars and 64.6% reported having worse AR symptoms while on trains. AR frequencies were 40.15% perennially and 59.85% seasonally. Among the Total Nasal Symptoms Scores (TNSS), significant differences were found between rhinorrhea and sneezing and between nasal itching and sneezing. The Rhino-Conjunctivitis Quality of Life Questionnaire (RQLQ) showed significant correlations between all seven sections. TNSS was significantly associated with the RQLQ. Scores of both the TNSS and RQLQ showed that the severity of AR symptoms (rp = 0.103) and the impact on quality of life (rp = 0.113) correlated significantly with seniority.CONCLUSIONS: The prevalence of self-reported AR among train crew working in passenger cars is higher than that of the general Chinese population. The severity of AR symptoms and the impact on quality of life are associated with seniority, meaning the number of years working on trains.Yu R-L, Ning H-Y, Lan T-F, He H, Zheng C-B, Wang X-Y, Wang H-T, Wang X-Y. Self-reported allergic rhinitis prevalence and risk factors in employees of the China National Railway. Aerosp Med Hum Perform. 2023; 94(11):821-826.

Ten-eleven translocation 2 modulates allergic inflammation by 5-hydroxymethylcytosine remodeling of immunologic pathways

Allergic rhinitis (AR) is an allergen specific IgE-mediated inflammatory disease. Both genetic and environmental factors could play a role in the pathophysiology of AR. 5-methylcytosine (5-mC) can be converted to 5-hydroxymethylcytosine (5hmC) by the Ten-Eleven Translocation (TET) family of proteins as part of active DNA de-methylation pathway. 5hmC plays an important role in regulation of gene expression and differentiation in immune cells. Here we show that loss of ten-eleven translocation protein 2 (Tet2) could impact the severity of AR in the ovalbumin-induced mouse model. Genome-wide 5hmC profiling of both wildtype and Tet2 KO mice in response to AR revealed that the loss of Tet2 could lead to 5hmC alteration at specific immune response genes. Both partial loss and complete loss of Tet2 alters the 5hmC dynamic remodeling for the adaptive immune pathway, as well as cytokines. Thus, our results reveal a new role of Tet2 in immunology, and Tet2 may serve as a promising target in regulating the level of immune response.

Self-Reported Allergic Rhinitis Prevalence and Related Factors in Civil Aviation Aircrew of China

INTRODUCTION: Allergic rhinitis (AR) is a global health problem with gradually increasing prevalence. No large-scale, systematic, and comprehensive study on AR among civil aviation aircrew of China has been reported. We aimed to demonstrate the prevalence of and risk factors for self-reported AR among Chinese civil aviation aircrew.METHODS: This study randomly surveyed 4059 civil aviation aircrew members from 12 cities in mainland China. A structured questionnaire was tailored, designed, and electronically delivered to all participants. Based on self-reported results, prevalence of and risk factors for AR were calculated/analyzed.RESULTS: The prevalence of self-reported AR was 23.38%. Among aircrew members, 10.37% presented with ear barotraumas, whereas 9.95% reported symptom aggravation during flight. Of aircrew members, 10.32% had symptoms related to flight duration, whereas 4.43% of symptoms related to flight altitude. Significant differences between rhinorrhea and sneezing, as well as between nasal itching and sneezing, were observed in the Total Nasal Symptoms Scores (TNSS). The Rhino-conjunctivitis Quality of Life Questionnaire (RQLQ) showed significant correlation between each section. TNSS was significantly related to RQLQ. Both TNSS and RQLQ significantly correlated with flight time.CONCLUSIONS: The prevalence of self-reported AR among civil aviation aircrew is higher than the general population in China. The severity of nasal symptoms and complications are significantly associated with quality of life and flying duties.Bai Y, Hu M, Ma F, Liu K, Xu H, Wu X, Wang H. Self-reported allergic rhinitis prevalence and related factors in civil aviation aircrew of China. Aerosp Med Hum Perform. 2021; 92(1):2531.

Respiratory diseases and allergy in farmers working with livestock: a EAACI position paper

Farmers constitute a large professional group worldwide. In developed countries farms tend to become larger, with a concentration of farm operations. Animal farming has been associated with negative respiratory effects such as work-related asthma and rhinitis. However, being born and raised or working on a farm reduces the risk of atopic asthma and rhinitis later in life. A risk of chronic bronchitis and bronchial obstruction/COPD has been reported in confinement buildings and livestock farmers. This position paper reviews the literature linking exposure information to intensive animal farming and the risk of work-related respiratory diseases and focuses on prevention. Animal farming is associated with exposure to organic dust containing allergens and microbial matter including alive microorganisms and viruses, endotoxins and other factors like irritant gases such as ammonia and disinfectants. These exposures have been identified as specific agents/risk factors of asthma, rhinitis, chronic bronchitis, COPD and reduced FEV₁. Published studies on dust and endotoxin exposure in livestock farmers do not show a downward trend in exposure over the last 30 years, suggesting that the workforce in these industries is still overexposed and at risk of developing respiratory disease. In cases of occupational asthma and rhinitis, avoidance of further exposure to causal agents is recommended, but it may not be obtainable in agriculture, mainly due to socio-economic considerations. Hence, there is an urgent need for focus on farming exposure in order to protect farmers and others at work in these and related industries from developing respiratory diseases and allergy.

Allergen sensitization pattern of allergic adults and children in southern China: a survey based on real life data

Background

Allergic diseases are increasing yearly. We aimed to evaluate the difference in allergen sensitization pattern between adults and children in southern China by analyzing a large sample size of real-life data, and to provide the evidence for formulating the prevention and management strategies.

Methods

Retrospective analysis was conducted on 39,813 serum allergen-specific IgE (sIgE) results collected in southern China from January to December in 2017. Sensitization patterns and how these allergens could lead to the allergic diseases were analyzed for adults and children respectively. The difference of allergen positive rate between groups was calculated using the Chi square test.

Results

The top five most sensitized allergens in southern China were house dust mite (28.1%), cockroach (24.3%), shrimp (19.2%), crab (15.5%) and egg white (9.9%). While cockroach had the highest positive rate in adults (29.2%), the most sensitized allergen in children was house dust mite (29.7%). The positive rates of egg white and cow’s milk in children were higher than in adults for the whole year (p < 0.001); whereas for adults, the positive rate to cockroach, shrimp and crab were higher than in children (p < 0.001). The positive rate of house dust mite in coastal cities (32.4%) was higher than that in landlocked cities (24.0%) in children, but in adults, the rate in landlocked cities (31.1%) was higher than that in coastal cities (25.3%). Optimal scaling analysis showed that the sIgEs of crab and shrimp had the closest correlation with cockroach-sIgE (Cronbach’s α = 0.891). The positive rate to mold allergens increased from summer to autumn, reaching its plateau in October (6.2%). Patients with skin diseases were found to receive the highest sIgE prescription from doctors (56.9%).

Conclusions

Doctors tend to prescribe more sIgE tests for patients with skin disorders in southern China. In addition to house dust mite, cockroach was found to be another important allergen. Adults with multiple sensitization always showed co-sensitization with shrimp, crab and house dust mite. These should be taken into consideration when giving allergen avoidance advice to patients.

Electronic supplementary material

The online version of this article (10.1186/s13223-019-0357-y) contains supplementary material, which is available to authorized users.

Burnt sugarcane harvesting is associated with rhinitis symptoms and inflammatory markers

INTRODUCTION

Burnt sugarcane harvesting requires intense physical exertion in an environment of high temperature and exposure to particulate matter.

OBJECTIVE

To evaluate the effects of burnt sugarcane harvesting on rhinitis symptoms and inflammatory markers in sugarcane workers.

METHODS

A total of 32 male sugarcane workers were evaluated with questionnaire for rhinitis symptoms, and for inflammatory markers on peripheral blood and nasal lavage, in the non-harvesting, and 3 and 6 months into the sugarcane harvesting period. Weather data and particulate matter fine concentrations were measured in the same day.

RESULTS

The particulate matter concentrations in sugarcane harvesting were 27 (23-33μg/m3), 112 (96-122μg/m3), and 63 (17-263μg/m3); 24h temperatures were 32.6 (25.4-37.4°C), 32.3 (26.7-36.7°C) and 29.7 (24.1-34.0°C) and relative humidities were 45.4 (35.0-59.7%), 47.9 (39.1-63.0%), and 59.9 (34.7-63.2%) in the non-harvesting period, three and 6 months of the harvesting period. The age was 37.4±10.9 years. The prevalence of rhinitis symptoms was significantly higher at 3 months of the harvesting period (53.4%), compared to non-harvesting period (26.7%; p=0.039) and at 6 months into the harvesting period (20%; p=0.006). Concentrations of interleukin 6 (IL-6) in nasal lavage increased after 3 months of the harvesting period compared to the non-harvesting period (p=0.012). The presence of rhinitis symptoms, after 3 months of the harvesting period, was directly associated with blood eosinophils and inversely associated with neutrophils.

CONCLUSIONS

After 3 months of work in burnt sugarcane harvesting the prevalence of rhinitis symptoms and IL-6 in nasal lavage increased. Furthermore, eosinophil counts were directly associated with the rhinitis symptoms in the period of higher concentration of particulate matter.

A clear urban-rural gradient of allergic rhinitis in a population-based study in Northern Europe

BACKGROUND

The protective effect of farm upbringing on allergic rhinitis is well known, but how upbringing in other environments influences the development of allergic rhinitis is scarcely investigated. The aim of this study was to investigate the association between place of upbringing and pet keeping in childhood and allergic rhinitis and nasal symptoms in adulthood.

METHODS

The population-based Respiratory Health in Northern Europe study includes subjects from Denmark, Norway, Sweden, Iceland, and Estonia born in 1945-1973. This paper analyses 13,376 participants of the third study wave. Six categories of place of upbringing were defined: farm with livestock, farm without livestock, village in rural area, small town, city suburb, and inner city. Pets in the home at birth and during childhood were recorded. Data were analysed using adjusted logistic regression models.

RESULTS

Livestock farm upbringing predicted less adult allergic rhinitis [odds ratio (OR) 0.68, 0.54-0.85] and nasal symptoms (OR 0.82, 0.68-0.99) than city upbringing, and an urban-rural gradient with decreasing risk per level of urbanisation was observed (OR 0.92, 0.88-0.94). Pets in the home at birth (OR 0.78, 0.68-0.88) and during childhood (OR 0.83, 0.74-0.93) were associated with less subsequent allergic rhinitis. Pet keeping did not explain the protective effect of place of upbringing.

CONCLUSION

Risk of allergic rhinitis and nasal symptoms in adulthood was inversely associated with the level of urbanisation during upbringing. Pets at birth decreased the risk further, but did not explain the urban-rural gradient. Persistent beneficial effects of microbial diversity in early life might be an explanation for the findings.