Allergen Characteristics And Nasal Microflora Analysis Of Patients With Allergic Rhinitis In Zhangjiakou Area

Allergic Rhinitis(AR)is a common Allergic disease that often leads to bronchial asthma,allergic conjunctivitis,chronic rhinosinusitis,secretory otitis media,and other associated diseases.According to the epidemiological survey in recent years,the incidence of AR is increasing year by year.Research showed that the differences in geographical location,climatic environment and vegetation cover in different regions led to different types of allergens inducing AR.In addition,there is no report on AR epidemiology in Zhangjiakou.Therefore,the investigation of the allergen distribution characteristics of AR patients can provide a certain reference basis for the prevention and control of allergic rhinitis in this region.As the first portal of respiratory tract,the local resident flora of nasal cavity plays an important role in the maintenance of body health and the occurrence of disease.The "hygiene hypothesis" proposed that exposure to nasal pathogens may increase the body’s tolerance,further increasing the chance of allergic diseases.In recent years,the relationship between the composition of nasal flora and allergic rhinitis has also received close attention.Therefore,by studying the composition of nasal flora in patients with allergic rhinitis,the relationship between the composition of nasal flora in patients with AR and allergic rhinitis is further explored,so as to provide a new strategy for the prevention and treatment of allergic rhinitis in Zhangjiakou aera.Serum specific Ig E antibody of nine common inhaled allergen was detected in 532 suspected AR patients in the Department of Otolaryngology,Head and Neck Surgery of the First Affiliated Hospital of Hebei North University form April 2019 to August 2020.Allergic rhinitis was diagnosed when one allergen was positive(case group).A total of 245 family members of outpatients and inpatients in our hospital during the same period,excluding family members of respiratory department,dermatology department and otolaryngology department were selected as the case control group.All the subjects were investigated by self-made “Questionnaire on Factors Related to Allergic Rhinitis in Zhangjiakou”,and the data were collected and statistically analyzed.Five AR patients with typical clinical symptoms and in the clinical onset stage(AR group)were selected,and five corresponding healthy volunteers(HC group)with similar age,gender,and living area were selected.The nasal secretions of the subjects were collected respectively for 16 S rDNA high-throughput sequencing.Bioinformatics and medical statistics were used to analyze the differences of nasal microflora composition between AR patients and healthy individual.388 of the 532 suspected AR patients were positive for at least one allergen and were diagnosed with AR.The positive rate of 72.93%.The top three inhaled allergens were mugwort(89.95%),common ragweed(44.07%),and cat epithelium(21.39%).There were 136 cases of single allergens positive(35.05%),122 cases of double allergen positive(31.44%),65 cases of triple allergens positive(16.75%),34 cases of quadruple allergens positive(8.76%)and 31 cases of five-fold or above allergens positive(7.99%),among which the single and double allergens positive patients was the most.In the patients with AR,male patients accounted for 54.12%,female patients accounted for 45.88%,and there was significant difference between them(P<0.05).The positive rates of common ragweed,cat epithelium,house dust and alternaria in male patients were higher than those in female patients,and the positive rate of house dust mite was lower than that in female patients,with statistical significance(P<0.05).According to age,subject were divided into five groups: 3～14 years old,15～24 years old,25～34 years old,35～44 years old,and >44 years old.The difference of allergen total positive rate in different age groups was statistically significant(P<0.05).The total positive rate of inhaled allergens was the highest in the 3-14 years group,and the total positive rate decreased gradually with the increase of age.The positive rates of mugwort,common ragweed,cat epithelium,house dust,house dust mite and Alternaria were significantly different in different age groups(P<0.05).According to its unique geographical location,zhangjiakou region can be divided into barupper region and bar-low region and the positive detection rates of mugwort,common ragweed and cat epithelium were statistically significant between them(P<0.05).The peak number of AR patients was concentrated in July to September,among which August had the largest number of visits.Multivariate logistic regression analysis showed that previous allergic,parents with AR,history of asthma,secondhand smoke exposure,staying up late,age 3-24 years old were the high risk factors for allergic rhinitis(OR>1),regular physical exercise was an effective protective factor for allergic rhinitis(OR<1).According to 16 S rDNA high-throughput sequencing analysis,there are certain differences in the nasal microbiota between of patients with allergic rhinitis and healthy controls,and the relative abundance at the multimicrobial level is also different.At phylum level,the relative abundance of Firmicutes in nasal flora in AR group was lower than that in HC group,while the Actinobacteria and Proteobacteria was higher than that in HC group.At the level of genus,two genera were found to have significant differential abundances between them.The main inhalation allergens in Zhangjiakou area are mugwort and common ragweed.The distribution of allergens is correlated with the month,region,gender and age of the patients.Previous allergies,history of asthma,parents having allergic rhinitis,staying up late and so on are risk factors for allergic rhinitis.The flora composition of nasal of AR patients is significantly different form that of healthy individual.