Investigation On Pollen Allergen Sensitization In Children With Respiratory Allergic Diseases From Multiple Centers In Western China And Analysis Of Pollen Allergen Components

Section Ⅰ Investigation on pollen allergen sensitization in children with respiratory allergic diseases from multiple centers in western ChinaObjective:To investigate the pollen allergen sensitization in children with respiratory allergic diseases in western China and provide the basis for preventing and treating respiratory allergic diseases.Methods:A total of 663 children with allergic rhinitis and/or asthma from Lanzhou,Yinchuan,Xi’an and Kunming were investigated by skin prick test and allergy questionnaire.Results:The positive rate of mugwort(49.5%)was the highest,followed by goosefoots(33.2%),ragweed(33.0%),white poplar(31.1%)and elm(30.0%).Mugwort were the most common pollen allergens in patients with allergic rhinitis/allergic asthma/allergic rhinitis and asthma.The positive rates of ragweed,mugwort,timothy grass,London plane tree and common reed in allergic rhinitis combined with asthma group were significantly higher than those in allergic rhinitis group and allergic rhinitis group(all P<0.05).SPT positive rates in>6～12 years old group and>12 years old group were significantly higher than that in≤6 years old group,and the positive rates of silver birch,timothy grass,wheat,elm and London plane tree increased significantly with age(all P<0.05).SPT positive rates of pollen allergen mostly reached the peak in spring and autumn,and the positive rate of mugwort was the highest in each season.In addition,SPT positive rates of pollen allergen in Xi’an were generally lower than those in the other three regions.Six pollen allergens(mugwort,white poplar,bermuda grass,silver birch,London plane tree and timothy grass)allowed identifcation>95%of pollen-sensitized subjects in western China.Conclusions:Mugwort is the most important pollen allergen causing respiratory allergic diseases in multi-center children in western China.The distribution of pollen allergens varied in different regions,seasons,ages and diseases.Children with respiratory allergic diseases should regularly detect allergens and pay attention to avoid them.Section Ⅱ Major grass pollen allergen components and CCD detection in children sensitized to mugwort in western ChinaObjective:Mugwort is a common pollen allergen.This study aimed to investigate the molecular sensitization patterns to major grass pollen allergens(mugwort,ragweed,bermuda grass and timothy grass)and cross-reactive carbohydrate determinants(CCD)in children sensitized to mugwort in western China.Methods:Serum specific Ig E(sIgE)of mugwort were detected in 121 mugwort SPT-positive children with respiratory allergic disease in western China via EUROBlot Master system.If the mugwort-sIgE were positive,sIgE of mugwort allergen components(Art v 1,Art v 3 and Art v 4),ragweed and allergen components(Amb a 1),bermuda grass and allergen components(Cyn d 1 and Cyn d 12),timothy grass and allergen components(Phl p 1,Phl p 4,Phl p 5,Phl p 7 and Phl p 12),and CCD were tested.CCD inhibition test was further performed on serum of patients with positive CCD-sIgE.Results:In the 121 mugwort SPT-positive patients,100 patients were mugwort sIgE-positive.In mugwort sIgE-positive patients,52.0%,41.0%and 31.0%patients were sIgE-positive to Art v 1,Art v 3,Art v 4,respectively.The concentration of sIgE to mugwort in patients with Art v 1 positive was significantly higher than in patients with Art v 1 negative(52.00 k U/L[15.95,62.75 k U/L]versus 13.10 k U/L[2.40,33.75 k U/L],P<0.001).The concentration of sIgE to mugwort in patients with Art v 3 positive was significantly higher than in patients with Art v 3 negative(43.00 k U/L[15.55,61.00 k U/L]versus 15.30 k U/L[2.80,52.00 k U/L],P=0.0038).In addition,patients who were sensitized to mugwort were co-sensitized to ragweed(36.0%),bermuda grass(42.0%),and timothy grass(36.0%).13.9%ragweed sIgE-positive patients were sensitized to Amb a 1.21.4%and 38.1%bermuda grass sIgE-positive patients were sensitized to Cyn d 1 and Cyn d 12,and all Cyn d 12positive patients were combined with Art v 4 and Phl p 12 positive.44.4%and27.8%timothy grass sIgE-positive patients were sensitized to Phl p 12 and Phl p 1.Spearman correlation analysis showed that Phl p 12,Art v 4 and Cyn d 12 were highly correlated(r_s≥0.785,P<0.01).With the increasing sensitization level of mugwort allergen,the sIgE positive rate increased in Art v 1,Art v 3,Art v 4,Cyn d12 and Phl p 12,while decreased in bermuda grass,timothy grass and CCD.CCD sIgE levels had significant positive correlation with ragweed,Amb a 1,bermuda grass,timothy grass and Phl p 4(P<0.05),and CCD-Inhibitor can highly inhibit the above allergens sIgE.Conclusions:Art v 1 was the main allergenic component of mugwort.Cyn d 12 was a cross-reactive component of bermuda grass.Phl p 12 and Phl p 4 were the cross-reactivity components of timothy grass.CCD may have less interference in the detection of mugwort,and there were wide cross-reaction between ragweed,bermuda grass and timothy grass caused by CCD.General conclusions of the study:1.Mugwort is the most important pollen allergen causing respiratory allergic diseases in multi-center children in western China.The distribution of pollen allergens varied in different regions,seasons,ages and diseases.Children with respiratory allergic diseases should regularly detect allergens and pay attention to avoid them.2.Six pollen allergens(mugwort,white poplar,bermuda grass,silver birch,London plane tree and timothy grass)allowed identifcation>95%of pollen-sensitized subjects in western China.3.Art v 1 was the main allergenic component of mugwort.Cyn d 12 was a cross-reactive component of bermuda grass.Phl p 12 and Phl p 4 were the cross-reactivity components of timothy grass.CCD may have less interference in the detection of mugwort,and there were wide cross-reaction between ragweed,bermuda grass and timothy grass caused by CCD.