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Research Asia Pacific

Bio, China
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Zheng Dr. Y.,Research Asia Pacific | Lai X.,Research Asia Pacific | Gjesing B.,Research Asia Pacific | Zhong N.,Guangzhou University | Spangfort M.D.,Research Asia Pacific
Chinese Medical Journal | Year: 2012

Background Haikou locates in tropical island with unique mite propagation. The aim of this stuy is to determine mite allergens levels in Haikou, and to investigate the prevalence of mite specific IgE-sensitization and IgE cross-reactivity between house dust mites. Methods Allergen and antigen concentrations against six mite species were tested by enzyme-linked immunosorbent assay (ELISA). Specific IgE concentrations and cross-inhibitions were measured with ADVIA Centaur®. Results Allergen or antigen Dermatophagoides pteronyssinus (Der p 1), Blomia tropicalis (Blo t) and Tyrophagus putrescentia (Tyr p) were detected in dust samples. Dermatophagoides farinae (Der f 1), Lepidoglyphus destructor (Lep d 2), and Acarus siro (Aca s) were found in very few samples. Specific IgE tests showed high prevalence of sensitizations against all tested mites with high IgE levels to Der p, Der f, and Blo t. Storage mites, Blo t, Tyr p, Lep d, and Aca s, could inhibit Der p from 0 to 50%. Storage mites could inhibit Der f between 30% and 100%. Der p IgE could be inhibited by Der f with up to 90%, and vice versa. Der p could inhibit Blo t from 40% to 80%. Blo t was able to fully inhibit IgE binding to Lep d, Tyr p, and Aca s compared to partial inhibition by Der p. Conclusions Der p is the dominating mite and has the highest specific IgE prevalence among asthmatic children. Blo t represents an important source of storage mite sensitization and some patients may be independently sensitized to both Der p and Blo t. High prevalence of sensitization to Der f may be due to IgE-mediated cross-reactivity with Der p and Blot.

PubMed | Nanjing Medical University, Research Asia Pacific, Guangzhou University, Uppsala University and Chongqing Medical University
Type: Journal Article | Journal: Biomedical and environmental sciences : BES | Year: 2015

Chinese allergic subjects have high levels of sensitization to house dust mite (HDM) and other indoor allergens. This study quantifies common indoor allergen levels in Chinese households.Dust samples were collected from nine cities. Major allergens Der p 1 and Der f 1 from Dermatophagoides pteronyssinus and D. farinae, and specific antigens of Blomia tropicalis, Tyrophagus putrescentiae, Acarus siro, and cockroach species Blattella germanica and Periplaneta americana were measured by ELISA.HDM allergens were found in dust samples from bedding in 95% of the Chinese households. The median levels varied from <0.006 to 9.2 g/g of dust, depending on the city. The percentages of households having HDM allergen levels associated with the risk of developing allergy sensitization and asthma were 65% and 25%, respectively. Specific antigens of the storage mite and cockroach were only found in samples from the southern and tropical regions of China. Levels of mite allergens were generally higher in samples from bedding compared to samples from the living room, even for storage mites, whereas levels of cockroach antigens were higher in the living room samples.HDM allergens are present in bedding dust samples from most Chinese households. Cities in southern and central China have relatively high levels of HDM major allergens compared to cities in northern and western China. Antigens of storage mites and cockroaches are not as common as HDM allergens.

PubMed | Chinese University of Hong Kong, Guangzhou University, Ludwig Maximilians University of Munich, University of Eastern Finland and 3 more.
Type: Journal Article | Journal: Chest | Year: 2016

Environmental factors may play important roles in asthma, but findings have been inconsistent.The goal of this study was to determine the associations between early life exposures, environmental factors, and asthma in urban and rural children in southeast China.A screening questionnaire survey was conducted in 7,164 children from urban Guangzhou and 6,087 from rural Conghua. In the second stage, subsamples of 854 children (419 from Guangzhou, 435 from Conghua) were recruited for a case-control study that included a detailed questionnaire enquiring on family history, early life environmental exposures, dietary habits, and laboratory tests (including histamine airway provocation testing, skin prick tests, and serum antibody analyses). House dust samples from 76 Guangzhou families and 80 Conghua families were obtained to analyze levels of endotoxins, house dust mites, and cockroach allergens.According to the screening survey, the prevalence of physician-diagnosed asthma was lower in children from Conghua (3.4%) than in those from Guangzhou (6.9%) (P < .001). A lower percentage of asthma was reported in rural subjects compared with urban subjects (2.8% vs. 29.4%; P < .001) in the case-control study. Atopy (OR, 1.91 [95% CI, 1.58-2.29]), parental atopy (OR, 2.49 [95% CI, 1.55-4.01]), hospitalization before 3 years of age (OR, 2.54 [95% CI, 1.37-4.70]), high consumption of milk products (OR, 1.68 [95% CI, 1.03-2.73]), and dust Dermatophagoides farinae group 1 allergen (OR, 1.71 [95% CI, 1.34-2.19]) were positively associated with asthma. Living in a crop-farming family at < 1 year of age (OR, 0.15 [95% CI, 0.08-0.32]) and dust endotoxin levels (OR, 0.69 [95% CI, 0.50-0.95]) were negatively associated with asthma.Rural children from an agricultural background exhibited a reduced risk of asthma. Early life exposure to crop farming and high environmental endotoxin levels might protect the children from asthma in southern China.

Li J.,Guangzhou Medical College | Huang Y.,Chongqing Medical University | Lin X.,General Hospital of Shenyang Military Command | Zhao D.,Nanjing Childrens Hospital | And 7 more authors.
American Journal of Rhinology and Allergy | Year: 2012

Background: Allergen sensitization is influenced by genetic and environmental factors; however, the factors related to sensitizations in patients with rhinitis and asthma in China are largely unknown. This study investigated the factors associated with allergen sensitizations in patients with asthma and rhinitis in China. Methods: A cross-sectional survey was performed in 6304 patients with asthma and/or rhinitis from four regions of China. Patients completed a standardized questionnaire related to respiratory and allergic symptoms, family history of allergic diseases, smoking history, environmental exposure, and eating behaviors. They underwent skin-prick tests (SPTs) with 13 common aeroallergens. Blood samples were collected from 2268 of patients for specific IgE (sIgE) measurements against 16 common aeroallergens. Results: Patients with both asthma and rhinitis had higher prevalence of SPT and sIgE positivity to most allergens than those with asthma or rhinitis alone (p < 0.0001). Male gender, family history of allergic rhinitis, air-conditioner usage, sleeping on a mattress, and frequently eating meat were associated with increased risk of SPT and sIgE positivity. Using air-conditioner and sleeping on a mattress were further found to be associated with sIgE positivity to mites and molds. However, increased age and fish, fruit, and raw vegetable intake decreased the risk of SPT and sIgE positivity. Conclusion: Family history of allergic rhinitis, male gender, using an air conditioner, sleeping on a mattress, and frequent meat consumption are risk factors for allergen sensitizations, whereas increased age and frequent fish, fruit, and raw vegetable consumption may protect patients with asthma and/or rhinitis from developing sensitizations in China. Copyright © 2012, OceanSide Publications, Inc.

Hao G.-D.,Tangshan Gongren Hospital | Zheng Y.-W.,Research Asia Pacific | Gjesing B.,Research Asia Pacific | Kong X.-A.,Tangshan Gongren Hospital | And 5 more authors.
Journal of Zhejiang University: Science B | Year: 2013

Objective: Weed pollens are common sources of allergens worldwide. The prevalence of weed pollen sensitization is not yet fully known in China. The purpose of this study was to investigate the prevalence of sensitization to weed allergens from Artemisia, Ambrosia, and Humulus in northern China. Methods: A total of 1 144 subjects (aged from 5 to 68 years) visiting our clinic from June to October 2011 underwent intradermal testing using a panel of 25 allergen sources. Subjects with positive skin responses to any pollen were further tested for their serum concentrations of IgE antibodies against Artemisia vulgaris, Ambrosia artemisiifolia, and Humulus scandens, and against the purified allergens, Art v 1 and Amb a 1. Results: Of 1 144 subjects, 170 had positive intradermal reactions to pollen and 144 donated serum for IgE testing. The prevalence of positive intradermal responses to pollens of Artemisia sieversiana, Artemisia annua, A. artemisiifolia, and H. scandens was 11.0%, 10.2%, 3.7%, and 6.6%, respectively. Among the intradermal positive subjects, the prevalence of specific IgE antigens to A. vulgaris was 58.3%, to A. artemisiifolia 14.7%, and to H. scandens 41.0%. The prevalence of specific IgE antigens to the allergen Art v 1 was 46.9%, and to Amb a 1 was 11.2%. The correlation between the presence of IgE antibodies specific to A. vulgaris and to the Art v 1 antigen was very high. Subjects with A. artemisiifolia specific IgE also had A. vulgaris specific IgE, but with relatively high levels of A. vulgaris IgE antibodies. There were no correlations between the presence of IgE antibodies to H. scandens and A. vulgaris or to H. scandens and A. artemisiifolia. Conclusions: The intradermal prevalence of weed pollen sensitization among allergic subjects in northern China is about 13.5%. Correlations of specific IgE antibodies suggest that pollen allergens from Artemisia and Humulus are independent sources for primary sensitization. © 2013 Zhejiang University and Springer-Verlag.

Sun B.-Q.,Guangzhou University | Lai X.-X.,Research Asia Pacific | Gjesing B.,Research Asia Pacific | Spangfort M.D.,Research Asia Pacific | Zhong N.-S.,Guangzhou University
Chinese Medical Journal | Year: 2010

Background Cockroaches are an important indoor allergen source causing allergic rhinitis and asthma. The aim of this study was to investigate the cockroach prevalence in mainland of China and the cross-reactivity of IgE between cockroach and house dust mite allergen in Chinese patients. Methods The cockroach sensitization pattern was based on a skin prick test (SPT) obtained from a national multicenter prevalence study, in which 6304 patients from 25 allergy centers across China participated. Factors, including different regions of China, age, gender and the correlations between the American and German cockroaches and house dust mite Der p were investigated. Eighteen out of 1236 clinical sera from south China were selected to perform the cross-inhibition assay between house dust mites and cockroaches. Results Totally 25.7% of patients were SPT positive to the American cockroach (Periplaneta Americana, Per a) and 18.7% SPT positive to the German cockroach (Blattella germanica, Bla g). The prevalence of positive cockroach SPT was higher in southern than in northern China, higher in adults than in children, and higher in males than in females. Patients had relatively low levels of cockroach SPT reactions, mainly class 1 or 2. Of the SPT positive cockroach patients, 88% were also SPT positive to house dust mite (Dermatophagoides pteronyssinus, Der p). An IgE cross-inhibition study confirmed that Der p sensitization could cause false positive SPT reactions against cockroach. Conclusions A relatively high prevalence of cockroach sensitivity was found in mainland of China. However, a cross-inhibition study showed that only a small number of patients appear to have Bla g and/or Per a as primary sensitizing source. The importance of cockroaches as a risk factor for sensitization and triggers of allergic symptoms in mainland of China needs to be further investigated.

Zhang C.,Guangzhou University | Gjesing B.,Research Asia Pacific | Lai X.,Research Asia Pacific | Li J.,Guangzhou University | And 2 more authors.
Allergy: European Journal of Allergy and Clinical Immunology | Year: 2011

Background: High levels of sensitization to house dust mites have been observed in Chinese allergic patients. This study has measured levels and distributions of mite and cockroach allergens in household dust in Guangzhou. Influences of home characteristics and seasonal changes on allergen levels were also investigated. Methods: Dust samples were collected from bedding and living room from households in Guangzhou. Major allergens from Dermatophagoides pteronyssinus, D. farinae, D. microceras, Blomia tropicalis and cockroach allergens were measured by ELISA. Home characteristics were obtained from a questionnaire. Results: Four hundred and four dust samples were collected from 107 homes during October 2006 to November 2007. House dust mite allergen levels were detectable in 99% of the bedding samples. Der f 1 levels were significantly higher than Der p 1 levels. High levels of mite allergens (>10 Iμg/g) were observed in 88% of all the bedding samples. Cockroach allergens were detected in 93% of households and were higher in living room samples than in bedding samples. Blo t 5 and Der m 1 could not be detected in the dust samples. Having fabric furniture was a predictor of high allergen levels. Der f 1 levels were higher in summer time than in winter time. Cockroach allergens were higher in winter time than in summer time. Conclusion: In Guangzhou, Der f 1 is the predominant mite allergen in dust with very high levels in bedding. Cockroach allergens are also common. © 2010 John Wiley & Sons A/S.

Zhang C.,Guangzhou University | Li J.,Guangzhou University | Lai X.,Research Asia Pacific | Zheng Y.,Research Asia Pacific | And 3 more authors.
Asian Pacific Journal of Allergy and Immunology | Year: 2012

Summary Background: In China, house dust mites are important inducers of allergic disease. The importance of allergens from storage mites is less well known. Objective: The aim of this study is to access the prevalence of house dust mite and storage mite sensitization and investigate the IgE crossreactivity between house dust mite and storage mite. Method: The skin prick test (SPT) and specific IgE against the mite species D. pteronyssinus, D. farinae, B. tropicalis, Lepidoglyphus destructor, Glycyphagus domesticus, Tyrophagus putrescentiae and Acarus siro were measured. Included were 412 patients with asthma and/or rhinitis for SPT, 244 for specific IgE and 29 sera for IgE inhibition studies. Results: The positive SPT prevalence for D. pteronyssinus was 80.3% and for D. farinae 83.7%. The specific IgE prevalence for D. pteronyssinus was 61.1% and for D. farinae 60.2%. The storage mite species, B. tropicalis and T. putrescentiae had the highest positive SPT prevalence, 66% and 63%, respectively. The specific IgE prevalence was highest for B. tropicalis and G. domesticus, 41% and 37%, respectively. Both SPT and specific IgE levels were much higher for house dust mites compared to storage mites. Inhibition measurements showed that none of the storage mites could fully inhibit the specific IgE against D. pteronyssinus. Only in half of the sera could D. pteronyssinus fully inhibit the IgE against L. destructor and G. domesticus while inhibition of the other storage mites were much lower. Nearly all the specific IgE against storage mites could be inhibited by the other storage mites, though B. tropicalis showed a slightly different pattern from the other storage mites. Conclusion: IgE reactivity against storage mites in Chinese patients is due to both storage mite specific IgE and due to IgE mediated crossreactivity to D. pteronyssinus.

Han D.,Capital Medical University | Lai X.,Research Asia Pacific | Gjesing B.,Research Asia Pacific | Zhong N.,Guangzhou University | And 2 more authors.
Acta Oto-Laryngologica | Year: 2011

Conclusion: Specific immunoglobulin E (IgE) reactivity towards the major mugwort allergen Art v 1 is a good indicator for Art v sensitization. Allergens from the ragweed species Amb t and Amb a possibly share common IgE-binding epitopes. Objective: The aim of this study was to investigate the reactivity pattern of IgE in Chinese patients with weed pollen-induced allergic rhinitis. Methods: Sera from 50 weed pollen-induced allergic rhinitis patients were tested for specific serum IgE reactivity against allergenic extracts of mugwort (Artemisia vulgaris, Art v), short ragweed (Ambrosia artemisiifolia, Amb a), giant ragweed (Ambrosia trifida, Amb t), and single allergens of Art v 1, Art v 3, Amb a 1, and profilin. Results: Sera from 88% of the patients demonstrated positive specific IgE reactivity to Art v, and of these 82% were positive to Art v 1. Sera from 38% of the patients showed positive specific IgE reactivity to both ragweed species Amb t and Amb a. A strong correlation was found between the specific IgE levels of Amb t and Amb a. Of the Amb a IgE-positive patients, 38% were positive for Amb a 1. Of all patient sera tested, 12% were specific IgE-positive to profilin. © 2011 Informa Healthcare.

Lai X.,Research Asia Pacific | Li J.,Guangzhou Medical College | Xiao X.,Zhongshan Bo Ai Hospital | Liu E.,Chongqing Medical University | And 5 more authors.
International Archives of Allergy and Immunology | Year: 2013

Background: Specific IgG4 induced by allergen-specific immunotherapy (SIT) is an immunological marker related to the appearance of clinical tolerance. But specific IgG4 levels in different age, gender and allergic disease populations have not been fully investigated. Methods: This study involved 226 children and 109 adults with allergic rhinitis and/or asthma receiving a 156-week course of Dermatophagoides pteronyssinus (Der p) subcutaneous SIT. Symptom and medication scores, forced expiratory volume after 1 s (FEV1) and Der p-specific IgG4 levels at weeks 0, 5, 10, 25, 52, 104 and 156 were analyzed. Results: Rhinitis symptom and medication scores and FEV1 % predicted in children showed significantly greater improvement than in adults at week 104 and 156 (p < 0.05). Levels of Der p-specific IgG4 showed a significant increase after 10 weeks of subcutaneous SIT (p < 0.0001) and continued to increase during the 156-week SIT period. Before SIT, the initial Der p-specific IgG4 level was higher in children than adults (p = 0.0004). The increase ratio of Der p-specific IgG4 was higher in children than adults at 52 weeks (p < 0.001) and 104 weeks (p = 0.0156) of SIT, and was higher in rhinitis compared to asthma patients at 156 weeks of SIT (p = 0.0244). There was no difference between males and females at any time points. Conclusion: Children are more responsive to SIT, demonstrating clinical and FEV1 improvement and producing higher levels of allergen-specific IgG4 during a shorter SIT period compared to adults. Rhinitis patients show a higher increase in specific IgG4 compared to patients with asthma symptoms. The increase of Der p-specific IgG4 reflects a specific response of the immune system towards the SIT vaccine being administrated. Copyright © 2012 S. Karger AG, Basel.

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