title: Prevalence of sensitivity to cockroach allergens and IgE cross-reactivity between cockroach and house dust mite allergens in Chinese patients with allergic rhinitis and asthma.
abstract: 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.
authors.affiliation: State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, Guangdong 510120, China. baoqingsun@yahoo.com.cn
authors.forename: Bao-Qing
authors.initials: BQ
authors.lastname: Sun
authors.forename: Xu-Xin
authors.initials: XX
authors.lastname: Lai
authors.forename: Birgitte
authors.initials: B
authors.lastname: Gjesing
authors.forename: Michael Dho
authors.initials: MD
authors.lastname: Spangfort
authors.forename: Nan-Shan
authors.initials: NS
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D001249:Asthma / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003058:Cockroaches / Q000276:immunology*; D003429:Cross Reactions; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D007073:Immunoglobulin E / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012221:Rhinitis, Allergic, Perennial / Q000209:etiology*; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology*
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D007073:Immunoglobulin E