title: Differences in both prevalence and titre of specific immunoglobulin E among children with asthma in affluent and poor communities within a large town in Ghana.
abstract: BACKGROUND
  Reports from several African countries have noted an increasing prevalence of asthma in areas of extensive urbanization.
  
  
  OBJECTIVE
  To investigate the relevance of allergen-specific sensitization and body mass index (BMI) to asthma/wheezing and exercise-induced bronchospasm (EIB) among children from affluent and poorer communities within a large town in Ghana.
  
  
  METHODS
  Children with physician-diagnosed asthma and/or current wheezing aged 9-16 years (n=99; cases) from three schools with differing socio-economic backgrounds [urban affluent (UA), urban poor (UP) or suburban/rural (SR)] were recruited from a cross-sectional study (n=1848) in Kumasi, Ghana, and matched according to age, sex and area of residence with non-asthmatic/non-wheezy controls. We assayed sera for IgE antibodies to mite, cat, dog, cockroach, Ascaris and galactose-α-1,3-galactose.
  
  
  RESULTS
  Children from the UA school had the lowest total serum IgE. However, cases from the UA school had a higher prevalence and mean titre of sIgE to mite (71.4%, 21.2 IU/mL) when compared with controls (14.3%, 0.8 IU/mL) or cases from UP (30%, 0.8 IU/mL) and SR community (47.8%, 1.6 IU/mL). While similar findings were observed with EIB in the whole population, among cases there was no difference in IgE antibody prevalence or titre between children with or without EIB. BMI was higher among UA children with and without asthma; in UP and SR communities, children with EIB (n=14) had a significantly higher BMI compared with children with asthma/wheezing without EIB (n=38) (18.2 vs. 16.4, respectively, P<0.01).
  
  
  CONCLUSIONS
  In the relatively affluent school, asthma/wheezing and EIB were associated with high titre IgE antibodies to mite, decreased total IgE, and increased BMI. This contrasted with children in the urban poor school and suggests that changes relevant to a Western model of childhood asthma can occur within a short geographical distance within a large city in Africa.
authors.affiliation: University of Virginia Asthma and Allergic Diseases Center, Charlottesville, VA, USA.
authors.forename: W
authors.initials: W
authors.lastname: Stevens
authors.forename: E
authors.initials: E
authors.lastname: Addo-Yobo
authors.forename: J
authors.initials: J
authors.lastname: Roper
authors.forename: A
authors.initials: A
authors.lastname: Woodcock
authors.forename: H
authors.initials: H
authors.lastname: James
authors.forename: T
authors.initials: T
authors.lastname: Platts-Mills
authors.forename: A
authors.initials: A
authors.lastname: Custovic
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D001200:Ascaris / Q000276:immunology; D001249:Asthma / Q000453:epidemiology* / Q000276:immunology*; D001250:Asthma, Exercise-Induced / Q000276:immunology; D015992:Body Mass Index; D016022:Case-Control Studies; D002415:Cats; D002648:Child; D003058:Cockroaches / Q000276:immunology; D003430:Cross-Sectional Studies; D004285:Dogs; D005260:Female; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology; D008297:Male; D008925:Mites / Q000276:immunology; D015995:Prevalence; D012111:Residence Characteristics
chemical_list: D000485:Allergens; D007073:Immunoglobulin E