title: Indoor determinants of Der p 1 and Der f 1 concentrations in house dust are different.
abstract: BACKGROUND
  Exposure to mite allergens is a major risk factor for sensitization and the development of asthma. Der p 1 and Der f 1 content in homes and probably the proportion of both antigens is highly variable even in the same geographical area.
  
  
  OBJECTIVE
  We investigated specific indoor determinants of Der p 1 and Der f 1 concentrations in house dust of two German cities, Erfurt and Hamburg (n = 405 homes).
  
  
  METHODS
  Mite allergen levels were determined using monoclonal antibodies against Der p 1 and Der f 1 by the ELISA method. Indoor relative humidity and temperature were monitored continuously in the homes over 1 week. The characteristics of homes and occupants were assessed by questionnaire to obtain information on factors which may have an impact on the mite antigen concentration in house dust. These determinants were studied by multivariate regression analysis.
  
  
  RESULTS
  The correlation between concentrations of Der p 1 and Der f 1 inside the homes was weak (r = 0.29-0.35), indicating that different determinants are relevant. Concentrations of the allergens were significantly higher on lower floors (ratios 2-8 times, Der p 1, Der f 1), on old mattresses (ratios 3-13 times, Der p 1, Der f 1), in post-war buildings (ratio 6 times, Der p 1), for non-central heating (ratio 2 times, Der p 1), for old carpets (ratio 3 times, Der p 1) and for the presence of a dog in the house (ratio 3 times, Der f 1). Furthermore, mite concentration increases with raising relative humidity (ratio 1.03 per 1%, Der p 1) and with decreasing temperature (ratio 0.86 per 1 degrees C, Der p 1) indoors.
  
  
  CONCLUSIONS
  Both Der p 1 and Der f 1 concentrations should be measured in house dust, since they are only weakly correlated and have different determinants.
authors.affiliation: GSF - Forschungszentrum für Umwelt und Gesundheit, Institut für Epidemiologie, Neuherberg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Gross
authors.forename: J
authors.initials: J
authors.lastname: Heinrich
authors.forename: B
authors.initials: B
authors.lastname: Fahlbusch
authors.forename: L
authors.initials: L
authors.lastname: Jäger
authors.forename: W
authors.initials: W
authors.lastname: Bischof
authors.forename: H E
authors.initials: HE
authors.lastname: Wichmann
mesh_terms: D000328:Adult; D016902:Air Pollution, Indoor; D000485:Allergens / Q000032:analysis*; D000818:Animals; D039741:Antigens, Dermatophagoides; D004391:Dust; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000032:analysis*; D006798:Housing; D006801:Humans; D008925:Mites
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D004391:Dust; D006023:Glycoproteins