title: The effects of various doses of bacterial lipopolysaccharide on the expression of CD63 and the release of histamine by basophils of atopic and non-atopic patients.
abstract: OBJECTIVE
  We tested the effect of various doses of bacterial lipopolysaccharide (LPS, endotoxin) on the expression of CD63 and the in vitro release of histamine by basophils stimulated with ragweed allergen in patients with or without ragweed and mite allergies.
  
  
  METHODS
  The peripheral blood of 11 patients with ragweed allergy, 10 patients with mite allergy and 14 control patients was incubated with ragweed allergen extract following pretreatment with varying doses of LPS. The expression of CD63 in basophils was measured by flow cytometry, and the release of histamine was determined by ELISA.
  
  
  RESULTS
  In the samples of patients with ragweed allergy that were exposed to specific allergen, only high doses of LPS significantly elevated the expression of CD63 (200 ng/ml; 1,000 EU/ml) and the release of histamine (2,000 ng/ml; 10,000 EU/ml). There was no effect of LPS in any other cases.
  
  
  CONCLUSIONS
  Bacterial LPS (endotoxin) concentrations higher than 200 ng/ml (1,000 EU/ml), which rarely occurs in nature, could only activate the basophils from atopic patients whilst in the presence of the specific allergen. Thus, the restoration of the urban, "microbe-poor" milieu with endotoxin (as LPS) can be a promising and harmless approach for allergy prevention.
authors.affiliation: Division of Clinical Immunology, Department of Medicine, Medical and Health Science Centre, University of Debrecen, Móricz Zs U. 22, Debrecen 4032, Hungary.
authors.forename: E
authors.initials: E
authors.lastname: Gyimesi
authors.forename: F
authors.initials: F
authors.lastname: Gönczi
authors.forename: M
authors.initials: M
authors.lastname: Szilasi
authors.forename: G
authors.initials: G
authors.lastname: Pál
authors.forename: S
authors.initials: S
authors.lastname: Baráth
authors.forename: S
authors.initials: S
authors.lastname: Sipka
mesh_terms: D000293:Adolescent; D000328:Adult; D031164:Ambrosia / Q000276:immunology; D039741:Antigens, Dermatophagoides / Q000276:immunology; D052179:Antigens, Plant / Q000276:immunology; D001491:Basophils / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006636:Histamine Release / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D008070:Lipopolysaccharides; D008297:Male; D010940:Plant Proteins / Q000276:immunology; D060149:Tetraspanin 30 / Q000276:immunology*; D055815:Young Adult
chemical_list: D039741:Antigens, Dermatophagoides; D052179:Antigens, Plant; D008070:Lipopolysaccharides; D010940:Plant Proteins; D060149:Tetraspanin 30