title: Differences in IgE mediated basophil degranulation induced by proteic fractions from whole flea body extract in patients with papular urticaria by flea bite and healthy controls.
abstract: BACKGROUND
  Papular urticaria by flea bite (PUFB) is a chronic inflammatory disease in children. The aim of this study was to assess the functional activity of IgE to protein fractions from flea body extract, through basophil degranulation in PUFB patients and controls.
  
  
  METHODS
  Basophil degranulation, measured by overexpression of CD63 surface molecules, was evaluated by flow cytometry in samples from patients and controls. Cell stimulation was performed with three fractions with different molecular weight from flea body extract using a Basotest® modified protocol. Mann-Whitney U-test was used for comparisons.
  
  
  RESULTS
  Specific IgE from PUFB patients and healthy controls induced basophil degranulation to flea body extract with no significant differences between them (16.2 ± 3.1% vs 13.6 ± 2.8% p = 0.77). However, when flea extract was analyzed in fractions with proteins ranging different molecular weights, significant differences were observed on the response from patients compared with controls to <50 kD (14.9 ± 5.1% vs 9.7 ± 2.1% p = 0.0058) and 50-100 kD proteic fractions (8.3 ± 3.2% vs 2.8 ± 1.6% p = 0.0021).
  
  
  CONCLUSIONS
  In this study, was established that the differential response by IgE, in PUFB, depends from the molecular weight of the antigens contained in the flea extract. These antigens may be related to 30-35 kD proteins previously described as major allergens.
authors.affiliation: Sección de Alergia y Dermatología Pediátrica, Fundación Santa Fe de Bogotá, Carrera 9 Nº 117-20, oficina 205, Bogotá, DC, Colombia. eligarcia.gomez@gmail.com.
authors.forename: Omar
authors.initials: O
authors.lastname: Dominguez-Amorocho
authors.forename: Silvia
authors.initials: S
authors.lastname: Duarte
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Garcia
authors.forename: Evelyne
authors.initials: E
authors.lastname: Halpert
authors.forename: Adriana
authors.initials: A
authors.lastname: Cuellar
authors.forename: Adriana
authors.initials: A
authors.lastname: Rodriguez