title: Efficacy of recombinant allergens for diagnosis of cockroach allergy in patients with asthma and/or rhinitis.
abstract: BACKGROUND
  Immunoglobulin E (IgE) reactivity to individual allergens among cockroach-allergic patients has revealed wide variability. The aim of this study was to assess the effectiveness of recombinant cockroach allergens for skin testing, and to determine sensitization profiles among cockroach-allergic patients living in Brazil.
  
  
  METHODS
  Fifty-seven cockroach-allergic patients with asthma and/or rhinitis were recruited. Skin testing with recombinant (r) allergens from Periplaneta americana (rPer a 1 and rPer a 7) and Blattella germanica (rBla g 2, rBla g 4 and rBla g 5) were performed at 10 μg/ml and 5 μg/ml (rPer a 1). IgE antibodies to rPer a 7 and rPer a 1 were quantitated by ELISA.
  
  
  RESULTS
  Of 57 patients tested, 3 (5.3%), 24 (42.1%), 4 (7%), 3 (5.3%) and 4 (7%) showed positive reactions to rPer a 1, rPer a 7, rBla g 2, rBla g 4 and rBla g 5, respectively. Twenty-eight patients (49.1%) had positive tests to at least one allergen. In keeping with skin test results, 31/57 patients (54.4%) and 5/55 patients (9%) had detectable IgE to rPer a 7 and rPer a 1, respectively. Levels of IgE to rPer a 7 were higher in patients with positive tests to rPer a 7 than those with negative tests (geometric mean 13.2 and 1.8 IU/ml, p < 0.05). There was good concordance of results of skin tests and measurements of serum IgE to rPer a 7.
  
  
  CONCLUSIONS
  IgE reactivity to rPer a 7 (P. americana tropomyosin) was dominant among patients in Brazil. However, 50% of the patients did not present reactivity to any of the recombinant allergens tested.
authors.affiliation: Department of Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Michelle C R
authors.initials: MC
authors.lastname: Barbosa
authors.forename: Ana Beatriz R
authors.initials: AB
authors.lastname: Santos
authors.forename: Virginia P L
authors.initials: VP
authors.lastname: Ferriani
authors.forename: Anna
authors.initials: A
authors.lastname: Pomés
authors.forename: Martin D
authors.initials: MD
authors.lastname: Chapman
authors.forename: L Karla
authors.initials: LK
authors.lastname: Arruda
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D001249:Asthma / Q000150:complications / Q000175:diagnosis; D020048:Blattellidae / Q000276:immunology*; D002648:Child; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010526:Periplaneta / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D012220:Rhinitis / Q000150:complications / Q000175:diagnosis; D012882:Skin Tests
chemical_list: D000485:Allergens; D011994:Recombinant Proteins; D007073:Immunoglobulin E