Supplementary Material for: Efficacy of Recombinant Allergens for Diagnosis of Cockroach Allergy in Patients with Asthma and/or Rhinitis

<b><i>Background:</i></b> 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. <b><i>Methods:</i></b> Fifty-seven cockroach-allergic patients with asthma and/or rhinitis were recruited. Skin testing with recombinant (r) allergens from <i>Periplaneta americana</i> (rPer a 1 and rPer a 7) and <i>Blattella germanica </i>(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. <b><i>Results:</i></b> 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. <b><i>Conclusion:</i></b> IgE reactivity to rPer a 7 (<i>P. americana</i> tropomyosin) was dominant among patients in Brazil. However, 50% of the patients did not present reactivity to any of the recombinant allergens tested.