title: Basophil responsiveness in patients with insect sting allergies and negative venom-specific immunoglobulin E and skin prick test results.
abstract: BACKGROUND
  Current guidelines do not adequately address the question of how best to manage patients with a convincing history of insect allergy, but negative venom-specific IgE and skin test results.
  
  
  METHODS
  Forty-seven patients out of a total of 1219 (4%), with a positive history of sting allergy, were recruited over a period of 4.5 years. All recruited patients had a convincing history of a severe or a life-threatening anaphylactic reaction of Mueller grade II-IV (median grade III) after Hymenoptera sting, but negative venom-specific IgE and skin prick test results. Diagnostic work-up was prospectively followed by the CD63 basophil activation test and by intradermal skin testing. A control group of 25 subjects was also assessed.
  
  
  RESULTS
  Thirty-five out of 47 (75%) patients demonstrated a positive basophil CD63 response after stimulation with bee and/or wasp venom. Intradermal venom skin tests were performed for 37 patients, 17 (46%) of whom showed positive results. Out of 20 patients who demonstrated negative intradermal test results, 12 patients showed a positive CD63 response (60%). In contrast, out of 9 patients who showed a negative CD63 response, only one was detected by intradermal testing (11%). In the control group, only two out of 25 (4%) subjects displayed a positive basophil response and/or intradermal test.
  
  
  CONCLUSIONS
  Here we show that, in complex cases with inconclusive diagnostic results, the CD63 activation test could be particularly useful and more sensitive than intradermal skin testing.
authors.affiliation: Laboratory for Clinical Immunology & Molecular Genetics, University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia. peter.korosec@klinika-golnik.si
authors.forename: P
authors.initials: P
authors.lastname: Korosec
authors.forename: R
authors.initials: R
authors.lastname: Erzen
authors.forename: M
authors.initials: M
authors.lastname: Silar
authors.forename: N
authors.initials: N
authors.lastname: Bajrovic
authors.forename: P
authors.initials: P
authors.lastname: Kopac
authors.forename: M
authors.initials: M
authors.lastname: Kosnik
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000707:Anaphylaxis / Q000276:immunology*; D000818:Animals; D000918:Antibody Specificity / Q000187:drug effects / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D001180:Arthropod Venoms / Q000276:immunology / Q000494:pharmacology*; D001491:Basophils / Q000276:immunology*; D005260:Female; D006801:Humans; D006927:Hymenoptera; D007073:Immunoglobulin E / Q000276:immunology*; D007299:Insect Bites and Stings / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D012882:Skin Tests; D060149:Tetraspanin 30
chemical_list: D015703:Antigens, CD; D001180:Arthropod Venoms; C554586:CD63 protein, human; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30; D007073:Immunoglobulin E