title: Diagnosis of immediate-type beta-lactam allergy in vitro by flow-cytometric basophil activation test and sulfidoleukotriene production: a multicenter study.
abstract: BACKGROUND
  This multicenter study aimed to evaluate the diagnostic value of 2 cellular tests based on basophil reactivity--the basophil activation test (BAT, Flow-CAST) and the sulfidoleukotriene release assay (CAST-ELISA)--in immediate-type beta-lactam allergy, particularly in patients with a clinical history of allergy and a negative skin test result.
  
  
  METHODS
  In a multicenter study encompassing 10 European centers, 181 patients with a history of immediate-type beta-lactam allergy, and 81 controls, we evaluated the diagnostic efficiency of specific IgE determinations and of 2 cellular tests based on basophil reactivity, the BAT and the sulfidoleukotriene release assay.
  
  
  RESULTS
  With Flow-CAST, sensitivity varied for individual beta-lactam allergens from 16% for penicilloyl-polylysine to 33% for amoxicillin, reaching 50% when all 5 allergens were considered. In beta-lactam-allergic patients with negative skin test results (22.8%), Flow-CAST showed positive results for at least 1 of the 5 allergens in 37%. Specificity varied from 89% to 97%, depending on the allergens used. In CAST-ELISA, the overall sensitivity in skin test-positive patients was 41.7%; in patients with negative skin test results it was 27.9%. Both tests were not absolutely correlated, so that when all the results were considered together, sensitivity increased to 64.3% and specificity varied for both tests combined from 73% to 92%. In contrast, specific IgE determinations in the same population yielded a lower sensitivity (28.3%).
  
  
  CONCLUSIONS
  A diagnostic algorithm including skin tests and specific IgE, followed by cellular tests in negative patients and controlled challenge enabled us to confirm beta-lactam allergy in 92% of cases. This procedure would also allow us to avoid two-thirds of the required controlled challenges.
authors.affiliation: Department of Allergology and Clinical Immunology, University of Navarra, Collaborative Center of GA2LEN, Pamplona, Spain.
authors.forename: A L
authors.initials: AL
authors.lastname: De Week
authors.forename: M L
authors.initials: ML
authors.lastname: Sanz
authors.forename: P M
authors.initials: PM
authors.lastname: Gamboa
authors.forename: W
authors.initials: W
authors.lastname: Aberer
authors.forename: G
authors.initials: G
authors.lastname: Sturm
authors.forename: M B
authors.initials: MB
authors.lastname: Bilo
authors.forename: M
authors.initials: M
authors.lastname: Montroni
authors.forename: M
authors.initials: M
authors.lastname: Blanca
authors.forename: M J
authors.initials: MJ
authors.lastname: Torres
authors.forename: L
authors.initials: L
authors.lastname: Mayorga
authors.forename: P
authors.initials: P
authors.lastname: Campi
authors.forename: M
authors.initials: M
authors.lastname: Manfredi
authors.forename: M
authors.initials: M
authors.lastname: Drouet
authors.forename: J
authors.initials: J
authors.lastname: Sainte-Laudy
authors.forename: A
authors.initials: A
authors.lastname: Romano
authors.forename: H
authors.initials: H
authors.lastname: Merk
authors.forename: J M
authors.initials: JM
authors.lastname: Weber
authors.forename: T M
authors.initials: TM
authors.lastname: Jermann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015549:Basophil Degranulation Test; D002469:Cell Separation; D004342:Drug Hypersensitivity / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D015289:Leukotrienes / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012882:Skin Tests; D013440:Sulfides / Q000276:immunology* / Q000378:metabolism; D047090:beta-Lactams / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D015289:Leukotrienes; D013440:Sulfides; D047090:beta-Lactams; D007073:Immunoglobulin E