title: Individual IL-3 priming is crucial for consistent in vitro activation of donor basophils in patients with chronic urticaria.
abstract: BACKGROUND
  The in vivo autologous serum skin test (ASST) is the diagnostic gold standard to detect autoantibodies against FcεRI or IgE itself, as well as other autoreactive serum components, in patients with chronic spontaneous urticaria (CU). Coincubation of patient sera with donor basophils and measuring their degranulation in vitro could be a safe alternative but has shown inconsistent results.
  
  
  OBJECTIVE
  Optimization of the basophil activation test to detect autoreactive serum components in patients with CU.
  
  
  METHODS
  The ability of patient sera to induce CD63 and CD203c in donor basophils (n = 15) was measured by means of flow cytometry. Sera of 20 patients with CU (10 with positive ASST results), 15 patients with cold urticaria, and 27 healthy control subjects were included to optimize test conditions with donor basophils and a basophil cell line (RBL703/21) followed by testing of 110 consecutive patients from clinical routine.
  
  
  RESULTS
  We demonstrate that individual IL-3 priming normalized the initially inconsistent basophil reactivity and led to reproducible and comparable test results irrespective of the basophil donors used. CD203c as an activation marker and the use of a basophil cell line were less suitable for this purpose.
  
  
  CONCLUSIONS
  The basophil activation test with individualized IL-3 priming for each basophil donor is a reproducible and reliable alternative to the ASST. There are several advantages over the ASST: no risk of accidental infection, no influence of antihistamines on the test result, quantifiable results, and a potential in providing treatment monitoring. The exact nature of the degranulating factor or factors in patient sera remains an open question.
authors.affiliation: Department of Rheumatology, Clinical Immunology and Allergology, Inselspital, University Bern, Bern, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gentinetta
authors.forename: Tatjana
authors.initials: T
authors.lastname: Pecaric-Petkovic
authors.forename: Daniel
authors.initials: D
authors.lastname: Wan
authors.forename: Franco H
authors.initials: FH
authors.lastname: Falcone
authors.forename: Clemens A
authors.initials: CA
authors.lastname: Dahinden
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Pichler
authors.forename: Oliver V
authors.initials: OV
authors.lastname: Hausmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015549:Basophil Degranulation Test / Q000379:methods*; D001491:Basophils / Q000276:immunology* / Q000378:metabolism; D002469:Cell Separation; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007377:Interleukin-3 / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D014581:Urticaria / Q000175:diagnosis* / Q000276:immunology; D055815:Young Adult
chemical_list: C508596:IL3 protein, human; D007377:Interleukin-3