title: Cysteinyl-leukotriene release test (CAST) in the diagnosis of immediate drug reactions.
abstract: BACKGROUND
  The diagnosis of allergic reactions to drugs is difficult. Most skin tests are not standardized, and in vitro tests are needed to avoid provocation tests. Cross-linking of IgE on basophils is known to cause the release of both cysteinyl leukotriene (Cys-LT) and histamine. We aimed to evaluate the diagnostic utility (sensitivity, specificity, and efficiency) of measurement of sulfidoleukotrienes in drug allergy.
  
  
  METHODS
  We performed a prospective study in 55 patients with proven immediate adverse reactions to drugs (30 to beta-lactams, six to acetaminophen, and 19 to aspirin) and 64 drug-exposed nonallergic controls. Positive diagnosis was established by history, skin tests, and, if needed, oral provocation tests. Cys-LT release was determined after drug-allergen stimulation by the cellular antigen stimulation test (CAST(R)) technique. Histamine release was also assessed on the same samples by enzyme immunoassay. Spontaneous and anti-FcepsilonRIalpha-induced mediator release was also studied in all subjects. Sensitivity, specificity, and efficiency were calculated.
  
  
  RESULTS
  Net Cys-LT release was over the maximal threshold given by the manufacturer in 19/55 patients and in 9/64 controls. Net histamine release was over 5% of total histamine content in 28/55 patients and 34/64 controls. The efficiency of both tests was low.
  
  
  CONCLUSIONS
  Thus, in most cases, the in vitro Cys-LT test has little or no diagnostic utility and is not superior to histamine release.
authors: Maladies Respiratoires, INSERM U454 - IFR3, CHU de Montpellier, Montpellier Cedex, France.
authors: B
authors: B
authors: Lebel
authors: D
authors: D
authors: Messaad
authors: V
authors: V
authors: Kvedariene
authors: M
authors: M
authors: Rongier
authors: J
authors: J
authors: Bousquet
authors: P
authors: P
authors: Demoly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003545:Cysteine / Q000378:metabolism*; D019937:Diagnostic Techniques and Procedures; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006636:Histamine Release / Q000502:physiology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis*; D018836:Inflammation Mediators; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D008722:Methods; D008875:Middle Aged; D010865:Pilot Projects; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000379:methods
chemical_list: D018836:Inflammation Mediators; D015289:Leukotrienes; C112381:cysteinyl-leukotriene; D003545:Cysteine