title: Use of CD63 expression as a marker of in vitro basophil activation and leukotriene determination in metamizol allergic patients.
abstract: BACKGROUND
  We assessed the reliability of basophil activation test (FAST) and sulphidoleukotriene production (CAST) in the in vitro diagnosis of allergy to metamizol, evaluating its sensitivity and specificity.
  
  
  METHODS
  Twenty-six patients allergic to metamizol and 30 control individuals were studied. Skin tests with metamizol, FAST, and CAST were performed.
  
  
  RESULTS
  FAST sensitivity was 42.3% and specificity 100%. The PPV of FAST is 100% and the NPV 99.4%. The likelihood ratio for a positive value cannot be calculated because the specificity is 100% and the likelihood ratio for a negative value is 0.58. CAST sensitivity was 52%, and specificity 90%. The PPV of the test is 5% and the NPV 99.5%. The likelihood ratio for a positive result was 5.2 and that for a negative result 0.53. FAST detects a larger number of cases when patients are studied within the first 6 months after the clinical reaction (chi = 4.2, P = 0.04) than later. Together with skin tests, FAST allowed detection of 69.2% patients allergic to metamizol, the same as CAST 76%. The joint use of the three techniques allowed identification of 76.9% of cases.
  
  
  CONCLUSIONS
  FAST and CAST are useful for the diagnosis of allergy to pyrazolones. Its usefulness clearly increases when recent reactions are studied.
authors.affiliation: Servicio de Alergología, Hospital de Basurto, Bilbao.
authors.forename: P M
authors.initials: PM
authors.lastname: Gamboa
authors.forename: M L
authors.initials: ML
authors.lastname: Sanz
authors.forename: M R
authors.initials: MR
authors.lastname: Caballero
authors.forename: I
authors.initials: I
authors.lastname: Antépara
authors.forename: I
authors.initials: I
authors.lastname: Urrutia
authors.forename: I
authors.initials: I
authors.lastname: Jáuregui
authors.forename: G
authors.initials: G
authors.lastname: González
authors.forename: I
authors.initials: I
authors.lastname: Diéguez
authors.forename: A L
authors.initials: AL
authors.lastname: De Weck
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000276:immunology*; D015703:Antigens, CD / Q000097:blood*; D001491:Basophils / Q000187:drug effects*; D016022:Case-Control Studies; D004177:Dipyrone / Q000009:adverse effects / Q000276:immunology*; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007159:Immunologic Tests / Q000379:methods; D066298:In Vitro Techniques; D015289:Leukotrienes / Q000097:blood*; D016013:Likelihood Functions; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012882:Skin Tests; D014581:Urticaria / Q000139:chemically induced
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D015703:Antigens, CD; D015289:Leukotrienes; D004177:Dipyrone