title: Relevance of the determination of serum-specific IgE antibodies in the diagnosis of immediate beta-lactam allergy.
abstract: BACKGROUND
  Allergic reactions to beta-lactams are the most frequent cause of adverse drug reactions mediated by specific immunologic mechanisms. They can be explored by in vivo and/or in vitro tests. The measurement of serum-specific immunoglobulin E (IgE) presents several advantages: safety, simplicity, and availability to nonallergologist physicians.
  
  
  OBJECTIVE
  To establish the diagnostic value of specific IgE determination in the diagnosis procedure of immediate beta-lactam allergy.
  
  
  METHODS
  The in vitro determination of beta-lactam-specific IgE antibodies was compared in three well-defined groups of patients (n=45): one with negative skin tests and a positive drug provocation test, another with positive skin tests, and a third control exposed population with good tolerance. Two techniques were used: the CAP-FEIA system (Phadia) commercially available and a homemade radioallergosorbent test (RAST).
  
  
  RESULTS
  The specificity of CAP-FEIA ranged from 83.3% to 100% and sensitivity from 0% to 25% depending on initial clinical manifestations. The specificity of RAST was between 66.7% and 83.3% and sensitivity 42.9% and 75%. In the subgroup of patients with an anaphylactic shock and negative skin tests, the sensitivity and specificity of RAST were 75%. Positive and negative predictive values were 45.5% and 77.1% with CAP-FEIA and 38.5% and 81.5% with RAST, respectively.
  
  
  CONCLUSIONS
  These results indicate that, although the specificity of beta-lactam-specific IgE measurement is good, sensitivity is low. Immunoglobulin E measurement should be limited to patients with a clinical history of anaphylactic shock and negative skin tests in order to avoid a drug provocation test. More sensitive assays should be developed.
authors.affiliation: Exploration des allergies - Maladies Respiratoires and INSERM U454 - IFR3, Hôpital Arnaud de Villeneuve, University Hospital of Montpellier, Montpellier Cedex 5, France.
authors.forename: C
authors.initials: C
authors.lastname: Fontaine
authors.forename: C
authors.initials: C
authors.lastname: Mayorga
authors.forename: P J
authors.initials: PJ
authors.lastname: Bousquet
authors.forename: B
authors.initials: B
authors.lastname: Arnoux
authors.forename: M-J
authors.initials: MJ
authors.lastname: Torres
authors.forename: M
authors.initials: M
authors.lastname: Blanca
authors.forename: P
authors.initials: P
authors.lastname: Demoly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002511:Cephalosporins / Q000009:adverse effects / Q000276:immunology; D002648:Child; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis*; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010406:Penicillins / Q000009:adverse effects / Q000276:immunology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012882:Skin Tests; D047090:beta-Lactams / Q000009:adverse effects* / Q000276:immunology*
chemical_list: D002511:Cephalosporins; D010406:Penicillins; D047090:beta-Lactams; D007073:Immunoglobulin E