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Original Article


Diagnosis of Immediate-Type ß-Lactam Allergy In Vitro by Flow-Cytometric Basophil Activation Test and Sulfidoleukotriene Production: A Multicenter Study


AL De Weck,1 ML Sanz,1 PM Gamboa,2 W Aberer,3 G Sturm,3 MB Bilo,4 M Montroni,4 M Blanca,5 MJ Torres,5 L Mayorga,5 P Campi,6 M Manfredi,6 M Drouet,7 J Sainte-Laudy,8 A Romano,9 H Merk,10 JM Weber,11 TM Jermann,11 and members of ENDA (European Network for Drug Allergy)

1 Department of Allergology and Clinical Immunology, University of Navarra, Collaborative Center of GA2LEN, Pamplona, Spain
2 Allergy Division, Hospital Basurto, Bilbao, Spain
3 Department of Dermatology, University of Graz, Graz, Austria
4 University Hospital, Ancona, Italy
5 Hospital Haya, Malaga, Spain
6 University Hospital, Florence, Italy
7 Centre Hospitalier Universitaire, Angers, France
8 Centre Hospitalier Universitaire, Limoges, France
9 Allergy Unit, Complesso Integrato Columbus, Rome, Italy
10 Dermatology Clinic, University Hospital, Aachen, Germany
11 Bühlmann Laboratories AG, Allschwil, Switzerland

J Investig Allergol Clin Immunol 2009; Vol. 19(2): 91-109



Introduction: 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 sulfi doleukotriene release assay (CAST-ELISA)—in immediate-type ß-lactam allergy, particularly in patients with a clinical history of allergy and a negative skin test result.

Material and Methods: In a multicenter study encompassing 10 European centers, 181 patients with a history of immediate-type ß-lactam allergy, and 81 controls, we evaluated the diagnostic effi ciency of specifi c IgE determinations and of 2 cellular tests based on basophil reactivity, the BAT and the sulfi oleukotriene release assay.

Results: With Flow-CAST, sensitivity varied for individual ß-lactam allergens from 16% for penicilloyl-polylysine to 33% for amoxicillin, reaching 50% when all 5 allergens were considered. In ß-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%. Specifi city 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 specifi c IgE, followed by cellular tests in negative patients and controlled
challenge enabled us to confi rm ß-lactam allergy in 92% of cases. This procedure would also allow us to avoid two-thirds of the required
controlled challenges.

Key words: Immediate-type ß-lactam allergy. In vitro diagnosis. Cellular tests. BAT. Sulfidoleukotriene production.