Scientific publications
Diagnosis of Immediate-Type ß-Lactam Allergy In Vitro by Flow-Cytometric Basophil Activation Test and Sulfi doleukotriene 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)
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 sulfidoleukotriene 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 specifi city varied for both tests combined from 73% to 92%. In contrast, specifi c 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.
CITATION J Investig Allergol Clin Immunol. 2009;19(2):91-109