Diagnosis of immediate-type beta-lactam allergy in vitro by flow-cytometric basophil activation test and sulfidoleukotriene production: a multicenter study.
BACKGROUND
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 sulfidoleukotriene release assay (CAST-ELISA)--in immediate-type beta-lactam allergy, particularly in patients with a clinical history of allergy and a negative skin test result.


METHODS
In a multicenter study encompassing 10 European centers, 181 patients with a history of immediate-type beta-lactam allergy, and 81 controls, we evaluated the diagnostic efficiency of specific 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 beta-lactam allergens from 16% for penicilloyl-polylysine to 33% for amoxicillin, reaching 50% when all 5 allergens were considered. In beta-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%. Specificity 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 specific IgE, followed by cellular tests in negative patients and controlled challenge enabled us to confirm beta-lactam allergy in 92% of cases. This procedure would also allow us to avoid two-thirds of the required controlled challenges.
De Week
A L
AL
Department of Allergology and Clinical Immunology, University of Navarra, Collaborative Center of GA2LEN, Pamplona, Spain.
Sanz
M L
ML
Gamboa
P M
PM
Aberer
W
W
Sturm
G
G
Bilo
M B
MB
Montroni
M
M
Blanca
M
M
Torres
M J
MJ
Mayorga
L
L
Campi
P
P
Manfredi
M
M
Drouet
M
M
Sainte-Laudy
J
J
Romano
A
A
Merk
H
H
Weber
J M
JM
Jermann
T M
TM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015549:Basophil Degranulation Test; D002469:Cell Separation; D004342:Drug Hypersensitivity / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D015289:Leukotrienes / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012882:Skin Tests; D013440:Sulfides / Q000276:immunology* / Q000378:metabolism; D047090:beta-Lactams / Q000008:administration & dosage / Q000276:immunology*
D015289:Leukotrienes; D013440:Sulfides; D047090:beta-Lactams; D007073:Immunoglobulin E