Erythromycin Allergen – for use in combination with the BÜHLMANN CAST® assays

BÜHLMANN CAST® Allergens are optimized for in vitro Basophil Activation using BÜHLMANN CAST® assays: CAST® ELISA (EK-CAST) and Flow CAST® (FK-CCR).

CAST® drug allergens. Before using it in CAST® assays, they are to be reconstituted with test specific Stimulation Buffer: CAST® ELISA: B-CAST-STB and Flow CAST®: B-CCR-STB.

Add 250μl Stimulation Buffer into the vial and vortex until the allergen has completely dissolved. For some allergens an additional dilution with Stimulation Buffer is recommended.
Remark: Some individuals react positive either at high or at low allergen concentrations, whereas others react positive over a broad range of concentration.

Storage and Stability: Unopened CAST® Allergens are to be stored Store at ≤ -20°C. Do not use the reagents beyond the expiration date printed on the labels.

Important: Reconstituted or diluted allergens must not be stored and used again!

Blood samples must be drawn for CAST® assays before carrying out a skin test or in vivo provocation with the presumed allergen as in vivo exposure to an allergen can cause an activation of the leucocytes.

Limitations: A negative CAST® assay result for a specific allergen does not exclude potential (even serious) clinical symptoms. Individuals who developed „allergic“ reactions towards protein or drug allergens in the past and whose CAST® assay was negative, should thus be verified with additional methods like the in vivo provocation or skin test before a drug is administered or a patient is exposed to the allergen.

Concentrations and cut-off: Concentrations and cut-off of these allergen groups were optimised regarding maximum specificity and sensitivity. Concentrations to be used in the test and cut-off of individual allergens are reported in the specifications of the allergens. For Flow CAST®, BÜHLMANN recommends the application of the stimulation index (SI) as an additional diagnostic criterion. The SI is defined as the ratio of allergen specific basophil activation and background activation.

Remarks: In order to apply allergen specific cut-offs, QC criteria published in the CAST® instructions must be fulfilled. Cut-offs should serve only as recommendations. Clinically defined cut-offs should be established by each laboratory or through clinical studies.