A new basophil activation test using CD63 and CCR3 in allergy to antibiotics

Flow cytometric basophil activation tests (BAT) have been developed as cellular tests for in vitro diagnosis of IgE-mediated reactions. Different markers and techniques have been used after stimulation with various allergens.

It was the aim of the present study to compare an established BAT (Flow-CAST) with a newly developed basophil activation protocol using CD63 and CCR3 (Flow2 CAST) in patients with type-I allergy to antibiotics.

Twenty-four patients with a history of type-I allergy to antibiotics were examined. A careful allergy history was taken, and skin tests and determination of specific IgE antibodies were performed. Two different BAT using CD63 expression but different protocols were carried out after stimulation with different concentrations of antibiotics. Fifteen healthy subjects without a history of antibiotic allergy were studied as controls.

The Flow2 CAST showed a higher sensitivity than the Flow-CAST (55% vs. 53%) with regard to patients' history. Specificity was 80% both for the Flow2 CAST and for the Flow-CAST with regard to controls with negative history and negative RAST.

These results show the value of two different BAT as cellular tests in the in vitro diagnosis of patients with antibiotic allergy with equal specificity and a slightly higher sensitivity for the Flow2 CAST.