Comparision of two-flow cytometry methods for basophil degranulation in patients sensitized to grass pollen


Prof. Bogdan Petrunov
National Center of Infectious and Parasitic Diseases
Laboratory of Allergy
26, Yanko Sakazov Blvd.
1504 Sofia


Background:  Two-flow cytometry methods for quantification of degranulated basophil after allergen-specific activation were discussed. The methods are discerned by used membrane receptors – FcɛRI or IL-3Rα Our goal was to evaluate the diagnostic potential of the methods and to correlate them to allergen-specific IgE detection and skin prick test (SPT).

Methods:  Patient's and control's groups were studied with Bulgarian grass pollen allergen B1 simultaneously by flow cytometry kits: Basotest and BD FastImmune test. Allergy diagnosis was based on clinical history and SPT. The determination of specific IgE was performed by ELISA - RIDASCREENR.

Results:  There were no significant differences between the patient's results from Basotest and FastImmune (P > 0.05). A significant correlation between values, analyzed by Basotest and by FastImmune was found (r = 0.88). The sensitivity and specificity of the Basotest, FastImmune, specific IgE and SPT were 85%, 72%, 92% and 92% sensitivity and 100%, 92%, 100% and 85% specificity respectively. The efficiency was between 82% and 97%. There were a significant correlation between the specific IgE and flow cytometry tests: tau = 0.92 (Basotest) and tau = 0.71 (FastImmune) and a moderate significant correlation between the SPT and the in vitro tests: tau = 0.26 (Basotest) and tau = 0.31 (FastImmune).

Conclusion:  The successful use of the Bulgarian grass pollen allergen B1 and both flow cytometry tests was presented. These methods could be as specific tools for IgE-mediated diagnosis especially FastImmune in the case of low IgE receptor expression.