[Flow cytometric analysis for the activation of peripheral immunoregulatory cells from patients with bronchial...

By use of flow cytometry, we have investigated intracellular activated eosinophil cationic protein (ECP) in eosinophils and mitogen-induced cytokine production of T cells in peripheral blood from children with acute severe asthma. In addition, we measured ECP releasability (serum ECP/lysate ECP) as a maker of activated eosinophils. The monoclonal antibody EG2 (anti-activated ECP/EPX antibody) was used for measuring the amount of intracellular activated ECP. ECP releasability and mean fluorescence intensity (MFI) values of EG2-positive eosinophils increased at the time of asthmatic attack and reduced after treatment with improvement in peak expiratory flow. Furthermore, the frequency of T cells which produced IL-4, IL-5 and IFN-gamma stimulated with phorbol myristate acetate and ionomycin increased and reduced in parallel with MFI of EG2-positive cells. These observations suggest that flow cytometric analysis for intracellular ECP and mitogen-induced cytokine production reflects the activation of T cells in bronchial mucosa, and is useful for monitoring airway inflammation in bronchial asthma.