Background: Cytokine flow cytometry (CFC) or intracellular cytokine staining (ICS) can quantitate antigen-specific T cell responses in settings such as experimental vaccination. Standardization of ICS among laboratories performing vaccine studies would provide a common

We performed immunoblotting experiments to determine specific IgE and IgG subclass responses to Candida albicans antigens in allergic bronchopulmonary aspergillosis (ABPA) patients. This is a first report describing C. albicans antigens recognized by serum IgE and IgG subclasses of ABPA patients sensitized to that yeast. Among the various antigens reacting with serum IgE, a 43-kDa component was recognized by all seven patients and can be considered a major antigen of C. albicans for this particular group of patients. By comparison, only 20% of a group of asthmatic atopics (25 patients) and 10% of a group of normal controls (10 subjects) were 43-kDa positive. Multiple banding patterns, revealing no major antigen, were observed for all four IgG subclasses except for IgG1 in one case. In particular, the 43-kDa component was not always recognized by all the patients. Furthermore, oral or inhaled steroid treatment appears to have no impact on the specific IgE immunopatterns obtained. Using immunoelectron-microscopy, we localized IgE-binding primarily in the mannoprotein-containing layers of the C. albicans cell wall. In conclusion, C. albicans-IgE and IgG subclasses may participate in the physiopathology of ABPA by exacerbating pulmonary infiltrates (IgE) and inducing eosinophil-mediated inflammatory reaction (IgG1, IgG3).