Characterization of grass pollen-specific IgE, IgA, IgM classes and IgG subclasses in allergic patients.

Water-soluble grass pollen extracts (Dactylis glomerata) were separated by isoelectric focusing in a wide pH range (2-11) in agarose gel. After focusing, two successive gel prints were taken. The first one, on an ordinary nitrocellulose filter during 10 s, enabled the visualization of separated components of the pollen, after india ink staining. The second one, on a cyanogen bromide-activated nitrocellulose filter obtained after a 10-min transfer and saturation step, was incubated overnight with patient sera, and the specific antibodies bound to antigens or allergens were detected. The screening of different patient sera showed great variability in the antigen spectra. There was no obvious relationships between IgM and IgA antigen spectra as compared to IgE. Some association between IgE and IgG4 subclass was observed.