Recombinant allergens and diagnosis of grass pollen allergy.

To evaluate the use of recombinant allergens for the diagnosis of grass pollen allergies, we examined the levels of IgE antibodies specific for grass pollen as by immunoassays. SDS-PAGE analysis of two batches of Kentucky bluegrass pollen extracts demonstrated that there was considerable variability in allergen content of extracts, which in turn affected quantitation of specific IgE antibodies by different immunoassay procedures. Furthermore, the levels of IgE antibodies in human sera specific for a recombinant grass pollen allergen, rKBG8.3, were examined by enzyme immunoassay. The results demonstrated that quantitation of IgE antibodies specific for even one single allergen may be used to discriminate sera of allergic individuals with respect to IgE specific for grass pollen in general. A positive correlation, r = .82, was found for IgE binding of the recombinant allergen and the crude extracts of grass pollens. It is concluded from these results that a single recombinant allergen or a combination of a few major recombinant allergens can substitute the crude extract for in vitro as well as in vivo diagnostic purposes.