L. Boluda et al., DETERMINATIONS OF PAR-J-1 BY A COMPETITIVE ENZYME-IMMUNOASSAY USING HUMAN SPECIFIC IGE AND IGG - VALIDATION BY SKIN PRICK TESTING, Journal of investigational allergology & clinical immunology, 8(4), 1998, pp. 207-213
Par j 1 is the major allergen of Parietaria judaica. The objectives of
this study were the following: I) to purify Parj 1; 2) to develop an
enzyme immunoassay based on the bivalent properties of specific IgE an
d IgG to determine the Parj I content in several batches of P. judaica
extracts, and, 3) to study the contribution of Parj I to the total al
lergenicity and antigenicity of P. judaica extracts. P, judaica pollen
was extracted and subjected to hydrophobic interaction and gel filtra
tion chromatography for the purification of Par j 1. Inhibition enzyme
immunoassays, SDS-PAGE and immunoblotting were used to characterize t
he allergen content The in vivo biological potency of the extracts was
estimated by skin prick testing 26 P. judaica clinically sensitive pa
tients. The new enzyme immunoassay showed a high degree of specificity
and sensitivity, defecting from 2 to 100 ng Par j 1/ml. The range of
Parj I content in nine batches ranged from 23% to 78% of the total pro
tein in the extracts. The Par j I content showed a significant correla
tion with the allergenic potency of these extracts evaluated by specif
ic IgE inhibition and skin prick testing; the correlation with the spe
cific IgG inhibition capacity was not significant. Purified Parj I sho
ws great specific IgE and IgG binding capacity; its content can be det
ermined using this newly developed enzyme immunoassay. Parj 1 levels e
xhibit a significant correlation with the biological potency of the ex
tracts. This method allows the detection of Parj I isoforms.