Immunochemical characterisation of Glycine max. L merr. var Raiden, as a possible hypoallergenic substitute for cow’s milk allergic patients.

CURCIARELLO, RENATA; LAREU, FABRICIO; FOSSATI ALBERTO; DOCENA GUILLERMO; PETRUCCELLI SILVANA

CLINICAL AND EXPERIMENTAL ALLERGY

Blackwell Publishing

Año: 2008 vol. 38 p. 1559 - 1565

0954-7894

CMA. Objective The aim of this work was to analyse the in vitro reactivity of the soybean cultivar Raiden, which naturally lacks glycinin A4A5B3, to evaluate if this genotype could be a safe CMP substitute for CMA patients. Methods The reactivity of conventional soybean (CS) and Raiden soybean (RS) genotypes and also recombinant glycinin A4A5B3 and alpha beta-conglycinin with casein specific monoclonal antibodies and CMP specific polyclonal serum was evaluated by immunoblotting and ELISA. A sequential competitive ELISA with the polyclonal antiserum and different soluble inhibitors was performed. In addition, an indirect ELISA with sera of atopic children with CMA was carried out to analyse the IgE binding capacity of the different soybean components. Results. We have shown that CS contains four components that cross react with CMP, while RS has only one. The remaining cross-reactive component in RS was identified as a-subunit b-conglycinin. By means of inhibitory ELISA we demonstrated that CS, RS and the a-subunit b-conglycinin extracts inhibited the binding of CMP-specific antibodies to the CMP-coated solid phase. Finally, we showed that CS, RS and the recombinant proteins were recognized by human CMP-specific IgE antibodies. Conclusion This work shows that although Raiden has fewer cross-reactive components than conventional soybean, it still has a residual cross-reactive component: the a-subunit b-conglycinin. This reactivity might make this genotype unsuitable to treat CMA and also explains adverse reactions to soybean in CMA infants.