ENGLISH PLANTAIN AND PSYLLIUM - LACK OF CROSS-ALLERGENICITY BY CROSSED IMMUNOELECTROPHORESIS

Background: English plantain (Plantago lanceolata) weed pollen and psy llium (Plantago ovata) husk dust are inhalant allergens. Because of th e phylogenetic relationship between these plant species, cross-allerge nicity has been a concern. Objective: The purpose of this study was to investigate the possible cross-allergenicity of plantain and psyllium . Methods: Homologous and heterologous crossed immunoelectrophoresis ( CIE) were performed using a commercial English plantain pollen extract and an extract of psyllium seed embryo. Crossed radioimmunoelectropho resis (CRIE) was per formed using sera from subjects who were RAST pos itive only to plantain (group A), PAST positive only to psyllium (grou p B), PAST positive to both plantain and psyllium (group C), or RAST n egative to both (group D). Results: All of the group A plantain subjec ts showed IgE binding to at least one of the six plantain allergens in homologous plantain CRIEs while only one of the sera from the group B subjects reacted very weakly to these plantain allergens. In homologo us psyllium CRIE, all group B subjects showed pronounced IgE binding t o 2 to 7 of the seven psyllium allergens. Several of the plantain subj ects demonstrated only very weak binding to psyllium allergens. Hetero logous CRIEs demonstrated little relevant IgE binding, Conclusions: Th ese results indicate that there is little cross-allergenicity between psyllium husk and English plantain pollen.