GRASS-POLLEN IMMUNOTHERAPY INDUCES HIGHLY CROSS-REACTIVE IGG ANTIBODIES TO GROUP-V ALLERGEN FROM DIFFERENT GRASS SPECIES

Sera from two groups of patients receiving grass pollen immunotherapy were tested on IgG reactivity with group V allergen from six different grass species. One group of patients was treated with a mixture of 10 grass species, and the other with a mixture of five. Only Lolium pere nne, Dactylis glomerata, and Phleum pratense were present in both mixt ures. Although Anthoxanthum odoratum and Secale cereale were absent fr om the mixture of five, IgG responses to Ant o V and Sec c V were comp arable in both patient groups. This reactivity was inhibited for 92-99 % with L. perenne extract, illustrating the cross-reactive nature of t he Ige antibodies. The presence of A. odoratum and S. cereale in the m ixture resulted in only minor amounts of species-specific anti-group V IgG. These results indicate that application of just one grass specie s in immunotherapy might be sufficient to induce an IgG response that covers other relevant Gramineae species as well.