A comparison of the immune response to immunotherapy with polymerized grass allergen and monomeric grass allergen

This study compares the immune response of ten patients treated with polymerized grass (PG) immunotherapy with that of 12 patients treated with conventional monomer grass (MG) immunotherapy. The patients treated with PG immunotherapy received a mean cumulative dose of 44,840 protein nitrogen units (PNU), and those treated with MG immunotherapy received a mean cumulative dose of 46,083 PNU. Total antibody binding of perennial rye grass groups I, II, and III (RGGI, RGGII, and RGGIII) was measured in the serum of each individual. In addition, IgG titers to partially purified extracts of Bermuda, timothy, and orchard grass were also determined. A significant increase in the total antibody binding of RGGI, as well as an increase in the mean IgG titer to Bermuda, timothy, and orchard grass was demonstrated after treatment in the patients who had received PG immunotherapy. The mean total antibody binding of RGGII and RGGIII also increased in these patients, although not significantly. No significant difference in the mean total antibody binding of RGGI, RGGII, or RGGIII nor in the mean IgG titer to the three grass extracts was found in the sera of the two groups of patients. This study demonstrates a comparable immune response between immunotherapy with PG and MG, and retention of antigenic determinants during the polymerization process.