Long-term immunotherapy with aqueous and aluminum-precipitated grass extracts.

The incidence of reactions and changes in specific IgE and IgG were measured during three to four years of immunotherapy with the aluminum-precipitated and glycerosaline grass extracts. Therapy with aluminum-precipitated extract resulted in far fewer local and systemic reactions and higher mean extract doses were obtained with this preparation. The decline in specific IgE was similar in both treatment groups. However, the higher individual and total doses in the group receiving the aluminum-precipitated extract were accompanied by significantly higher levels of specific IgG (blocking) antibody.