CHANGES IN SKIN-SENSITIZING ANTIBODY TITER AFTER INJECTIONS OF AQUEOUS POLLEN EXTRACT

Titers of SSA decreased in 10 of 21 previously untreated patients with hay fever after treatment with injections of aqueous extract for 13 to 48 months. Quantity of antigen injected did not appear to influence the change in titer. Patients with the highest titers before treatment changed least after therapy. All patients with the lowest pretreatment titers showed significant declines in titer after treatment. Fifteen subjects did not receive injections of extract. Titers did not change in 12 and increased in 3 during a period of 2 to 3 years. Titers of SSA were determined in 2 other groups of patients. In one group, treated with aqueous extracts for many years, titers did not change during one additional year of therapy. The average of this group's first titers was low and suggested that previous therapy had caused a decrease in titer during early years of treatment. Forty other patients received repository injections of extract for 3 consecutive years. No difference existed between the average titers of pre- and postreatment sera. Titers of 5 patients in this group increased significantly. Results suggest that aqueous injection therapy frequently causes a decrease in SSA, hyposensitization." One hypothesis to explain hyposensitization is that injected antigen suppresses antibody synthesis. Hyposensitization may be analagous to partial immune tolerance. © 1969."