Changes of allergen-specific antibodies, circulating immune complexes and restoration of polymorphonuclear leukocyte function after hyposensitization.

: To explore the working mechanism(s) and the safety of long-term hyposensitization (HS) with house dust (HD), a series of studies were undertaken on 30 newly diagnosed and 30 hyposensitized asthmatic children. Twenty age- and sex-matched school children were included as control. The results showed: (1) HS was able to decrease the total serum IgE and increase the production of allergen-specific IgG blocking antibody, however, the allergen-specific IgE antibody remained nearly the same after HS for a couple of years, (2) Normal controls had allergen-specific IgG antibody but no IgE antibody, (3) Circulating immune complex concentration in the treated group did not differ significantly from the untreated group, (4) HS was able to suppress in vivo and in vitro histamine production and restore polymorphonuclear leukocyte (PMN) function in terms of Fc gamma R expression. These results suggest that HS is a specific and safe treatment, and provide solid rationale for its use in the treatment of respiratory allergic disease.