Blocking antibodies to inhalant allergens and asthma

The mechanisms of specific immunotherapy are not still established. Among the lot of immunological changes, induced by immunotherapy, the increase of specific IgG 1, and then of IgG 4 antibodies, during the first months is well demonstrated. The skin-tests, the histamine-release and the human basophil degranulation are significantly decreased after incubation of allergen with the serum of desensitized patients. This antigen neutralizing capacity (blocking antibodies) disappeared when IgG 4 were suppressed from the serum by the mean of activated columns linked either with allergen, or protein A or antihuman IgG4 antibodies. Conversely, the total amount of serum blocking activity was found using pure IgG 4. However, the role of IgG 4 antibodies remains a subject of controversy. Since a clear correlation has yet to be established with symptom scores.