Abstract
To investigate the influence of hyposensitization therapy on sensitivity of respiratory tract to allergen and acetylcholine (=ach.), inhalative provocation test with house dust and inhalative ach. test were carried out, prior to and also after the therapy, on 16 asthmatic patients who had been found to have positive inhalative provocation test with house dust. The patients were hyposensitized by multiple or repository injection methods. (1) Decrease of FEV_<1.0> caused by inhalation of aerozolized house dust extract became significantly less by both multiple and repository injection treatments. (2) Respiratory sensitivity to inhaled ach. showed no significant change by hyposensitization therapy. (3) Inhalative provocation test was considered to be a good way to know the effect of hyposensitization therapy, since decrease of FEV_<1.0> caused by inhalation of aerozolized house dust extract became significantly less after hyposensitization therapy in 12 cases out of 16, and all of them showed a clinical improvement except one case, and in the other 4 cases the decrease of FEV_<1.0> did not become less after therapy and no clinical improvement was proved. It was considered from the above mentioned results that the mechanism of hyposensitization consisted in depressing the production of chemical mediators caused by inhalation of allergens.
