Effect of immunotherapy in chronic asthmatic children

Ten children with chronic intractable asthma whose airway sensitivity had been established by means of inhalation challenges to specific antigens were hyposensitized over a period of 5 to 12 months. Five additional asthmatic children acted as “controls.” Various aqueous antigens were used both for immunotherapy and for inhalational challenges. Therapy was given uninterruptedly. The total dose varied from 1,000 to 8,000 protein nitrogen units (PNU) in the controls and from 30,000 to 230,000 PNU in the subjects. Repeat challenges in the low-dose “control” group showed no changes in bronchial sensitivity. Ten children who received high total dosage all showed decreased bronchial sensitivity to specific antigens. Three children who were under study for 12 months could be evaluated clinically as well as physiologically since all four seasons were covered. There was no evidence of clinical, physiologic, or medication improvement in any of them, despite significant decreases in bronchial sensitivity. High-dose therapy appeared to decrease bronchial sensitivity significantly in all except two subjects. The effect was not related to the antigen dose but appeared to be an individual response of the subject.