Significant reduction of nonspecific bronchial reactivity in patients with Dermatophagoides pteronyssinus-sensitive allergic asthma under therapy with allergen-antibody complexes

Abstract

Thirty-nine asthmatic patients hypersensitive to Dermatophagoides pteronyssinus were treated for a total of 4 yr with injections of complexes made of allergen and autologous specific antibodies. The results obtained throughout the first 2 yr of a double-blind placebo-controlled trial have been published (1) and we now report the results of such therapy during an additional 2 yr. Three groups of patients had been defined: Groups A and B were comprised of patients treated with either "higher" doses of complexes (Group A) or "lower" doses (Group B), whereas Group C received the placebo preparation. Four injections of complexes were performed during the third yr and none during the fourth yr. The clinical benefit resulting from such injections was maintained until the end of the study, whereas medication intake, especially systemic or high doses of inhaled corticosteroids, was much reduced. Skin reactivity to allergen was significantly decreased in both treated groups. Bronchial provocation tests were carried out at 1-yr intervals with either allergen or acetylcholine (ACh). Reactivity to allergen inhalation was significantly decreased at each time point. Reactivity to ACh was significantly decreased at the end of Years 3 and 4. Fifty percent of treated patients who underwent bronchial challenges lost their bronchial reactivity to the highest concentrations of both allergen and ACh. A significant improvement in the basal lung function was observed in both treated groups. The long-term effects of immunotherapy with allergen-antibody complexes in allergic asthma patients thus include reduction in nonspecific bronchial reactivity.