Release of Histamine and Leukotrienes C₄ and B₄, and Bronchial Hyperresponsiveness in Elderly Patients with Asthma

Thirty patients with atopic asthma in whose asthma IgE-mediated allergic reaction participates, were selected for this study. They were divided into three age groups: elderly patients aged 60 and over, middle-aged patients between the ages of 40 and 59, and young patients between 20 and 39, to clarify the effects of aging on the mechanism of onset of asthma. In the cellular composition of bronchoalveolar lavage (BAL) fluid, the proportion of BAL lymphocytes was increased in elderly patients, and the proportion of BAL eosinophils was increased in young patients, although there was no statistically significant difference between the proportions of these cells in the three age groups. The propor- tion of BAL basophilic cells (basophils and mast cells) was significantly lower in elderly patients than in young patients (p<0.05). The release of histamine from BAL cells was significantly lower in elderly patients than in middle-aged patients (p<0.05) and young patients (p<0.02). There was, however, no significant difference between the release of leukotrienes C₄ (LTC₄) and B₄ (LTB₄) in the three age groups. The release of histamine, LTC₄ and LTB₄ from peripheral leucocytes was not significantly different between the three age groups. Finally, Bronchial reactivity to methcholine showed a tendency to decrease with aging.