[Characteristics of clinical asthma types in elderly patients with bronchial asthma]

Asthma was classified into four types, Ia-1 (bronchospasm with 0-49 ml/day of expectoration), Ia-2 (with 5-99 ml/day), Ib (over 100 ml/day) and II (bronchiolar obstruction), according to clinical symptoms. Characteristics of airway responses in each clinical asthma type were compared between 25 elderly (mean age, 65.2 years) and 30 younger subjects (mean age, 44.9 years) with bronchial asthma, by observing ventilatory function and cellular composition in bronchoalveolar lavage (BAL) fluid. 1. In patients with types 1a-2 and Ib, the %V25 value was significantly lower in the elderly subjects than in the younger subjects. 2. Comparing the values of ventilatory parameters of type Ia-1 cases with other asthma types, %V25 value was lower in other asthma types than in type Ia-1 in the elderly. All ventilatory parameters examined were generally lower in type II cases than in other asthma types in the elderly, but this difference was not significant. In contract, in the younger subjects, the values of %MMF, %V50 and %V25 were significantly lower in type II cases than in other asthma types. 3. The proportion of neutrophils in bronchoalveolar lavage (BAL) fluid was higher in the younger patients with type II than in the elderly patients with the same type, although there was no significant difference between older and younger subjects. The proportion of BAL eosinophils in patients with type Ib was significantly higher in younger subjects than in elderly subjects. These results indicate that airway responses which are characteristic of each asthma type are stronger in younger patients than in elderly patients.