高齢者喘息における気腫化傾向 - 加齢変化と病的変化（肺気腫）の相違点

高齢者喘息の病態的特徴を臨床的に観察した。その結果は以下のごとくであった。 1．血清IgE値や抗原に対するIgE抗体の陽性率は一般的に低いが，しかしアレルギー疾患の家族歴を有する症例の頻度は高く，アトピー性の素因を有する症例の頻度がかなり高いこと，そして，このような症例ではIgE系反応の関与が示唆された。　 2．気道過敏性は加齢とともに低下する傾向が見られた。　 3．換気機能，ガス交換能は加齢とともに低下し，特に70才以上 の症例では若青年者喘息と比べ有意の低下が見られた。　 4．肺容積は，加齢とともに増大し，70才以上の症例では有意の増大傾向が見られた。また，この肺容積の増大は，HRCT上の－950HU以下の肺% UIAと有意の相関が見られ，肺の過膨張の状態が存在することが示唆された。

Pathophysiological changes by aging were examined in asthmatics in the elderly. 1 . A level of serum IgE and frequency of positive RAST score for allergens were in general low. However, the frequency of patients with family history of allergic diseases was considerably high, and in these patients with family history having allergic diseases the presence of IgE-mediated allergic reaction was frequently observed. 2 . Bronchial hyperresponsiveness tended to decrease with aging. 3 . Ventilatory function and gas exchange (DLco) showed a decrease with aging, and the decrease in ventilatory function and DLco in older patients over age 70 was significantly lower than the decrease in younger patients with asthma under age 49. 4 . The volume of the lungs, evaluated by % residual volume (% RV) , tended to increase with aging. The low attenuation area (LAA) of the lungs < -950 HU on HRCT, which represents hyperinflation in asthma, was also increased with aging. A significant correlation was found between % RV and % LAA of the lungs <-950HU on HRCT in patients over age 70.