Humoral and cellular immune response in elderly patients with bronchial asthma

Humoral and cellular immune responses in bronchial asthma were examined by comparing the results of older asthmatics (group OA) with those of older healthy subjects (group OH) and of younger asthmatics (group YA). In humoral immune response, IgE-mediated immune system expressed by elevated serum IgE levels and IgE antibodies for house dust mite (HDm) and/or Candida albicans was clearly found in older asthmatics, while there was no finding showing the presence of IgE-mediated immune response in older healthy subjects. There was no significant difference in levels of serum IgG and IgA among the three groups. However, the serum IgM level was significantly lower in older asthmatics than in younger asthmatics. IgE antibodies to HDm and/or Candida albicans were more frequently found in older asthmatics compared with older healthy subjects. In contrast, IgG(4) antibodies to HDm were not different among the three groups. IgG(4) antibodies to Candida albicans were significantly higher in both older groups than in younger group. However, there was no significant difference between asthmatic and healthy subjects in the elderly. Delayed skin reaction to PPD was significantly more decreased in older asthmatics. These results show that bronchial asthma in the elderly is characterized by the presence of IgE-mediated immune response and by the changes of immune response with aging.

気管支喘息における液性および細胞性免疫反応について,老年者気管支喘息,老年者健常人,および若年者気管支喘息の間で比較検討を行った｡1.まず,液性免疫では,血清IgE値高値,ハウスダストやカンジダに対するIgE抗体陽性などのIgE系反応は,老年者気管支喘息においては明らかに観察されたが,老年者健常人では全く観察されなかった｡血清IgGおよびIgA値には3者間に有意の差は見られなかったが,血清IgMは,若年者喘息に比べ老年者喘息で有意に低い値を示した｡2.ハウスダストやカンジダに対するIgE抗体は老年者喘息において老年者健常人に比べより高い頻度で陽性であったが,一方,ハウスダストに対するIgG(4)抗体は3者聞に有意の差は見られなかった｡また,カンジダに対するIgG(4)抗体は,老年者喘息および健常人において,若年者喘息に比べ有意の高値を示した｡しかし,老年者の喘息と健常人との間には有意の差は見られなかった｡3.PPDによる遅延型皮膚反応は,若年者喘息に比べ老年者喘息において有意の減弱傾向を示した｡これらの結果は,老年者喘息はIgE系反応を有していること,そして,加齢による免疫反応の変化の影響を受けること,を示している｡