ABSTRACT
The capacity of IL-2 production of peripheral blood lymphocyte (PBL) were determined in 54 patients with pneumonia in acute stage (23 cases of 20-57 years old and 31 cases over 60 years old) and 33 cases in convalescent stage. 20 elderly COPD in remission patients and 59 healthy control (32 aged 20-55 and 27 over 60) were determined also. It was shown that the capacity of IL-2 production of the patients with pneumonia in acute stage were markedly lower than healthy control (P less than 0.01), and that of the elderly patients' were markedly lower than elderly COPD patients also (P less than 0.01). The IL-2 level were also lower in the patients with pneumonia in convalescence than in the healthy control (P less than 0.01). The capacity of IL-2 production of elderly COPD patients and healthy elderly donors were at the same level (P greater than 0.05), both of the two groups' IL-2 level were significantly lower than that of the healthy young-middle age donors. It was suggested that the lowered immune function may be one of the important factors causing the COPD patients and the elderly people susceptible to infection, and it may be one of the important causes of the more severe condition and protracted course in elderly patients.