Inoue M, Hashimoto S, Nakaya Y, Horie T
First Department of Internal medicine, Nihon University School of Medicine.
Nihon Ronen Igakkai Zasshi. 1993 Jun;30(6):480-6. doi: 10.3143/geriatrics.30.480.
It has been generally agreed that the elderly had a greater susceptibility, morbidity, and mortality in regard to a variety of bacterial infections. To clarify the host defence mechanism in the elderly, we studied the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on neutrophil functions, the production of G-CSF by peripheral blood monocytes in response to lipopolysaccharide (LPS) and the serum levels of G-CSF in patients with bacterial pneumonia. There was no significant difference in the phagocytic activity of neutrophils between the elderly and control young adults. rhG-CSF enhanced phagocytosis by neutrophils, and a similar degree of enhancement was obtained in both group. Killing activity of neutrophils assessed by the new nitroblue tetrazolium reduction test in the elderly was significantly lower than that in young adults (p < 0.001), however, pretreatment with rhG-CSF resulted in an increase of killing activity in the elderly, raising their response to a level compatible to that of young adults pretreated with rhG-CSF. The amount of G-CSF in the culture supernatants from LPS-stimulated peripheral blood monocytes of the elderly was significantly lower than that of young adults (p < 0.05). The serum levels of G-CSF in the acute phase of bacterial pneumonia in the elderly were significantly lower than those of young adults (p < 0.01). These results indicated that impaired monocyte function may contribute, at least in part, to susceptibility to bacterial infection in the elderly.
人们普遍认为，老年人对各种细菌感染的易感性、发病率和死亡率更高。为了阐明老年人的宿主防御机制，我们研究了重组人粒细胞集落刺激因子（rhG-CSF）对中性粒细胞功能的影响、外周血单核细胞对脂多糖（LPS）反应产生G-CSF的情况以及细菌性肺炎患者血清中G-CSF的水平。老年人和对照的年轻人中性粒细胞的吞噬活性没有显著差异。rhG-CSF增强了中性粒细胞的吞噬作用，两组的增强程度相似。通过新的硝基蓝四氮唑还原试验评估，老年人中性粒细胞的杀伤活性显著低于年轻人（p < 0.001），然而，用rhG-CSF预处理可使老年人的杀伤活性增加，使其反应提高到与用rhG-CSF预处理的年轻人相当的水平。老年人LPS刺激的外周血单核细胞培养上清液中G-CSF的量显著低于年轻人（p < 0.05）。老年人细菌性肺炎急性期血清G-CSF水平显著低于年轻人（p < 0.01）。这些结果表明，单核细胞功能受损可能至少部分导致老年人对细菌感染的易感性。
