沙尘天气对健康老年人呼吸道菌群及免疫功能的影响

Effects of dust storm on immunofunction and respiratory tract flora of the aged

目的探讨沙尘天气对健康老年人呼吸道菌群及免疫功能的影响。方法选择门诊体检健康老年人52例(65岁以上)为研究对象,分别在沙尘天气及非沙尘天气时对其咽部菌群进行定性、定量分析,同时观察其外周血T淋巴细胞亚群和自然杀伤(NK)细胞的变化。结果沙尘天气时健康老年人咽部正常菌群明显减少,而非正常菌群及可能性致病菌检出率明显增多。沙尘天气时老年人外周血T淋巴细胞计数、CD4^+T淋巴细胞计数、CD4^+T/CD8^+T比值均降低,差异有显著性(P<0.05),NK细胞计数也降低(P<0.05),而CD8^+T淋巴细胞计数无明显变化(P>0.05)。结论沙尘天气显著影响呼吸道的免疫功能和微生态平衡,这可能是导致沙尘天气期间老年人呼吸道疾病患病率增高的原因。

Objective To discuss the effects of dust storm on immunofunction and respiratory tract flora of the aged. Methods People over 65 years old taking health examinations were selected and determined qualita- tively and quantitatively for their oral pharynx flora, and flow cytometry was used to detect the changes of T lymph cells and the natural killer （NK） cells in peripheral blood. Results During dust storm weather, the normal flora in pharynx from the elderly decreased significantly, and the detection rate of abnormal flora and possible pathogenic bacteria increased obviously. T lymph cell and CD4^＋T cell counts decreased remarkably in dust storm weather than in normal weather, so did CD4^＋T/CD8^＋T ratio and their difference was significant （P 〈 0.05）; NK cells were also reduced significantly in dust events （P 〈 0.05）, while CDS^＋T lymph cell count showed no remarkable change. Conclusion The immunofunction and imbalance of microecosystem in the re- spiratory tract were markedly affected in the dust storm weather, and therefore the morbidity from respiratory diseases increased in old people.