Methods The percentages of monocyte HLA-DR, and the levels of CD3, CD4 and CD8 were measured by flow cytometry in 20 normal old men and 20 healthy adults.

• 方法采用免疫荧光标记流式细胞技术测定20例健康老年人和20例健康年轻人外周血单核细胞HLA-DR和CD3、CD4、CD8的水平。