Department of Pediatrics, Division of Infectious Diseases and Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands.
J Pediatr. 2010 May;156(5):804-9, 809.e1-809.e5. doi: 10.1016/j.jpeds.2009.12.006. Epub 2010 Feb 20.
To analyze the frequency and phenotype of cells of the innate immune system in the peripheral blood of children with Down syndrome (DS).
Flow cytometric analysis of expression of cell surface markers was performed in children with DS (n = 41) and healthy age-matched controls (n = 41).
Compared with controls, children with DS had significantly lower absolute total leukocyte counts, lymphocytes, monocytes, and granulocytes, but 1.5-times higher absolute numbers of CD14(dim)CD16(+) monocytes (147 x 10(6)/L vs 93 x 10(6)/L; P = .02). This difference is fully explained by a higher percentage of CD14(dim)CD16(+) monocytes within the monocyte compartment (28.7% vs 13.4%; P <.001). The absolute numbers of myeloid dendritic cells were lower in DS (13.8 x 10(6)/L vs 22.7 x 10(6)/L; P <.001). The numbers of plasmacytoid dendritic cells and natural killer cells were normal. Absolute numbers of invariant natural killer T cells were very low overall, but significantly lower in children with DS than in controls (1.2 x 10(6)/L vs 3.7 x 10(6)/L; P = .01).
Children with DS exhibited distinct abnormalities in cells of the innate immune system. Most strikingly, they had a high number of proinflammatory CD14(dim)CD16(+) monocytes. This elevated level of CD14(dim)CD16(+) monocytes may play an important role in the onset and maintenance of chronic inflammatory disease in DS.
分析唐氏综合征（DS）患儿外周血固有免疫细胞的频率和表型。
对 41 例 DS 患儿（n = 41）和 41 例年龄匹配的健康对照者进行细胞表面标志物表达的流式细胞术分析。
与对照组相比，DS 患儿的总白细胞计数、淋巴细胞、单核细胞和粒细胞绝对值明显较低，但 CD14(dim)CD16(+)单核细胞绝对值高 1.5 倍（147×10^6/L 比 93×10^6/L；P =.02）。这种差异完全由单核细胞群中 CD14(dim)CD16(+)单核细胞的比例较高（28.7%比 13.4%；P <.001）来解释。髓样树突状细胞的绝对值在 DS 中较低（13.8×10^6/L 比 22.7×10^6/L；P <.001）。浆细胞样树突状细胞和自然杀伤细胞的数量正常。固有自然杀伤 T 细胞的绝对值总体上很低，但 DS 患儿明显低于对照组（1.2×10^6/L 比 3.7×10^6/L；P =.01）。
DS 患儿固有免疫细胞存在明显异常。最显著的是，他们有大量促炎 CD14(dim)CD16(+)单核细胞。这种高水平的 CD14(dim)CD16(+)单核细胞可能在 DS 慢性炎症性疾病的发生和维持中发挥重要作用。
