不同喂养方式的足月儿3月龄时免疫功能特点分析的前瞻性队列研究

目的 探究足月健康新生儿生后3月龄时的免疫功能特点，并分析其与喂养方式及性别的关系。 方法 前瞻性选取北京及呼和浩特4家医院出生的足月健康新生儿84例为研究对象，生后4月龄内喂养方式不变，根据喂养方式分为母乳喂养组（26例）和奶粉喂养组（58例）。于生后3月龄时采集两组婴儿外周静脉血标本，检测细胞免疫、体液免疫功能及血常规，比较上述实验室指标在不同喂养方式、性别的婴儿中有无显著性差异。 结果 母乳喂养组T细胞第二信号受体CD28表达比例、免疫球蛋白M、中性粒细胞比例及计数均显著低于奶粉喂养组（P<0.05），CD8⁺T细胞表面激活标记物HLA-DR的计数及比例、淋巴细胞比例显著高于奶粉喂养组（P<0.05）。男婴白细胞计数低于女婴，嗜酸性粒细胞比例高于女婴（P<0.05）。 结论 性别对3月龄足月婴儿淋巴细胞亚群比例无显著影响；不同喂养方式可改变其CD28⁺T细胞（淋巴细胞功能亚群）和HLA-DR⁺T细胞（淋巴细胞激活亚群）表达比例，提示喂养方式对3月龄足月婴儿免疫功能发育过程存在一定影响。

Characteristics of immune function of full-term infants with different feeding patterns at the age of 3 months: a prospective cohort study

Objective To explore the characteristics of immune function of healthy full-term infants at the age of 3 months, and to analyze the relationship of immune function with feeding pattern and sex. Methods A total of 84 healthy full-term infants born in four hospitals in Beijing and Hohhot, China were prospectively recruited. Their feeding patterns remained unchanged within 4 months after birth. They were divided into a breast-feeding group and a milk powder feeding group according to their feeding patterns. At the age of 3 months after birth, peripheral venous blood samples of the two groups were collected to evaluate cellular immunity and humoral immunity and perform routine blood test. The laboratory indices were compared between infants with different feeding patterns and sexes. Results Compared with the milk powder feeding group, the breast-feeding group had significantly lower proportion of T cell second signal receptor CD28, immunoglobulin M, and proportion and absolute count of neutrophils (P<0.05) and significantly higher expression and proportion of HLA-DR, a surface activation marker of CD8+ T cells, and proportion of lymphocytes (P<0.05). The male infants had a significantly lower white blood cell count and a significantly higher proportion of eosinophils compared with the female infants (P<0.05). Conclusions Sex has no significant effect on the proportion of lymphocyte subsets in 3-month-old full-term infants, but feeding patterns are associated with the proportion of CD28+ T cells (lymphocyte functional subset) and HLA-DR+ T cells (lymphocyte activation subset), suggesting that feeding patterns have a certain effect on the development of immune function in 3-month-old full-term infants.