Raqib Rubhana, Alam Dewan S, Sarker Protim, Ahmad Shaikh Meshbahuddin, Ara Gul, Yunus Mohammed, Moore Sophie E, Fuchs George
International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh.
Am J Clin Nutr. 2007 Mar;85(3):845-52. doi: 10.1093/ajcn/85.3.845.
Low birth weight is generally an outcome of a fetal insult or nutritional insufficiency. Recent studies have shown that such exposure early in life may have long-term implications for later immunocompetence and susceptibility to infectious diseases.
We aimed to investigate the effect of birth weight on immune function in preschool-age children.
A birth cohort cross-sectional study was conducted in children (n = 132) aged 60.8 +/- 0.32 mo who were born in Matlab, a rural area of Bangladesh, and whose weight and length were measured within 72 h of birth. The outcome measures were thymopoiesis, T cell turnover, acute phase response, and percentage of lymphocytes.
Children born with low birth weight (<2500 g; LBW group, n = 66) had significantly higher concentrations of T cell receptor excision circles in peripheral blood mononuclear cells-a biomarker for thymopoiesis-and significantly higher serum bactericidal activity and C-reactive protein concentrations than did children born with normal birth weight (>or=2500 g; NBW group, n = 66) (P < 0.05 for both). The LBW group children had significantly lower concentrations of interleukin 7 in plasma (P = 0.02), shorter telomere length in peripheral blood mononuclear cells (P = 0.02), and a lower percentage of CD3 T cells (P = 0.06) than did the NBW group children.
Greater peripheral T cell turnover (shorter telomeres and lower CD3 concentrations) due to immune activation (elevated C-reactive protein concentrations and bactericidal activity) may have resulted in a greater need for replenishment from the thymus (higher T cell receptor excision circles); these events may cause lower immune functional reserve in preschool-age children born with LBW. Thus, LBW has implications for immunocompetence and increased vulnerability to infectious diseases in later life.
低出生体重通常是胎儿受到损伤或营养不足的结果。最近的研究表明，生命早期的这种暴露可能对后期的免疫能力和感染性疾病易感性产生长期影响。
我们旨在研究出生体重对学龄前儿童免疫功能的影响。
对出生于孟加拉国农村地区马特莱的132名60.8±0.32月龄儿童进行了出生队列横断面研究，这些儿童在出生后72小时内测量了体重和身长。观察指标为胸腺生成、T细胞更新、急性期反应和淋巴细胞百分比。
低出生体重儿（<2500g；低体重组，n = 66）外周血单个核细胞中T细胞受体切除环（一种胸腺生成的生物标志物）浓度显著高于正常出生体重儿（≥2500g；正常体重组，n = 66），血清杀菌活性和C反应蛋白浓度也显著更高（两者P均<0.05）。低体重组儿童血浆白细胞介素7浓度显著低于正常体重组儿童（P = 0.02），外周血单个核细胞端粒长度显著缩短（P = 0.02），CD3 T细胞百分比也较低（P = 0.06）。
免疫激活（C反应蛋白浓度和杀菌活性升高）导致外周T细胞更新加快（端粒缩短和CD3浓度降低），可能使胸腺补充需求增加（T细胞受体切除环更高）；这些情况可能导致低出生体重学龄前儿童的免疫功能储备降低。因此，低出生体重对免疫能力有影响，并增加了后期生活中感染性疾病的易感性。
