Laboratorio de Inmunobiología Molecular, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Pediatr Res. 2012 May;71(5):590-7. doi: 10.1038/pr.2012.6. Epub 2012 Feb 1.
Current advances in neonatology have improved survival among preterm and low-birth-weight infants. However, the risk of neonatal death in preterm infants is much greater than in full-term neonates and is frequently associated with infections.
Little is known about the immune status of preterm neonates; therefore, we analyzed the frequency and absolute counts of different immune populations in 211 cord blood samples taken from very-preterm to full-term neonates.
We found that absolute counts of all the immune subsets analyzed (i.e., monocytes, granulocytes, B cells, natural killer (NK) cells, CD4(+), and CD8(+) T cells) were markedly lower in preterm infants than in full-term infants. Surprisingly, we observed that regulatory T cells (Tregs) were the only cell subset that did not decrease in preterm infants, and their frequency was even higher than in full-term infants.
Tregs are crucial to maternal-fetal tolerance, but their suppressive role could be also implicated in the leukopenia observed in preterm infants. We did not observe differences in thymic function, but we found that plasma levels of interleukin (IL)-7 and the frequency of its receptor were significantly decreased in preterm infants. Our results could help to identify leukopenia and to implement immune therapies that significantly diminish mortality in preterm neonates.
新生儿医学的最新进展提高了早产儿和低出生体重儿的存活率。然而，早产儿的新生儿死亡风险远高于足月儿，且常与感染有关。
早产儿的免疫状态知之甚少；因此，我们分析了 211 份取自极早产儿至足月儿的脐血样本中不同免疫群体的频率和绝对计数。
我们发现，与足月儿相比，所有分析的免疫亚群（即单核细胞、粒细胞、B 细胞、自然杀伤（NK）细胞、CD4(+)和 CD8(+)T 细胞）的绝对计数在早产儿中明显较低。令人惊讶的是，我们观察到调节性 T 细胞（Tregs）是唯一在早产儿中没有减少的细胞亚群，其频率甚至高于足月儿。
Tregs 对母婴耐受至关重要，但它们的抑制作用也可能与早产儿中观察到的白细胞减少有关。我们没有观察到胸腺功能的差异，但我们发现，早产儿血浆白细胞介素（IL）-7 水平及其受体的频率显著降低。我们的研究结果有助于识别白细胞减少症，并实施免疫治疗，显著降低早产儿的死亡率。
