Southern Medical University, Guangzhou, Guangdong Province, China; Department of Neonatology, Shenzhen Bao'an Maternal and Child Health Hospital, Guangzhou, Guangdong Province, China.
Scand J Immunol. 2014 Jul;80(1):50-6. doi: 10.1111/sji.12181.
Immune status in the early life of preterm infants and its association with late onset infection has not been fully described. To investigate immune status of lymphocyte subsets in the first week in preterm neonates and its association with late onset infection, 143 preterm neonates (84 neonates ≤32 weeks, 59 neonates of 33-36 weeks) and 49 term neonates were recruited. Absolute counts and percentages of lymphocyte subsets were measured by flow cytometry in umbilical cord or venous blood at birth (in all neonates), on day 3 and 7 (in preterm neonates). The presence of late onset infection was recorded in very preterm neonates ≤32 weeks. At birth, absolute counts of most lymphocyte subsets in all preterm neonates and percentages of B cell and NK cell in those ≤32 weeks were reduced compared with term neonates. Absolute counts of all the subsets in preterm neonates showed decline after birth then beginning to rise after day 3. Late onset infections were documented in 33 of 84 very preterm infants ≤32 weeks and 27 of 45 very preterm infants ≤30 weeks. Percentages of NK cell at birth in very preterm neonates ≤30 weeks with late onset infection were significantly reduced compared with those without infection (P < 0.01). In conclusion, immune status of lymphocyte subsets in preterm neonates at birth is less developmental than in term neonates, in spite of the ability of getting improvement in the first week. Reduced NK cell percentage at birth would increase the risk of subsequent infection in very preterm infants.
早产儿早期的免疫状态及其与迟发性感染的关系尚未完全描述。为了研究早产儿出生后第一周淋巴细胞亚群的免疫状态及其与迟发性感染的关系，招募了 143 例早产儿（84 例≤32 周，59 例 33-36 周）和 49 例足月产儿。通过流式细胞术测量脐血或出生时（所有新生儿）、第 3 天和第 7 天（早产儿）静脉血中淋巴细胞亚群的绝对计数和百分比。记录≤32 周的极早产儿迟发性感染的发生情况。出生时，所有早产儿的大多数淋巴细胞亚群的绝对计数和≤32 周的 B 细胞和 NK 细胞的百分比均低于足月儿。早产儿所有亚群的绝对计数出生后下降，然后在第 3 天后开始上升。在 84 例≤32 周的极早产儿中，有 33 例发生迟发性感染，在 45 例≤30 周的极早产儿中，有 27 例发生迟发性感染。出生时患有迟发性感染的≤30 周极早产儿 NK 细胞的百分比明显低于无感染的患儿（P<0.01）。总之，尽管在出生后第一周内能够得到改善，但早产儿出生时的淋巴细胞亚群免疫状态发育不成熟，与足月儿相比。出生时 NK 细胞百分比降低会增加极早产儿随后感染的风险。
