Xiong Fei, Tong Yu, You Yong, Li Ping, Huo Tingzhu, Tu Wenwei, Mao Meng
Department of Pediatrics, West China Second University Hospital, Sichuan University , Chengdu, Sichuan , PR China.
J Matern Fetal Neonatal Med. 2012 Dec;25(12):2773-7. doi: 10.3109/14767058.2012.715219. Epub 2012 Aug 22.
To evaluate lymphocyte subpopulations' change and impact on the pregnancy outcome in fetal growth restriction (FGR) through a prospective cohort study.
Sixty singleton pregnancies with FGR and 20 normal pregnant women were enrolled at the third trimester of pregnancy in this study. FGR was defined according to fundal height and abdominal circumference through obstetric examination and ultrasound examination. Third trimester peripheral blood and umbilical cord blood lymphocyte subpopulations were analysed by flow cytometry. The cytotoxic activity of lymphocytes using umbilical cord blood mononuclear activated kill cells as the effector cells, K562 cells as the target cells was measured by MTT deoxidation assay.
There were no significant differences about the age, parity, gestational age enrolled, BMI before pregnancy between the FGR and control group. The birth weight, length and head circumference of the neonates from FGR group were less than that from normal control. The percentages of B-lymphocytes in peripheral blood at the third trimester were significantly increased in FGR group compared to that in control group (P < 0.05). In umbilical cord blood, FGR group had a higher percentage of both CD3 and CD4 lymphocyte, lower absolute cell counts and percentage of B-lymphocyte, and higher CD4/CD8 ratio than control group (P < 0.05). Most importantly, the kill cell activity of the lymphocytes in cord blood from FGR group was significantly higher than that from control group (P < 0.05). The significant positive correlations were also found that the percentage and number of B lymphocytes in umbilical cord blood with birthweight, birthlength and birth head circumference, but CD4/CD8 ratio, the kill cell activity in umbilical cord blood had negative correlations with that. The percentage of B lmyphocyte in third trimester and CD4/CD8 ratio, kill cell activity in umbilical cord blood are associated with an increased risk of prematurity and SGA birth, but contrary result was found with the percentage and number of B lmyphocyte in cord blood.
Fetal immunological rejection could be involved in the pathogenesis of FGR. The changes of T lymphocyte subpopulations and B-cells, enhanced kill cell activity might cause FGR and preterm birth.
通过一项前瞻性队列研究，评估淋巴细胞亚群的变化及其对胎儿生长受限（FGR）妊娠结局的影响。
本研究纳入了60例单胎FGR孕妇和20例正常孕妇，均处于妊娠晚期。通过产科检查和超声检查，根据宫高和腹围定义FGR。采用流式细胞术分析妊娠晚期外周血和脐血淋巴细胞亚群。以脐血单个核活化杀伤细胞为效应细胞、K562细胞为靶细胞，采用MTT比色法检测淋巴细胞的细胞毒活性。
FGR组与对照组在年龄、产次、入组时孕周、孕前BMI方面无显著差异。FGR组新生儿的出生体重、身长和头围均低于正常对照组。与对照组相比，FGR组妊娠晚期外周血B淋巴细胞百分比显著升高（P<0.05）。脐血中，FGR组CD3和CD4淋巴细胞百分比更高，B淋巴细胞绝对细胞计数和百分比更低，CD4/CD8比值高于对照组（P<0.05）。最重要的是，FGR组脐血淋巴细胞的杀伤细胞活性显著高于对照组（P<0.05）。还发现脐血中B淋巴细胞的百分比和数量与出生体重、出生身长和出生头围呈显著正相关，但与CD4/CD8比值、脐血杀伤细胞活性呈负相关。妊娠晚期B淋巴细胞百分比、CD4/CD8比值、脐血杀伤细胞活性与早产和小于胎龄儿出生风险增加有关，但脐血中B淋巴细胞的百分比和数量则相反。
胎儿免疫排斥可能参与FGR的发病机制。T淋巴细胞亚群和B细胞的变化、增强的杀伤细胞活性可能导致FGR和早产。
