Pahal G S, Jauniaux E, Kinnon C, Thrasher A J, Rodeck C H
Academic Department of Obstetrics and Gynaecology, Institute of Child Health, University College London, London, United Kingdom.
Am J Obstet Gynecol. 2000 Oct;183(4):1029-34. doi: 10.1067/mob.2000.106976.
The aim of this study was to compare the hematologic compositions of fetal blood and liver and to phenotypically quantify the hematopoietic stem and progenitor cells during early human gestation.
Fifty fetal blood samples and 50 fetal livers were collected at 10 to 17 weeks' gestation and 8 to 17 weeks' gestation, respectively. Investigations included fetal blood cell counts, determinations of red blood cell index values, and flow cytometric analyses of mononuclear cells.
Fetal red blood cell, white blood cell, and platelet counts all increased with gestation, reflecting hematologic development. The proportion of normoblasts decreased dramatically with gestation. Individual mature red blood cells were larger and contained more hemoglobin during early gestation. Circulating and hepatic T lymphocytes increased in number shortly before the 13th week of gestation, which reflected thymic maturation. As a proportion fetal liver contained fewer T lymphocytes than did fetal blood (2.5% vs 18.6%; P =.003) but more CD34(+) hematopoietic stem and progenitor cells (17.5% vs 4.3%; P =. 004). As a proportion, fetal liver contained more of the primitive CD34(+) and CD38(-) hematopoietic stem and progenitor cells than did fetal blood (32% vs 17%; P =.04).
Both fetal blood and liver provide a rich source of hematopoietic stem and progenitor cells. Fetal liver provides a richer source of more primitive hematopoietic stem and progenitor cells than does fetal blood. For stem cell transplantation we suggest that fetal livers be collected before the 13th week of gestation, because T lymphocytes are present in much greater numbers in the fetal liver after this stage of gestation. Further, we suggest that in utero stem cell transplantations in fetuses with normal immune development should be performed before the 13th week of gestation.
本研究旨在比较胎儿血液和肝脏的血液学组成，并对人类妊娠早期的造血干细胞和祖细胞进行表型定量分析。
分别在妊娠10至17周和8至17周时收集50份胎儿血液样本和50份胎儿肝脏样本。研究包括胎儿血细胞计数、红细胞指数值测定以及单核细胞的流式细胞术分析。
胎儿红细胞、白细胞和血小板计数均随孕周增加而升高，反映了血液学发育情况。早幼红细胞比例随孕周显著下降。妊娠早期单个成熟红细胞更大且血红蛋白含量更高。循环和肝脏T淋巴细胞在妊娠第13周前不久数量增加，这反映了胸腺成熟。胎儿肝脏中T淋巴细胞比例低于胎儿血液（2.5%对18.6%；P = 0.003），但CD34(+)造血干细胞和祖细胞更多（17.5%对4.3%；P = 0.004）。胎儿肝脏中原始的CD34(+)和CD38(-)造血干细胞和祖细胞比例高于胎儿血液（32%对17%；P = 0.04）。
胎儿血液和肝脏均提供了丰富的造血干细胞和祖细胞来源。胎儿肝脏比胎儿血液提供了更丰富的更原始造血干细胞和祖细胞来源。对于干细胞移植，我们建议在妊娠第13周前收集胎儿肝脏，因为在此妊娠阶段后胎儿肝脏中T淋巴细胞数量更多。此外，我们建议对免疫发育正常的胎儿进行宫内干细胞移植应在妊娠第13周前进行。
