Klitkou Louise, Dahl Mette, Hviid Thomas Vauvert F, Djurisic Snezana, Piosik Zofia Maria, Skovbo Peter, Møller Anna Margrethe, Steffensen Rudi, Christiansen Ole B
Department of Obstetrics and Gynecology, Aalborg University Hospital, 9000 Aalborg, Denmark.
Department of Clinical Biochemistry, Centre for Immune Regulation and Reproductive Immunology (CIRRI), Copenhagen University Hospital (Roskilde) and Roskilde Hospital, 7-13 Køgevej, DK-4000 Roskilde, Denmark.
Hum Immunol. 2015 Apr;76(4):254-9. doi: 10.1016/j.humimm.2015.01.013. Epub 2015 Jan 28.
Human leukocyte antigen (HLA)-G is a class Ib molecule with restricted tissue distribution expressed on trophoblast cells and has been proposed to have immunomodulatory functions during pregnancy. Soluble HLA-G1 (sHLA-G1) can be generated by the shedding of membrane-bound HLA-G molecules; however, three soluble isoforms also exist (HLA-G5 to -G6). During pregnancy, it is unknown whether there is a correlation between sHLA-G levels in maternal and fetal blood. In 246 pregnancies, we have measured the levels of sHLA-G1/-G5 in maternal blood plasma samples from gestational week 20 (GW20) and at term, as well as in umbilical cord blood samples. Soluble HLA-G levels declined by 38.4% in maternal blood from GW20 to term, and sHLA-G levels were significantly lower in maternal blood at term than in GW20 (P<0.001). At term, the sHLA-G levels were significantly higher in maternal blood than in umbilical blood (P<0.001). HLA-G levels in maternal blood in GW20 and at term, and in maternal blood at term and umbilical cord blood, were correlated (P<0.001 and P<0.01, respectively). This is the first large study simultaneously measuring sHLA-G in both maternal and umbilical cord blood. The finding that sHLA-G levels are significantly lower in fetal compared with maternal blood at term documents for the first time that sHLA-G is not freely transferred over the placental barrier. Soluble HLA-G levels in maternal and fetal blood were found to be correlated, which may be due to shared genetic factors of importance for production of sHLA-G in the mother and child, or it may support the theory that sHLA-G in the pregnant woman and the fetus is partly derived from a "shared organ", the placenta.
人类白细胞抗原（HLA）-G是一种I类b分子，组织分布受限，在滋养层细胞上表达，并且有人提出其在妊娠期间具有免疫调节功能。可溶性HLA-G1（sHLA-G1）可通过膜结合HLA-G分子的脱落产生；然而，也存在三种可溶性异构体（HLA-G5至-G6）。在妊娠期间，母血和胎儿血中sHLA-G水平之间是否存在相关性尚不清楚。在246例妊娠中，我们测量了妊娠20周（GW20）和足月时母血血浆样本以及脐带血样本中sHLA-G1/-G5的水平。从GW20到足月，母血中可溶性HLA-G水平下降了38.4%，足月时母血中sHLA-G水平显著低于GW20时（P<0.001）。足月时，母血中sHLA-G水平显著高于脐带血（P<0.001）。GW20时和足月时母血中的HLA-G水平，以及足月时母血和脐带血中的HLA-G水平具有相关性（分别为P<0.001和P<0.01）。这是第一项同时测量母血和脐带血中sHLA-G的大型研究。足月时胎儿血中sHLA-G水平显著低于母血这一发现首次证明sHLA-G不能自由通过胎盘屏障。母血和胎儿血中的可溶性HLA-G水平被发现具有相关性，这可能是由于对母婴sHLA-G产生具有重要意义的共同遗传因素，或者它可能支持这样一种理论，即孕妇和胎儿体内的sHLA-G部分来源于“共享器官”胎盘。
