Human leukocyte antigen (HLA)-G during pregnancy part I: correlations between maternal soluble HLA-G at midterm, at term, and umbilical cord blood soluble HLA-G at term

TY - JOUR

T1 - Human leukocyte antigen (HLA)-G during pregnancy part I

T2 - correlations between maternal soluble HLA-G at midterm, at term, and umbilical cord blood soluble HLA-G at term

AU - Klitkou, Louise

AU - Dahl, Mette

AU - Hviid, Thomas Vauvert F

AU - Djurisic, Snezana

AU - Piosik, Zofia Maria

AU - Skovbo, Peter

AU - Møller, Anna Margrethe

AU - Steffensen, Rudi

AU - Christiansen, Ole B

N1 - Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

PY - 2015/4

Y1 - 2015/4

N2 - 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.

AB - 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.

KW - Cohort Studies

KW - Female

KW - Fetal Blood

KW - Follow-Up Studies

KW - Gestational Age

KW - HLA-G Antigens

KW - Humans

KW - Immunity, Maternally-Acquired

KW - Placental Circulation

KW - Pregnancy

KW - Pregnancy Trimester, Second

KW - Journal Article

U2 - 10.1016/j.humimm.2015.01.013

DO - 10.1016/j.humimm.2015.01.013

M3 - Journal article

C2 - 25636573

SN - 0198-8859

VL - 76

SP - 254

EP - 259

JO - Human Immunology

JF - Human Immunology

IS - 4

ER -