Oocyte donation (OD) pregnancies are characterized by more fetal-maternal human leukocyte antigen (HLA) mismatches compared with naturally conceived (NC) and in vitro fertilization (IVF)... Show moreOocyte donation (OD) pregnancies are characterized by more fetal-maternal human leukocyte antigen (HLA) mismatches compared with naturally conceived (NC) and in vitro fertilization (IVF) pregnancies. The maternal immune system has to cope with greater immunogenetic dissimilarity, but involved immunoregulation remains poorly understood. We examined whether the amount of regulatory T cells (Tregs) and immunoregulatory cytokines in decidua basalis of OD pregnancies differs from NC and IVF pregnancies. The cohort included 25 OD, 11 IVF and 16 NC placentas, maternal peripheral blood, and umbilical cord blood of uncomplicated pregnancies. Placenta slides were stained for FOXP3, IL-10, IL-6, gal-1, TGF-0 and Flt-1. Semi-quantitative (FOXP3+ Tregs) and computerized analysis (cytokines) were executed. The blood samples were typed for HLA class I and II to calculate fetal-maternal HLA mismatches. The percentage of Tregs was significantly higher in pregnancies with 4-6 HLA class I mismatches (n = 17), compared to 0-3 mismatches (n = 35; p = 0.04). Cytokine analysis showed significant differences between OD, IVF and NC pregnancies. Flt-1 was significantly lower in pregnancies with 4-6 HLA class I mismatches (p = 0.004), and in pregnancies with 6-10 HLA mismatches in total (p = 0.024). This study suggests that immunoregulation at the fetal-maternal interface in OD pregnancies with more fetal-maternal HLA mismatches is altered.(c) 2021 The Authors. Published by Elsevier Inc. on behalf of American Society for Histocompatibility and Immunogenetics. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/). Show less
van't Hof, L.J.; Dijkstra, K.L.; Keur, C. van der; Eikmans, M.; Baelde, H.J.; Bos, M.; Hoorn, M.L.P. van der 2020
Oocyte donation (OD) pregnancies are characterized by a complete immunogenetic dissimilarity between mother and fetus, which requires enhanced immunoregulation compared to naturally conceived (NC)... Show moreOocyte donation (OD) pregnancies are characterized by a complete immunogenetic dissimilarity between mother and fetus, which requires enhanced immunoregulation compared to naturally conceived (NC) pregnancies. The trophoblast expresses co-inhibitory ligands crucial for regulation of the maternal T cell response. Therefore, we studied the role of placental immune checkpoint inhibitors for the establishment of fetal tolerance and their relation to the development of preeclampsia in OD compared to NC pregnancies. Placental tissue from uncomplicated OD (n = 21) and NC (n = 21) pregnancies, and OD (n = 9) and NC (n = 15) pregnancies complicated with preeclampsia were studied. Protein expression of co-inhibitory ligands PD-L1 and CD200 was double blind semi-quantitatively determined by immunohistochemistry. Messenger RNA expression of PD-L1, CD200 and indoleamine 2,3-dioxygenase (IDO) was determined using qPCR. Decreased PD-L1 and CD200 protein expression and increased IDO mRNA expression was observed in uncomplicated OD versus NC pregnancies (all p < 0.05). CD200 protein expression was positively correlated with PD-L1 expression in all groups, with the number of HLA total mismatches and with HLA class I mismatches in uncomplicated OD cases (all p < 0.05). Preeclamptic cases showed lower PD-L1 protein and CD200 protein and mRNA expression in OD compared to NC pregnancies (all p < 0.05). This study shows that signaling by co-inhibitory PD-L1 and CD200 and by immunosuppressive IDO is altered in the placenta of OD pregnancies, suggesting a contribution to the higher risk for preeclampsia. These insights provide future prospects in unraveling the immune paradox of oocyte pregnancy, which are applicable for better risk management and treatment of uncomplicated and preeclamptic pregnancies. Show less
Bentem, K. van; Bos, M.; Keur, C. van der; Brand-Schaaf, S.H.; Haasnoot, G.W.; Roelen, D.L.; ... ; Hoorn, M.L.P. van der 2020
In oocyte donation (OD) pregnancy, a fetus can be completely allogeneic to the recipient. Consequently, the maternal immune system has to cope with greater immunogenetic dissimilarity compared to... Show moreIn oocyte donation (OD) pregnancy, a fetus can be completely allogeneic to the recipient. Consequently, the maternal immune system has to cope with greater immunogenetic dissimilarity compared to naturally conceived pregnancy. Previously, we showed an association between successful OD pregnancy and lower immunogenetic dissimilarity, reflected by the number of fetal-maternal Human Leukocyte Antigen (HLA) mismatches, than expected by chance. In this study we aimed to determine whether the development of preeclampsia in OD pregnancies is related to the number of fetal-maternal HLA mismatches.A retrospective, nested case-control study was performed within a cohort of 76 singleton OD pregnancies. Maternal and fetal umbilical cord blood was typed for HLA-A, -B, -C, -DR and -DQ, and the number of fetal-maternal HLA mismatches was calculated. In addition, the incidence of child-specific HLA antibodies was determined.13 pregnancies were complicated by preeclampsia. To demonstrate an influence of HLA mismatches on the development of preeclampsia, a univariate logistic regression analysis was performed adjusted for maternal age and socio-economic status. A significant association between the number of fetal-maternal HLA class II mismatches and the development of preeclampsia was observed (OR = 3.8, 95 % CI: 1.6-9.0; p = 0.003). This association was not linked to the development of HLA class II antibodies.According to our findings, an increased number of HLA class II mismatches is a risk factor for the development of preeclampsia in OD pregnancies. The effect of HLA class II mismatches might be explained by the induction of a cellular rather than a humoral immune response. Show less
