Development of the DONOR prediction model on the risk of hypertensive complications in oocyte donation pregnancy:Study protocol for a multicentre cohort study in the Netherlands

Introduction: Oocyte donation (OD) pregnancy is accompanied by a high incidence of hypertensive complications, with serious consequences for mother and child. Optimal care management, involving early recognition, optimisation of suitable treatment options and possibly eventually also prevention, is in high demand. Prediction of patient-specific risk factors for hypertensive complications in OD can provide the basis for this. The current project aims to establish the first prediction model on the risk of hypertensive complications in OD pregnancy. Methods and analysis: The present study is conducted within the DONation of Oocytes in Reproduction project. For this multicentre cohort study, at least 541 OD pregnancies will be recruited. Baseline characteristics and obstetric data will be collected. Additionally, one sample of maternal peripheral blood and umbilical cord blood after delivery or a saliva sample from the child will be obtained, in order to determine the number of fetal-maternal human leucocyte antigen mismatches. Following data collection, a multivariate logistic regression model will be developed for the binary outcome hypertensive complication 'yes' and 'no'. The Prediction model Risk Of Bias ASsessment Tool will be used as guide to minimise the risk of bias. The study will be reported in line with the 'Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis' guideline. Discrimination and calibration will be determined to assess model performance. Internal validation will be performed using the bootstrapping method. External validation will be performed with the 'DONation of Oocytes in Reproduction individual participant data' dataset. Ethics and dissemination: This study is approved by the Medical Ethics Committee LDD (Leiden, Den Haag, Delft), with protocol number P16.048 and general assessment registration (ABR) number NL56308.058.16. Further results will be shared through peer-reviewed journals and international conferences.</p

Inflammatory placental lesions are specifically observed in healthy oocyte donation pregnancies with extreme fetal-maternal incompatibility

Introduction: Oocyte donation (OD) pregnancy is a risk factor for pre-eclampsia (PE). Due to a higher extent of fetal-maternal human leukocyte antigens (HLA) mismatching in OD pregnancies compared to naturally conceived (NC) and in vitro fertilization (IVF) pregnancies, the immune response in OD placentas is probably divergent and affects clinical outcomes. We hypothesized that placental pathology varies among diverse pregnancy conditions and is related to fetal-maternal HLA incompatibility. Methods: Placental lesions were scored in four patient groups: OD-PE (n = 16), OD-healthy (n = 37), NC-PE (n = 45), and IVF-healthy (n = 17). All combinations were genotyped for HLA-A, -B, -C, -DR, and -DQ to calculate fetal-maternal HLA mismatches. Placentas showing chronic deciduitis with plasma cells were immunofluorescently stained with CD138 and the anti-inflammatory cytokine interleukin-10 (IL-10).Results: The distribution and severity of placental lesions varied among groups. The OD-healthy group had the highest inflammation score and greatest extent of chronic deciduitis with plasma cells (p &lt; 0.05). However, the majority of CD138+ plasma cells (90%) in OD-healthy group expressed IL-10, in contrast to the OD-PE group (58%). The OD-healthy group was separated into semi-allogeneic (≤5 HLA mismatches) and fully allogeneic (&gt;5 mismatches) subgroups. The elevated inflammatory pathology score and chronic deciduitis with plasma cells were found more often in the HLA-class-I fully allogeneic OD-healthy group than the IVF-healthy group (p &lt; 0.05). Discussion: Placental inflammatory lesions are most often present in uncomplicated OD pregnancies. Immune cells that infiltrate these lesions might play an immunosuppressive role to protect OD pregnancies from complications when facing a higher extent of fetal-maternal HLA mismatching.</p

Circulating Levels of Anti-C1q and Anti-Factor H Autoantibodies and Their Targets in Normal Pregnancy and Preeclampsia

Preeclampsia (PE) generally manifests in the second half of pregnancy with hypertension and proteinuria. The understanding of the origin and mechanism behind PE is incomplete, although there is clearly an immune component to this disorder. The placenta constitutes a complicated immune interface between fetal and maternal cells, where regulation and tolerance are key. Stress factors from placental dysfunction in PE are released to the maternal circulation evoking the maternal response. Several complement factors play a role within this intricate landscape, including C1q in vascular remodeling and Factor H (FH) as the key regulator of alternative pathway complement activation. We hypothesize that decreased levels of C1q or FH, or disturbance of their function by autoantibodies, may be associated with PE. Autoantibodies against C1q and FH and the concentrations of C1q and FH were measured by ELISA in maternal sera from women with preeclamptic and normal pregnancies. Samples originated from cohorts collected in the Netherlands (n=63 PE; n=174 control pregnancies, n=51 nonpregnant), Finland (n=181 PE; n=63 control pregnancies) and Norway (n=59 PE; n=27 control pregnancies). Serum C1q and FH concentrations were higher in control pregnancy than in nonpregnant women. No significant differences were observed for serum C1q between preeclamptic and control pregnancy in any of the three cohorts. Serum levels of FH were lower in preeclamptic pregnancies compared to control pregnancies in two of the cohorts, this effect was driven by the early onset PE cases. Neither anti-C1q autoantibodies nor anti-FH autoantibodies levels differed between women with PE and normal pregnancies. In conclusion, levels of anti-C1q and anti-FH autoantibodies are not increased in PE. C1q and FH are increased in pregnancy, but importantly, a decrease in FH concentration is associated with PE.Peer reviewe

Identification of a unique intervillous cellular signature in chronic histiocytic intervillositis

Introduction: Chronic histiocytic intervillositis (CHI) is a rare histopathological lesion in the placenta characterized by an infiltrate of CD68+ cells in the intervillous space. CHI is associated with adverse pregnancy outcomes such as miscarriage, fetal growth restriction, and (late) intrauterine fetal death. The adverse pregnancy outcomes and a variable recurrence rate of 25–100% underline its clinical relevance. The pathophysiologic mechanism of CHI is unclear, but it appears to be immunologically driven. The aim of this study was to obtain a better understanding of the phenotype of the cellular infiltrate in CHI. Method: We used imaging mass cytometry to achieve in-depth visualization of the intervillous maternal immune cells and investigated their spatial orientation in situ in relation to the fetal syncytiotrophoblast. Results: We found three phenotypically distinct CD68+HLA-DR+CD38+ cell clusters that were unique for CHI. Additionally, syncytiotrophoblast cells in the vicinity of these CD68+HLA-DR+CD38+ cells showed decreased expression of the immunosuppressive enzyme CD39. Discussion: The current results provide novel insight into the phenotype of CD68+ cells in CHI. The identification of unique CD68+ cell clusters will allow more detailed analysis of their function and could result in novel therapeutic targets for CHI

Identification of a unique intervillous cellular signature in chronic histiocytic intervillositis

Introduction: Chronic histiocytic intervillositis (CHI) is a rare histopathological lesion in the placenta characterized by an infiltrate of CD68+ cells in the intervillous space. CHI is associated with adverse pregnancy outcomes such as miscarriage, fetal growth restriction, and (late) intrauterine fetal death. The adverse pregnancy outcomes and a variable recurrence rate of 25-100% underline its clinical relevance. The pathophysiologic mechanism of CHI is unclear, but it appears to be immunologically driven. The aim of this study was to obtain a better understanding of the phenotype of the cellular infiltrate in CHI.Method: We used imaging mass cytometry to achieve in-depth visualization of the intervillous maternal immune cells and investigated their spatial orientation in situ in relation to the fetal syncytiotrophoblast.Results: We found three phenotypically distinct CD68+HLA-DR+CD38+ cell clusters that were unique for CHI. Additionally, syncytiotrophoblast cells in the vicinity of these CD68+HLA-DR+CD38+ cells showed decreased expression of the immunosuppressive enzyme CD39.Discussion: The current results provide novel insight into the phenotype of CD68+ cells in CHI. The identification of unique CD68+ cell clusters will allow more detailed analysis of their function and could result in novel therapeutic targets for CHI.Research into fetal development and medicin

Identification of a unique intervillous cellular signature in chronic histiocytic intervillositis

Introduction: Chronic histiocytic intervillositis (CHI) is a rare histopathological lesion in the placenta characterized by an infiltrate of CD68+ cells in the intervillous space. CHI is associated with adverse pregnancy outcomes such as miscarriage, fetal growth restriction, and (late) intrauterine fetal death. The adverse pregnancy outcomes and a variable recurrence rate of 25–100% underline its clinical relevance. The pathophysiologic mechanism of CHI is unclear, but it appears to be immunologically driven. The aim of this study was to obtain a better understanding of the phenotype of the cellular infiltrate in CHI. Method: We used imaging mass cytometry to achieve in-depth visualization of the intervillous maternal immune cells and investigated their spatial orientation in situ in relation to the fetal syncytiotrophoblast. Results: We found three phenotypically distinct CD68+HLA-DR+CD38+ cell clusters that were unique for CHI. Additionally, syncytiotrophoblast cells in the vicinity of these CD68+HLA-DR+CD38+ cells showed decreased expression of the immunosuppressive enzyme CD39. Discussion: The current results provide novel insight into the phenotype of CD68+ cells in CHI. The identification of unique CD68+ cell clusters will allow more detailed analysis of their function and could result in novel therapeutic targets for CHI

Placental Complement Activation in Fetal and Neonatal Alloimmune Thrombocytopenia: An Observational Study

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a disease that causes thrombocytopenia and a risk of bleeding in the (unborn) child that result from maternal alloantibodies directed against fetal, paternally inherited, human platelet antigens (HPA). It is hypothesized that these alloantibodies can also bind to the placenta, causing placental damage. This study aims to explore signs of antibody-mediated placental damage in FNAIT. We performed a retrospective study that included pregnant women, their newborns, and placentas. It comprised 23 FNAIT cases, of which nine were newly diagnosed (14 samples) and 14 were antenatally treated with intravenous immune globulins (IVIg) (21 samples), and 20 controls, of which 10 had anti-HLA-class I antibodies. Clinical information was collected from medical records. Placental samples were stained for complement activation markers (C1q, C4d, SC5b-9, and mannose-binding lectin) using immunohistochemistry. Histopathology was examined according to the Amsterdam criteria. A higher degree of C4d deposition was present in the newly diagnosed FNAIT cases (10/14 samples), as compared to the IVIg-treated FNAIT cases (2/21 samples, p = 0.002) and anti-HLA-negative controls (3/20 samples, p = 0.006). A histopathological examination showed delayed maturation in four (44%) placentas in the newly diagnosed FNAIT cases, five (36%) in the IVIg-treated FNAIT cases, and one in the controls (NS). C4d deposition at the syncytiotrophoblast was present in combination with low-grade villitis of unknown etiology in three newly diagnosed FNAIT cases that were born SGA. We conclude that a higher degree of classical pathway-induced complement activation is present in placentas from pregnancies with untreated FNAIT. This may affect placental function and fetal growth

Comparison and appraisal of (inter)national recurrent pregnancy loss guidelines

Investigations and treatment options of recurrent pregnancy loss (RPL) differ internationally. This manuscript reviews the similarities and differences between international guidelines. The European Society of Human Reproduction and Embryology (ESHRE) guideline (2017), the American Society for Reproductive Medicine (ASRM) Committee Opinion (2013) and the Royal College of Obstetricians and Gynaecologists (RCOG) guideline (2011) were appraised using the AGREE II criteria. The guidelines were checked for definitions, risk factors, investigations and therapeutic options. The guidelines agreed on acquired thrombophilia analysis. All guidelines agreed on a regimen for the treatment of antiphospholipid antibody syndrome consisting of aspirin and heparin, but only the ESHRE guideline specified the order of starting these medications. Treatment of thrombophilia and uterine anomalies was advised against; all guidelines recommended supportive care for unexplained RPL. The guidelines did not agree on the definition of RPL and differed in investigations regarding lifestyle, karyotype analysis of parents and/or pregnancy tissue, and the diagnostic tool for uterine anomalies. All three guidelines indicate an association between lifestyle and RPL; the ESHRE recommends health behaviour changes. Couples suffering from RPL should be informed about possible investigations and treatment options, and whether those are evidence-based. It is important for clinicians to realize that the guidelines differ internationally