To evaluate drug pharmacodynamics in an open-label phase 2 study evaluating nipocalimab, an anti-FcRn (neonatal Fc receptor) blocking antibody, for prevention of fetal anemia, intrauterine transfusions (IUTs), and poor outcomes in pregnancies at high risk of early-onset severe hemolytic disease of the fetus and newborn (EOS HDFN). The UNITY study (Clinical trials.gov #NCT03842189) enrolled 14 RhD or Kell (K) alloimmunised singleton pregnancies with a prior obstetric history of HDFN onset at ≤24 weeks of gestation. One pregnancy was not included in analysis due to an early elective abortion for an unrelated reason. Weekly nipocalimab (30 or 45 mg/kg) was administered from 14 to 35 weeks of gestation with delivery targeted for 37 weeks of gestation. Pharmacodynamic markers, serum total IgG, alloantibody titer, and FcRn occupancy were assessed every 2 weeks in mothers and in cord blood at delivery or at IUTs. Full FcRn occupancy, IgG lowering, and alloantibody decreases were observed within 2 weeks after the initiation of nipocalimab treatment. Decreases from baseline for IgG ranged from –80% to –85% and for alloantibody titers ranged from 4- to 32-fold. FcRn occupancy was rapidly lost within 2-3 weeks after the last dose followed by rises in IgG and alloantibody titers. IgG and alloantibody titers from IUT cordocentesis (fetal) and in cord blood at delivery (newborns) were lower than concurrent maternal levels during full FcRn occupancy but were similar several weeks after dose cessation and loss of occupancy. Nipocalimab demonstrates rapid and reversible FcRn occupancy, lowering of maternal IgG alloantibodies and evidence for decreased placental IgG alloantibody transfer. As a result, nipocalimab warrants further evaluation in a global phase 3 study in HDFN.
There are scarce data on the management of chronic hypoparathyroidism (hypoPT) in pregnant women.The aim of this study was to evaluate pregnancy outcome and total number of births in maternal chronic hypoPT.The Swedish National Patient Register, The Swedish Prescribed Drug Register, Swedish Medical Birth Register, and the Total Population Register were used to identify 97 women with chronic hypoPT and 1030 age-matched controls who delivered 139 and 1577 singleton infants, respectively, following diagnosis between 1997 and 2017.Women in the chronic hypoPT group had more frequent diabetes (DM) and chronic kidney disease (CKD) compared with the control group (P = 0.043 and P < 0.001, respectively). After adjusting for DM, CKD, maternal age at delivery, and calendar year of delivery, chronic hypoPT cases were associated with increased risk of induction of labor (OR, 1.82; 95% CI, 1.13-2.94) and birth of infants with lower birth weight (β-coefficient -188 g; 95% CI, -312.2 to -63.8) compared with controls. No difference was found in infant length, small for gestational age, or head circumference after adjustments. Mean gestational age at delivery after controlling for DM, CKD, and pre-eclampsia was not significantly younger (P = 0.119). There was no difference in congenital malformations or perinatal death and no difference in the total number of infants born between groups (P = 0.518).The majority of women with chronic hypoPT had normal pregnancy outcomes, and the overall risks appear low. Maternal chronic hypoPT is, however, associated with higher risk of induction of labor and slightly lower infant birth weight.
Routine antenatal anti-D prophylaxis (RAADP) to RhD-negative women is most often administered in gestational age (GA) 28-30 weeks with the next anti-D dose administered postpartum. The aim of this study was to analyse the proportion of RhD-negative women where RAADP is not detectable at term and in a pilot study to investigate whether RAADP administered in GA 28 and 38 results in detectable levels at term, post-term and post-delivery.In a retrospective analysis, 4280 RhD-negative women carrying an RHD positive fetus were included and the proportion with a negative antibody screen at delivery was determined. In the second part, 39 pregnancies were included prospectively, a second dose of RAADP was administered in GA 38 weeks, and anti-D was quantified before the second dose and then weekly for 5 weeks.In the retrospective analysis, 20·5% (856/4280) with RAADP administered in GA 28 were negative in routine antibody screening at delivery. In the small prospective study, 18% (7/39) had a negative antibody screen and 26% (10/39) had levels below 0·005 IU/ml, in the quantification assay, in GA 38. Anti-D prophylaxis administered in GA 38 showed detectable levels of anti-D up to 30 days post-delivery, with concentration at delivery 0·060 ± 0·034 IU/ml (mean ± SD).Approximately 20% of the RhD-negative women show non-detectable levels of anti-D at term. A second dose of RAADP at GA 38 results in stable concentrations of anti-D at term, post-term and post-delivery, but with large interindividual variation.
The lack of fetal immune responses to foreign antigens, i.e., fetal immunologic tolerance, is the most compelling rationale for prenatal stem cell and gene therapy. However, the frequency of engraftment following in utero hematopoietic cell transplantation (IUHCT) in the murine model is reduced in allogeneic, compared with congenic, recipients. This observation supports the existence of an immune barrier to fetal transplantation and challenges the classic assumptions of fetal tolerance. Here, we present evidence that supports the presence of an adaptive immune response in murine recipients of IUHCT that failed to maintain engraftment. However, when IUHCT recipients were fostered by surrogate mothers, they all maintained long-term chimerism. Furthermore, we have demonstrated that the cells responsible for rejection of the graft were recipient in origin. Our observations suggest a mechanism by which IUHCT-dependent sensitization of the maternal immune system and the subsequent transmission of maternal alloantibodies to pups through breast milk induces a postnatal adaptive immune response in the recipient, which, in turn, results in the ablation of engraftment after IUHCT. Finally, we showed that non-fostered pups that maintained their chimerism had higher levels of Tregs as well as a more suppressive Treg phenotype than their non-chimeric, non-fostered siblings. This study resolves the apparent contradiction of induction of an adaptive immune response in the pre-immune fetus and confirms the potential of actively acquired tolerance to facilitate prenatal therapeutic applications.
The main, but not sole, indication for an Ex-utero Intrapartum Treatment (EXIT) delivery is an airway obstruction due to either laryngeal atresia or tumors in the head and neck region. Here we present our Institution's experience with eleven cases: three teratomas, four lymphatic malformations, two laryngeal atresias and two dermoid cysts. The EXIT procedure was used to secure the fetal airway while maintaining uteroplacental gas exchange and fetal hemodynamic stability through the umbilical circulation. Five fetuses required tracheostomy. Only one fetal death occurred due to extensive growth of a teratoma preventing us from establishing an airway. No other fetal or major maternal complication occurred. The EXIT procedure is a complex procedure and these rare cases should be referred to a center with a dedicated and experienced multidisciplinary team.
To retrospectively investigate perinatal outcome of monoamniotic twin pregnancies in a tertiary center during a 10 year period.A retrospective analysis of all monoamniotic pregnancies managed at Karolinska University Hospital, Stockholm, Sweden 2010-2019 was performed. The primary outcomes were live birth rate, neonatal death and perinatal survival. The secondary outcomes were late miscarriage, gestational age at delivery and frequency of fetal complications.Twenty-two monoamniotic pregnancies, with 44 fetuses, were identified. Thirty-five of 44 fetuses (80%) were liveborn. Of 36 fetuses reaching 24 weeks gestation, 35 (97%) were liveborn. There were no neonatal deaths, thus the perinatal survival was 97%. The mean gestational age at birth was 32.5 weeks (SD ± 1.5).The live birth rate and perinatal survival of monoamniotic pregnancies managed at Karolinska University Hospital was high and comparable to previously published data.
To estimate the cost-effectiveness of first trimester non-invasive fetal RHD screening for targeted antenatal versus no routine antenatal anti-D prophylaxis (RAADP) or versus non-targeted RAADP.Model based on a population-based cohort study.The Swedish health service.Intervention subjects in the underlying cohort study were RhD-negative pregnant women receiving first trimester fetal RHD screening followed by targeted anti-D in 2010-2011 (n = 6723). Historical comparators were RhD-negative women who delivered in 2008-2009 when standard care did not include RAADP (n = 7099).Healthcare costs for the three strategies were included for the first and subsequent pregnancies. For the comparison with non-targeted RAADP, the immunisation rate was based on the observed rate for targeted therapy and adjusted downwards by removing the influence of false negatives.Additional cost per RhD immunisation averted.Compared with RAADP, targeted prophylaxis was associated with fewer immunisations (0.19 versus 0.46% per pregnancy) and lower costs (cost-savings of €32 per RhD-negative woman). The savings were from lower costs during pregnancy and delivery, and lower costs of future pregnancies through fewer immunisations. Non-targeted anti-D was estimated to result in 0.06% fewer immunisations and an additional €16 in cost-savings per mother, compared with targeted anti-D.Based on effect data from a population-based cohort study, targeted prophylaxis was associated with lower immunisation risk and costs versus no RAADP. Based on effect data from theoretical calculations, non-targeted RAADP was predicted to result in lower costs and immunisation risk compared with targeted prophylaxis.Fetal RHD screening and targeted prophylaxis resulted in lower immunisation risk and costs compared with no RAADP.
During pregnancy, the maternal immune system must tolerate the developing foetus, and yet retain a potent antimicrobial response to prevent infections. Mucosal associated invariant T (MAIT) cells recognize microbial-derived vitamin B metabolites presented on the MR1 molecule, but their presence and function at the foetal-maternal interface is not known. We here isolated mononuclear cells from paired samples of peripheral blood (PB), intervillous blood (IVB), and decidua parietalis (DP) following uncomplicated term pregnancies. Interestingly, MAIT cells were highly enriched in IVB compared to PB and DP. The activation status of IVB MAIT cells was similar to that of PB MAIT cells, except for a lower expression of PD-1. Both IVB MAIT cells and conventional T cells were more dominated by an effector memory phenotype compared to PB MAIT cells and T cells. IVB MAIT cells also responded more vigorously with expression of IFN-γ, granzyme B, and perforin in response to Escherichia coli stimulation compared to PB. MR1 was not expressed in syncytiotrophoblasts, but in placental villous and decidual macrophages. These data indicate that maternal MAIT cells accumulate in the intervillous space of the placenta and that they are highly armed to quickly respond if bacteria are encountered at the foetal-maternal interface.