The basis and value of currently used immunomodulatory therapies in recurrent miscarriage

Intralipid therapy and adverse reproductive outcome: is there any evidence?

Controversy exists regarding the benefits of intravenous intralipid therapy in patients with a poor reproductive history. It is frequently reported that there is no evidence to support the effectiveness, utility or safety for this treatment. While individual studies may be perceived as weak, a systematic review and meta-analysis were performed to determine if there is any advantage to patients. PubMed, Embase and Scopus searches were performed with the target populations being either recurrent pregnancy loss (RPL), or recurrent implantation failure (RIF) undergoing assisted reproductive technology (ART) and receiving intralipid infusions. These cohorts were compared with either placebo, no intervention or alternative treatments. The most relevant outcome measures were considered to be clinical pregnancy rate (CPR), live birth rate (LBR), implantation rate (IR) and miscarriage rate (MR). Twelve studies encompassing 2676 participants met the criteria for selection and were included and reviewed. Treatment of the target population with intralipid led to an improvement in IR (Odds Ratio (OR): 2.97, 2.05–4.29), pregnancy rate (OR: 1.64, 1.31–2.04), and LBR (OR: 2.36, 1.75–3.17), with a reduction in MR (OR: 0.2, 0.14–0.30). Although intravenous intralipid is not recommended as a routine treatment for recurrent miscarriage or implantation failure, there is enough data to suggest consideration in selected patients where routine testing is unremarkable, standard treatments have failed and immunological risk factors are present. The presence of abnormal uterine natural killer (uNK) cells needs more study as a target marker to determine those who could benefit.

Th17/Regulatory T cells ratio evolution: A prospective study in a group of healthy pregnant women

During pregnancy, the maternal immune system is challenged to tolerate a semi-allogenic fetus. A shift toward a tolerogenic profile is essential to ensure a healthy fetal and placental development. One of the most important mechanisms involved in the maternal immune tolerance towards the fetal antigens is expressed in the activity of the regulatory T (Treg) and Th17 cells. The behavior and equilibrium of these two T lymphocyte populations were rarely studied in normal healthy pregnancies through the beginning of gestation to the postpartum period. We conducted a prospective longitudinal observational study where peripheral blood lymphocyte subsets were analyzed in each trimester of pregnancy and postpartum period in a group of healthy pregnant women. Our study observed a consistent reduction in peripheric Treg cell count through all pregnancy while the Th17 cell count remained stable. The Th17/Treg ratio increases significantly throughout pregnancy to the postpartum period. These changes could be justified by the migration of the immunotolerant Treg cells to the maternal decidua and lead to the establishment of a systemic pro-inflammatory profile by the end of pregnancy. This data could explain why systemic syndromes like preeclampsia develop in susceptible women during the second half of pregnancy or why many autoimmune disorders flourish in the first weeks postpartum.

A novel update on vitamin D in recurrent pregnancy loss (Review)

Recurrent pregnancy loss (RPL) is usually characterized as ≥3 miscarriages before 20 weeks of gestation. Patients with RPL may have autoimmune abnormalities or alloimmune problems. Vitamin D has a major function on the mechanism of immunomodulation at the maternal-fetal interface. However, whether vitamin D can be used as an effective method to treat patients with RPL requires investigation. It has been reported that vitamin D could prevent the occurrence of antiphospholipid syndrome (APS) by reducing the expression levels of anti-β2 glycoprotein and tissue factor in RPL cases with APS. In addition, there is an opposite relationship between vitamin D and thyroid peroxidase antibody levels in autoimmune thyroid disease cases with RPL. Vitamin D changes the ratio of T helper (Th) 1/Th2 and regulatory T cell/Th17 to a certain extent, as well as affects the activity of natural killer cells and the production of cytokines to reduce the incidence of RPL. The objective of the current review was to address the research progress of vitamin D in RPL in recent years, which could facilitate the use of vitamin D treatment to enhance the pregnancy outcome of RPL. Collectively, it was suggested that vitamin D may be used as an important and effective immunotherapeutic agent for patients with RPL.

Decidualization score identifies an endometrial dysregulation in samples from women with recurrent pregnancy losses and unexplained infertility

OBJECTIVE

To study decidualization-associated endometrial factors.

DESIGN

Retrospective cohort study to compare endometrial gene expression patterns in women experiencing reproductive failure including recurrent pregnancy loss or unexplained infertility versus fertile controls.

SETTING

University Reproductive Medicine Center.

PATIENTS

Women experiencing recurrent reproductive failure including recurrent pregnancy loss or unexplained infertility (n = 42) and fertile controls (n = 18).

INTERVENTIONS

Endometrial biopsy samples were analyzed with targeted ribonucleic acid sequencing via next-generation sequencing.

MAIN OUTCOME MEASURES

The primary end point measurements were the expression of genes important for endometrial transformation during decidualization measured singly and in a combined/cumulative score approach. The secondary end point measurements were receiver operating curve analysis and comparisons between the specific biomarkers.

RESULTS

The comparison revealed differential expression of factors associated with decidualization, tissue homeostasis, and immune regulation: FOXO1, GZMB, IL15, SCNN1A, SGK1, and SLC2A1. A combined evaluation of these 6 signature factors was designated as a decidualization score in which the maximal score was "6" and the minimal was "0". Among controls, 89% of the samples had a score ≥5 and 11% had a score of "4". A total of 76% of samples in the patient group had scores ≤4 and 19% had the lowest score of "0". A decidualization score <4 provided evidence of abnormality in the decidualization process with a sensitivity of 76% (95% CI 61%-88%) and specificity of 89% (95% CI 65%-99%).

CONCLUSIONS

Decidualization scoring can determine whether the endometrial molecular profile is implantation-friendly. Further validation of this testing approach is necessary to determine a particular patient population in whom it could be used for selecting patients that require therapeutic actions to improve endometrial conditions prior to the in vitro fertilization procedure.

Beyond Uterine Natural Killer Cell Numbers in Unexplained Recurrent Pregnancy Loss: Combined Analysis of CD45, CD56, CD16, CD57, and CD138

Changes in the number and cytotoxic potential of uterine Natural Killer (uNK) cells have been associated with reduced fertility. To provide a better characterization of immunophenotypes in the endometrium of women with uRPL (unexplained recurrent pregnancy loss), we examined the applicability of a set of five immune cell markers. The concentration (cells/mm²) of CD45⁺ leukocytes, CD56⁺ uNK cells, and CD138⁺ plasma cells as well as of CD16⁺ and CD57⁺ cells, which indicate high cytotoxic uNK cells, were assessed by immunohistochemistry in endometrial biopsies from 61 uRPL patients and 10 controls. Control fertile endometria presented 90-300 CD56⁺ uNK cells/mm². uRPL cases were classified in subgroups of low (uRPL-CD56^low < 90 cells/mm²), normal (uRPL-CD56^normal 90-300 cells/mm²), and high uNK cell counts (uRPL-CD56^high > 300 cells/mm²). Some cases from the uRPL-CD56^low and uRPL-CD56^normal subgroups showed elevated proportions of cytotoxic CD16⁺ and CD57⁺ cells in relation to CD56⁺ cells. In the uRPL-CD56^high subgroup, the CD57/CD56 ratio was reduced in most samples and the CD16/CD56 ratio was unaltered. Analysis of CD138 excluded the influence of chronic endometritis on these observations. Our results reinforce a link between uRPL and a dysfunctional endometrial environment associated with distinct immune cell profiles.

Phosphorylated STAT3 inhibited the proliferation and suppression of decidual Treg cells in unexplained recurrent spontaneous abortion

This study aimed to investigate the effects of signal transducer and activators of transcription 3 (STAT3) phosphorylation on the function of decidual regulatory T (Treg) cells in unexplained recurrent spontaneous abortion (URSA) patients and to explore the mechanism of STAT3 in URSA. Treg cells were sorted out from the decidual tissue by magnetic beads. The inhibitor Stattic was utilized to alter the phosphorylation status of STAT3 (pSTAT3) in Treg cells. The proliferation and suppression of Treg cell were detected by flow cytometry, real-time quantitative fluorescent PCR and ELISA. The factors that caused the hyperphosphorylation of Treg cells were detected. Our results showed that the proportion of pSTAT3 cells in the decidual Treg cells of URSA patients was significantly increased. pSTAT3 inhibited the proliferation of Treg cells by downregulating the expression of STAT5 and Foxp3 and increased the number of responder T cells. pSTAT3 decreased the secretion of TGF-β1 and IL-10 in Treg cells. Overexpression of pro-inflammatory cytokines IL-6 and IL-23 stimulated STAT3 phosphorylation in Treg cells. This study suggests that hyperphosphorylation of STAT3 impairs the proliferation, suppression and cytokine secretion of Treg cells, while inhibiting the phosphorylation of STAT3 restores these functions. These findings clarify the role of STAT3 in the pathogenesis of URSA and provide new ideas for the treatment of URSA.

Intralipid Immunotherapy for Repeated IVF Failure

The intravenous fat emulsion, intralipid, has been hypothesised to be an effective and safe treatment for repeated in vitro fertilisation (IVF), implantation failure and pregnancy loss. This exploratory, retrospective cohort study determined pregnancy outcomes and documented adverse events associated with intralipid use. Ninety-three women were identified as having received intralipid for a history of repeated unsuccessful IVF cycles and pre-viable pregnancy loss in two Australian IVF units that independently recruited between October 2014 and July 2016. Pregnancy outcomes and adverse events were recorded in fresh and frozen embryo transfer cycles in which the infusion was administered. The 93 women who received intralipid had a clinical pregnancy rate of 40.0%, compared with 35.0% in 651 age-matched controls undergoing IVF, which was not significantly different. The intralipid group had a livebirth rate of 35.7%. Apart from flushing, which was experienced by one individual, there were no adverse events associated with intralipid use. As a prelude to definitive evidence of benefit, we did not identify a safety concern or reduced pregnancy rates in intralipid users compared to controls. Indeed, these outcomes were better than expected in a poor prognosis group. This data supports an argument for large, randomised controlled trials to determine the benefit of intralipid in the treatment of recurrent implantation failure or miscarriage.

Smoking, HIV, and risk of pregnancy loss

OBJECTIVE

Cigarette smoking during pregnancy increases risks of poor pregnancy outcomes including miscarriage and stillbirth (pregnancy loss), but the effect of smoking on pregnancy loss among HIV-infected women has not been explored. Here, investigated the impact of smoking on risk of pregnancy loss among HIV-positive and HIV-negative women, and estimated the potential impact of realistic smoking cessation interventions on risk of pregnancy loss among HIV-positive women.

DESIGN

We analyzed pregnancy outcomes in HIV-positive and HIV-negative participants in the Women's Interagency HIV Study between 1994 and 2014.

METHODS

We estimated effects of current smoking at or immediately before pregnancy on pregnancy loss; we controlled for confounding using regression approaches, and estimated potential impact of realistic smoking cessation interventions using a semiparametric g-formula approach.

RESULTS

Analysis examined 1033 pregnancies among 659 women. The effect of smoking on pregnancy loss differed dramatically by HIV status: adjusted for confounding, the risk difference comparing current smokers to current nonsmokers was 19.2% (95% confidence limit 10.9-27.5%) in HIV-positive women and 9.7% (95% confidence limit 0.0-19.4%) in HIV-negative women. These results were robust to sensitivity analyses. We estimated that we would need to offer a realistic smoking cessation intervention to 36 women to prevent one pregnancy loss.

CONCLUSION

Smoking is a highly prevalent exposure with important consequences for pregnancy in HIV-positive pregnant women in the United States, even in the presence of potent highly active antiretroviral therapy. This evidence supports greater efforts to promote smoking cessation interventions among HIV-positive women, especially those who desire to become pregnant.

Intralipid supplementation in women with recurrent spontaneous abortion and elevated levels of natural killer cells

OBJECTIVE

To investigate the efficacy of intralipid supplementation in women with recurrent spontaneous abortion (RSA) and elevated natural killer cell activity undergoing in vitro fertilization/intracytoplasmic sperm injection.

METHODS

Between February 10, 2013, and April 30, 2015, a double-blind randomized controlled study was conducted at a center in Egypt. Women with unexplained secondary infertility, RSA, and elevated levels of natural killer cells (>12%) were enrolled and randomly assigned to receive intralipid (2mL diluted at 20% in 250mL saline) or saline (250mL) infusion on the day of oocyte retrieval using random numbers and sealed envelopes. Patients and attending physicians were masked to group assignment. The infusions were repeated within 1week of a positive pregnancy test and then every 2weeks until the end of the first trimester. The primary outcome was chemical pregnancy 14days after embryo transfer. Analyses were by intention-to-treat.

RESULTS

Overall, 296 women were enrolled. Chemical pregnancy was recorded for 84 (58.3%) of 144 women in the intralipid group and 76 (50.0%) of 152 in the control group (P=0.129).

CONCLUSION

Intralipid supplementation did not increase frequency of chemical pregnancy. However, findings related to ongoing pregnancy and live birth should be investigated further. ClinicalTrials.gov:NCT01788540.

Immunogenetic contributions to recurrent pregnancy loss

While sporadic pregnancy loss is common, occurring in 15 % of pregnancies, recurrent pregnancy loss (RPL) impacts approximately 5 % of couples. Though multiple causes are known (including structural, hormonal, infectious, autoimmune, and thrombophilic causes), after evaluation, roughly half of all cases remain unexplained. The idiopathic RPL cases pose a challenging therapeutic dilemma in addition to incurring much physical and emotional morbidity. Immunogenetic causes have been postulated to contribute to these cases of RPL. Natural Killer cell, T cell expression pattern changes in the endometrium have both been shown in patients with RPL. Human leukocyte antigen (HLA) and cytokine allelic variations have also been studied as etiologies for RPL. Some of the results have been promising, however the studies are small and have not yet put forth outcomes that would change our current diagnosis and management of RPL. Larger database studies are needed with stricter control criteria before reasonable conclusions can be drawn.

Chinese herbal medicines for unexplained recurrent miscarriage

BACKGROUND

Recurrent miscarriage affects 1% to 3% of women of reproductive age and mostly occurs before the 10th week of gestation (and around the same gestational week in subsequent miscarriages). Although most pregnant women may not recognise a miscarriage until uterine bleeding and cramping occur, a repeat miscarriage after one or more pregnancy loss and the chance of having a successful pregnancy varies. To date, there is no universally accepted treatment for unexplained recurrent miscarriage. Chinese herbal medicines have been widely used in Asian societies for millennia and have become a popular alternative to Western medicines in recent years. Many clinical studies have reported that Chinese herbal medicines can improve pregnancy outcomes for pregnant women who had previously suffered recurrent miscarriage. This systematic review evaluated the efficacy of Chinese herbal medicines for recurrent miscarriage.

OBJECTIVES

To assess the effectiveness and safety of Chinese herbal medicines for the treatment of unexplained recurrent miscarriage.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (01 June 2015), Embase (1980 to 01 June 2015); Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 01 June 2015); Chinese Biomedical Database (CBM) (1978 to 01 June 2015); China Journal Net (CJN) (1915 to 01 June 2015); China Journals Full-text Database (1915 to 01 June 2015); and WanFang Database (Chinese Ministry of Science & Technology) (1980 to 01 June 2015). We also searched reference lists of relevant trials and reviews. We identified and contacted organisations, individual experts working in the field, and medicinal herb manufacturers.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials, including cluster-randomised trials, with or without full text, comparing Chinese herbal medicines (alone or combined with other intervention or other pharmaceuticals) with placebo, no treatment, other intervention (including bed rest and psychological support), or other pharmaceuticals as treatments for unexplained recurrent miscarriage. Cross-over studies were not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all the studies for inclusion in the review, assessed risk of bias and extracted the data. Data were checked for accuracy.

MAIN RESULTS

We included nine randomised clinical trials (involving 861 women). The trials compared Chinese herbal medicines (various formulations) either alone (one trial), or in combination with other pharmaceuticals (seven trials) versus other pharmaceuticals alone. One study compared Chinese herbal medicines and other pharmaceuticals versus psychotherapy. We did not identify any trials comparing Chinese herbal medicines with placebo or no treatment, including bed rest.Various Chinese herbal medicines were used in the different trials (and some of the classical the formulations were modified in the trials). The Western pharmaceutical medicines included tocolytic drugs such as salbutamol and magnesium sulphate; hormonal supplementation with human chorionic gonadotrophin (HCG), progesterone or dydrogesterone; and supportive supplements such as vitamin E, vitamin K and folic acid.Overall, the methodological quality of the included studies was poor with unclear risk of bias for nearly all the 'Risk of bias' domains assessed.Chinese herbal medicines alone versus other pharmaceuticals alone - the live birth rate was no different between the two groups (risk ratio (RR) 1.05; 95% confidence interval (CI) 0.67 to 1.65; one trial, 80 women). No data were available for the outcome of pregnancy rate (continuation of pregnancy after 20 weeks of gestation).In contrast, the continuing pregnancy rate (RR 1.27 95% CI 1.10 to 1.48, two trials, 189 women) and live birth rate (average RR 1.55; 95% CI 1.14 to 2.10; six trials, 601 women, Tau² = 0.10; I² = 73%) were higher among the group of women who received a combination of Chinese herbal medicines and other pharmaceuticals when compared with women who received other pharmaceuticals alone.For Chinese herbal medicines and psychotherapy versus psychotherapy alone (one study) - there was a higher live birth rate (RR 1.32; 95% CI 1.07 to 1.64; one trial, 90 women) in the group of women who received a combination of Chinese herbal medicines and psychotherapy compared to those women who received psychotherapy alone. No data were available on the continuing pregnancy rate for this comparison.Other primary outcomes (maternal adverse effect and toxicity rate and the perinatal adverse effect and toxicity rate) were not reported in most of the included studies. Two trials (341 women) reported that no maternal adverse effects were found (one trial compared (combined) medicines with other pharmaceuticals, and one trial compared combined Chinese herbal medicine alone versus other pharmaceuticals). One trial (Chinese herbal medicine alone versus other pharmaceuticals alone) reported that there were no abnormal fetuses (ultrasound) or after delivery.There were no data reported for any of this review's secondary outcomes.

AUTHORS' CONCLUSIONS

We found limited evidence (from nine studies with small sample sizes and unclear risk of bias) to assess the effectiveness of Chinese herbal medicines for treating unexplained recurrent miscarriage; no data were available to assess the safety of the intervention for the mother or her baby. There were no data relating to any of this review's secondary outcomes. From the limited data we found, a combination of Chinese herbal medicines and other pharmaceuticals (mainly Western medicines) may be more effective than Western medicines alone in terms of the rate of continuing pregnancy and the rate of live births. However, the methodological quality of the included studies was generally poor.A comparison of Chinese herbal medicines alone versus placebo or no treatment (including bed rest) was not possible as no relevant trials were identified.More high-quality studies are needed to further evaluate the effectiveness and safety of Chinese herbal medicines for unexplained recurrent miscarriage. In addition to assessing the effect of Chinese herbal medicines on pregnancy rate and the rate of live births, future studies should also consider safety issues (adverse effects and toxicity for the mother and her baby) as well as the secondary outcomes listed in this review. This review would provide more valuable information if the included studies could overcome the problems in their designs, such as lacking of qualified placebo-controlled trials, applying adequate randomisation methods and avoiding potential bias.

Effectiveness and potential mechanisms of intralipid in treating unexplained recurrent spontaneous abortion

AIM

Abnormal natural killer (NK) cell activity has been suggested to be a high-risk factor associated with unexplained recurrent spontaneous abortion (URSA). Intralipid, like immunoglobulin, is able to lower the activity of NK cells, which has been reported to be useful for improving URSA outcomes in pregnancy. This study aimed to determine whether intralipid could be used as an alternative treatment to intravenous immunoglobulin (IVIG) which is expensive and has many side-effects.

METHODS

A prospective, randomized clinical trial was conducted from December 2010 to December 2012. Eligible participants were matched and sorted randomly into the intralipid and the IVIG group. The primary outcome was the rate of successful pregnancy. In addition, comparisons of peripheral NK cell activities were accessed by flow cytometry. Moreover, the effects of intralipid on trophoblasts were investigated using a Matrigel assay with the JEG-3 cell line.

RESULTS

Seventy-six patients in the intralipid group and 78 in the IVIG group completed the trial. There were no statistically significant differences in successful pregnancy rates between the two groups (92.1 vs 88.2 %, P = 0.415). The reduced NK cell concentrations revealed the cytotoxic effects of the treatments in both groups. The invasive ability of JEG-3 cells was inhibited during co-culture with patient PBMCs. However, the inhibitory effect could be alleviated if the patient PBMCs were stimulated with intralipid.

CONCLUSIONS

Intralipid can be used as an alternative treatment to IVIG for URSA, and its potential mechanism of action may occur by regulating NK cell function and promoting trophoblast invasion.

The clinical use of corticosteroids in pregnancy

BACKGROUND

The use of antenatal steroid therapy is common in pregnancy. In early pregnancy, steroids may be used in women for the treatment of recurrent miscarriage or fetal abnormalities such as congenital adrenal hyperplasia. In mid-late pregnancy, the antenatal administration of corticosteroids to expectant mothers in anticipation of preterm birth is one of the most important advances in perinatal medicine; antenatal corticosteroids are now standard care for pregnancies at risk of premature delivery in high- and middle-income countries. The widespread uptake of this therapy is due to a compelling body of evidence demonstrating improved neonatal outcomes following antenatal corticosteroid exposure, stemming most notably from corticosteroid-driven maturation of fetal pulmonary function. As we approach the 50th anniversary of landmark work in this area by Liggins and Howie, it is apparent that much remains to be understood with regards to how we might best apply antenatal corticosteroid therapy to improve pregnancy outcomes at both early and mid to late gestation.

METHODS

Drawing on advances in laboratory science, pre-clinical and clinical studies, we performed a narrative review of the scientific literature to provide a timely update on the benefits, risks and uncertainties regarding antenatal corticosteroid use in pregnancy. Three, well-established therapeutic uses of antenatal steroids, namely recurrent miscarriage, congenital adrenal hyperplasia and preterm birth, were selected to frame the review.

RESULTS

Even the most well-established antenatal steroid therapies lack the comprehensive pharmacokinetic and dose-response data necessary to optimize dosing regimens. New insights into complex, tissue-specific corticosteroid signalling by genomic-dependent and independent mechanisms have not been used to inform corticosteroid treatment strategies. There is growing evidence that some fetal corticosteroid treatments are either ineffective, or may result in adverse outcomes, in addition to lasting epigenetic changes in a variety of homeostatic mechanisms. Nowhere is the need to better understand the intricacies of corticosteroid therapy better conveyed than in the findings of Althabe and colleagues who recently reported an increase in overall neonatal mortality and maternal morbidity in association with antenatal corticosteroid administration in low-resource settings.

CONCLUSIONS

New research to clarify the benefits and potential risks of antenatal corticosteroid therapy is urgently needed, especially with regard to corticosteroid use in low-resource environments. We conclude that there is both significant scope and an urgent need for further research-informed refinement to the use of antenatal corticosteroids in pregnancy.

IL-17 Induces Fetal Loss in a CBA/J×BALB/c Mouse Model, and an Anti-IL-17 Antibody Prevents Fetal Loss in a CBA/J×DBA/2 Mouse Model

PROBLEM

Many researchers have demonstrated that the expression of interleukin-17(IL-17) is higher in spontaneous abortion. However, whether Th17 cells are an independent factor in inducing abortion is not known.

METHOD OF STUDY

This study investigated the effect of exogenous recombinant IL-17 and an anti-IL-17 antibody in a normal and an abortion mouse model using flow cytometry, enzyme-linked immunosorbent assay, real-time PCR, and Western blot.

RESULTS

Th17 cells and the related factors, IL-17 and RORγt, were significantly upregulated in abortion mice, and Treg cells and the related factor, Foxp3, were downregulated. Intraperitoneal injection of recombinant IL (rIL)-17 induced fetal loss in a normal mouse model, and an anti-IL-17 antibody prevented fetal loss in an abortion mouse model.

CONCLUSION

This study confirmed an imbalance of the Th17/Treg paradigm in abortion mice and IL-17 as a risk factor of fetal loss. An anti-IL-17 antibody may prevent abortion.

Association between KIAA0319L, PXK and JAZF1 gene polymorphisms and unexplained recurrent pregnancy loss in Chinese Han couples

KIAA0319L, PXK and JAZF1 gene polymorphisms were investigated to determine whether they conferred susceptibility to unexplained recurrent pregnancy loss (URPL) in a group of Chinese Han patients. Genotyping and sequencing of the single nucleotide polymorphisms (SNP) rs2275247(A/G) in KIAA0319L, rs2176082(C/T) and rs6445975(G/T) in PXK and the rs1635852(C/T) in JAZF1 were carried out in 84 couples with URPL and 102 healthy couples with at least one live birth. Frequencies of the SNP rs2176082(C/T) in PXK gene were significantly different between women with URPL and control women: P < 0.05; OR 95% CI 0.530 (0.287 to 0.979); OR 95% CI 0.482 (0.254 to 0.911) but were not significantly different after Bonferroni correction. The frequencies of the SNP rs2176082(C/T) in PXK gene showed no difference between the husband of a woman with URPL and a control husband: OR 95% CI 1.494 (0.821 to 2.721); OR 95% CI 1.567 (0.841 to 2.921). No statistically significant differences were observed in the distribution of any genotype or allele frequency or any genetic model of the other three SNPs between couples with URPL and control couples. Therefore, the rs2176082(C/T) polymorphism of PXK might play a possible role in the development of URPL in Chinese Han women.

Sphingolipid pathway regulates innate immune responses at the fetomaternal interface during pregnancy

For a successful pregnancy, the mother's immune system has to tolerate the semiallogeneic fetus. A deleterious immune attack is avoided by orchestration of cellular, hormonal, and enzymatic factors. However, the precise mechanisms underlying fetomaternal tolerance are not yet completely understood. In this study, we demonstrate that sphingolipid metabolism constitutes a novel signaling pathway that is indispensable for fetomaternal tolerance by regulating innate immune responses at the fetomaternal interface. Perturbation of the sphingolipid pathway by disruption of the sphingosine kinase gene (Sphk) during pregnancy caused unusually high expression of neutrophil chemoattractants, CXCL1 and CXCL2, in the decidua, leading to a massive infiltration of neutrophils into the fetomaternal interface with enhanced oxidative damage, resulting in early fetal death. Sphk-deficient mice also exhibited neutrophilia in the peripheral blood, enhanced generation of granulocytes in the bone marrow, and a decrease in the number of decidual natural killer cells. The blockage of neutrophil influx protected Sphk-deficient mice against pregnancy loss. Notably, a similar result was obtained in human decidual cells, in which Sphk deficiency dramatically increased the secretion of CXCL1 and IL-8. In conclusion, our findings suggest that the sphingolipid metabolic pathway plays a critical role in fetomaternal tolerance by regulating innate immunity at the fetomaternal interface both in mice and humans, and it could provide novel insight into the development of therapeutic strategies to treat idiopathic pregnancy loss in humans.

Th17 cells and related cytokines in unexplained recurrent spontaneous miscarriage at the implantation window

Unexplained recurrent spontaneous abortion (RSA) might be caused by the mother's immunological rejection of the fetus. In this cross-sectional study, the percentage of T helper 17 (Th17), T regulatory (Treg) cells and their cytokines as the main players of immunomodulation in peripheral blood lymphocytes during the luteal phase of 20 women with unexplained RSA were compared with 20 normal non-pregnant women. The percentage of Treg cells in the former was significantly lower compared with controls. The percentage of Th17 cells in the former was higher than controls. Expression of IL-23, IL-17, IL-6 cytokines in the former was significantly higher than controls, but the higher expression of IL-21 was not significant. The gene expression of TGF-β and FoxP3 in the former was lower than controls. Significant positive correlations were found between the percentage of Th17 cells with IL-23, IL-6 and IL-17 and between expression of IL-23 and IL-6 and IL-17. IL-6 gene expression showed a significant positive correlation with IL-17. Therefore, imbalance of Th17-Treg cells and the consequent changes in cytokine expression might be implicated in the pathogenesis of unexplained RSA and may provide new insight into the immunoregulatory events at the maternal-fetal interface.

Experience in IVIg therapy for selected women with recurrent reproductive failure and NK cell expansion

PROBLEM

Recurrent reproductive failure (RRF) has been associated with expansion of circulating NK cells, key cells for maternal tolerance, decidual vasculogenesis and embryo growth. This study reports our experience in intravenous immunoglobulin (IVIg) therapy of a large cohort of women with RRF with expanded circulating NK and/or NKT-like cells (blood NKT cells are a heterogeneous subset of T cells that share properties of both T cells and NK cells).

METHOD OF STUDY

Observational study of RRF women with NK or NKT-like expansion (>12% or 10% cutoff levels of total lymphocytes, respectively), treated with IVIg for the next gestation.

RESULTS

By multivariant logistic regression analysis after adjusting for age, NK cells subsets and other therapies, IVIg significantly improved the live birth rate to 96.3% in women with recurrent miscarriage (RM) compared with 30.6% in case not receiving IVIg (P < 0.0001). In women with recurrent implantation failure (RIF), in comparison with women not receiving IVIg, treatment increased the pregnancy rate from 26.2 to 93.8% (P ≤ 0.0001) and the live birth rate from 17.9 to 80.0% in RIF (P ≤ 0.0001).

CONCLUSIONS

Immunomodulation with IVIg in our selected group of RRF patients with immunologic alterations enhanced clinical pregnancy and live birth rates. Our results may facilitate the design of future clinical trials of IVIg in this pathology.

'There and back again': revisiting the pathophysiological roles of human endogenous retroviruses in the post-genomic era

Almost 8% of the human genome comprises endogenous retroviruses (ERVs). While they have been shown to cause specific pathologies in animals, such as cancer, their association with disease in humans remains controversial. The limited evidence is partly due to the physical and bioethical restrictions surrounding the study of transposons in humans, coupled with the major experimental and bioinformatics challenges surrounding the association of ERVs with disease in general. Two biotechnological landmarks of the past decade provide us with unprecedented research artillery: (i) the ultra-fine sequencing of the human genome and (ii) the emergence of high-throughput sequencing technologies. Here, we critically assemble research about potential pathologies of ERVs in humans. We argue that the time is right to revisit the long-standing questions of human ERV pathogenesis within a robust and carefully structured framework that makes full use of genomic sequence data. We also pose two thought-provoking research questions on potential pathophysiological roles of ERVs with respect to immune escape and regulation.

Mechanism of human chorionic gonadotrophin-mediated immunomodulation in pregnancy

Human chorionic gonadotrophin (hCG) is released within hours of fertilization and has a profound ability to downregulate maternal cellular immunity against trophoblastic paternal antigens. It also promotes angiogenic activity of the extravillous trophoblast, and impairment of this function may lead to inadequate placentation and an increased risk of preeclampsia. There is increasing evidence that hCG alters the activity of dendritic cells via an upregulation of indoleamine 2,3-dioxygenase activity. This reduces T-cell activation and cytokine production, as well as encouraging Treg cell recruitment to the fetal-maternal interface. These changes are critical in promoting maternal tolerance. hCG is also able to increase the proliferation of uterine natural killer cells, while reducing the activity of cytotoxic peripheral blood natural killer cells. There are rare reports of autoantibodies directed against hCG or the luteinizing hormone/hCG receptor in women with recurrent miscarriage. These autoantibodies are more frequent in women with thyroid autoimmunity. This may explain the association between thyroid autoimmunity and impaired fertility. Downregulating these anti-hCG and anti-luteinizing hormone/hCG receptor autoantibodies may be helpful in some women with early miscarriage or recurrent failed in vitro fertilization.

Demystifying animal models of adverse pregnancy outcomes: touching bench and bedside

This represents an overview of the use of animal models to study the adverse pregnancy outcomes seen in humans. The purpose is to entice clinicians to utilize some of this information to seek out the literature and have more meaningful and profitable discussions with their academic colleagues and enhance transdisciplinary research in reproductive health.

Preimplantation genetic diagnosis: recent triumphs and remaining challenges

Over the last 20 years, preimplantation genetic diagnosis (PGD) has changed from being an experimental procedure to one that is carried out in specialized diagnostic centers worldwide. Genetic awareness and the rapid identification of germline mutations or chromosomal abnormalities enable individuals to know their risk of transmitting a genetic disease before they have children. This has created a demand for PGD from couples who wish to avoid terminations of affected pregnancies. Although PGD is expensive because it requires couples to go through IVF, there is a trend for diagnosis to move towards automation, which will reduce cost and the need for specialized expertise. This will allow diagnosis to be carried out in routine molecular diagnostic laboratories.

Birds, babies and blood

This is an autobiographical review describing the author's career in immunology research and summarizing his current understanding of the areas involved. Contributions to autoimmunity, immune deficiency, transfusion immunology, HLA-disease associations, reproductive immunology, cellular therapies, and innate immunity are included; also discussion of medical research ethics and various research-related activities.