Antiphospholipid antibodies prevent extravillous trophoblast differentiation

Impact of Inherited Thrombophilia in Women with Obstetric Antiphospholipid Syndrome: A Single-Center Study and Literature Review

Inherited thrombophilia (IT) has been implicated as a potential causal factor of adverse pregnancy outcomes (APOs), including recurrent miscarriage with and without the presence of antiphospholipid syndrome (APS). The aim of this study was to assess the prevalence and impact of IT on fetal-maternal outcomes and thrombotic risk in women within the spectrum of obstetric APS. Three hundred and twenty-eight women with APS-related obstetric morbidity ever pregnant were included. Of these, 74 met the APS classification criteria, 169 were non-criteria (NC)-APS, and 85 were seronegative (SN)-APS. Patients with other autoimmune diseases were excluded. APOs included early pregnancy loss, fetal death, preeclampsia, abruptio placentae, and preterm birth. Successful pregnancy was defined as the achievement of a live newborn. A literature search was also performed. The mean age of the overall group was 33.9 ± 5.3 years, and the patients were followed up for 35 (11-79) months. During the study period, there were 1332 pregnancies. Nearly 14% of the patients had an associated IT. IT patients more frequently received the standard-of-care (SoC) therapy. The presence of IT was not associated with worse maternal-fetal outcomes in patients treated with SoC treatment. Overall, IT patients had a lower frequency of newborns without treatment, especially those without definite APS. In addition, IT did not increase the risk of thrombosis during pregnancy or the postpartum period. A detailed analysis of the literature review identified only four publications related to our study and did not show conclusive evidence of the impact of IT on patients with obstetric APS. The group of women with APS-related obstetric morbidity and IT who did not receive treatment, especially those without definite APS, had a worse prognosis in terms of a live birth. However, with SoC therapy, the prognosis is similar in those patients without IT. The association of IT with APS does not seem to predispose to the development of thrombosis during pregnancy and/or the postpartum period.

Innate and adaptive immune dysregulation in women with recurrent implantation failure

Recurrent implantation failure (RIF) is a condition where a woman fails to obtain pregnancy after multiple embryo transfer cycles, even with superior-quality blastocysts. There are various factors that can contribute to RIF, including immunologic disturbances. The immune system is extremely important during pregnancy. Immune cells such as T cells, B cells, natural killer (NK) cells, and macrophages (MQ) are present in the female reproductive tract and are accountable for regulating the immune response to invading pathogens and maintaining tissue homeostasis. Dysregulation of these immune cells can lead to inflammation, which can impair fertility. One of the most common immunological disturbances observed in RIF is an altered Th1/Th2 ratio, along with changes in NK cell and macrophage numbers. In addition, the presence of some antibodies, such as anti-ovarian antibodies, can also contribute to RIF. Interleukins have been implicated in the development of an inflammatory response that can interfere with successful embryo implantation. As a result, a comprehensive understanding of immunological compartments in RIF women could assist us in determining the immunological origins of this disease. We will discuss immunological factors that might contribute to RIF etiology, including cellular and molecular components.

Prophylactic low-molecular-weight heparin in women with thrombophilia undergoing in vitro fertilization

OBJECTIVE

To verify whether low-molecular-weight heparin (LMWH) could increase pregnancy rates and/or decrease abortion rates in women with thrombophilia undergoing assisted reproduction cycles.

METHODS

Cross-sectional study with patients undergoing in vitro fertilization (IVF) (N = 104). Women without thrombophilia (control group, n = 20), women with thrombophilia who did not receive LMWH (untreated group, n = 30), and women with thrombophilia, treated with daily enoxaparin from the day of embryo transfer until week 36 of gestation (treated group, n = 54). All women underwent controlled ovarian hyperstimulation. IVF was performed by intracytoplasmic sperm injection, and embryos were transferred on day 3. Pregnancy was detected by β-human chorionic gonadotropin (biochemical pregnancy) and fetal heartbeat at week 5 to 6. Ongoing pregnancy was determined by ultrasound on week 12.

RESULTS

Patients in the untreated thrombophilia group presented with significantly lower ongoing pregnancy rates and live birth rates and significantly higher early pregnancy loss and abortion rates when compared with the control and the treated thrombophilia groups.

CONCLUSIONS

In women with diagnosed coagulation disorders, use of LMWH is important to avoid miscarriages.

Association between ovarian reserve and spontaneous miscarriage and their shared genetic architecture

STUDY QUESTION

Can potential mechanisms involved in the likely concurrence of diminished ovarian reserve (DOR) and miscarriage be identified using genetic data?

SUMMARY ANSWER

Concurrence between ovarian reserve and spontaneous miscarriage was observed, and may be attributed to shared genetic risk loci enriched in antigen processing and presentation and autoimmune disease pathways.

WHAT IS KNOWN ALREADY

Previous studies have shown that lower serum anti-Müllerian hormone (AMH) levels are associated with increased risk of embryo aneuploidy and spontaneous miscarriage, although findings have not been consistent across all studies. A recent meta-analysis suggested that the association between DOR and miscarriage may not be causal, but rather a result of shared underlying causes such as clinical conditions or past exposure. Motivated by this hypothesis, we conducted the present analysis to explore the concurrence between DOR and miscarriage, and to investigate potential mechanisms using genetic data.

STUDY DESIGN, SIZE, DURATION

Three data sources were used in the study: the clinical IVF data were retrospectively collected from an academically affiliated Reproductive Medicine Center (17 786 cycles included); the epidemiological data from the UK Biobank (UKB), which is a large-scale, population-based, prospective cohort study (35 316 white women included), were analyzed; and individual-level genotype data from the UKB were extracted for further analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

There were three modules of analysis. First, clinical IVF data were used to test the association between ovarian reserve biomarkers and the subsequent early spontaneous miscarriage risk. Second, the UKB data were used to test the association of spontaneous miscarriage history and early menopause. Third, individual-level genotype data from the UKB were analyzed to identify specific pleiotropic genes which affect the development of miscarriage and menopause.

MAIN RESULTS AND THE ROLE OF CHANCE

In the analysis of clinical IVF data, the risk of early spontaneous miscarriage was 1.57 times higher in the group with AMH < 1.1 ng/ml group (P < 0.001), 1.62 times for antral follicular count <5 (P < 0.001), and 1.39 times for FSH ≥10 mIU/ml (P < 0.001) in comparison with normal ovarian reserve groups. In the analysis of UKB data, participants with a history of three or more miscarriages had a one-third higher risk of experiencing early menopause (odds ratio: 1.30, 95% CI 1.13-1.49, P < 0.001), compared with participants without spontaneous miscarriage history. We identified 158 shared genetic risk loci that affect both miscarriage and menopause, which enrichment analysis showed were involved in antigen processing and presentation and autoimmune disease pathways.

LIMITATIONS, REASONS FOR CAUTION

The analyses of the UKB data were restricted to participants of European ancestry, as 94.6% of the cohort were of white ethnicity. Further studies are needed in non-white populations. Additionally, maternal age at the time of spontaneous miscarriage was not available in the UKB cohort, therefore we adjusted for age at baseline assessment in the models instead. It is known that miscarriage rate in IVF is higher compared to natural conception, highlighting a need for caution when generalizing our findings from the IVF cohort to the general population.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings have implications for IVF clinicians in terms of patient counseling on the prognosis of IVF treatment, as well as for genetic counseling regarding miscarriage. Our results highlight the importance of further research on the shared genetic architecture and common pathophysiological basis of DOR and miscarriage, which may lead to new therapeutic opportunities.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Hunan Youth Science and Technology Innovation Talent Project (2020RC3060), the International Postdoctoral Exchange Fellowship Program (Talent-Introduction Program, YJ20220220), the fellowship of China Postdoctoral Science Foundation (2022M723564), and the Natural Science Foundation of Hunan Province, China (2023JJ41016). This work has been accepted for poster presentation at the 39th Annual Meeting of ESHRE, Copenhagen, Denmark, 25-28 June 2023 (Poster number: P-477). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Low-molecular-weight heparin in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection: A meta-analysis

INTRODUCTION

This meta-analysis aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) on pregnancy outcomes in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

MATERIAL AND METHODS

A systematic literature search of PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure was performed to identify randomized controlled trials (RCTs) comparing LMWH with no treatment or placebo published from database inception until February 19, 2023. Primary outcomes were the clinical pregnancy rate and implantation rate, and secondary outcomes were the live birth rate, miscarriage rate, and the risk of bleeding events. The certainty of the evidence was rated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Meta-analysis was conducted using STATA 14.0.

RESULTS

Five RCTs involving 1094 thrombophilic women receiving IVF/ICSI were finally included. Administration of LMWH was associated with statistically higher clinical pregnancy rate (4 RCTs, risk ratio [RR] 1.50, 95% confidence interval [CI] 1.23-1.82, p < 0.001, low certainty evidence), implantation rate (5 RCTs, RR 1.49, 95% CI 1.25-1.78, p < 0.001, very low certainty evidence), and live birth rate (2 RCTs, RR 2.15, 95% CI 1.60-2.89, p < 0.001, very low certainty evidence), but with statistically lower miscarriage rate (2 RCTs, RR 0.36, 95% CI 0.15-0.86, p = 0.021, very low certainty evidence). However, using LMWH was linked to a higher risk of bleeding events (2 RCTs, RR 2.36, 95% CI 1.49-3.74, p < 0.001, very low certainty evidence).

CONCLUSIONS

Very low certainty evidence suggests that administration of LMWH may benefit pregnancy outcomes in thrombophilic women receiving IVF/ICSI treatment, although it may also increase the risk of bleeding events. However, before putting our findings into practice, healthcare professionals should conduct an in-depth evaluation of the available evidence and specific patient situations. Furthermore, due to the low methodological quality of the included studies, more high-quality studies are needed to validate our findings in the future.

Trophoblast Cell Function in the Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a complex thrombo-inflammatory autoimmune disease characterized by the presence of antiphospholipid antibodies (aPL). Women with APS are at high risk of recurrent early pregnancy loss as well as late obstetrical complications-premature birth due to placental insufficiency or severe preeclampsia. Accumulating evidence implies that vascular thrombosis is not the only pathogenic mechanism in obstetric APS, and that the direct negative effect of aPL on the placental cells, trophoblast, plays a major role. In this review, we summarize the current findings regarding the potential mechanisms involved in aPL-induced trophoblast dysfunction. Introduction on the APS and aPL is followed by an overview of the effects of aPL on trophoblast-survival, cell function and aPL internalization. Finally, the implication of several non-coding RNAs in pathogenesis of obstetric APS is discussed, with special emphasis of their possible role in trophoblast dysfunction and the associated mechanisms.

Heparin for women with recurrent miscarriage and inherited thrombophilia (ALIFE2): an international open-label, randomised controlled trial

BACKGROUND

Anticoagulant therapy might reduce the number of miscarriages and adverse pregnancy outcomes in women with recurrent pregnancy loss and inherited thrombophilia. We aimed to assess use of low-molecular-weight heparin (LMWH) versus standard care in this population.

METHODS

The ALIFE2 trial was an international open-label, randomised controlled trial undertaken in hospitals in the UK (n=26), the Netherlands (n=10), the USA (n=2), Belgium (n=1), and Slovenia (n=1). Women aged 18-42 years who had two or more pregnancy losses and confirmed inherited thrombophilia, and who were trying to conceive or were already pregnant (≤7 weeks' gestation), were eligible for inclusion. Women were randomly assigned (1:1) to use low-dose LMWH or not (alongside standard care in both groups) once they had a positive urine pregnancy test. LMWH was started at or before 7 weeks' gestation and continued until the end of pregnancy. The primary outcome measure was livebirth rate, assessed in all women with available data. Safety outcomes included bleeding episodes, thrombocytopenia, and skin reactions, and were assessed in all randomly assigned women who reported a safety event. The trial was registered within the Dutch Trial Register (NTR3361) and EudraCT (UK: 2015-002357-35).

FINDINGS

Between Aug 1, 2012, and Jan 30, 2021, 10 625 women were assessed for eligibility, 428 were registered, and 326 conceived and were randomly assigned (164 to LMWH and 162 to standard care). 116 (72%) of 162 women with primary outcome data in the LMWH group and 112 (71%) of 158 in the standard care group had livebirths (adjusted odds ratio 1·08, 95% CI 0·65 to 1·78; absolute risk difference, 0·7%, 95% CI -9·2% to 10·6%). 39 (24%) of 164 women in the LMWH group and 37 (23%) of 162 women in the standard care group reported adverse events.

INTERPRETATION

LMWH did not result in higher livebirth rates in women who had two or more pregnancy losses and confirmed inherited thrombophilia. We do not advise use of LMWH in women with recurrent pregnancy loss and inherited thrombophilia, and we advise against screening for inherited thrombophilia in women with recurrent pregnancy loss.

FUNDING

National Institute for Health and Care Research and the Netherlands Organization for Health Research and Development.

Hemostasis in the Pregnant Woman, the Placenta, the Fetus, and the Newborn Infant

The hemostasis system is composed of procoagulant, anticoagulant, and fibrinolytic proteins that interact with endothelial and blood cells and with each other in a complex system of checks and balances to maintain blood flow while preventing both hemorrhage and thrombosis. Pregnancy is a unique physiological state in which biological alterations predispose both mother and fetus to both bleeding and clotting. The placenta is a vascular interface for maternal and fetal blood exchange which predisposes the mother to hemorrhage. Maternal hemostasis presents a compensatory hypercoagulability including elevated factor VIII, von Willebrand factor, fibrinogen and thrombin generation, decreased thrombin regulation with resistance to activated protein C and decreased free protein S, and decreased fibrinolysis with increased plasminogen activator inhibitors. The placental vascular surface is of fetal trophoblastic origin that derives many characteristics of endothelium but differs in that tissue factor is constitutively expressed. Ontogeny of fetal hemostasis is characteristic. Platelets, von Willebrand factor, factor VIII, and fibrinogen are expressed and mature early in gestation, while vitamin K-dependent and contact factors exhibit delayed development. The fetal hemostatic system has a decreased capacity to generate or regulate thrombin, resulting in a fragile balance with little capacity to compensate under stress conditions, particularly in the infant born prematurely. Dysfunction of the maternal/placental/fetal unit gives rise to gestational disorders including preeclampsia, fetal growth restriction, placental abruption, and premature delivery. Knowledge of normal hemostasis levels and function are critical to evaluate bleeding or clotting syndromes in the pregnant woman and her fetus or newborn infant.

Anticardiolipin and/or anti-β2-glycoprotein-I antibodies are associated with adverse IVF outcomes

OBJECTIVE

The purpose of the study is to evaluate the effects of anticardiolipin (aCL) and/or anti-β2-glycoprotein-I (aβ2GPI) antibodies, namely antiphospholipid antibodies (aPL), on in vitro fertilization (IVF) outcomes.

MATERIALS AND METHODS

The study group comprised infertile women with aPL undergoing IVF-ET cycles. Controls were infertile women with tubal etiology without aPL. The impact of aPL on reproductive outcomes, such as oocyte quality, embryo quality, and implantation capacity, was compared between the study group and controls. Additionally, peripheral blood T cell subsets, such as T helper (Th)1, Th2, Th17, and T regulatory (Treg) cells and cytokines, were analyzed by the flow cytometry. Differences between the study group and controls were analyzed.

RESULTS

A total of 132 infertile women, including 44 women with aPL, and 88 controls were sequentially recruited for this study. Women with aPL had lower numbers of total and perfect/available embryos and lower rates of MII oocytes, blastocyst formation, perfect and available embryos, implantation, clinical pregnancy, and take-home baby. Additionally, imbalanced Th1/Th2 and Th17/Treg ratios, significantly higher levels of serum IL-2, TNF-α, IFN-γ, and IL-17A, and a significantly lower serum IL-4 were noticed in women with aPL compared to controls.

CONCLUSION

Women with aPL such as aCL and/or aβ2GPI antibodies were associated with adverse IVF outcomes. Early screening for aPL and appropriate consultation for couples undergoing IVF should be considered. In addition, underlying immunopathology and inflammatory immune mechanisms associated with aPL should be further explored.

Antiphospholipid antibodies in women with recurrent embryo implantation failure: A systematic review and meta-analysis

OBJECTIVE

Antiphospholipid antibodies (aPL) are related to poor pregnancy outcomes, but their effect on embryo implantation is unclear. We aimed to assess the prevalence of different aPL in women with recurrent implantation failure (RIF).

METHODS

We searched studies in PubMed (MEDLINE), Scopus and Cochrane Library. Quality of studies was scored by the Newcastle-Ottawa Scale and risk of bias assessment by items described in RevMan5 software. Statistical analyses were made using random-effects model and presented as pooled Odds Ratio (OR), 95% confidence interval (CI). Heterogeneity was assessed by I²% and D²%.

RESULTS

This systematic review and meta-analysis included 17 studies and showed a high degree of variability in aPL positivity in RIF. In the latter, the risk of bias assessment suggested unclear bias on study performance with a median sample size and interquartile range for RIF patients and fertile women of 96 (57-417) and 100 (60.5-202.5), respectively. Among the criteria aPL, IgG anticardiolipin autoantibodies (OR 5.02, 95% CI [1.95, 12.93]) were associated with RIF. Within the non-criteria aPL, anti-β2 glycoprotein I-IgA (OR 64.8, 95% CI [9.74, 431.0]), and antiphosphatidylglycerol-IgG and IgM (OR 10.74, 95% CI [5.25, 22.0]; OR 4.26, 95% CI [1.76,10.31]; respectively) were associated with RIF, too.

CONCLUSIONS

Anticardiolipin-IgG is a prevalent autoantibody in women with RIF. Three other non-criteria aPL, aβ2GP I-IgA, aPG-IgG and aPG-IgM also present a positive rate in RIF. Overall, these results advise about testing them as indicators of RIF risk in women seeking IVF treatment.

Risk of Thrombosis, Pregnancy Morbidity or Death in Antiphospholipid Syndrome

The antiphospholipid syndrome is an autoimmune disease characterized by thrombosis and pregnancy morbidity. The manifestations are caused by antibodies targeting cell membrane phospholipids and/or associated proteins. The triggers leading to these antibodies' production are unknown but recent work suggests cross-reactivity between the autoantigens and peptides produced by the intestinal microbiome. Work on how the autoantibodies could cause clinical manifestations implicates different mechanisms. Binding to surface proteins of different cell types can induce intracellular signaling leading to cell activation and tissue factor expression. Complement activation and neutrophil extracellular-traps are also involved, and recent evidence implicates endothelial protein C receptor-lysobisphosphatidic acid complex. Pregnancy is a high-risk situation for antiphospholipid syndrome patients due to the increased risk of thrombosis and obstetric complications. Epidemiological and clinical research on APS is hampered by heterogeneity in populations, testing and treatment strategies. About one in 10 to one in fifty APS pregnancies is complicated by thrombosis, despite treatment. Pregnant patients with prior thrombosis are prescribed therapeutic dose heparins and low dose aspirin. Without prior thrombosis a prophylactic dose is used. The most frequent obstetrical manifestation is recurrent early pregnancy loss. The association of APS antibodies with late pregnancy loss is stronger, however. Prevention of recurrence is achieved with aspirin and prophylactic dose heparin, although the evidence is of low certainty. The third obstetrical classifying manifestation comprises preterm delivery due to placenta-mediated complications and is treated in subsequent pregnancies with aspirin with or without prophylactic dose heparin, again based on low quality evidence. New therapies are under investigation.

Pathogenesis, Diagnosis and Management of Obstetric Antiphospholipid Syndrome: A Comprehensive Review

Antiphospholipid syndrome is an autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity associated with persistent antiphospholipid antibody positivity. Cases fulfilling the Sydney criteria for obstetric morbidity with no previous thrombosis are known as obstetric antiphospholipid syndrome (OAPS). OAPS is the most identified cause of recurrent pregnancy loss and late-pregnancy morbidity related to placental injury. Cases with incomplete clinical or laboratory data are classified as obstetric morbidity APS (OMAPS) and non-criteria OAPS (NC-OAPS), respectively. Inflammatory and thrombotic mechanisms are involved in the pathophysiology of OAPS. Trophoblasts, endothelium, platelets and innate immune cells are key cellular players. Complement activation plays a crucial pathogenic role. Secondary placental thrombosis appears by clot formation in response to tissue factor activation. New risk assessment tools could improve the prediction of obstetric complication recurrences or thromboses. The standard-of-care treatment consists of low-dose aspirin and prophylactic low molecular weight heparin. In refractory cases, the addition of hydroxychloroquine, low-dose prednisone or IVIG improve pregnancy outcomes. Statins and eculizumab are currently being tested for treating selected OAPS women. Finally, we revisited recent insights and concerns about the pathophysiology, diagnosis and management of OAPS.

Antiphospholipid antibodies and pregnancy outcome of assisted reproductive treatment: A systematic review and meta-analysis

PROBLEM

Antiphospholipid antibodies (aPLs) are a group of autoantibodies associated with a variety of pregnancy complications, but the impact of aPL on the outcomes of assisted fertility treatment (ART) is controversial. This systematic review and meta-analysis were designed to explore the association between aPL and ART outcomes and to explore in which stages does aPL play a role.

METHOD OF STUDY

PubMed and Cochrane database were systematically retrieved, and odds ratios (ORs) or risk ratios (RRs) with 95% confidence intervals (CIs) were calculated in a random-effect model or fixed-effect model according to the heterogenicity assessed by the Cochran Q and I²  statistic test. Of 246 records identified by the search, 10 case-control studies and 13 cohort studies that explored the association between aPL and in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI) were analyzed.

RESULTS

The results showed that aPL positive rate was higher in females who failed in IVF/ICSI than those who succeeded in IVF/ICSI (OR: 3.62, 95% CI: 1.95-6.74). This study also indicated that females positive for aPL have a higher miscarriage rate (RR: 1.68, 95% CI: 1.24-2.28) than those negative for aPL, but live birth rate, biochemical pregnancy rate, and clinical pregnancy rate were similar between two groups (RR: 1.01, 95% CI: 0.91-1.12; RR: 1.18, 95% CI: 0.57-2.43 and RR: 0.95, 95% CI: 0.80-1.13).

CONCLUSIONS

There was higher aPL prevalence in females with adverse IVF/ICSI outcomes. It seems that aPL mainly affects the miscarriage rate, but has little effect on live birth rate, biochemical pregnancy rate, and clinical pregnancy rate. Routine detection of aPL before IVF/ICSI treatment is meaningful.

Female Unexplained Infertility: A Disease with Imbalanced Adaptive Immunity

Unexplained infertility (UI) among women consists of only 10-17% of infertile females. Unexplained or idiopathic infertility is a condition, in which couples are not able to conceive without any definite causes. The presence of the decidual immune system (innate or adaptive) is essential for a successful pregnancy and fertility that is mediated by T helper (Th) 1, Th2, Th17, T follicular helper, CD8+ CD28− T, and regulatory T cells, as well as autoantibodies such as antiphospholipid antibody, antithyroid antibody, antiovarian antibody, cytokines, and chemokines. Therefore, altered proportions or levels of the mentioned compartments of the adaptive immune system may cause pregnancy failure and infertility, especially in UI. Consequently, a deep understanding of immunological compartments in females with UI may help us to define the causes of this disease with regard to immunology. This review will discuss immunological factors, including cellular, molecular components, and transcription factors that are involved in the etiology of UI.

Modulation of trophoblast function by concurrent hyperglycemia and antiphospholipid antibodies is in part TLR4-dependent

PROBLEM

While diabetes and APS are individually associated with increased risk of poor perinatal outcomes, in particular preeclampsia, recent studies have demonstrated an association between concurrent aPL and diabetes leading to an increased risk of pregnancy morbidity. Hyperglycemia and aPL have independently been shown to alter human trophoblast function by inducing a pro-inflammatory, anti-angiogenic, and antimigratory response. However, little is known about the effects of concurrent hyperglycemia and aPL on trophoblast function.

METHOD OF STUDY

A human first-trimester extravillous trophoblast cell line was exposed to glucose at 5 mmol/L (normoglycemia) or 25 mmol/L (hyperglycemia), all in the presence or absence of low-dose aPL or control IgG. For some experiments, the TLR4 antagonist, LPS-RS, was included. Cell culture supernatants were measured for inflammatory IL-1β and IL-8, and angiogenic PlGF, sFlt-1, and sEndoglin by ELISA. Inflammasome-associated uric acid was measured using a bioassay; caspase-1 was measured using an activity assay. Trophoblast migration was quantified using a two-chamber colorimetric assay.

RESULTS

Compared to excess glucose alone, combination excess glucose and low-dose aPL (a) further augmented trophoblast inflammatory IL-1β, inflammasome-associated uric acid and caspase-1, and pro-angiogenic PlGF; (b) dampened trophoblast inflammatory IL-8, anti-angiogenic sEndoglin, and sFlt-1; and (c) further reduced trophoblast migration.

CONCLUSION

Our findings indicate that while concurrent aPL and hyperglycemia are overall detrimental to trophoblast function, the presence of two simultaneous insults triggers some protective effects.

Antiphospholipid Antibodies Inhibit Trophoblast Toll-Like Receptor and Inflammasome Negative Regulators

OBJECTIVE

Women with antiphospholipid antibodies (aPL) are at risk for pregnancy complications associated with poor placentation and placental inflammation. Although these antibodies are heterogeneous, some anti-β₂ -glycoprotein I (anti-β₂ GPI) antibodies can activate Toll-like receptor 4 (TLR-4) and NLRP3 in human first-trimester trophoblasts. The objective of this study was to determine the role of negative regulators of TLR and inflammasome function in aPL-induced trophoblast inflammation.

METHODS

Human trophoblasts were not treated or were treated with anti-β₂ GPI aPL or control IgG in the presence or absence of the common TAM (TYRO3, AXL, and Mer tyrosine kinase [MERTK]) receptor ligand growth arrest-specific protein 6 (GAS6) or the autophagy-inducer rapamycin. The expression and function of the TAM receptor pathway and autophagy were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). Antiphospholipid antibody-induced trophoblast inflammation was measured by qRT-PCR, activity assays, and ELISA.

RESULTS

Anti-β₂ GPI aPL inhibited trophoblast TAM receptor function by reducing cellular expression of the receptor tyrosine kinases AXL and MERTK and the ligand GAS6. The addition of GAS6 blocked the effects of aPL on the TLR-4-mediated interleukin-8 (IL-8) response. However, the NLRP3 inflammasome-mediated IL-1β response was not affected by GAS6, suggesting that another regulatory pathway was involved. Indeed, anti-β₂ GPI aPL inhibited basal trophoblast autophagy, and reversing this with rapamycin inhibited aPL-induced inflammasome function and IL-1β secretion.

CONCLUSION

Basal TAM receptor function and autophagy may serve to inhibit trophoblast TLR and inflammasome function, respectively. Impairment of TAM receptor signaling and autophagy by anti-β₂ GPI aPL may allow subsequent TLR and inflammasome activity, leading to a robust inflammatory response.

Low molecular weight heparin and aspirin exacerbate human endometrial endothelial cell responses to antiphospholipid antibodies

PROBLEM

Women with antiphospholipid antibodies (aPL) are at risk for pregnancy complications despite treatment with low molecular weight heparin (LMWH) or aspirin (ASA). aPL recognizing beta2 glycoprotein I can target the uterine endothelium, however, little is known about its response to aPL. This study characterized the effect of aPL on human endometrial endothelial cells (HEECs), and the influence of LMWH and ASA.

METHOD OF STUDY

HEECs were exposed to aPL or control IgG, with or without low-dose LMWH and ASA, alone or in combination. Chemokine and angiogenic factor secretion were measured by ELISA. A tube formation assay was used to measure angiogenesis.

RESULTS

aPL increased HEEC secretion of pro-angiogenic VEGF and PlGF; increased anti-angiogenic sFlt-1; inhibited basal secretion of the chemokines MCP-1, G-CSF, and GRO-α; and impaired angiogenesis. LMWH and ASA, alone and in combination, exacerbated the aPL-induced changes in the HEEC angiogenic factor and chemokine profile. There was no reversal of the aPL inhibition of HEEC angiogenesis by either single or combination therapy.

CONCLUSION

By aPL inhibiting HEEC chemokine secretion and promoting sFlt-1 release, the uterine endothelium may contribute to impaired placentation and vascular transformation. LMWH and ASA may further contribute to endothelium dysfunction in women with obstetric APS.

Immunoglobulins from sera of APS patients bind HTR-8/SVneo trophoblast cell line and reduce additional mediators of cell invasion

Immunoglobulins from sera of patients with antiphospholipid syndrome (APS) decrease trophoblast cell invasion in vitro. This study aimed to extend understanding of cellular effects of immunoglobulins from APS (aPL+) in HTR-8/SVneo cells. aPL+ IgG induced change in effector molecules important for cell invasion was investigated further. After 1h of culture 21% cells bound aPL+ IgG, as opposed to 6% in control (aPL-). This was accompanied by increase in phospho-p38 at 30min. After 24h treatment aPL+IgG decreased protein levels of integrin subunits α1 (78% of control; p<0.01), α4 (65% of control, p<0.01), α5 (76% of control; p<0.01) and β1 (80% of control; p<0.01), and secreted gal-1 (68% of control; p<0.05). ProMMP-9 was reduced to 70% of control (p<0.001). Treatment with inhibitor of p38 MAPK signaling SB202190 reversed inhibition in integrin β1 and secreted gal-1. Involvement of p38 MAPK signaling and decrease in integrin subunit α4_, proMMP-9, and secreted gal-1 in HTR-8/SVneo cells are novel and extend the list of mediators of trophoblast invasion affected by aPL.

Quantitative changes of extravillous trophoblast cells in placentas of systemic lupus erythematosus patients

In the present study, quantitative changes of extravillous trophoblast cells (EVTs) in the placentas of SLE patients were investigated compared to healthy controls using stereological methods. Volumetric parameters and number of EVTs per unit volume of the placenta were estimated respectively, using Cavalieri's principle and Physical Disector stereological methods. Placental volume in the SLE group was increased compared to the control group, but this increase was not statistically significant (p > .05). Placental weight in the patient group showed a significant decrease compared to controls (p < .05). Total volume of EVTs, diameter and volume of the nucleus and cytoplasm and the N/C ratio of EVTs in the SLE group showed a significant increase compared to the controls (p < .05). In SLE placentas the total number of EVTs per unit volume of the placenta was increased significantly compared to the control group (p < .05). Impact statement In the present study, there is a new insight to placenta structure that may be useful in understanding possible mechanisms of pregnancy complications and the achievement of new therapeutic strategies. In the present study, for the first time quantitative changes of extravillous trophoblast cells (EVTs) in the placental bed of SLE patients were investigated compared to healthy controls using stereological methods. Results showed that volumetric parameters and number of EVTs were significantly altered in SLE placentas. These changes can be associated with disturbances in trophoblastic invasion in SLE pregnancies and may affect the development and survival of the embryo. Further investigation on the molecular biology of these cells in pregnancy complications will be needed to clarify this hypothesis.

The role of anti-phospholipid antibodies in autoimmune reproductive failure

Anti-phospholipid antibodies (aPL) are autoantibodies that are associated with thrombosis and a range of pregnancy complications including recurrent pregnancy loss and pre-eclampsia. The three clinically relevant, well-characterized aPL are anti-cardiolipin antibodies, lupus anticoagulant and anti-beta-2-glycoprotein I (β2GPI) antibodies. aPL do not bind directly to phospholipids but instead bind to a plasma-binding ‘cofactor’. The most extensively studied cofactor is β2GPI, whose role in pregnancy is not fully elucidated. Although the pathogenicity of aPL in recurrent pregnancy loss is well established in humans and animal models, the association of aPL with infertility does not appear to be causative. aPL may exert their detrimental effects during pregnancy by directly binding trophoblast cells of the placenta, altering trophoblast signalling, proliferation, invasion and secretion of hormones and cytokines, and by increasing apoptosis. Heparin is commonly used to treat pregnant women with aPL; however, as thrombotic events do not occur in the placentae of all women with aPL, it may exert a protective effect by preventing the binding of aPL to β2GPI or by acting through non-thrombotic pathways. The aim of this review is to present evidence summarizing the current understanding of this field.

Antiphospholipid antibody-induced miR-146a-3p drives trophoblast interleukin-8 secretion through activation of Toll-like receptor 8

STUDY QUESTION

What is the role of microRNAs (miRs) in antiphospholipid antibody (aPL)-induced trophoblast inflammation?

SUMMARY ANSWER

aPL-induced up-regulation of trophoblast miR-146a-3p is mediated by Toll-like receptor 4 (TLR4), and miR-146a-3p in turn drives the cells to secrete interleukin (IL)-8 by activating the RNA sensor, TLR8.

WHAT IS KNOWN ALREADY

Obstetric antiphospholipid syndrome (APS) is an autoimmune disorder characterized by circulating aPL and an increased risk of pregnancy complications. We previously showed that aPL recognizing beta2 glycoprotein I (β2GPI) elicit human first trimester trophoblast secretion of IL-8 by activating TLR4. Since some miRs control TLR responses, their regulation in trophoblast cells by aPL and functional role in the aPL-mediated inflammatory response was investigated. miRs can be released from cells via exosomes, and therefore, miR exosome expression was also examined. A panel of miRs was selected based on their involvement with TLR signaling: miR-9; miR-146a-5p and its isomiR, miR-146a-3p; miR-155, miR-210; and Let-7c. Since certain miRs can activate the RNA sensor, TLR8, this was also investigated.

STUDY DESIGN, SIZE, DURATION

For in vitro studies, the human first trimester extravillous trophoblast cell line, HTR8 was studied. HTR8 cells transfected to express a TLR8 dominant negative (DN) were also used. Plasma was evaluated from pregnant women who have aPL, either with or without systemic lupus erythematous (SLE) (n = 39); SLE patients without aPL (n = 30); and healthy pregnant controls (n = 20).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Trophoblast HTR8 wildtype and TLR8-DN cells were incubated with or without aPL (mouse anti-human β2GPI mAb) for 48-72 h. HTR8 cells were also treated with or without aPL in the presence and the absence of a TLR4 antagonist (lipopolysaccharide from Rhodobacter sphaeroides; LPS-RS), specific miR inhibitors or specific miR mimics. miR expression levels in trophoblast cells, trophoblast-derived exosomes and exosomes isolated from patient plasma were measured by qPCR. Trophoblast IL-8 secretion was measured by ELISA.

MAIN RESULTS AND THE ROLE OF CHANCE

aPL significantly increased trophoblast cellular and exosome expression of miR-146a-5p, miR-146a-3p, miR-155 and miR-210. aPL-induced up-regulation of trophoblast miR-146a-5p, miR-146a-3p and miR-210, but not miR-155, was inhibited by the TLR4 antagonist, LPS-RS. While inhibition or overexpression of miR-146a-5p had no effect on aPL-induced trophoblast IL-8 secretion, miR-146a-3p inhibition significantly reduced this response. aPL-induced trophoblast IL-8 secretion was inhibited by the presence of the TLR8-DN. In the absence of aPL, transfection of trophoblast cells with a miR-146a-3p mimic significantly increased IL-8 secretion and this was inhibited by the presence of the TLR8-DN. Patients with aPL and adverse pregnancy outcomes (APOs) expressed significantly higher levels of circulating miR-146a-3p compared with healthy pregnant controls with no pregnancy complications (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

While the enrichment of miR-146a-3p in trophoblast-derived exosomes support the role of this miR acting in a paracrine or endocrine manner through exosome delivery, this has not been demonstrated. However, miR-146a-3p may also exert its pro-inflammatory effect intracellularly within the same trophoblast cell targeted by aPL.

WIDER IMPLICATIONS OF THE FINDINGS

These findings provide a novel mechanism of trophoblast inflammation through miRs activating RNA-sensing receptors. Furthermore, circulating exosomal-associated miR-146a-3p in APS patients may serve clinically as a biomarker for related APOs.

STUDY FUNDING/COMPETING INTERESTS

This study was supported in part by grants from the American Heart Association (#10GRNT3640032 to V.M.A.), the March of Dimes Foundation (Gene Discovery and Translational Research Grant #6-FY12-255 to V.M.A.), NICHD, NIH (R01HD049446 to V.M.A.), the Gina M. Finzi Memorial Student Summer Fellowship from the Lupus Foundation of America (to S.M.G.), and the Yale University School of Medicine Medical Student Fellowship (to S.M.G.). The authors declare no competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Human extravillous trophoblasts bind but do not internalize antiphospholipid antibodies

INTRODUCTION

Obstetric morbidity in women with antiphospholipid antibodies (aPLs) may reflect the adverse effects of aPLs on placental cells such as extravillous trophoblasts and the syncytiotrophoblast. Antiphospholipid antibodies may affect the syncytiotrophoblast after being internalised by members of the Low-density lipoprotein receptor (LDLR) family and the antigen of aPLs, β2 glycoprotein I.

AIM

This study aimed to determine whether aPL internalization was a mechanism by which aPLs adversely affect extravillous trophoblasts.

METHOD

of

STUDY

Fluorescently-labelled monoclonal aPLs IIC5 or ID2 were incubated with first trimester extravillous trophoblast outgrowths and visualized by microscopy. The subcellular expression of β2 glycoprotein I and LDLR family members was investigated by live/permeabilised immunocytochemistry.

RESULTS

Unlike the syncytiotrophoblast of anchoring villi, monoclonal aPLs were not internalised by extravillous trophoblasts, which expressed LDLR family members intracellularly. The aPL IIC5 bound to the surface of extravillous trophoblasts in a pattern similar to the extracellular expression of β2 glycoprotein I.

CONCLUSIONS

The mechanisms of action of aPLs are different in extravillous trophoblasts and the syncytiotrophoblast. The interaction of aPLs with the extravillous trophoblast surface, which may involve β2 glycoprotein I, is consistent with reports that aPLs trigger intracellular signaling cascades through cell-surface receptors.

ALIFE2 study: low-molecular-weight heparin for women with recurrent miscarriage and inherited thrombophilia--study protocol for a randomized controlled trial

BACKGROUND

A large number of studies have shown an association between inherited thrombophilia and recurrent miscarriage. It has been hypothesized that anticoagulant therapy might reduce the number of miscarriages and stillbirth in these women. In the absence of randomized controlled trials evaluating the efficacy of anticoagulant therapy in women with inherited thrombophilia and recurrent miscarriage, a randomized trial with adequate power that addresses this question is needed. The objective of the ALIFE2 study is therefore to evaluate the efficacy of low-molecular-weight heparin (LMWH) in women with inherited thrombophilia and recurrent miscarriage, with live birth as the primary outcome.

METHODS/DESIGN

Randomized study of LMWH plus standard pregnancy surveillance versus standard pregnancy surveillance alone.

STUDY POPULATION

pregnant women of less than 7 weeks' gestation, and confirmed inherited thrombophilia with a history of 2 or more miscarriages or intra-uterine fetal deaths, or both.

SETTING

multi-center study in centers from the Dutch Consortium of Fertility studies; centers outside the Netherlands are currently preparing to participate.

INTERVENTION

LMWH enoxaparin 40 mg subcutaneously once daily started prior to 7 weeks gestational age plus standard pregnancy surveillance or standard pregnancy surveillance alone. Main study parameters/endpoints: the primary efficacy outcome is live birth. Secondary efficacy outcomes include adverse pregnancy outcomes, such as miscarriage, pre-eclampsia, syndrome of hemolysis, elevated liver enzymes and low platelets (HELLP syndrome), fetal growth restriction, placental abruption, premature delivery and congenital malformations. Safety outcomes include bleeding episodes, thrombocytopenia and skin reactions.

DISCUSSION

After an initial period of slow recruitment, the recruitment rate for the study has increased. Improved awareness of the study and acknowledgement of the need for evidence are thought to be contributing to the improved recruitment rates. We aim to increase the number of recruiting centers in order to increase enrollment into the ALIFE2 study. The study website can be accessed via www.ALIFE2study.org.

TRIAL REGISTRATION

The ALIFE2 study was registered on 19 March 2012 under registration number NTR3361.

Antiphospholipid antibodies and the placenta: a systematic review of their in vitro effects and modulation by treatment

BACKGROUND

Antiphospholipid antibodies (aPL) are a family of auto-antibodies that are associated with an increased risk of recurrent miscarriage, intrauterine growth restriction and preterm birth. The placenta is a major target of aPL and it is likely that these antibodies promote pregnancy morbidity by affecting trophoblast function. Numerous studies have investigated the effect of aPL on trophoblast function in vitro. However, different trophoblast models and a variety of culture conditions have been employed, resulting in a myriad of different reported findings. This review systematically summarized those published studies that have investigated the effect of aPL on trophoblast function in vitro. In addition, the reported effects of pharmacological treatment on trophoblast function in the presence of aPL were also systematically reviewed.

METHODS

PubMed, Scopus, Embase and Web of Science databases were searched using the keywords 'placenta OR trophoblast' AND 'antiphospholipid antibody OR antiphospholipid syndrome' up to 25 April 2014. Studies were excluded based on the absence of appropriate controls. The effects of aPL on trophoblast proliferation, death, syncytialization, invasion, hormone production, cytokine production, coagulation and complement activation were recorded. The effects of different treatments on the function of trophoblasts in the presence of aPL were also recorded.

RESULTS

A total of 1071 records were retrieved from the four databases. After removing duplicates, the titles and abstracts of 529 articles were reviewed. Of those, 48 articles were read and relevant experimental results were extracted from 47 articles.

CONCLUSIONS

This systematic review provides an overview of all the studies performed to date on the effects of aPL on trophoblast function in vitro. There is considerable support for aPL decreasing trophoblast viability, syncytialization and invasion in vitro. Some work has also suggested that aPL may affect the production of hormones and signalling molecules by trophoblasts, and may stimulate coagulation and complement activation in vitro. Current reports of the in vitro effects of therapeutic treatments on trophoblast function in the presence of aPL are inconclusive. This systematic review has highlighted many gaps in our knowledge of how aPL work and may direct future research in this area.

Hydroxychloroquine restores trophoblast fusion affected by antiphospholipid antibodies

BACKGROUND

Obstetric antiphospholipid syndrome (APS) is defined by pregnancy complications associated with antiphospholipid antibodies (aPL). The mechanisms of the pathogenic effects of aPL in pregnancy are poorly understood. Toll-like receptors (TLR) have been implicated previously in APS.

OBJECTIVES

The aims of our study were (1) to determine aPL effects on trophoblastic cell fusion and differentiation, (2) to identify which TLR is involved in this process, and (3) to evaluate the efficacy of hydroxychloroquine (HCQ) to counteract the effects of aPL.

METHODS

BeWo cells are a model for trophoblast fusion and differentiation. Fusion index was assessed by immunocytochemical examination, and biochemical differentiation by using ELISA-measured β-human choronic gonadotropin hormone (β-hCG) secretion. We used three types of aPL to study their effect on cell fusion and differentiation: aPL derived from obstetric APS patients and affinity purified and polyclonal rabbit anti-β2-glycoprotein-1 (anti-β2GP1) antibodies. Experiments on fusion were confirmed using primary cytotrophoblastic cells.

RESULTS

All of the types of aPL used decreased the fusion index in BeWo and primary trophoblastic cells (64%, 52%, and 41% for BeWo cells and 67% and 62% for primary cells, respectively), and anti-β2GP1 antibodies decreased hCG secretion in BeWo cells (41%). To block TLR4 antibodies or to abolish TLR4 cell surface expression restored fusion index in both cell types and β-human choronic gonadotropin hormone excretion in BeWo cells. HCQ treatment induced the same effect and decreased TLR4 mRNA (40% and 35%, respectively) and protein expressions (62% and 42%, respectively) in BeWo cells.

CONCLUSION

Anti-β2GP1 antibodies decrease trophoblastic differentiation via TLR4. This effect is restored by HCQ, suggesting its therapeutic interest in APS pregnancies.

The term basal plate of the human placenta as a source of functional extravillous trophoblast cells

BACKGROUND

Extravillous trophoblast (EVT) cells are of pivotal importance in human embryo implantation and homeostasis of the maternal fetal interface. Invasion of the endometrium by EVT contributes to placental anchorage, spiral artery remodeling, immunological defense, tolerogenic responses, and several collaborative cross talks involved in establishing and maintaining a successful pregnancy. We report here an improved protocol for the isolation of fully differentiated EVT cells from the basal plate of the human term placenta.

METHODS

The basal plate was carefully dissected from the villous tissue and the amniochorion membrane prior to enzymatic digestion. Term basal EVT cells were isolated using a 30 and 60% Percoll gradient. A panel of markers and characteristics of the isolated cells were used to confirm the specificity and efficiency of the method so that their potential as an investigative tool for placental research could be ascertained.

RESULTS

Isolated cells were immunoreactive for cytokeratin-7 (CK-7), placental growth factor, placental alkaline phosphatase, human leukocyte antigen G1 (HLA-G1), and α1 and α5 integrins, similarly to the EVT markers from first trimester placental villi. Around 95% of the isolated cells labeled positively for CK-7 and 82% for HLA-G1. No significant change in viability was observed during 48 h of EVT culture as indicated by propidium iodide incorporation and trypan blue test exclusion. Genes for metalloproteinases MMP-2 and MMP9 (positive regulators of trophoblast invasiveness) were expressed up to 48 h of culturing, as also the gelatinolytic activity of the isolated cells. Transforming growth factor (TGF)-beta, which inhibits proliferation, migration, and invasiveness of first-trimester EVT cells, also reduced invasion of isolated term EVT cells in transwell assays, whereas epidermal growth factor was a positive modulator.

CONCLUSIONS

Term basal plate may be a viable source of functional EVT cells that is an alternative to villous explant-derived EVT cells and cell lines. Isolated term EVT cells may be particularly useful in investigation of the role of trophoblast cells in pathological gestations, in which the precise regulation and interactive ability of extravillous trophoblast has been impaired.

A novel human endogenous retroviral protein inhibits cell-cell fusion

While common in viral infections and neoplasia, spontaneous cell-cell fusion, or syncytialization, is quite restricted in healthy tissues. Such fusion is essential to human placental development, where interactions between trophoblast-specific human endogenous retroviral (HERV) envelope proteins, called syncytins, and their widely-distributed cell surface receptors are centrally involved. We have identified the first host cell-encoded protein that inhibits cell fusion in mammals. Like the syncytins, this protein, called suppressyn, is HERV-derived, placenta-specific and well-conserved over simian evolution. In vitro, suppressyn binds to the syn1 receptor and inhibits syn1-, but not syn2-mediated trophoblast syncytialization. Suppressyn knock-down promotes cell-cell fusion in trophoblast cells and cell-associated and secreted suppressyn binds to the syn1 receptor, ASCT2. Identification of the first host cell-encoded inhibitor of mammalian cell fusion may encourage improved understanding of cell fusion mechanisms, of placental morphogenesis and of diseases resulting from abnormal cell fusion.

Antithrombotic therapy for pregnancy loss

BACKGROUND Although an association between thrombophilia and pregnancy loss has been observed in many studies, little is known about the pathophysiological mechanisms behind this association. Considering the association between thrombophilia and pregnancy loss, the efficacy of antithrombotic therapy for women with pregnancy loss (with or without thrombophilia) has been studied for the past 30 years. METHODS We performed a comprehensive review of the literature on the strength of the association between thrombophilia and pregnancy loss, the pathophysiological mechanisms and the efficacy of antithrombotic therapy to increase the chance of live birth. RESULTS The association between pregnancy loss and thrombophilia varies according to the type of thrombophilia (e.g. antiphospholipid syndrome versus forms of inherited thrombophilia) and according to the type of pregnancy loss (single versus recurrent pregnancy loss and early versus late pregnancy loss). Thrombophilia may induce thrombosis in decidual vessels or impair placentation through hypercoagulability and inflammation, but these hypotheses need further verification. For women with antiphospholipid syndrome, evidence from small-sized trials suggests a beneficial effect of antithrombotic therapy but additional randomized controlled trials are essential to confirm this. Whether antithrombotic therapy increases the chance of live birth in women with inherited thrombophilia is unknown. Recent randomized controlled trials have consistently shown that antithrombotic therapy does not increase the chance of live birth in women with unexplained recurrent miscarriage. CONCLUSIONS There are large gaps in knowledge and a lack of evidence for treatment of women with pregnancy loss with thrombophilia. To provide a solid base for clinical practice, further studies on the role of coagulation in reproduction, as well as international collaborations in randomized controlled trials of antithrombotic therapy in women with pregnancy loss, and antiphospholipid syndrome or inherited thrombophilia are urgently needed.

Impact of anticardiolipin antibody on the outcome of in vitro fertilization and embryo transfer

PROBLEM

To investigate the impact of anticardiolipin antibody (ACA) on the outcome of in vitro fertilization and embryo transfer (IVF-ET).

METHODS

A total of 76 infertile women positive for anticardiolipin antibody (ACA+ group) and 819 controls negative for anticardiolipin antibody (ACA- group) undergoing IVF-ET in the First Affiliated Hospital, to Sun Yat-Sen University, were retrospectively analyzed. Women were diagnosed as having pure tubal factor infertility.

RESULTS

The proportion of patients with a history of spontaneous abortion in the ACA+ group was significantly higher than that in ACA- group (19.7% versus 8.9%). The IVF rate, pregnancy rate and implantation rate in the ACA+ group were markedly lower than those in the ACA- group (75.5% versus 78.9%, 31.3% versus 48.6% and 16.1% versus 28.1%, respectively). Furthermore, the incidence of pregnancy loss in the ACA+ group was higher than that in the ACA- group (32.0% versus 15.1%).

CONCLUSION

ACA-positive patients had significantly decreased IVF rate, pregnancy rate and implantation rate and high risk of abortion. Therefore, ACA positivity predicts poor outcome of IVF-ET, and pre-treatment to lower ACA level may be clinically beneficial for patients receiving IVF-ET.

Recurrent miscarriage and antiphospholipid antibodies: prognosis of subsequent pregnancy

BACKGROUND

 Although women with antiphospholipid antibodies (APLAs) are at increased risk of recurrent miscarriage, the outcome of a subsequent pregnancy is not clearly elucidated.

OBJECTIVES

To assess the pregnancy outcome of a subsequent pregnancy in women with APLAs and compare this outcome with women with unexplained recurrent miscarriage.

METHODS

 We performed a cohort study among all women who attended the Miscarriage Clinic at Liverpool Women's Hospital between 1987 and 2006 after being referred due to recurrent miscarriage (≥2 consecutive pregnancy losses). All women underwent a standardized investigation sequence. Women with other reasons for recurrent miscarriage were excluded.

RESULTS

 A total of 693 women fulfilled the selection criteria, of whom 176 (25%) had APLAs. One hundred and twenty-two (69%) women with APLAs had a subsequent live birth compared with 324 (63%) women with unexplained recurrent miscarriage (OR 1.3, 95% CI 0.9-1.9). No differences were found for birth weight, gestational age, and intra-uterine growth restriction. When treatment was analyzed, 53/67 (79%) of women with APLAs who had received aspirin and heparin during their pregnancy had a live birth, compared with 64/104 (62%) of women with APLAs who received aspirin only (adjusted OR 2.7, 95% CI 1.3-5.8). In unexplained recurrent miscarriage, stratification for treatment showed no differences in outcome.

CONCLUSION

The prognosis of a subsequent pregnancy in women with APLAs is good. Although this was not a randomized clinical trial, combined treatment of aspirin and heparin seemed associated with a better outcome in women with APLAs, but not in women with unexplained recurrent miscarriage.

Management of 273 cases of recurrent implantation failure: results of a combined evidence-based protocol

This study evaluated the results of a management protocol combining a number of investigations and interventions, previously proven beneficial in randomized controlled trials in IVF/intracytoplasmic sperm injection (ICSI) patients with apparently unexplained recurrent implantation failure (defined as two or more previous failed cycles, during which at least six good-quality embryos were transferred). It was a prospective cohort study and included 273 couples with previous recurrent implantation failure. Each patient (all under 40) underwent a pre-treatment work-up, consisting of pelvic ultrasound scan for hydrosalpinx, hysteroscopy and screening for acquired and congenital thrombophilia. Detected abnormalities were dealt with accordingly: proximal occlusion for hydrosalpinx, hysteroscopic management for intrauterine pathology and thromboprophylaxis with daily low-molecular weight heparin from the day of embryo transfer for thrombophilia. The patients then underwent IVF/ICSI with laser-assisted hatching. 112 patients (41%; group 1) had abnormalities detected (17 hydrosalpinx, 11 intrauterine pathology, 63 congenital thrombophilia, 21 acquired thrombophilia) and the remaining 161 (59%; group 2) had normal work-up. The pregnancy rates per cycle started for all patients, group 1 and group 2 were 47%, 55% and 41%, respectively. This suggests that using the described management protocol in couples with previous recurrent implantation failure leads to a favourable chance of success.

Prevalence of antiphospholipid antibodies among women experiencing unexplained infertility and recurrent implantation failure

The prevalences of antiphospholipid antibodies (APAs) among 1,325 women with a history of unexplained infertility and 676 women experiencing recurrent implantation failure were compared with 789 women experiencing recurrent pregnancy loss and 205 fertile control women. Eight percent and 9% of women with a history of unexplained infertility and recurrent implantation failure had more than one positive APA compared with 1.5% of fertile negative control women and 11% of positive control women experiencing recurrent pregnancy loss.

Anti-phospholipid antibodies and other immunological causes of recurrent foetal loss--a review of literature of various therapeutic protocols

PROBLEM

An immune-based aetiology is one of the several accepted causes for recurrent foetal loss (RFL). However, most of the immunological theories have not fulfilled the criteria for causality. This is a review of the various immunological causes of RFL and the outcome of different treatment protocols.

METHOD OF STUDY

Both auto- and alloimmune maternal immunological abnormalities have been proposed to account for foetal loss. Among the autoimmune factors, anti-phospholipid antibodies (APAs) have been demonstrated to be the strongest risk factors for foetal loss, the prevalence of which is as high as 40% in women with RFL. Other autoimmune antibodies implicated in RFL are anti-nuclear antibodies (ANAs), anti-thyroid antibodies and anti-endothelial cell antibodies. The alloimmune factors implicated in pregnancy loss of unknown aetiology include abnormal natural killer (NK) cell activity, alteration in T helper 1 (Th1) and T helper 2 (Th2) ratios, presence of alloimmune antibodies like anti-paternal cytotoxic antibodies, anti-idiotypic antibodies, mixed lymphocyte reaction blocking antibodies and abnormal expression of HLA-G molecules. Management of patients with RFL is mainly based on immunomodulatory (prednisolone, intravenous immunoglobulins, plasma exchange, paternal lymphocyte therapy), anti-aggregation (aspirin) or anti-coagulation (unfractionated or low molecular weight heparin) agents.

RESULTS

Low-molecular-weight heparin with low-dose aspirin has been found to be the most effective treatment for women with APAs and RFL. Differences in dosage, timing of treatment, inclusion criteria, outcome assessment parameters etc. are some of the factors which have resulted in discrepancies in various reports.

CONCLUSION

Identification of the immunological mechanisms involved in pregnancy loss and the action of different therapeutic reagents is important so that effective therapies can be designed and investigated.

Mechanisms of antiphospholipid antibody-associated pregnancy complications

Women with antiphospholipid syndrome (APS) and antiphospholipid antibodies (aPL) are at high risk for recurrent spontaneous miscarriage and late pregnancy complications, such as preeclampsia and preterm labor. Recent clinical and experimental observations suggest that the pathophysiology of pregnancy failure in patients with APS may involve inflammation at the maternal-fetal interface and disruption of normal trophoblast function and survival, rather than a pro-thrombotic event. While treatment with heparin and aspirin from early pregnancy has been shown to significantly increase the live birth rate in recurrent miscarriage patients with APS, the incidence of severe late pregnancy complications still remains high. This review will discuss what is currently known about the mechanisms by which aPL may compromise pregnancy outcome.

Antiphospholipid antibodies induce a pro-inflammatory response in first trimester trophoblast via the TLR4/MyD88 pathway

PROBLEM

Women with antiphospholipid antibodies (aPL) are at risk for recurrent miscarriage, pre-eclampsia, and pre-term labor. aPL target the placenta directly by binding to beta(2)-glycoprotein I (beta(2)GPI) expressed on the surface of trophoblast cells. The objective of this study was to determine the effects of aPL on trophoblast function and the mechanisms involved.

METHOD OF STUDY

First trimester trophoblast cells were treated with anti-beta(2)GPI monoclonal antibodies and patient-derived aPL, after which cell survival and function was evaluated.

RESULTS

We report that anti-beta(2)GPI antibodies trigger an inflammatory response in trophoblast, characterized by increased secretion of interleukin (IL)-8, MCP-1, GRO-alpha, and IL-1beta, and that this occurs in a TLR-4/MyD88-dependent manner. At high concentrations, these antibodies also induce caspase-mediated cell death. This was attenuated upon disabling of the MyD88 pathway, suggesting that anti-beta(2)GPI-induced inflammatory mediators compromise trophoblast survival by acting in an autocrine/paracrine manner. Enhanced IL-8, GRO-alpha, and IL-1beta secretion also occurred when trophoblast cells were incubated with antibodies from patients with antiphospholipid syndrome. Heparin, which acts as a pro-survival factor in human trophoblast, attenuated the anti-beta(2)GPI antibody-mediated cell death, and also the pro-inflammatory response, but only at high concentrations.

CONCLUSION

These findings demonstrate that aPL triggers a placental inflammatory response via the TLR-4/MyD88 pathway, which in turn compromises trophoblast survival. Thus, the TLR-4/MyD88 pathway may provide a new therapeutic target to improve pregnancy outcome in antiphospholipid syndrome patients.