The placental bed in pregnancies complicated by primary antiphospholipid syndrome

Criteria and non-criteria antiphospholipid autoantibodies screening in patients with late pregnancy morbidity: A cross-sectional study

INTRODUCTION

Antiphospholipid syndrome (APS) is a cause of pregnancy morbidity. We aim to determine the frequency of criteria and non-criteria anti-phospholipid (aPL) autoantibodies in patients admitted for unexplained fetal death (UFD), pre-eclampsia (PE) and/or fetal growth restriction (FGR).

METHODS

All consecutive patients with UFD, PE and/or FGR followed in the department of Obstetrics, Bichat Hospital, University of Paris, Paris, between January 2019 and December 2021 were screened. Patients with available serum stored from the index pregnancy were included. Patients with previously known APS or twin pregnancy were excluded. Testing for aPL autoantibodies included anti-cardiolipin (aCL), anti-β2GPI (aβ2GPI), anti-phosphatidylethanolamine (aPE), anti-phosphatidylserine/prothrombin (aPS/PT) IgG/IgM and anti-annexin V IgG. When available, placenta specimens were analyzed by a pathologist blinded to the aPL status. All clinical characteristics, pregnancy features, and comorbidities were extracted from electronic medical records.

RESULTS

Overall 167 (32 (28.8-35.7) years) patients with UFD (n = 28; 16.8 %), PE (n = 60; 35.9 %) and/or FGR (n = 105; 62.9 %) were screened for aPL autoantibodies. Moderate titers of aPL autoantibodies were detected in 33 (n = 33/167, 19.8 %) patients. aPL autoantibodies were non-criteria aPE IgG/IgM in most cases (n = 28/33, 84.8 %). aPS/PT IgG/IgM were found in 11 (n = 11/33, 33.3 %) cases and aCL or aβ2GP1 IgG/IgM in 4 (n = 4/33, 12.1 %). Multivariable logistic regression showed that aPL autoantibodies were mostly associated with UFD (OR 4.37 [1.72-11.20], p = 0.002), PE ≤ 34th week of gestation (3.22 [0.86-11.90], p = 0.070) and chronic deciduitis (8.03 [0.89-67.2], p = 0.060) DISCUSSION: The frequency of aPL autoantibodies, mostly aPE, is high in patients with late pregnancy morbidity and may qualify obstetrical APS.

Single-cell transcriptome analyses reveal disturbed decidual homoeostasis in obstetric antiphospholipid syndrome

OBJECTIVES

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disease characterised by the presence of antiphospholipid antibodies in circulation and pathological pregnancy. However, the pathogenesis of OAPS remains unknown. We aimed to reveal cellular compositions and molecular features of decidual cells involved in the development of OAPS using single-cell RNA sequencing (scRNA-seq).

METHODS

We performed unbiased scRNA-seq analysis on the first-trimester decidua from five OAPS patients and five healthy controls (HCs), followed by validations with flow cytometry, immunohistochemical staining and immunofluorescence in a larger cohort. Serum chemokines and cytokines were measured by using ELISA.

RESULTS

A higher ratio of macrophages but a lower ratio of decidual natural killer (dNK) cells was found in decidua from OAPS compared with HCs. Vascular endothelial cells shrinked in OAPS decidua while having upregulated chemokine expression and conspicuous responses to IFN-γ and TNF-α. Macrophages in OAPS had stronger phagocytosis function, complement activation signals and relied more on glycolysis. dNK cells were more activated in OAPS and had enhanced cytotoxicity and IFN-γ production. Downregulation of granules in OAPS dNK cells could be associated with suppressed glycolysis. Moreover, stromal cells had a prosenescent state with weakened immune surveillance for senescent cells in OAPS. In addition, the cellular interactions between decidual immune cells and those of immune cells with non-immune cells under disease state were altered, especially through chemokines, IFN-γ and TNF-α.

CONCLUSION

This study provided a comprehensive decidual cell landscape and identified aberrant decidual microenvironment in OAPS, providing some potential therapeutic targets for this disease.

Pregnancy in antiphospholipid syndrome: what should a rheumatologist know?

This review focuses on the management of reproductive issues in women who have antiphospholipid syndrome (APS) or are carriers of antiphospholipid antibodies (aPL). The importance of aPL detection during preconception counselling relies on their pathogenic potential for placental insufficiency and related obstetric complications. The risk of adverse pregnancy outcomes can be minimized by individualized risk stratification and tailored treatment aimed at preventing placental insufficiency. Combination therapy of low-dose acetylsalicylic acid and heparin is the mainstay of prophylaxis during pregnancy; immunomodulation, especially with hydroxychloroquine, should be considered in refractory cases. Supplementary ultrasound surveillance is useful to detect fetal growth restriction and correctly tailor the time of delivery. The individual aPL profile must be considered in the stratification of thrombotic risk, such as during assisted reproduction techniques requiring hormonal ovarian stimulation or during the follow-up after pregnancy in order to prevent the first vascular event.

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.

Effects of anti-beta 2-glycoprotein 1 antibodies and its association with pregnancy-related morbidity in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by venous, arterial, or small-vessel thrombosis and/or pregnancy-related morbidity, associated with persistent positivity of antiphospholipid antibodies (aPL). Pregnancy-related morbidity in APS patients is characterized by unexplained fetal deaths, premature birth of morphologically normal newborns, and/or consecutive pregnancy losses before the 10^th week of gestation. Beta 2-glycoprotein 1 (ß2GP1) is the main antigen recognized by aPL and plays an essential role in the pathogenesis of APS. Antibodies against ß2GP1 (aß2GP1) are involved in damage-generating mechanisms in APS due to their interaction with trophoblasts, decidua, and endothelial cells. aß2GP1 might be used as a prognostic tool for obstetric risk stratification and ß2GP1 could be a target for molecular-targeted treatment to prevent pregnancy morbidity in APS. This review describes these aspects of aß2GP1, including effects on different cellular targets, its association with the severity of obstetric manifestations and the potential of ß2GP1-targeted therapies for APS.

Obstetric anti-phospholipid syndrome: from pathogenesis to treatment

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by clinical manifestations such as thrombosis and obstetric complications with documented persistence of antiphospholipid antibodies (aPLs). Recent studies have revealed that the cause of aPL-related obstetric complications is dysfunction of placental trophoblasts and inflammation of the maternal-fetal interface induced by aPLs, not thrombosis. Although aPLs are associated with recurrence of serious complications during pregnancy, appropriate combination therapy with heparin and low-dose aspirin can improve the course of 70-80% of subsequent pregnancies. Preconception counseling and patient-tailored treatment are fundamental to improving maternal and fetal outcomes. Non-anticoagulant treatments such as hydroxychloroquine and statins are being developed for cases refractory to conventional treatment. Risk factors for thrombosis after pregnancy complications were identified based on the analysis of large databases of obstetric APS.

Role of placental inflammatory mediators and growth factors in patients with rheumatic diseases with a focus on systemic sclerosis

Objectives

Pregnancy in SSc is burdened with an increased risk of obstetric complications. Little is known about the underlying placental alterations. This study aimed to better understand pathological changes and the role of inflammation in SSc placentas. Leucocyte infiltration, inflammatory mediators and atypical chemokine receptor 2 (ACKR2) expression in SSc placentas were compared with those in other rheumatic diseases (ORD) and healthy controls (HC).

Methods

A case–control study was conducted on eight pregnant SSc patients compared with 16 patients with ORD and 16 HC matched for gestational age. Clinical data were collected. Placentas were obtained for histopathological analysis and immunohistochemistry (CD3, CD20, CD11c, CD68, ACKR2). Samples from four SSc, eight ORD and eight HC were analysed by qPCR for ACKR2 expression and by multiplex assay for cytokines, chemokines and growth factors involved in angiogenesis and inflammation.

Results

The number of placental CD3, CD68 and CD11 cells was significantly higher in patients affected by rheumatic diseases (SSc+ORD) compared with HC. Hepatocyte growth factor was significantly increased in the group of rheumatic diseases patients (SSc+ORD) compared with HC, while chemokine (C-C motif) ligand 5 (CCL5) was significantly higher in SSc patients compared with ORD and HC. CCL5 levels directly correlated with the number of all local inflammatory cells and higher levels were associated with histological villitis.

Conclusions

Inflammatory alterations characterize placentas from rheumatic disease patients and could predispose to obstetric complications in these subjects.

Comparison of treatments for the prevention of fetal growth restriction in obstetric antiphospholipid syndrome: a systematic review and network meta-analysis

Women with criteria and non-criteria obstetric antiphospholipid syndrome (APS) carry an increased risk of pregnancy complications, including fetal growth restriction (FGR). The management of obstetric APS traditionally involves clinicians, obstetricians and gynaecologists; however, the most appropriate prophylactic treatment strategy for FGR prevention in APS is still debated. We performed a systematic review and network meta-analysis (NetMA) to summarize current evidence on pharmacological treatments for the prevention of FGR in APS. We searched PubMed and Embase from inception until July 2020, for randomized controlled trials and prospective studies on pregnant women with criteria or non-criteria obstetric APS. NetMA using a frequentist framework were conducted for the primary outcome (FGR) and for secondary outcomes (fetal or neonatal death and preterm birth). Adverse events were narratively summarised. Out of 1124 citations, we included eight studies on 395 pregnant patients with obstetric APS treated with low-dose aspirin (LDA) + unfractionated heparin (UFH) (n = 132 patients), LDA (n = 115), LDA + low molecular weight heparin (n = 100), LDA + corticosteroids (n = 29), LDA + UFH + intravenous immunoglobulin (n = 7), or untreated (n = 12). No difference among treatments emerged in terms of FGR prevention, but estimates were largely imprecise, and most studies were at high/unclear risk of bias. An increased risk of fetal or neonatal death was found for LDA monotherapy as compared to LDA + heparin, and for no treatment as compared to LDA + corticosteroids. The risk of preterm birth was higher for LDA + UFH + IVIg as compared to LDA or LDA + heparin, and for LDA + corticosteroids as compared to LDA or LDA + LMWH. No treatment was associated with an increased risk of bleeding, thrombocytopenia or osteopenia.

Risk factors for pregnancy failure in patients with antiphospholipid antibody positivity and prior pregnancy losses: A retrospective study

OBJECTIVES

To analyze the risk factors associated with pregnancy failure in patients with positive antiphospholipid antibodies (aPL) and prior pregnancy losses, with or without a diagnosis of antiphospholipid syndrome.

METHODS

We retrospectively reviewed the medical records of all the pregnant patients with positive aPL that visited the Peking University Third Hospital on an inpatient or outpatient basis from 2010 to 2019. According to the pregnancy outcome during this study, patients were divided into successful and unsuccessful groups. The clinical characteristics, laboratory tests and treatments were collected.

RESULTS

In total, 105 patients were included. 74/105 (70.48 %) patients were in the successful group and 31/105 (29.52 %) patients were in the unsuccessful group. In univariate analysis, the patients with successful pregnancies had a significant prevalence of low-dose aspirin (LDA) prior to pregnancy (P = 0.049) and heparin plus LDA plus hydroxychloroquine (HCQ) and/or steroids (P = 0.037). Triple aPL positivity (P = 0.026), prior pregnancy losses ≥3 (P = 0.036), maternal age at pregnancy ≥35 years (P = 0.001) and no treatment during pregnancy (P < 0.001) were significantly prevalent in patients with unsuccessful pregnancies. In multivariate analysis, prior pregnancy losses ≥3 (P = 0.039; odds ratio (OR) 4.5; 95 %CI 1.3, 14.3), maternal age at pregnancy ≥35 years (P = 0.019; OR 4.3; 95 %CI 1.1, 18.5) and no treatment (P < 0.001; OR 0.03; 95 %CI 0.004, 0.2) were independent risk factors for subsequent pregnancy losses.

CONCLUSION

The risk factors affecting pregnancy outcomes for patients with aPL positivity and prior pregnancy losses included prior pregnancy losses ≥3, maternal age at pregnancy ≥35 years and no treatment during pregnancy.

Pediatric antiphospholipid syndrome

Despite its potential to cause significant morbidity in children, pediatric antiphospholipid syndrome (APS) is an understudied condition. In this review, we will cover what is known about pediatric APS epidemiology and how the clinician might approach the diagnosis of pediatric APS. We will highlight similarities and differences with the adult disease, both for primary APS and in the context of lupus. Clinical manifestations beyond thrombosis, especially neurologic and hematologic in nature, will be discussed. We will also consider what unique implications antiphospholipid antibody-positivity may have for children with lupus and for neonates born to mothers with APS. The approach to treatment will be covered, including the unique impact of APS medications on children as compared with adults. Finally, the importance of future mechanistic research is emphasized as physicians endeavor to provide the personalized care that children with APS clearly deserve.

What's new in obstetric antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a rare systemic autoimmune disease, the obstetric features of which include recurrent early miscarriage, fetal death at or beyond 10 weeks of gestation, and early delivery for severe preeclampsia or placental insufficiency. Controversies regarding the specificity of these obstetric clinical features, as well as the laboratory diagnostic criteria, are the subject of current debate and reanalysis. Clinical and laboratory features can be used to stratify women with APS in terms of risk of adverse second and third trimester pregnancy outcomes. Numerous "treatments" have been used in high-risk and refractory patients, but rigorously designed clinical trials are needed. APS is a rare disease that requires innovative investigative approaches to provide credible results.

Role of NOD2 in antiphospholipid antibody-induced and bacterial MDP amplification of trophoblast inflammation

Women with antiphospholipid antibodies (aPL) are at high risk for pregnancy complications, such as preeclampsia. We previously demonstrated that aPL recognizing β₂GPI promote an extravillous trophoblast pro-inflammatory, anti-migratory and anti-angiogenic profile similar to that seen in preeclampsia. Since preeclampsia in the absence of aPL may have an underlying infectious element, women with aPL may be at increased risk for preeclampsia or other adverse outcomes if an infection is present. Our objective was to determine the impact the common bacterial component, muramyl dipeptide (MDP), has on trophoblast responses to aPL. Herein, we report that bacterial MDP amplifies trophoblast IL-1β expression, processing, and secretion in the presence of aPL through activation of NOD2. In the absence of MDP, NOD2 also mediates anti- β₂GPI antibody-induced trophoblast IL-1β and VEGF secretion. Additionally, we report a role for extravillous trophoblast vimentin as a novel danger signal that contributes to the aPL-induced trophoblast IL-1β production. Together our data indicate that NOD2 mediates trophoblast inflammatory and angiogenic responses to aPL alone, and mediates trophoblast inflammation in the presence of bacterial MDP. These findings suggest that a bacterial infection at the maternal-fetal interface may exacerbate the impact aPL have on trophoblast inflammation and, thus, on pregnancy outcome.

Mechanisms of Endothelial Dysfunction in Antiphospholipid Syndrome: Association With Clinical Manifestations

The endothelium is a monolayer of cells that covers the inner surface of blood vessels and its integrity is essential for the maintenance of vascular health. Endothelial dysfunction is a key pathological component of antiphospholipid syndrome (APS). Its systemic complications include thrombotic endocarditis, valvular dysfunction, cerebrovascular occlusions, proliferative nephritis, deep vein thrombosis, and pulmonary embolism. In women, APS is also associated with pregnancy complications (obstetric APS). The conventional treatment regimens for APS are ineffective when the clinical symptoms are severe. Therefore, a better understanding of alterations in the endothelium caused by antiphospholipid antibodies (aPL) may lead to more effective therapies in patients with elevated aPL titers and severe clinical symptoms. Currently, while in vivo analyses of endothelial dysfunction in patients with APS have been reported, most research has been performed using in vitro models with endothelial cells exposed to either patient serum/plasma, monoclonal aPL, or IgGs isolated from patients with APS. These studies have described a reduction in endothelial cell nitric oxide synthesis, the induction of inflammatory and procoagulant phenotypes, an increase in endothelial proliferation, and impairments in vascular remodeling and angiogenesis. Despite these lines of evidence, further research is required to better understand the pathophysiology of endothelial dysfunction in patients with APS. In this review, we have compared the current understanding about the mechanisms of endothelial dysfunction induced by patient-derived aPL under the two main clinical manifestations of APS: thrombosis and gestational complications, either alone or in combination. We also discuss gaps in our current knowledge regarding aPL-induced endothelial dysfunction.

Obstetric Anti-phospholipid Syndrome: State of the Art

PURPOSE OF REVIEW

This review focuses on new pathogenesis and clinical-therapeutic aspects of obstetric anti-phospholipid syndrome (ob-APS) in the last 5 years.

RECENT FINDINGS

The pathogenesis of ob-APS is multifactorial, including placental infarctions, infiltration of inflammatory cells that cause acute and chronic inflammation, leading to uncontrolled inflammation and poor pregnancy outcomes. A preconception counseling and a patient-tailored treatment are fundamental to improve maternal and fetal outcomes. Thanks to conventional treatment, based on low-dose aspirin and heparin, 70% of women with ob-APS can have successful pregnancies. Women with positive anti-phospholipid antibodies (aPL) without clinical manifestations ("aPL carriers") or with obstetric manifestation not fulfilling ob-APS criteria need to be further investigated in order to assess their best management. Great interest has been given to drugs that could interact in the pathophysiological mechanisms, such as hydroxychloroquine, statins, and eculizumab. These drugs could be considered for patients refractory to conventional therapy.

Current insights in obstetric antiphospholipid syndrome

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is defined as the association of thrombotic events and/or obstetric morbidity in patients persistently positive for antiphospholipid antibodies (aPL). In this review, we will highlight the most important clinical presentations of APS with a focus on the obstetric morbidity, the current management strategies and the outlook for the future.

RECENT FINDINGS

The use of aspirin and heparin has improved the pregnancy outcome in obstetric APS and approximately 70% of pregnant women with APS have a successful pregnancy outcome. Unfortunately, the current standard of care does not prevent all pregnancy complications as the current treatment fails in 20-30% of APS pregnancies. This therefore highlights the need for alternative treatments to improve obstetrical outcome. Other treatment options are currently explored and retrospective studies show that pravastatin for example is beneficial in women with aPL-related early preeclampsia. Moreover, the immunmodulator hydroxychloroquine may play a beneficial role in the prevention of aPL-related pregnancy complications.

SUMMARY

APS is among the most frequent acquired risk factors for a treatable cause of recurrent pregnancy loss and increases the risk of conditions associated with ischaemic placental dysfunction, such as fetal growth restriction, preeclampsia, premature birth and intrauterine death. Current treatment is mainly based on aspirin and heparin. Studies to inform on alternative treatment options are urgently needed.

Cellular and Molecular Mechanisms of Anti-Phospholipid Syndrome

The primary anti-phospholipid syndrome (APS) is characterized by the production of antibodies that bind the phospholipid-binding protein β2 glycoprotein I (β2GPI) or that directly recognize negatively charged membrane phospholipids in a manner that may contribute to arterial or venous thrombosis. Clinically, the binding of antibodies to β2GPI could contribute to pathogenesis by formation of immune complexes or modification of coagulation steps that operate along cell surfaces. However, additional events are likely to play a role in pathogenesis, including platelet and endothelial cell activation. Recent studies focus on neutrophil release of chromatin in the form of neutrophil extracellular traps as an important disease contributor. Jointly, the participation of both the innate and adaptive arms of the immune system in aspects of the APS make the complete understanding of crucial steps in pathogenesis extremely difficult. Only coordinated and comprehensive analyses, carried out in different clinical and research settings, are likely to advance the understanding of this complex disease condition.

Pregnancy outcomes among Chinese women with and without systemic lupus erythematosus: a retrospective cohort study

OBJECTIVE

To completely and quantifiably determine the effect of systemic lupus erythematosus (SLE) on pregnancy outcomes in a Chinese cohort.

DESIGN

A retrospective cohort study.

SETTING

Data were collected at a tertiary medical centre located in Shanghai, China, from September 2011 to May 2017.

PARTICIPANTS

We assigned 338 pregnant women with SLE to the study cohort and 1014 randomly selected pregnant women without SLE (three for every woman with SLE) to a comparison cohort. The relevant medical records of all pregnant women were retrospectively reviewed. Cases of multiple pregnancy and cases in which an artificial abortion was performed for personal reasons were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

Maternal and fetal outcomes were primary outcomes, and management of antenatal care was the secondary outcome.

RESULTS

The risks of pregnancy-induced hypertension (OR 2.68, 95% CI 1.75 to 4.09), pre-eclampsia (OR 3.13, 95% CI 1.95 to 5.03) and premature rupture of membranes (OR 2.53, 95% CI 1.46 to 4.40) were significantly different between women with and without SLE. Gestational diabetes was negatively associated with SLE in pregnant women (OR 0.49, 95% CI 0.28 to 0.85). Pregnant women with SLE displayed significantly higher rates of fetal loss (OR 10.23, 95% CI 5.08 to 20.59), including spontaneous abortion (OR 4.42, 95% CI 1.52 to 12.80), therapeutic abortion (OR 16.57, 95% CI 5.80 to 47.35) and stillbirth (OR 13.25, 95% CI 1.49 to 118.11), and a higher risk of preterm birth (OR 3.15, 95% CI 2.21 to 4.50), intrauterine growth restriction (OR 2.20, 95% CI 1.35 to 3.58), a child who was small for the gestational age (OR 1.86, 95% CI 1.11 to 3.13), a caesarean section (OR 4.73, 95% CI 3.30 to 6.80) or a neonatal intensive care unit admission (OR 3.48, 95% CI 2.21 to 5.48) than women in the non-SLE population after adjusting for confounding factors.

CONCLUSIONS

In this study, SLE significantly increased the risk of adverse pregnancy outcomes. Therefore, a preconception assessment and close antenatal monitoring by both rheumatologists and obstetricians should be performed in pregnant women with SLE.

Antiphospholipid syndrome: an update for clinicians and scientists

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is a leading acquired cause of thrombosis and pregnancy loss. Upon diagnosis (which is unlikely to be made until at least one morbid event has occurred), anticoagulant medications are typically prescribed in an attempt to prevent future events. This approach is not uniformly effective and does not prevent associated autoimmune and inflammatory complications. The goal of this review is to update clinicians and scientists on mechanistic and clinically relevant studies from the past 18 months, which have especially focused on inflammatory aspects of APS pathophysiology.

RECENT FINDINGS

How antiphospholipid antibodies leverage receptors and signaling pathways to activate cells is being increasingly defined. Although established mediators of disease pathogenesis (like endothelial cells and the complement system) continue to receive intensive study, emerging concepts (such as the role of neutrophils) are also receiving increasing attention. In-vivo animal studies and small clinical trials are demonstrating how repurposed medications (hydroxychloroquine, statins, and rivaroxaban) may have clinical benefit in APS, with these concepts importantly supported by mechanistic data.

SUMMARY

As anticoagulant medications are not uniformly effective and do not comprehensively target the underlying pathophysiology of APS, there is a continued need to reveal the inflammatory aspects of APS, which may be modulated by novel and repurposed therapies.

Investigating in utero fetal death: outcome of internal medicine consultation

AIM

The objectives were to determine the frequency of in utero fetal death (IUFD) related to placental disorders and to assess the frequency of antiphospholipid antibodies syndrome (APS) among women referred to the internal medicine department.

METHODOLOGY

A retrospective clinical study conducted in Rennes University Hospital, France. From January 2007 to December 2014, 53 women who presented an IUFD at 14 weeks or more of gestational age were included. The main cause for each IUFD was determined by expert agreement. Primary outcome was to analyze the final etiologies diagnosed and the prevalence of IUFD related to placental disorders. Secondary outcomes included the frequency of APS among patients with IUFD of placental origin and the pathological and clinical features associated with APS.

RESULTS

IUFD resulted from placental disorders in 36/53 (68%) patients, and remained unexplained in 11 cases (20.8%). Among the 36 patients with placental disorders, APS was diagnosed in five (13.9%) cases, and four (11.1%) patients were considered as having 'non-criteria' APS. History of thrombosis (P = 0.001) and placental infarcts (P = 0.047) were significantly associated with APS.

CONCLUSION

Placental disorders were the major cause for IUFD in patients who were referred to internal medicine specialists. Importantly, APS was seldom found in patients with placental disorders. Venous thromboembolism history and placental infarcts were both significantly associated with APS. Further studies are needed in order to deepen our understanding of the physiopathology of placental disorders and its underlying causes among non-APS women, and to determine the best treatment regimen for future pregnancies.

Complement inhibition by hydroxychloroquine prevents placental and fetal brain abnormalities in antiphospholipid syndrome

Placental ischemic disease and adverse pregnancy outcomes are frequently observed in patients with antiphospholipid syndrome (APS). Despite the administration of conventional antithrombotic treatment a significant number of women continue to experience adverse pregnancy outcomes, with uncertain prevention and management. Efforts to develop effective pharmacological strategies for refractory obstetric APS cases will be of significant clinical benefit for both mothers and fetuses. Although the antimalarial drug, hydroxychloroquine (HCQ) is increasingly used to treat pregnant women with APS, little is known about its efficacy and mechanism of action of HCQ. Because complement activation plays a crucial and causative role in placental ischemia and abnormal fetal brain development in APS we hypothesised that HCQ prevents these pregnancy complications through inhibition of complement activation. Using a mouse model of obstetric APS that closely resembles the clinical condition, we found that HCQ prevented fetal death and the placental metabolic changes -measured by proton magnetic resonance spectroscopy in APS-mice. Using 111In labelled antiphospholipid antibodies (aPL) we identified the placenta and the fetal brain as the main organ targets in APS-mice. Using this same method, we found that HCQ does not inhibit aPL binding to tissues as was previously suggested from in vitro studies. While HCQ did not affect aPL binding to fetal brain it prevented fetal brain abnormal cortical development. HCQ prevented complement activation in vivo and in vitro. Complement C5a levels in serum samples from APS patients and APS-mice were lower after treatment with HCQ while the antibodies titres remained unchanged. HCQ prevented not only placental insufficiency but also abnormal fetal brain development in APS. By inhibiting complement activation, HCQ might also be an effective antithrombotic therapy.

Antiphospholipid Syndrome and the Kidney

The antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by a combination of arterial and/or venous thrombosis, pregnancy morbidity, and the persistent presence of circulating antiphospholipid antibodies (aPL). APS has been described as primary APS when it occurs in the absence of any features of other autoimmune disease, and as secondary in the presence of other autoimmune diseases, mainly systemic lupus erythematosus (SLE). There is a well-known link between SLE and APS; 40% of SLE patients have aPL, and, in turn, some, but only a minority of patients with APS, eventually will develop features of SLE. Because SLE and APS can target the kidneys independently or at the same time, discriminating between inflammatory or thrombotic lesions is crucial in planning therapy. We provide an overview of the renal manifestations associated with the presence of aPL in patients with SLE, and discuss the impact of aPL in selected scenarios such as lupus nephritis, end-stage renal disease, and pregnancy.

Pravastatin improves pregnancy outcomes in obstetric antiphospholipid syndrome refractory to antithrombotic therapy

BACKGROUND

Administration of conventional antithrombotic treatment (low-dose aspirin plus low-molecular weight heparin [LDA+LMWH]) for obstetric antiphospholipid syndrome (APS) does not prevent life-threatening placenta insufficiency-associated complications such as preeclampsia (PE) and intrauterine growth restriction (IUGR) in 20% of patients. Statins have been linked to improved pregnancy outcomes in mouse models of PE and APS, possibly due to their protective effects on endothelium. Here, we investigated the use of pravastatin in LDA+LMWH-refractory APS in patients at an increased risk of adverse pregnancy outcomes.

METHODS

We studied 21 pregnant women with APS who developed PE and/or IUGR during treatment with LDA+LMWH. A control group of 10 patients received only LDA+LMWH. Eleven patients received pravastatin (20 mg/d) in addition to LDA+LMWH at the onset of PE and/or IUGR. Uteroplacental blood hemodynamics, progression of PE features (hypertension and proteinuria), and fetal/neonatal outcomes were evaluated.

RESULTS

In the control group, all deliveries occurred preterm and only 6 of 11 neonates survived. Of the 6 surviving neonates, 3 showed abnormal development. Patients who received both pravastatin and LDA+LMWH exhibited increased placental blood flow and improvements in PE features. These beneficial effects were observed as early as 10 days after pravastatin treatment onset. Pravastatin treatment combined with LDA+LMWH was also associated with live births that occurred close to full term in all patients.

CONCLUSION

The present study suggests that pravastatin may improve pregnancy outcomes in women with refractory obstetric APS when taken at the onset of PE or IUGR until the end of pregnancy.

Maternal-placental syndrome and future risk of accelerated cardiovascular events in Parous Swedish women with systemic lupus erythematosus - a population-based retrospective cohort study with time-to-event analysis

OBJECTIVES

Women with SLE are at increased risk of cardiovascular events (CVEs), but a relationship with traditional cardiovascular and SLE-specific risk factors has not been established. In unselected populations, adverse pregnancy outcomes linked to maternal-placental syndrome (MPS) are associated with an increased risk of CVEs. However, the effect of MPS on CVEs is unknown in women with SLE. The aim of this study was to determine if MPS increased the risk and accelerated the development of CVEs in women with SLE.

METHODS

Utilizing Swedish population registries, parous women with SLE were identified. Exposures were the following: MPS defined as hypertensive disorders of pregnancy; small-for-gestational-age; placental abruption and stillbirth; and preterm delivery <34 weeks. Outcomes were CVE encompassing cardiovascular morbidity and mortality. Risk of an event was modelled using Cox proportional hazards adjusted for year of delivery, age at CVE, severity of SLE and cardiovascular risk factors. Time-to-CVE was estimated using Kaplan-Meier methods.

RESULTS

Over the 38-year study period, there were 3977 women with 7410 pregnancies, of whom 413 (10.2%) suffered a CVE. Hazard of CVE was higher in those with MPS, particularly when MPS (adjusted HR = 1.64; 95% CI: 1.31, 2.05) was combined with preterm delivery < 34 weeks' gestation (adjusted HR 1.99; 95% CI 1.39, 2.84). There was accelerated development of CVEs in women with MPS of 10.5% (vs 7.3% in uncomplicated pregnancies) over the 38-year interval (P < 0.05).

CONCLUSION

Pregnancy complicated by MPS and preterm delivery exerts an independent effect to increase the risk and accelerate the development of CVEs in parous women with SLE.

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

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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.

Histopathology in the placentae of women with antiphospholipid antibodies: A systematic review of the literature

BACKGROUND

Antiphospholipid antibodies (aPLs) are a heterogenous group of autoantibodies associated with recurrent miscarriage, stillbirth, foetal growth restriction and premature birth. The cause of obstetric morbidity in women with aPLs is not completely understood. Workers have attempted to understand the role of aPLs in obstetric morbidity by investigating the histopathology of placentae from aPL-positive women. However, it is unclear from these diverse, and at times contradictory reports what histopathological lesions are common in the placentae of women with aPLs. This systematic review was undertaken to generate a complete picture of the placental features associated with aPLs in an attempt to understand the pathological processes that occur in pregnancies affected by aPLs.

METHODS

Pubmed, Scopus, Web of Science and Embase were searched on the 27th November 2014 using the keywords "placenta" OR "trophoblast" AND "antiphospholipid antibody" OR "antiphospholipid antibody syndrome". Records that were relevant and eligible were qualitatively assessed and given a score out of 24.

RESULTS

Of the 1112 records that were retrieved from the systematic search, 34 records were eligible for review, and were qualitatively scored. Of the 44 histopathological features that were reported in 580 placentae from aPL-positive women, six features appeared to be more common in the placentae of aPL-positive women compared to control women, including: placental infarction, impaired spiral artery remodelling, decidual inflammation, increased syncytial knots, decreased vasculosyncytial membranes and the deposition of complement split product C4d.

CONCLUSION

Based on the evidence in this systematic review, a human placental aPL fingerprint has been proposed. The diversity of the human placental aPL fingerprint suggests that multiple pathological processes may occur in pregnancies affected by aPL.

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.

Reduced ANXA5 mRNA and protein expression in pregnancies complicated by preeclampsia

INTRODUCTION

The placental anticoagulant protein Annexin A5 (ANXA5) is a multifunctional protein that is highly expressed on the apical surfaces of syncytiotrophoblasts, and plays an important role in haemostatic regulations, maintaining blood fluidity of the placenta. The aim of this study was to investigate the expression of ANXA5 in pregnancies complicated by preeclampsia (PE).

MATERIALS AND METHODS

Placental tissue samples were collected from 23 pregnancies with PE and 34 normal pregnancies. ANXA5 mRNA levels were measured by quantitative Real-Time PCR (qPCR), while ANXA5 protein expression was measured by Western Blot (WB) and immunohistochemistry.

RESULTS

ANXA5 mRNA expression in PE samples was lower than 1% of its expression in normal samples (mean ± SD: 0.002 ± 0.004 vs. 0.55 ± 0.38, p < 0.001), while ANXA5 protein levels in PE samples were approximately at 65% of the average normal expression (mean ± SD: 0.53 ± 0.30 vs. 0.81 ± 0.25, p=0.001). Immunohistochemical analysis also verified the above results, since PE placentas tended to have low labelling indexes (LIs), in contrast to controls which demonstrated high LIs (p=0.020). Statistical analysis of the WB data revealed that ANXA5 protein expression was increased in PE smokers vs. PE non-smokers (mean ± SD: 0.64 ± 0.23 vs. 0.41 ± 0.33, p=0.027).

CONCLUSIONS

These results suggest that ANXA5 downregulation could be part of the pathophysiology of PE and the possible impairment in coagulation processes, which are seen in pregnancies that demonstrate PE. Further studies may investigate whether ANXA5 could be used as a biomarker for the early detection of PE and for the prediction of its severity.

Clinical advances of interest in the diagnosis and treatment of patients with antiphospholipid syndrome

In this paper we review recent studies and consensus documents that we consider relevant to the diagnosis and treatment of patients with antiphospholipid syndrome (APS). The diagnosis of APS is based on the Sydney classification criteria (2006), in which positive laboratory tests (anticardiolipin antibodies, anti-β2-glycoprotein I antibodies or lupus anticoagulant) are mandatory. However, it is not uncommon to see patients with clinical features highly suggestive of the syndrome in whom these antibodies are persistently negative. Therefore, we summarize the principal clinical and serological findings in a subgroup of patients with seronegative APS in the first series published up to date. In addition, a recent study draws attention to the safety and efficacy of the long-term use of low-molecular-weight heparins in patients with APS not susceptible to warfarin treatment. There is also a subgroup of women with APS and recurrent fetal loss with no response to the standard antithrombotic therapy; in this group the materno-fetal prognosis could be improved by the addition of low-dose prednisolone during the first trimester of pregnancy. Finally, we list the principal recommendations regarding thromboprophylaxis in APS drawn from the expert consensus document elaborated at the meeting held in Galvestone (2010).

Modulation of trophoblast angiogenic factor secretion by antiphospholipid antibodies is not reversed by heparin

PROBLEM  Women with antiphospholipid antibodies (aPL) are at risk of miscarriage and pre-eclampsia, obstetrical disorders associated with reduced trophoblast invasion and spiral artery transformation. aPL target the placenta by binding beta(2) -glycoprotein I (β(2) GPI) on the trophoblast. In this study, we determined whether aPL alter the trophoblast secretion of angiogenic factors and evaluated the effect of low molecular weight heparin (LMWH) on this response. METHOD OF STUDY  First-trimester trophoblast was treated with anti-β(2) GPI antibodies with or without LMWH. Angiogenic factor secretion was measured by enzyme-linked immunosorbent assay. RESULTS  Trophoblast cells produced more vascular endothelial growth factor (VEGF), placenta growth factor (PlGF), and soluble endoglin following exposure to anti-β(2) GPI Abs, and this occurred in both a MyD88-dependent and MyD88-independent manner. LMWH was unable to reverse the effects of the anti-β(2) GPI Abs on trophoblast VEGF secretion, but enhanced PlGF. Strikingly, LMWH upregulated soluble fms-like tyrosine kinase receptor-1 (sFlt-1) secretion independently of aPL. CONCLUSION  This study demonstrates that aPL perturb the secretion of trophoblast angiogenic factors. LMWH does not reverse this effect but exacerbates sFlt-1 secretion, a potent anti-angiogenic factor. These findings may help to explain why women with antiphospholipid syndrome, who are treated with heparin to prevent early pregnancy loss, remain at increased risk of developing late obstetrical complications, such as pre-eclampsia.

[Pathogenic mechanisms of the anti-phospholipid antibodies]

The antiphospolipid syndrome (APS) is an autoimmune disease characterized by recurrent fetal loss, thrombotic events (arterial or venous) and hemocytopenic disorders associated to high titers of circulating aPL. Two variants of the APS have been described. Primary APS is a clinical entity without evidence of any other autoimmune disease and secondary APS is a clinical disorder mainly associated with Systemic Lupus Erithematosus (SLE). aPL are a widely group of immunoglobulins directed against different components or proteins factors. In 1990 three groups of researchers identified that β(2)GP-I is the mainly antigenic target of aPL in APS patients. There are evidences that show that more than one pathogenic mechanism is involved in the development of the APS. The best documented clinical manifestations associated with the APS are recurrent fetal loss and thrombotic disorders. The latter is based on observations in vivo in animal models and in vitro on the effects caused by aβ(2)GP-I antibodies from patients with APS or from animals which cause experimental APS. The objective of the present paper is to show the pathogenic mechanisms that participate in the development of the APS. We also presented evidence that shows that aβ(2)GP-I induces pro-inflammatory, pro-adhesive and pro-coagulant disorder.

First-trimester low-dose prednisolone in refractory antiphospholipid antibody-related pregnancy loss

The objective of this study was to assess pregnancy outcome in women with a history of refractory antiphospholipid antibody-associated pregnancy loss(es) who were treated with early low-dose prednisolone in addition to aspirin and heparin. Eighteen women with antiphospholipid antibodies who had refractory pregnancy loss(es) were given prednisolone (10 mg) from the time of their positive pregnancy test to 14 weeks' gestation. Before low-dose prednisolone was given as treatment, 4 (4%) of 97 pregnancies had resulted in live births. Among 23 pregnancies supplemented with prednisolone, 9 women had 14 live births (61%), including 8 uncomplicated pregnancies. The remainder were complicated by preterm delivery, preeclampsia, and/or small-for-gestational-age infants. There were 8 first-trimester miscarriages and 1 ectopic pregnancy. There were no fetal deaths after 10 weeks' gestation and no evidence of maternal morbidity. The addition of first-trimester low-dose prednisolone to conventional treatment is worthy of further assessment in the management of refractory antiphospholipid antibody-related pregnancy loss(es), although complications remain elevated.

Placental bed disorders in preterm labor, preterm PROM, spontaneous abortion and abruptio placentae

Failure of physiologic transformation of the spiral arteries has been studied using placental bed biopsies in several obstetrical syndromes. Contrary to what was originally believed, this lesion is not restricted to preeclampsia and/or intrauterine growth restriction. A review of published evidence indicates that failure of physiologic transformation can be observed in women with spontaneous second trimester abortions, preterm labor with intact membranes, preterm prelabor rupture of membranes and abruptio placentae. Therefore, disorders of deep placentation are present in a wide range of complications of pregnancy, emphasizing the importance of understanding the physiology and pathology of transformation of the spiral arteries. We propose that changes in the population and function of immunocytes at the maternal-fetal interface can be part of the mechanism of disease of obstetrical disorders, and this requires further investigation.

Pathophysiology of the antiphospholipid antibody syndrome

Antiphospholipid antibodies (aPL) are associated with the recurrent pregnancy loss and thrombosis that characterizes the antiphospholipid antibody syndrome (APS). Although the ontogeny of these pathogenic antibodies has not been fully elucidated, there is evidence that indicates the involvement of both genetic and environmental factors. The ability of aPL to induce a procoagulant phenotype in APS patients plays a central role in the development of arterial and venous thrombotic manifestations typical of the disease. Inflammation serves as a necessary link between this procoagulant phenotype and actual thrombus development and is an important mediator of the placental injury seen in APS patients with obstetric complications. Recent evidence has indicated a role for abnormal cellular proliferation and differentiation in the pathophysiology of APS, especially in those patients with pregnancy morbidity and other more atypical manifestations that have no identifiable thrombotic cause. The interplay of genetic and environmental factors responsible for aPL development and the mechanisms by which these antibodies produce disease in APS patients is the focus of this review.

Complement activation and pregnancy failure

Pregnancy represents a physiologic condition where maternal immune system tolerates the semi-allogenic fetus. The fetal tissues are directly exposed to the maternal blood with potential attacks from maternal immune system, including the activation of complement cascade. Small amounts, of both early and late components, of complement are physiologically found in the placenta, maybe in relation to the vascular remodeling process. A significant increase of complement activation was associated with different pathologic pregnancy outcomes, namely pre-eclampsia, recurrent spontaneous abortions, intra-uterine growth retardation, and anti-phospholipid syndrome (APS). In some, but not in all, mice models of APS, complement activation plays a major role in pregnancy loss, with a massive accumulation of C3 in the placenta, while C3 deficient mice didn't show fetal resorption. Basing on these findings, anti-phospholipid antibodies and complement activation (via C3a, C5a, and MAC) may cooperate in triggering a local inflammatory process, eventually leading to placental thrombosis, hypoxia, and neutrophil infiltration. However, histological analysis of human placenta tissues from APS women shows small rather than widespread inflammation. In a similar manner, complement activation can be detected in human APS placentas but without any relationship with pregnancy outcome and therapy. Further studies are necessary to investigate whether complement activation and inflammatory processes found in animal models are really taking place in APS.

Antiphospholipid syndrome: pathogenesis and a window of treatment opportunities in the future

BACKGROUND

Antiphospholipid syndrome (APS) is a systemic autoimmune vascular disease characterized by recurrent thrombotic episodes and/or obstetric complications. Management of this disease has been restricted mainly to anticoagulation; however, in recent years, significant advancement has been made in elucidating the pathophysiology of the disease including antiphospholipid antibody (aPL)-induced activation of the platelets, endothelial cells, monocytes, complement and coagulation cascade. Stemming from these advances, potential targeted therapeutic approaches have been proposed.

MATERIALS AND METHODS

We utilized a computer-assisted search of the literature (MEDLINE, National Library of Medicine, Bethesda, MD, USA) up until September 2009 using the keywords: antiphospholipid syndrome, antiphospholipid antibodies, anticardiolipin antibodies, lupus anticoagulant, anti beta-2 glycoprotein antibodies, complement system, tissue factor, p38 mitogen-activated protein kinase (p38 MAPK), nuclear factor kappa B, toll-like receptors, annexin, Rituximab, statins and tumour necrosis factor.

RESULTS

Several study groups have separately demonstrated the importance of inflammatory mediators in the pathogenesis of APS. It was also established that tissue factor, MAPK, nuclear factors kappa B, and the complement system are integral to the disease process. Toll-like receptors and annexin have as well been associated with the disease pathophysiology. Some study groups proposed new targeted therapeutic strategies some of which have shown promising results in preclinical studies. These include Rituximab, complement inhibition, anti-cytokine therapy, p38 MAPK inhibitors, nuclear factor inhibitors and tissue factor inhibitors.

CONCLUSION

As more insight is being gained into the pathophysiology of APS, newer therapeutic strategies are being proposed that might lead to safer and more efficacious treatment modalities in the future.

Antiphospholipid antibodies limit trophoblast migration by reducing IL-6 production and STAT3 activity

PROBLEM

Women with antiphospholipid antibodies (aPL) are at risk of recurrent miscarriage and pre-eclampsia. aPL target the placenta by binding to beta(2)-glycoprotein I (beta(2) GPI) expressed by the trophoblast. The objective of this study was to evaluate if and how aPL affect first trimester trophoblast migration.

METHOD OF STUDY

First trimester trophoblast cells were treated with anti-beta(2) GPI monoclonal antibodies. Migration was determined using a two-chamber assay. Interleukin (IL)-6 production was evaluated by RT-PCR and enzyme-linked immunosorbent assay, and signal transducer and activator of transcription 3 (STAT3) activation was assessed by western blot.

RESULTS

Trophoblast cells constitutively secreted IL-6 in a time-dependent manner and this directly correlated with STAT3 phosphorylation. In the presence of anti-beta(2) GPI Abs, trophoblast IL-6 mRNA levels and secretion was downregulated in a Toll-like receptor 4/MyD88-independent manner and this correlated with a reduction in phosphorylated STAT3 levels. In addition, the anti-beta(2) GPI Abs reduced the migratory potential of trophoblast. Heparin was able to reverse aPL-dependent inhibition of trophoblast IL-6 secretion and migration.

CONCLUSION

This study demonstrates that aPL limit trophoblast cell migration by downregulating trophoblast IL-6 secretion and STAT3 activity. As heparin was unable to prevent these effects, our findings may explain why women with antiphospholipid syndrome, treated with heparin, remain at risk of developing obstetrical syndromes, associated with impaired deep placentation, such as pre-eclampsia.

Diagnosis of placental abruption: relationship between clinical and histopathological findings

OBJECTIVE

We evaluated the extent to which histologic lesions bearing a diagnosis of abruption conform to a diagnosis based on established clinical criteria. We further examined the profile of chronic and acute histologic lesions associated with clinical abruption.

METHODS

Data from the New Jersey-Placental Abruption Study - a multi-center, case-control study - were utilized to compare the clinical and histologic criteria for abruption. The study was based on 162 women with clinically diagnosed abruption and 173 controls. We examined the concordance between clinical indicators for abruption with those of a histopathological diagnosis. The clinical criteria for a diagnosis of abruption included (i) evidence of retroplacental clot(s); (ii) abruption diagnosed on prenatal ultrasound; or (iii) vaginal bleeding accompanied by nonreassuring fetal status or uterine hypertonicity. The pathological criteria for abruption diagnosis included hematoma, fibrin deposition, compressed villi, and hemosiderin-laden histiocytes in cases with older hematomas. Acute lesions included chorioamnionitis, funisitis, acute deciduitis, meconium stained membranes, villous stromal hemorrhage, and villous edema. Chronic lesions included chronic deciduitis, decidual necrosis, decidual vasculopathy, placental infarctions, villous mal-development (delayed or accelerated maturation), hemosiderin deposition, intervillous thrombus, and chronic villitis.

RESULTS

Of clinically diagnosed cases, the sensitivity and specificity for a histologic confirmation of abruption were 30.2% and 100%, respectively. Presence of retroplacental clots remained the single most common finding (77.1%) among clinically diagnosed cases. Among the acute lesions, chorioamnionitis and funisitis were associated with abruption. The only chronic histologic lesion associated with abruption was placental infarctions.

CONCLUSIONS

The concordance between clinical and pathologic criteria for abruption diagnosis is poor. The criteria for diagnosing a clinical abruption should include sonographic visualization of abruption, evidence of retroplacental clots, or vaginal bleeding accompanied by nonreassuring fetal status or uterine hypertonicity.

European Forum on Antiphospholipid Antibodies: research in progress

The research projects of the European Forum on Antiphospholipid Antibodies are representative of how dynamic is this area of investigation. The present review is focused on the most recent projects of the Forum on the aetiopathogenic aspects of the antiphospholipid syndrome (APS). Studies on the genetic background of the APS are ongoing in order to better define the proximity between APS and full-blown systemic lupus erythematosus. However, the analysis of the polymorphisms of genes coding for inflammatory mediators may offer new information on the role of inflammatory processes in triggering thrombotic events as well as the whole susceptibility for developing the vascular manifestations. A systematic and wide detection of serological markers of infectious processes will give new insight on the role of infectious agents in favouring autoimmunity in APS. Owing to the well-known role of vitamin D3 defect in autoimmune disease, the detection of vitamin plasma levels in APS patients will offer the rationale for a possible therapeutic supplementation. Additional projects are aimed to better characterize the diagnostic/prognostic value of antiphospholipid antibodies (aPL) by defining their epitope specificity and binding avidity. Pregnancy complications represent the obstetric side of APS. Research projects are focussed on the role of complement activation in placenta damage and on the potential ability of aPL to affect the fertility. Finally, a study has been planned in order to draw definitive conclusions on the associations between aPL and atherosclerosis.

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.