Anti-phospholipid antibody mediated fetal loss: still an open question from a pathogenic point of view

Predicting risk of subsequent pregnancy loss among women with recurrent pregnancy loss: An immunological factor-based multivariable model

PROBLEM

Studies on subsequent pregnancy loss prediction models specific for recurrent pregnancy loss (RPL) patients are very limited. This study aims to develop a risk predictive model based on the immunological parameters for the subsequent pregnancy loss risk in northwest Chinese RPL patients.

METHOD OF STUDY

Totally of 357 RPL patients recruited from Lanzhou University Second Hospital were included in this retrospective study. Univariate analysis was performed on RPL patients with outcomes of live birth or pregnancy loss. Subsequently, the least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression were utilized to select variables among baseline and clinical characteristics and to develop a pregnancy loss risk prediction model with all 357 RPL patients. The area under the curve (AUC), calibration curve and decision curve analyses were used to evaluate the performance of the prediction model; moreover, 10-fold cross-validation was used for internal validation.

RESULTS

Ten factors of maternal age, age of menarche, previous pregnancy loss, IL-10, complement 4, IgA, antiprothrombin antibody IgG/IgM, rheumatoid factor IgA, and lupus anticoagulant (LA) 1/LA2 ratio were finally selected as variables for the prediction model of pregnancy loss risk. The AUC value and Hosmer-Lemeshow test p-value of the model were .707 and .599, respectively, indicating a satisfactory discrimination and calibration performance. Moreover, the clinical decision curve suggested this prediction model have a good positive net benefit.

CONCLUSIONS

This is the first prediction model for the risk of subsequent pregnancy loss in northwest Chinese women with RPL, providing a user-friendly tool to clinicians for the early prediction and timely management of RPL patients.

Integrating the autoimmune connective tissue diseases for the medical student: A classification proposal based on pathogenesis and clinical phenotype

It is hard for medical students to recognize and understand the clinical presentation of systemic connective tissue diseases (SCTDs). In this study, we aimed to review the immune mechanisms of the main SCTDs and to propose a classification system focused on the student and based on each immune dysfunction's clinical phenotype. The search involved the MEDLINE database and included the terms "systemic lupus erythematosus," "antiphospholipid syndrome," "inflammatory myopathies," "rheumatoid arthritis," "Sjögren's syndrome" or "systemic sclerosis" and "pathogenesis," and "immunology" or "mechanism of disease." Systemic lupus erythematosus (SLE) is a prototypic immune-complex disease with a tendency toward vascular injury. Antiphospholipid syndrome (APS) is a diffuse immune-mediated thrombotic vasculopathy. In inflammatory myopathies (IMs), muscle inflammation leading to muscle weakness is the cardinal manifestation. Rheumatoid arthritis (RA) is a unique form of erosive and destructive polyarthritis. Sjögren's syndrome (SS) causes sicca symptoms due to infiltration of the exocrine glands. Disseminated fibrosis in systemic sclerosis (SSc) is caused by vascular injury with excessive fibroblast activation. After the review, we created a focus group involving all the authors to group the diseases according to their pathogenesis and clinical phenotype. Our group agreed that SCTDs can be divided in 3 groups based on the preferential clinical presentation and immune dysfunction: 1) vasculopathic features (SLE and APS), 2) tissue inflammation (IMs, RA, and SS), and 3) tissue fibrosis (SSc). In synthesis, we suggest that clustering SCTDs in groups based on clinical phenotype and presumptive immune dysfunction instead of ordering autoantibodies randomly can help students understand the diseases.

Antiphospholipid antibody-mediated NK cell cytotoxicity

Antiphospholipid syndrome (APS) is an autoimmune thrombophilia that is characterised by thrombosis and obstetric complications in the presence of antiphospholipid antibodies (aPL). Pregnancy complications remain a challenging problem for patients with APS, especially during the first trimester. Although natural killer (NK) cells constitute up to 70% of decidual lymphocytes during the first trimester, their contribution to early pregnancy loss in APS is largely unknown. We aimed to analyse whether aPL are able to recruit antibody-dependent cellular cytotoxicity (ADCC) of NK cells, with special emphasis on the differences in the effects of aPL containing anti-β2GPI domain 1 (anti-β2GPI-D1) antibodies (aPL+/D1+) and those that do not (aPL+/D1-). Our findings revealed a differential distribution of NK subsets in the presence of different aPL. Namely, aPL+/D1- IgGs increased CD56^dim/CD16^dim cells, while aPL+/D1 + IgGs increased the number of CD56^bright/CD16^dim cells. ADCC NK cell cytotoxicity was found to be higher in the presence of aPL+/D1- IgGs, as defined by an increased target cell death, degranulation and increased expression of CD11b, CD69 and NKG2D. Overall, our evidence showed that aPL are able to recruit ADCC, suggesting NK cells as candidate cells for APS-related obstetric complications.

Pregnancy outcome predictors in antiphospholipid syndrome: A systematic review and meta-analysis

OBJECTIVE

To identify and assess the magnitude of effect of pregnancy outcome predictors in women with antiphospholipid syndrome (APS) by means of systematic review and meta-analysis.

METHODS

PubMed and Embase were searched (13th June 2020) for studies reporting on pre-pregnancy risk factors of pregnancy outcomes in APS patients. Literature screening and data extraction were conducted by two reviewers independently, in a blinded standardized manner. Pooled univariate odds ratios (OR) were computed using a random effects model. Heterogeneity was assessed by I²%.

RESULTS

The search yielded 3013 unique results; 27 records were included in this meta-analysis. Previous thrombosis was associated with a decreased live birth risk (OR 0.60, p < 0.01, I² = 40%), increased neonatal mortality (OR 15.19, p < 0.01, I² = 0%), an increased risk of antenatal or postpartum thrombosis (OR 6.26, p < 0.01, I² = 0%) and an increased risk of delivering a small for gestational age neonate (SGA) (OR 2.60, p = 0.01, I² = 0%). Patients with an APS laboratory category I (double or triple positivity) profile had a decreased live birth risk (OR 0.66, p < 0.01, I² = 0%), an increased risk of SGA (OR 1.86, p = 0.01, I² = 43%) and preterm birth (OR 1.35, p < 0.01, I² = 49%). Triple positivity was associated with a decreased live birth risk (OR 0.33, p < 0.01, I² = 68%), an increased risk of preeclampsia (OR 2.43, p = 0.02, I² = 35%) and SGA (OR 2.47, p = 0.04, I² = 61%). Patients with lupus anticoagulant positivity had an increased risk of preeclampsia (OR 2.10, p = 0.02, I² = 48%), SGA (OR 1.78, p < 0.01, I² = 0%) and preterm birth (OR 3.56, p = 0.01, I² = 48%). Risk of bias assessment suggested considerable bias on study participation and statistical methods.

CONCLUSIONS

The results of this meta-analysis identified previous thrombosis, laboratory category I, triple positivity and lupus anticoagulant positivity as the most important predictors of adverse pregnancy outcomes. This up-to-date knowledge, can be used in preconception counseling and tailoring of obstetric care.

Biomarkers of neutrophil extracellular traps (NETs) and nitric oxide-(NO)-dependent oxidative stress in women who miscarried

Pregnancy loss is a multidisciplinary problem which concerns researchers from the fields of medicine, epidemiology, psychology, and public health. The primary objective of the present study was to explain the potential role of neutrophil extracellular traps (NETs) in the process of spontaneous miscarriage. Enzyme-linked immunosorbent assay to assess the levels of biomarkers of NETs in the serum of examined women was conducted. Furthermore, levels of nitric oxide (NO) and late markers of its action were measured in serum samples. Analyses results demonstrated the existence of NETs in the placental tissue of women who miscarried as well as a simultaneous increase in the levels of myeloperoxidase and pentraxin 3. This clearly confirms the participation of NETs in the course of pregnancy loss. Women who have had a miscarriage but did not show the presence of NETs in their placenta exhibited the highest contents of NO, nitrotyrosine, and malondialdehyde suggesting a different pathway leading to pregnancy loss associated with disturbed oxidative-antioxidative processes. Although study results demonstrate new aspects associated with the formation of NETs they are not, however, sufficient to unambiguously determine the role of NETs in the course of miscarriage.

Machine Learning (ML) based-method applied in recurrent pregnancy loss (RPL) patients diagnostic work-up: a potential innovation in common clinical practice

RPL is a very debated condition, in which many issues concerning definition, etiological factors to investigate or therapies to apply are still controversial. ML could help clinicians to reach an objectiveness in RPL classification and access to care. Our aim was to stratify RPL patients in different risk classes by applying an ML algorithm, through a diagnostic work-up to validate it for the appropriate prognosis and potential therapeutic approach. 734 patients were enrolled and divided into 4 risk classes, according to the numbers of miscarriages. ML method, called Support Vector Machine (SVM), was used to analyze data. Using the whole set of 43 features and the set of the most informative 18 features we obtained comparable results: respectively 81.86 ± 0.35% and 81.71 ± 0.37% Unbalanced Accuracy. Applying the same method, introducing the only features recommended by ESHRE, a correct classification was obtained only in 58.52 ± 0.58%. ML approach could provide a Support Decision System tool to stratify RPL patients and address them objectively to the proper clinical management.

The pathogenic role of autoantibodies in recurrent pregnancy loss

In the present manuscript, we review the recent research investigating the pathogenic association between most studied autoantibodies and recurrent pregnancy loss. Pregnancy loss represents a common obstetric complication occurring in about 15%-25% of all clinically recognized pregnancies. The recurrence of pregnancy loss identifies a distinct clinical entity, that is recurrent pregnancy loss (RPL), affecting about 2%-4% of couples. Several factors, including age, chromosomal abnormalities, uterine anomalies, thrombophilic disorders, endocrinopathies, hormonal and metabolic disorders, infections, sperm quality, and lifestyle issues, are involved in RPL. The role of autoantibodies in RPL is only partially determined. In some cases (antiphospholipid antibodies [aPL]), their involvement is well established. In other cases (anti-thyroid autoantibodies, antinuclear, anti-transglutaminase, and anti-endomysial antibodies), it is still debated, despite multiple, although not fully conclusive, evidences strongly suggest a possible involvement in RPL. Further extensive research is needed to definitively confirm or exclude their actual role.

Complementemia in pregnancies with antiphospholipid syndrome

Prognosis of pregnancies in women with antiphospholipid syndrome has dramatically improved over the past two decades using conventional treatment with low molecular weight heparin and low-dose aspirin. However, despite this regimen, 10-15% of antiphospholipid syndrome patients experience pregnancy losses. Several studies have been performed in order to identify risk factors predictive of complications. Thrombosis has been generally accepted as the key pathogenetic mechanism underlying pregnancy morbidity. However, the thrombogenic state alone is not able to explain all the different mechanisms leading to pregnancy failure. In fact, emerging evidence shows that complement pathway could play an important role in mediating clinical events in antiphospholipid syndrome. However, the exact mechanism through which complement mediates antiphospholipid syndrome complications remains unknown. Low complement levels (C3 and C4) are associated with poor pregnancy outcome in women with antiphospholipid syndrome in different studies. Hypocomplementemia could be indicated as an early predictor of adverse pregnancy outcome, available at the beginning of pregnancy for starting, if necessary, additional treatment to conventional therapy. However, future studies need to better understand the impact of low complement level on antiphospholipid syndrome pregnancy outcome.

Amniotic fluid antiphospholipid antibodies: potential role in antiphospholipid syndrome-independent aberrant implantation process

BACKGROUND

The direct role of antiphospholipid antibodies (aPL) at maternal-fetal interface has not been fully investigated, especially whether they are involved in physiological and pathological implantation conditions, in an antiphospholipid syndrome (APS)-independent manner. In fact, trophoblast cells and placental endothelial cells at the implantation site express potential aPL targeted-phospholipid antigens (PL Ags); thus, the local production and presence of their specific antibodies, not related to APS (characterized by aPL presence in the peripheral blood), could be a potential marker of aberrant invasion, implantation and fetal-maternal immune tolerance processes.

METHODS

Anti-Beta₂glycoprotein I (anti-β₂GPI) and anticardiolipin (aCL Ab) antibodies (the most clinically relevant aPL) were detected by immunoenzymatic assay (ELISA), in the amniotic fluid (AF) of 167 women with physiological and complicated common pregnancy conditions, sharing an aberrant implantation process, such as recurrent pregnancy loss (RPL), autoimmune hypothyroidism (ahT) and smoking. All women included in the study were negative to peripheral blood aPL.

RESULTS

aCL and anti-β₂GPI antibodies were detectable in all the AF samples. RPL, ahT and smoking patients had higher level of anti-β₂GPI Abs (IgM) compared to women with physiological pregnancies (p < 0.0001). Since IgM cannot cross the placenta, their local production in response to maternal-fetal interface stimuli, could be hypothesized.

CONCLUSIONS

The presence of aPL in the AF (not related to APS) could reveal a potential clinical significance at maternal-fetal interface in selected pregnancy complications, in which an aberrant implantation process, and in turn an impaired fetal-maternal immune tolerance cross-talk, could occur.

Effect of alpha-lipoic acid and myoinositol on endometrial inflammasome from recurrent pregnancy loss women

PROBLEM

A significant increased expression/activation of one of the most well-characterized inflammasomes, the NAcht leucine-rich-repeat protein-3 (NALP-3), in the endometrium from idiopathic recurrent pregnancy loss women (RPL) has been previously found by our research group. We therefore, suggested this event as being one of the molecular mechanisms altering endometrial inflammatory status during early pregnancy. In the present research, we attempt to investigate whether molecules with anti-inflammatory activity, alpha-lipoic acid (ALA), and/or myoinositol affect the endometrial NALP-3 expression and activation.

METHOD OF STUDY

Women with a history of idiopathic RPL (n = 30) were included in the study and compared to a control group (n = 15). Endometrial tissues were collected by hysteroscopy during the mid-luteal phase. RPL women underwent a three-month prescription of tablets containing ALA plus myoinositol (Sinopol^® ). After treatment, hysteroscopic biopsies were repeated in RPL patients. Inflammasome expression was evaluated by immunohistochemical and Western blot analysis. NALP-3 activation was studied by quantifying the secretion of both caspase-1 and interleukin (IL)-1ß and IL-18 through ELISA. In ex vivo experiments, the effects of each molecule on endometrial inflammasome were studied.

RESULTS

Sinopol^® significantly reduced the RPL endometrial inflammasome expression and activation. ALA, but not myoinositol, significantly reduced the endometrial inflammasome expression and activity.

CONCLUSION

Our data suggest a role for ALA on RPL inflammasome. Understanding the mechanisms involved in RPL and the observation that specific molecules are able to interfere with such complex at the endometrium might provide new rational design approaches to a personalized evaluation of endometrial status and, ultimately, a targeted medicine.

Insights into the diagnosis and pathogenesis of the antiphospholipid syndrome

The Antiphospholipid syndrome (APS), formerly known as Anticardiolipin or Hughes syndrome, is a systemic autoimmune disorder characterized by obstetrical complications and thrombotic events affecting almost every organ-system in patients persistently testing positive for antiphospholipid antibodies (aPL). The contribution of the extra-criteria aPL to the pathogenesis of APS have exceeded the expectations of a simple, direct pathologic 'hit' leading to thrombogenesis or obstetrical complications, and more pathologic pathways are being linked directly or indirectly to aPL. The value of extra-criteria aPL is on the rise, and these antibodies are nowadays evaluated as markers for risk assessment in the diagnostic approach to APS. A diagnosis of APS should be considered in pediatric patients with suggestive clinical and laboratory picture. Management of APS remains mostly based on anticoagulation, while other drugs are being tested for efficacy and side effects. Low-dose aspirin may have a role in the management of thrombotic and obstetric APS. Due to the high variability in disease severity and complication recurrence outcomes, new tools are being developed and validated to assess the damage index and quality of life of APS patients.

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.

Antiphospholipid and antioangiogenic activity in females with recurrent miscarriage and antiphospholipid syndrome

Background Antiphospholipid syndrome is an autoimmune disease characterized by thrombosis, fetal losses and thrombocytopenia associated to antiphospholipid antibodies. They are directed to phospholipids, such as cardiolipins (anticardiolipin) and lupus anticoagulant or to complexes formed by phospholipids and protein cofactors, such as β2 glycoprotein 1 (a-β2GP1) and annexin V (a-annexin V). These auto-antibodies may be considered as a family of antibodies involved in thrombotic events and antiphospholipid activity. On the other hand, some proangiogenic factors are involved in the normal development of placental vasculature, such as the vascular endothelial growth factor. Overexpression of vascular endothelial growth factor receptor in its soluble form (sVEGFR-1) has been associated to a higher antiangiogenic activity. Our aim was to analyse the association between anticardiolipin, lupus anticoagulant, a-β2GP1, a-annexin V and sVEGFR-1 with recurrent miscarriage before week 10 of gestation in females with antiphospholipid syndrome. Methods We studied 24 females (primary or secondary antiphospholipid syndrome), who were divided into two groups: females with recurrent miscarriage before week 10 of gestation (M; n = 12) and females with no history of fetal loss (NM; n = 12). Anticardiolipin, a-β2GP1, a-annexin V and sVEGF-R1 concentrations were assessed by ELISA, while lupus anticoagulant was assessed by screening and confirmatory tests. Results A significant association was observed between the number of positive biomarkers and the belonging group ( P < 0.05). Besides, a positive result for lupus anticoagulant and a-β2GP1 was found to be significantly associated to the M group ( P < 0.05). Conclusions Lupus anticoagulant and a-β2GP1 may be implicated in pregnancies complicated by recurrent miscarriage in females with antiphospholipid syndrome.

Antibodies to Phosphatidylserine/Prothrombin Complex in Antiphospholipid Syndrome: Analytical and Clinical Perspectives

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy-related morbidity accompanied by persistently positive antiphospholipid antibodies (aPL). Current laboratory criteria for APS classification recommend testing for lupus anticoagulant as well as IgG and IgM anticardiolipin, and beta-2 glycoprotein I (anti-β2GPI) antibodies. However, there appears to be a subset of patients with classical APS manifestations who test negative for the recommended criteria aPL tests. While acknowledging that such patients may have clinical features that are not of an autoimmune etiology, experts also speculate that these "seronegative" patients may test negative for relevant autoantibodies as a result of a lack of harmonization and/or standardization. Alternatively, they may have aPL that target other antigens involved in the pathogenesis of APS. In the latter, autoantibodies that recognize a phosphatidylserine/prothrombin (PS/PT) complex have been reported to be associated with APS and may have diagnostic relevance. This review highlights analytical and clinical attributes associated with PS/PT antibodies, taking into consideration the performance characteristics of criteria aPL tests in APS with specific recommendations for harmonization and standardization efforts.

Inflammosome in the human endometrium: further step in the evaluation of the "maternal side"

OBJECTIVE

To investigate the expression of inflammosome components (NALP-3, associated speck-like protein containing a CARD [ASC]) and their activation (caspase-1, interleukin [IL]-1β, and IL-18 secretion) in the human endometrium from fertile and women with history of recurrent pregnancy loss (RPL).

DESIGN

Experimental study.

SETTING

University hospital.

PATIENT(S)

Ten fertile women (control group [CTR]) and 30 women with RPL.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Endometrial samples were collected by hysteroscopy during the putative window of implantation and evaluated for chronic endometrial inflammation by hystopathological analysis. Inflammosome expression was analysed by immunohystochemical staining (27 RPL and 10 CTR women). The expression of NALP-3 and ASC protein was quantified by Western blot (30 RPL and 10 CTR women). Caspase-1 activation and IL-1β and IL-18 secretion was quantified by ELISA (30 RPL and 10 CTR women).

RESULT(S)

We observed a significantly increased expression of inflammasome NALP-3 and ASC protein, an increased activation of caspase-1, and increased levels of IL-1β and IL-18 in RPL endometrium compared with CTR.

CONCLUSION(S)

Abnormal activation of endometrial innate immunity by means of inflammosome, stimulated by pathogen- or damage-associated molecular patterns, may represent an additional mechanism, currently not investigated, negatively interfering with endometrial receptivity. More studies are required [1] to identify the primary trigger of endometrial inflammosome activation and its clinical impact in the occurrence of RPL; and [2] to validate the inflammosome components as a novel family of endometrial biomarkers and promising therapeutic targets in RPL.

Does the presence of autoantibodies without autoimmune diseases and hereditary thrombophilia have an effect on recurrent pregnancy loss?

OBJECTIVE

To assess whether the presence of autoantibodies has any effect on recurrent pregnancy loss (RPL) and obstetric complications in women who do not have autoimmune diseases and hereditary thrombophilia.

METHODS

Retrospectively, 515 patients who underwent antibody investigation with anti-nuclear antibody, extractable nuclear antigen, anti-double stranded DNA, anti-parietal cell, anti-smooth muscle, anti-mitochondrial (AMA), anti-thyroid peroxidase, anti-thyroglobulin (anti-TG) and anti-phospholipid (aPL) at Hacettepe University were included. Of those patients, 212 had one or more autoantibodies whereas the remaining 303 were negative for all autoantibodies. RPL was the primary outcome and was defined as ≥2 pregnancy losses (n = 119).

RESULTS

The frequency of RPL was significantly higher in the autoantibody positive group than controls (28.3% versus 14.5%, p<0.001). Anti-TG (21.2% versus 7.8%, p < 0.001), aPL (18.3% versus 5.6%, p < 0.001) and AMA (4.8% versus 0.5%, p = 0.001) antibodies were more common in patients with RPL. For the view of obstetric complications, oligohydramniosis (3.8% versus 0.7%, p = 0.03) and stillbirth (17.0% versus 10.6%, p = 0.002) were significantly higher in the autoantibody-positive group.

CONCLUSIONS

Even in women without autoimmune disease or hereditary thrombophilia, autoantibodies per se might directly increase the risk of RPL and obstetric complications. The screening anti-TG and aPL autoantibodies in the first step might be considered in patients with RPL.

Aspirin and heparin in pregnancy

INTRODUCTION

A pro-coagulant state during pregnancy can be involved in the occurrence of gestational vascular complications (GVCs) and venous thromboembolism (VTE).

AREAS COVERED

Antithrombotic drugs are used to prevent GVCs and VTE. Aspirin is not efficacious to prevent recurrences in women with previous early loss, while it can prevent pre-eclampsia in some groups of women. Heparins are not effective in the prevention of early recurrent loss and there is uncertainty about their efficacy in women carrying inherited thrombophilias. They could be efficacious in the prevention of GVCs in carriers of inherited thrombophilias, as GVCs have heterogeneous causes, and future studies have to focus on more homogeneous groups of patients. Not enough data are available regarding prophylaxis with heparins to prevent pregnancy-related VTE, but an accurate risk stratification of women during pregnancy and puerperium is crucial for administering prophylaxis in moderate-/high-risk women. Aspirin does not improve live births after assisted reproductive technologies, while heparins increase the number of clinical pregnancies and live births.

EXPERT OPINION

Aspirin is efficacious in the prevention of GVCs in women at risk for pre-eclampsia and in those with antiphospholipid antibodies syndrome. Heparins could give benefit to women at risk for GVCs and/or pregnancy-related VTE.

Detection of novel auto-antigens in patients with recurrent miscarriage: description of an approach and preliminary findings

Aim

To develop and test a protocol for isolation of potential auto-antigens from chorionic tissue that may be linked to recurrent miscarriage (RM).

Methods

The strategy included: 1) isolation of IgGs tightly bound to chorionic tissue of RM patients by protein G chromatography; 2) construction of affinity columns using the chorionic antibodies for isolation of auto-antigens; 3) enrichment of auto-antigens from detergent extracted solution of chorionic proteins by affinity chromatography; 4) separation by dodecyl sulfate-electrophoresis followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry identification.

Results

Five potential auto-antigens were detected: neutral alpha-glucosidase AB, endoplasmin, transitional endoplasmic reticulum ATPase, putative endoplasmin-like protein, and cytoplasmic actin 2.

Conclusions

We developed a strategy for identification of auto-antigens in the chorionic tissue of women with RM, which could be of diagnostic and prognostic value.

Obstetric antiphospholipid syndrome: a recent classification for an old defined disorder

Obstetric antiphospholipid syndrome (APS) is now being recognized as a distinct entity from vascular APS. Pregnancy morbidity includes >3 consecutive and spontaneous early miscarriages before 10weeks of gestation; at least one unexplained fetal death after the 10th week of gestation of a morphologically normal fetus; a premature birth before the 34th week of gestation of a normal neonate due to eclampsia or severe pre-eclampsia or placental insufficiency. It is not well understood how antiphospholipid antibodies (aPLs), beyond their diagnostic and prognostic role, contribute to pregnancy manifestations. Indeed aPL-mediated thrombotic events cannot explain the obstetric manifestations and additional pathogenic mechanisms, such as a placental aPL mediated complement activation and a direct effect of aPLs on placental development, have been reported. Still debated is the possible association between aPLs and infertility and the effect of maternal autoantibodies on non-vascular manifestations in the babies. Combination of low dose aspirin and unfractionated or low molecular weight heparin is the effective treatment in most of the cases. However, pregnancy complications, in spite of this therapy, can occur in up to 20% of the patients. Novel alternative therapies able to abrogate the aPL pathogenic action either by interfering with aPL binding at the placental level or by inhibiting the aPL-mediated detrimental effect are under active investigation.

Antiphospholipid antibodies in stillbirth

OBJECTIVE

To compare antiphospholipid antibodies in deliveries with and without stillbirth using a multicenter, population-based case-control study of stillbirths and live births.

METHODS

Maternal sera were assayed for immunoglobulin (Ig)G and IgM anticardiolipin and anti-β2-glycoprotein-I antibodies. Assays were performed in 582 stillbirth deliveries and 1,547 live birth deliveries.

RESULTS

Elevated levels of IgG anticardiolipin and IgG anti-β2-glycoprotein-I antibodies were associated with an approximate threefold increased odds of stillbirth (crude odds ratio [OR] 3.43, 95% confidence interval [CI] 1.79-6.60, 3.8% compared with 1.1% and OR 3.17, 95% CI 1.30-7.72, (1.9% compared with 0.6%, respectively) when all deliveries with stillbirth were compared with all deliveries with live birth. When the subset of stillbirths not associated with fetal anomalies or obstetric complications was compared with term live births, elevated IgG anticardiolipin antibodies were associated with stillbirth (5.0% compared with 1.0%; OR 5.30, 95% CI, 2.39-11.76; IgG anti-β2-glycoprotein-I antibodies (1.9% compared with 0.6%) had an OR of 3.00 (95% CI 1.01-8.90) and IgM anticardiolipin antibodies (6.0% compared with 3.0%) had an OR of 2.03 (95% CI 1.09-3.76). Elevated levels of anticardiolipin and anti-β2-glycoprotein-I antibodies were associated with a threefold to fivefold increased odds of stillbirth.

CONCLUSIONS

Our data support consideration of testing for antiphospholipid antibodies in cases of otherwise unexplained stillbirth.

LEVEL OF EVIDENCE

II.

Study on antiphospholipid/anticardioliplin antibodies in women with recurrent abortion

Background

Antiphospholipid antibodies are associated with recurrent abortion but correlation between level of antibodies and gestational age of abortion and duration post abortion is not clear.

Objectives

Aim of this study was study on relation between antiphospholipid antibodies in women with recurrent abortion and their gestational age and duration post abortion.

Patients and Methods

We performed a case-control study on 197 pregnant women who had history of spontaneous recurrent abortion as case group and 50 pregnant healthy women as control group. Demographic characteristic of all participants filled in questionnaire forms. Antipospholipid and anticardiolipin antibodies were measured in their serum by Enzyme linked Immunoassay with orgenec kits. Data analyzed by SPSS software (version 13) and T statistical test. P value less than 0.05 was considered significant.

Results

Mean age of participants was 24-39 years old. The average rate of antiphospolipid antibodies in patients with normal anticardiolipin was greater than those with abnormal anticardiolipin and T-test showed significant difference between two groups.(P = 0.000) In case group the number of abortions was more, mean of antiphosopolipid antibody levels were also higher. Mean anticardiolipin and antiphospholipid antibodies rate was greater with increasing gestational age at time of first abortion. Almost mean antipospholipid and anticardiolipin antibodies in all patients remained in high level just in first 5 years with any number of abortions and five years later, antibodies began to fall.

Conclusions

Antipospholipid antibodies based on number of abortions and gestational age of abortions were increased. Mean antipospholipid and anticardiolipin antibodies in all patients remained in high level just in first 5 years post abortion and then began to fall.

Obstetrical antiphospholipid syndrome: from the pathogenesis to the clinical and therapeutic implications

Antiphospholipid syndrome (APS) is an acquired thrombophilia with clinical manifestations associated with the presence of antiphospholipid antibodies (aPL) in patient plasma. Obstetrical APS is a complex entity that may affect both mother and fetus throughout the entire pregnancy with high morbidity. Clinical complications are as various as recurrent fetal losses, stillbirth, intrauterine growth restriction (IUGR), and preeclampsia. Pathogenesis of aPL targets trophoblastic cells directly, mainly via proapoptotic, proinflammatory mechanisms, and uncontrolled immunomodulatory responses. Actual first-line treatment is limited to low-dose aspirin (LDA) and low-molecular weight heparin (LMWH) and still failed in 30% of the cases. APS pregnancies should be a major field in obstetrical research, and new therapeutics are still in progress.

When conventional treatment fails: the role of intravenous immunoglobulin in recurrent pregnancy loss secondary to antiphospholipid syndrome

Recurrent pregnancy loss (RPL) is a well-recognized complication of antiphospholipid syndrome (APS). First line therapy consists of low dose aspirin and heparin. Despite conventional therapy some women fail to achieve a successful pregnancy outcome. We describe the case of a patient who had two live births following intravenous immunoglobulin therapy despite previous failure with conventional therapy for RPL in the setting of APS. We will summarize the available literature on intravenous immunoglobulin for this indication.

The advantage of specific intravenous immunoglobulin (sIVIG) on regular IVIG: experience of the last decade

During the last decade it has been shown that some components of intravenous immunoglobulin (IVIG) are responsible for their broadly therapeutic application. Currently, such specific subfractions are defined as specific IVIG (sIVIG) and are affinity-purified from commercial IVIGs that target specific antigens/antibodies related to a specific autoimmune disease. A remarkable example of the therapeutic potential of sIVIG is the proven enhanced anti-inflammatory potency of sialylated and recombinant sialylated IVIG obtained from total IVIG. In other experimental models, it has also been demonstrated that sIVIG work in many other contrivances, such as revealing anti-idiotypic networks blocking pathogenic antibodies ameliorating disease activity. sIVIG has also been shown to exert its action by modulating specific receptors expressed on immune cells in both inflammatory and autoimmune diseases. Indeed, sIVIG has emerged as a novel approach to treat different immune-mediated conditions in a more accurate antigen-specific manner. Herein we review experimental evidence supporting sIVIG-efficacy in treating autoimmune diseases and inflammation.

Management of pregnancy in systemic lupus erythematosus. Nat Rev Rheumatol. 2012;8:710-718. [PMID: 22907290 DOI: 10.1038/nrrheum.2012.133]

Systemic lupus erythematosus (SLE) is an autoantibody-mediated systemic autoimmune disease, predominantly affecting young females. Pregnancy is increasingly common in the setting of SLE, as survival and quality of life of patients improve. Although live births can be achieved in the most cases, pregnancy in patients with SLE remains a high-risk condition. Maternal and fetal mortality and morbidity are considerably increased, compared with the general population. Aberrations in pregnancy-related maternal immune adaptations are likely contributors. Active maternal disease, renal involvement, specific autoantibody subsets and advanced organ damage are predictors of poor outcome. Therapeutic options are limited during pregnancy as maternal benefit has to be weighed against fetal risk. Prevention of preterm birth and refractory pregnancy loss, as well as management of established neonatal heart block remain unmet needs. Further research should address these important issues that affect young patients with SLE and their babies.

Obstetric and vascular APS: Same autoantibodies but different diseases?

Beta2 glycoprotein I (β2GPI)-dependent antiphospholipid antibodies (aPLs) are the main pathogenic autoantibody population and at the same time the laboratory diagnostic tool for the antiphospholipid syndrome (APS).

These antibodies are responsible for both the vascular and the obstetric manifestations of the syndrome but the pathogenic mechanisms behind these manifestations are not the same. For example, thrombotic events do not appear to play a major role in APS miscarriages and a direct reactivity of β2GPI-dependent aPLs on decidual and trophoblast cells was reported. A local expression of β2GPI on these tissues was reported both in physiological conditions and in APS women, thus explaining the local tropism of the autoantibodies.

The two hit hypothesis was suggested to explain why the vascular manifestations of APS may occur only occasionally in spite of the persistent presence of aPLs. This is not apparently the case for the obstetric variant of the syndrome, making the difference even more striking. A different pathogenesis may also provide the rationale for the well-known fact that the vascular and the obstetric manifestations may occur independently although in a minority of cases.

Anti-phospholipid induced murine fetal loss: novel protective effect of a peptide targeting the β2 glycoprotein I phospholipid-binding site. Implications for human fetal loss

β2 glycoprotein I (β2GPI)-dependent anti-phospholipid antibodies (aPL) induce thrombosis and affect pregnancy. The CMV-derived synthetic peptide TIFI mimics the PL-binding site of β2GPI and inhibits β2GPI cell-binding in vitro and aPL-mediated thrombosis in vivo. Here we investigated the effect of TIFI on aPL-induced fetal loss in mice. TIFI inhibitory effect on in vitro aPL binding to human trophoblasts was evaluated by indirect immunofluorescence and ELISA. TIFI effect on aPL-induced fetal loss was investigated in pregnant C57BL/6 mice treated with aPL or normal IgG (NHS). Placenta/fetus weight and histology and RNA expression were analyzed. TIFI, but not the control peptide VITT, displayed a dose-dependent inhibition of aPL binding to trophoblasts in vitro. Injection of low doses of aPL at day 0 of pregnancy caused growth retardation and increased fetal loss rate, both significantly reduced by TIFI but not VITT. Consistent with observations in humans, histological analysis showed no evidence of inflammation in this model, as confirmed by the absence of an inflammatory signature in gene expression analysis, which in turn revealed a TIFI-dependent modulation of molecules involved in differentiation and development processes. These findings support the non-inflammatory pathogenic role of aPL and suggest innovative therapeutic approaches to aPL-dependent fetal loss.

In vivo distribution of β2 glycoprotein I under various pathophysiologic conditions

In vitro studies have documented β2 glycoprotein I (β2GPI) binding to endothelial cells (ECs) and trophoblast using antiphospholipid antibodies. The in vivo binding of β2GPI to these cells and the conditions that favor their interaction have not been investigated. We analyzed the in vivo distribution of cyanine 5.5-labeled β2GPI in mice and evaluated the effect of pregnancy and circulating antibodies on its tissue localization. The signal was detected in the liver by whole body scan and ex vivo analysis. The β2GPI failed to bind to the vascular endothelium and reacted only with the ECs of uterine vessels. In pregnant mice the protein was localized on ECs and trophoblast at the embryo implantation sites. Immunized mice showed a similar β2GPI biodistribution to naive mice but the immunized pregnant animals exhibited a significant increase in fetal loss associated with C3 and C9 deposition at the implantation sites. Treatment of mice with LPS after β2GPI-Cy5.5 injection promoted protein localization on gut and brain ECs associated with IgG, C1q, and C9 deposition in immunized mice. These findings indicate that β2GPI binding to EC requires priming with pro-inflammatory factors which is not needed for uterine and placental localization probably dependent on hormonal changes.

Rheumatic diseases and pregnancy

PURPOSE OF REVIEW

This review discusses how inflammatory rheumatic diseases [rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus (SLE)] of the mother can influence the course of pregnancy and the development of the fetus. Antirheumatic drug therapy of the mother and strategies to prevent fetal complications namely in SLE must be considered with care.

RECENT FINDINGS

The current literature is presented discussing hypotheses about the immunologic mechanisms leading to amelioration or exacerbation of the rheumatic symptoms in rheumatoid arthritis and ankylosing spondylitis during pregnancy. In SLE, several recent studies have been published concerning fetal complications in the antiphospholipid syndrome and in Ro/SSA-positive and La/SSB-positive mothers and how to diagnose, treat, or prevent these.

SUMMARY

Today, women with inflammatory rheumatic diseases are normally fertile and can be encouraged to become pregnant, when there is a stable and quiescent phase of the disease. This is in particular important for patients with SLE, although pregnancy outcome in SLE has improved over the last decades. Pregnancy in SLE is still a high-risk period during the disease course with the highest risk in women with active lupus nephritis. In contrast, women with rheumatoid arthritis develop amelioration of the rheumatic symptoms during the course of pregnancy in most cases; female ankylosing spondylitis patients are likely to show unaltered or aggravated symptoms of back pain and impaired function.

The embryotoxicity of sera from patients with autoimmune diseases on post-implantation rat embryos in culture persists during remission and is not related to oxidative stress

We evaluated the embryolethality and embryotoxicity of sera from patients suffering from autoimmune diseases during remission on post-implantation rat embryos cultured on these sera and determined the association between the patients' clinical history, high blood levels of specific antibodies, medications, and oxidative stress parameters. One hundred and eighty, 10.5-day-old rat embryos were cultured in their yolk sacs in 33 sera of systemic lupus erythematosus (SLE)/antiphospholipid syndrome (APS) patients, and compared with 84 embryos cultured in rat sera and 88 embryos cultured in control human sera. The sera proved to be lethal and embryotoxic but not teratogenic resulting in smaller yolk sacs and embryos, lower protein level and lower developmental score. Significantly less embryos cultured in 'toxic' SLE/APS sera had peak 2 of low molecular weight antioxidants (LMWA) wave, implying a delayed maturation of the antioxidant defense. Lower peak 1 of LMWA correlated with a history of recurrent abortions. Embryonic levels of superoxide dismutase (SOD) and catalase (CAT) did not correlate with sera toxicity, patients' clinical history or specific antibodies. We conclude that SLE/APS patients' clinical remission did not prevent death or developmental delay accompanied by later appearance of peak 2 of LMWA in post-implantation rat embryo cultures. The normal levels of the antioxidant enzymes evaluated may indicate that sera toxicity is not related to oxidative stress.