Obstetric anti-phospholipid syndrome: from pathogenesis to treatment

M2 macrophage derived exosomal miR-20a-5p ameliorates trophoblast pyroptosis and placental injuries in obstetric antiphospholipid syndrome via the TXNIP/NLRP3 axis

AIM

Obstetric antiphospholipid syndrome (OAPS) is a pregnancy-related complication characterized by trophoblast pyroptosis and placental injury induced by antiphospholipid antibodies (aPLs). M2-polarized macrophage-derived exosomes (M2-exos) exert anti-inflammatory, immunomodulatory, and growth-promoting effects in various autoimmune diseases and tumors. However, their role in OAPS is not yet clear. Therefore, in this study, we isolated M2-exos from M2 macrophages and investigated their effects on trophoblast proliferation, death, migration, invasion, and pyroptosis following stimulation using aPLs.

MAIN METHODS

First, we established an animal model of OAPS and thereafter treated the OAPS mice with exogenous M2-exos via injection through the tail vein. Then to clarify the roles of miR-20a-5p and thioredoxin-interacting protein (TXNIP) in OAPS, we performed gain- or loss-of-function assays, and used GraphPad Prism software to analyze the collected data with statistical significance set at P < 0.05.

KEY FINDINGS

MicroRNAs (miRNAs) sequencing revealed the enrichment of miR-20a-5p in M2-exos, and these M2-exos significantly alleviated aPLs-induced trophoblast dysfunction. Our results also indicated that M2-exos delivered miR-20a-5p to trophoblast cells directly targeted thioredoxin-interacting protein (TXNIP), and thus suppressed the TXNIP/NLRP3 pathway, reduced pyroptosis and inflammation in trophoblast cells, and improved placental function and fetal development.

SIGNIFICANCE

M2-exos improve pregnancy outcomes in OAPS via the miR-20a-5p/TXNIP/NLRP3 axis, and thus represent as a novel therapeutic approach for aPLs-induced OAPS.

Antiphospholipid syndrome in pregnancy: a comprehensive literature review

BACKGROUND

Antiphospholipid syndrome (APS) is an autoimmune disorder associated with thrombotic events and adverse obstetric outcomes, particularly in its obstetric form (OAPS). Affecting approximately 0.5% of the population, APS is a leading contributor to recurrent pregnancy loss (RPL), preeclampsia (PE), and fetal growth restriction ((FGR). Despite advancements in understanding its pathophysiology and management, optimal treatment strategies for APS in pregnancy remain challenging and require systematic evaluation. This review synthesizes current evidence on APS mechanisms, diagnostic criteria, and therapeutic interventions, with a focus on maternal and fetal outcomes in OAPS.

METHODS

A comprehensive search of PubMed, was conducted to identify studies exploring APS pathogenesis, diagnostic standards, and treatment efficacy in obstetric settings. Inclusion criteria prioritized randomized controlled trials, cohort studies, and systematic reviews with a clear focus on APS and pregnancy.

RESULTS

The review confirmed that APS current accepted pathogenesis is governed by a "two-hit" model, where antiphospholipid antibodies (aPLs) initiate endothelial damage, culminating in thrombosis and placental insufficiency. Epidemiological analysis underscores the prevalence and severity of APS in obstetric contexts, with lupus anticoagulant (LA) emerging as a significant predictor of adverse outcomes. Evidence supports the use of low-dose aspirin (LDA) and heparin to reduce miscarriage rates, while adjunctive treatments, such as hydroxychloroquine (HCQ), have shown promise in improving live birth rates and reducing preterm delivery in high-risk cases. Emerging therapies, including tumoral necrosis factor (TNF-alpha) inhibitors and nitric oxide modulators, may offer additional benefits in refractory cases.

CONCLUSION

APS remains a critical determinant of adverse pregnancy outcomes, necessitating precise diagnostic criteria and tailored management approaches. This systematic review emphasizes the importance of individualized therapeutic regimens to optimize maternal and fetal health in OAPS and highlights areas for future research, particularly regarding novel pharmacological approaches. Further studies are essential to refine treatment protocols and improve clinical guidelines for managing APS in pregnancy.

Clinical and Immunologic Manifestations of Antiphospholipid Syndrome Among Patients in King Abdulaziz Medical City (KAMC), Jeddah, Saudi Arabia

Introduction Antiphospholipid syndrome (APS) is a systemic autoimmune disorder marked by the presence of antiphospholipid antibodies (aPL), contributing to a heightened thrombotic risk and complications in pregnancy. This study explores the clinical and immunologic features of APS among patients at King Abdulaziz Medical City (KAMC) in Jeddah, Saudi Arabia, aiming to fill gaps in local APS data and enhance disease profiling. Methods A cross-sectional chart review was conducted for APS patients at KAMC from January 2008 to April 2023. Patients meeting the American College of Rheumatology (ACR) and European Alliance of Associations for Rheumatology (EULAR) APS criteria were included. Clinical manifestations, pregnancy-related complications, and immunologic profiles were documented, and gender differences were statistically analyzed. Results Eighty-eight patients were included, with a female predominance (76.1%). Deep vein thrombosis (35.2%) and recurrent miscarriages (33.0%) were the leading clinical manifestations in males and females, respectively. Stroke and pulmonary embolism were also prevalent, reported in 23.9% each. Anti-cardiolipin antibodies were the most common immunologic marker (56.8%), with a significant gender-based difference favoring males (76.2% vs. 50.7%). Notably, the prevalence of multiple aPL positivity was 31.8%, which was higher among males (42.9%) than females (28.4%), without statistical significance. Conclusion This study contributes essential epidemiological data on APS in Saudi Arabia, emphasizing gender differences and clinical heterogeneity. The findings align with other local studies, indicating younger age of onset in the Saudi population and unique gender-specific differences. High-risk APS patients, particularly males, show a higher risk of thrombosis, warranting personalized preventive strategies. These results underscore the need for tailored APS management, supporting future research to optimize APS care in this region.

Intravenous immunoglobulin treatment for obstetric antiphospholipid syndrome refractory to conventional therapy: A single-arm, open-labelled multicentre clinical trial

OBJECTIVES

The objective of the study was to compare the efficacy of intravenous immunoglobulin (IVIG) therapy for obstetric antiphospholipid syndrome (APS) refractory to conventional treatment.

METHODS

We conducted a single-arm, open-label multicentre clinical intervention trial. The enrolled criteria were patients with refractory APS who had a history of still or premature birth before 30 weeks of gestational age, even though they had been treated with conventional treatment, i.e. heparin and low-dose aspirin. After confirming the foetal heartbeats, a single course of IVIG (0.4 g/kg body weight daily for 5 days) was added to conventional treatment. The primary outcome was a live birth ratio of >30 weeks of gestational period, and the secondary outcome included improving pregnancy outcomes compared to previous pregnancy.

RESULTS

Twenty-five per cent of patients (2 of 8 cases) achieved a live birth after the 30th week of pregnancy by IVIG-only add-on treatment, which is the same prevalence as the historical control. However, by adding other second-line therapy to IVIG and conventional treatment, further three patients (37.5%) achieved improvements in pregnancy outcome compared to previous treatments. In total, five patients (62.5%) were able to achieve preferable pregnancy outcomes through combination treatment including IVIG.

CONCLUSIONS

This clinical trial could not demonstrate the efficacy of IVIG-only add-on therapy at improving the pregnancy outcomes of patients with obstetric APS refractory to conventional treatment. However, the combination of IVIG with rituximab or statins adding to conventional treatment improved pregnancy outcomes and resulted in more live births. Further studies are needed to investigate the efficacy of multi-targeted therapy to treat obstetric refractory APS.

Quantification of Antiphospholipid Antibodies: The Importance of Using an Appropriate Methodology for Each Clinical Profile

The presence of antiphospholipid antibodies (aPLs) is associated with antiphospholipid syndrome (APS), characterized by thrombosis and obstetric morbidity. aPLs included in APS classification criteria are lupus anticoagulant, anti-cardiolipin and anti-beta-2-glycoprotein-I of IgG or IgM isotypes. Enzyme-linked immunosorbent assay is the most used diagnostic technique to determine aPLs. Recently, new automated technologies mainly based in antigen-coated beads have been developed. The aim is to compare a fluorescence enzyme immunoassay (M1) and an antigen-coated bead assay (M2) in obstetric and thrombotic APS patients. All samples from the first 1020 patients received in the Immune Service Laboratory (Hospital 12 de Octubre) during the recruitment period, without exclusions, were analysed for aPLs. The weighted kappa for both methods in all the patients was 0.39 (0.30-0.47). Agreement increased to 0.56 (0.38-0.73) in patients with autoimmune disease. Sensitivity and specificity obtained for M1 were 17.1% and 89.3%, respectively, and 12.7% and 91.4% for M2. The sensibility and specificity of IgG isotypes were higher than the IgM ones. Regarding obstetric patients, M1 obtained significant diagnostic performance and had more sensitivity 23.75 (14.95-34.58) compared to M2 12.50 (6.16-21.79). In conclusion, clinical suspicion-based method selection for aPLs should be considered. To identify obstetric APS patients, solid phase methods remain more preferable.

Antiphospholipid syndrome in cardiovascular disease and cancer

Antiphospholipid syndrome is an autoimmune disorder which is characterized by the presence of heterogeneous antiphospholipid antibodies. There is an evidence on antiphospholipid (aPL) antibodies related to thromboembolic events in cancer patients. In fact, the thrombotic complications in patients with malignancy occur at a rather high frequency, compared to other risk factors. In parallel with standard therapies available, there is need of case-by-case monitoring of each patient and the introduction of new therapies and need for more clinical trials which will address many questions for the optimal management of patients. This paper presents a basic review of the literature on the aPL antibodies associated with cardiovascular disease and cancer, as well as its complications, which are reported so far in the bibliography.

The Diagnostics and Treatment of Recurrent Pregnancy Loss

Recurrent pregnancy loss is a common problem in the reproductive age population of women. It can be caused by many different conditions. This problem is addressed in international guidelines that take a slightly different approach to its diagnosis and treatment. The guidelines used in this review mainly use the guidelines of the Royal College of Obstetricians and Gynaecologists (RCOG), American Society of Reproductive Medicine (ASRM) and European Society of Human Reproduction and Embryology (ESHRE). This review shows how much the approach to miscarriages has changed and how much more needs to be explored and refined. The review also addresses the topic of unexplained pregnancy loss, which continues to be a challenge for clinicians.

Added value of antiphosphatidylserine/prothrombin antibodies in the workup of obstetric antiphospholipid syndrome: communication from the ISTH SSC Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies

BACKGROUND

The added value of antiphosphatidylserine/prothrombin antibodies (aPS/PT) in the diagnostic workup of antiphospholipid syndrome (APS) is unclear. Currently, diagnosis of thrombotic APS (TAPS) and obstetric APS (OAPS) requires persistent presence of lupus anticoagulant (LAC), anticardiolipin (aCL) immunoglobulin (Ig) G/IgM, or anti-β2-glycoprotein I (aβ2GPI) IgG/IgM antibodies.

OBJECTIVES

To evaluate the role of aPS/PT IgG and IgM in OAPS.

METHODS

aPS/PT IgG/IgM, aCL IgG/IgM, aβ2GPI IgG/IgM, and LAC were determined in 653 patients (OAPS, TAPS, and controls). In-house aPS/PT cut-off values were calculated, titers and prevalence were compared between OAPS, TAPS, and controls and type of pregnancy morbidity. Sensitivity, specificity, likelihood ratios, and odds ratios (OR) with 95% CI were calculated.

RESULTS

In OAPS, aPS/PT IgG and IgM showed an OR of 4.32 (95% CI, 2.54-7.36) and 3.37 (95% CI, 1.93-5.89), respectively, but the association was not independent of LAC. Prevalence and titers of aPS/PT IgG and IgM were lower in OAPS than in patients with TAPS. aPS/PT were more prevalent and showed higher titers in patients with late pregnancy loss than in patients with early pregnancy loss with a positivity of 86.4% and 39.3%, respectively. Higher aPS/PT titers did not increase the likelihood of having OAPS.

CONCLUSION

The added value of aPS/PT testing in the current diagnostic workup of OAPS seems limited compared with LAC, aCL, and aβ2GPI. aPS/PT might be useful in specific subsets of patients with OAPS. However, future multicentric studies are needed to elucidate the risk of less frequent and most severe obstetrical manifestations.

Obstetric Antiphospholipid Syndrome From the Perspective of a Rheumatologist

Antiphospholipid syndrome (APS) is an autoimmune disease that can lead to thrombotic or obstetric complications. Recent histopathological studies have shown the absence of placental thrombosis, leading to the consideration of other pathophysiological pathways such as inflammation and complement activation. Due to this, various clinical studies are being carried out with different drug agents in order to avoid their complications. The combination of prophylactic heparin treatment and low doses of aspirin today result in successful pregnancies in most cases. Despite this, a minority of patients require alternative therapies to avoid recurrent miscarriage and decrease obstetric morbidity. Thanks to the better understanding of its pathophysiology, other treatments such as low doses of glucocorticoids, hydroxychloroquine (HCQ), immunoglobulin, pravastatin, and plasmapheresis have been considered in refractory cases, achieving favorable results. Despite the great advances regarding its treatment, unfortunately, there are no treatments with a good level of evidence to reduce late obstetric complications. The evaluation of preconception risk factors, as well as the antiphospholipid antibody profile, is necessary to establish individual risk and thus anticipate possible complications.

Retrospective Analysis of Fondaparinux and Low-Molecular-Weight Heparin in the Treatment of Women With Recurrent Spontaneous Abortion

BACKGROUND

To compare the clinical efficacy of fondaparinux and LMWH and provide clinical evidence for the effectiveness of fondaparinux in the treatment of recurrent spontaneous abortion caused by PTS.

METHODS

A retrospective analysis was conducted for 120 patients diagnosed with a recurrent spontaneous abortion caused by PTS in Qingdao Jinhua Women's Hospital from March 2019 to April 2020. The patients were divided into two groups: 68 cases in the control group, treated with LMWH, 52 cases in the observational group, treated with fondaparinux. The pregnancy outcomes and adverse reactions between the two groups of recurrent miscarriage patients were compared.

RESULTS

No significant difference was detected in the general data between the two groups of patients before treatment (P>0.05). In the observational group, the R value was increased, and the α and MA values were decreased after three months of treatment compared to those before treatment (P<0.05). In the control group, the R value was increased, and the MA value was decreased after three months of treatment compared to those before treatment (P<0.05). After treatment, no significant difference was observed in the pregnancy outcome between the two groups (P>0.05). The total adverse reaction rate of the fondaparinux group was lower than that of the LMWH group (P<0.05).

CONCLUSIONS

In this study, no significant difference was detected in the pregnancy outcome between fondaparinux and LMWH in the treatment of recurrent spontaneous abortion caused by PTS, but fondaparinux had a low occurrence rate of adverse reactions and high safety.