Effect of hydroxychloroquine on antiphospholipid antibodies-inhibited endometrial angiogenesis

Deciphering the immunological interactions: targeting preeclampsia with Hydroxychloroquine's biological mechanisms

Preeclampsia (PE) is a complex pregnancy-related disorder characterized by hypertension, followed by organ dysfunction and uteroplacental abnormalities. It remains a major cause of maternal and neonatal morbidity and mortality worldwide. Although the pathophysiology of PE has not been fully elucidated, a two-stage model has been proposed. In this model, a poorly perfused placenta releases various factors into the maternal circulation during the first stage, including pro-inflammatory cytokines, anti-angiogenic factors, and damage-associated molecular patterns into the maternal circulation. In the second stage, these factors lead to a systemic vascular dysfunction with consecutive clinical maternal and/or fetal manifestations. Despite advances in feto-maternal management, effective prophylactic and therapeutic options for PE are still lacking. Since termination of pregnancy is the only curative therapy, regardless of gestational age, new treatment/prophylactic options are urgently needed. Hydroxychloroquine (HCQ) is mainly used to treat malaria as well as certain autoimmune conditions such as systemic lupus and rheumatoid arthritis. The exact mechanism of action of HCQ is not fully understood, but several mechanisms of action have been proposed based on its pharmacological properties. Interestingly, many of them might counteract the proposed processes involved in the development of PE. Therefore, based on a literature review, we aimed to investigate the interrelated biological processes of HCQ and PE and to identify potential molecular targets in these processes.

How to diagnose and manage antiphospholipid syndrome

Antiphospholipid antibodies (aPL) are autoimmune antibodies directed toward phospholipids or phospholipid-protein complexes, particularly those containing β2-glycoprotein I (β2GPI). Persistently positive aPL accompanied by arterial or venous thrombosis, or recurrent pregnancy loss, constitutes the antiphospholipid syndrome (APS). Several types of aPL with different specificities have been defined and may be detected in the clinical lab, including lupus anticoagulants (detected using clotting assays) and anticardiolipin, anti-β2GPI and anti-prothrombin/phosphatidylserine antibodies (detected by ELISA); each of the last 3 aPL may be either IgG, IgM, or IgA, though IgA antibodies are not included in criteria for APS. Due to the relative rarity of APS and the heterogeneity of aPL, thrombosis risk stratification is challenging, and randomized clinical trials for thrombosis treatment and prevention have been limited. This lack of high-quality data has made the clinical management of APS difficult, and existing guidelines are few and could not possibly cover many of the scenarios encountered in managing patients with APS. In this review, we present 3 patients with aPL and/or APS who highlight treatment dilemmas, and we discuss background information that may help guide clinical judgment in developing individualized treatment plans for patients with these enigmatic antibodies.

Anti-phospholipid autoantibodies in human diseases

Anti-phospholipid autoantibodies are a group of antibodies that can specifically bind to anionic phospholipids and phospholipid protein complexes. Recent studies have reported elevated serum anti-phospholipid autoantibody levels in patients with antiphospholipid syndrome, systemic lupus erythematosus, rheumatoid arthritis, metabolic disorders, malaria, SARS-CoV-2 infection, obstetric diseases and cardiovascular diseases. However, the underlying mechanisms of anti-phospholipid autoantibodies in disease pathogenesis remain largely unclear. Emerging evidence indicate that anti-phospholipid autoantibodies modulate NETs formation, monocyte activation, blockade of apoptotic cell phagocytosis in macrophages, complement activation, dendritic cell activation and vascular endothelial cell activation. Herein, we provide an update on recent advances in elucidating the effector mechanisms of anti-phospholipid autoantibodies in the pathogenesis of various diseases, which may facilitate the development of potential therapeutic targets for the treatment of anti-phospholipid autoantibody-related disorders.

SAMD1 attenuates antiphospholipid syndrome-induced pregnancy complications

OBJECTIVE

This study was intended to investigate the effect of SAMD1 on antiphospholipid syndrome (APS)-induced pregnancy complications in mice.

METHODS

The mRNA and protein expression of SAMD1 in APS patients and healthy controls was detected by qRT-PCR and western blot. Anti-B2 GPI and ACA levels were tested by ELISA, MMP-9, iNOS, ICAM-1 and MCP-1 mRNA and protein levels determined by qRT-PCR and western blot, cellular senescence detected by β-galactosidase staining, cell proliferation ability detected by CCK-8 assay, cell viability detected by trypan blue staining, cell mobility detected by Transwell, and cell angiogenesis ability detected by matrigel tube formation assay. An APS pregnant mouse model was constructed, and the embryo absorption rate was calculated.

RESULTS

SAMD1 expression was low in serum of APS patients, which was correlated with the history of thrombosis and the number of adverse pregnancies. Anti-B2 GPI and ACA levels were increased in APS. The expressions of MMP-9, iNOS, ICAM-1, and MCP-1 were also significantly upregulated in HUVECs treated with APS serum. APS promoted HUVEC senescence and inhibited cell proliferation, migration and angiogenesis. Overexpression of SAMD1 reversed the above results. Experiments on the APS pregnant mouse model confirmed that overexpression of SAMD1 reduced the rate of fetal loss.

CONCLUSION

SAMD1 may reduce APS-induced embryo loss by regulating cellular senescence, proliferation, migration, and angiogenesis.

Update on hydroxychloroquine use in pregnancy

It is well-known that hydroxychloroquine (HCQ) treats malaria, systemic lupus erythematosus, and rheumatoid arthritis in women for its immunomodulatory and anti-inflammatory action. Additionally, HCQ was used in cases with refractory antiphospholipid syndrome. HCQ safety was reinforced in pregnant women owing to insignificant reports of adverse pregnancy outcomes and major congenital malformation. Recently, HCQ was tested in cases with chronic placental inflammation with a promising result of increased life birth; however, its benefit needs further validation. We aimed to highlight the recent updates for HCQ use in various conditions in pregnancy.

The Impact of Hydroxychloroquine on Primary Feto-Placental Endothelial Cells from Healthy and Early-Onset Preeclamptic Placentas

Hydroxychloroquine (HCQ), an anti-malarial drug, is suggested as a promising candidate for the treatment of pregnancy-related disorders associated with endothelial activation, among which there is preeclampsia (PE). Arterial feto-placental endothelial cells (fpECAs) were isolated from control (CTR) and early-onset preeclamptic (EO-PE) placentas. The aim of this study was to test potential protective effects of HCQ in an in vitro model of endothelial activation as well as in cells isolated from EO-PE placentas. To mimic PE conditions, CTR fpECAs were exposed to a pro-inflammatory environment consisting of tumor necrosis factor α (TNF-α), interleukin (IL)-6 and IL-1β (furtherly referred as MIX) with or without varying concentrations of HCQ (1 µg/mL and 10 µg/mL). Their effect on wound healing and endothelial barrier integrity was analyzed. Variations in the expression of IL-8 and leukocyte adhesion molecules (LAM) on both mRNA and protein levels were determined between CTR and PE fpECAs in the presence or absence of HCQ. MIX decreased wound healing and stability of the endothelial barrier, but HCQ did not affect it. Significant differences between CTR and EO-PE fpECAs were observed in IL-8 mRNA, protein secretion, and vascular cell adhesion protein 1 (VCAM-1) mRNA expression levels. After challenging CTR fpECAs with MIX, upregulation of both mRNA and protein levels was observed in all molecules. Combined treatment of HCQ and MIX slightly lowered VCAM-1 total protein amount. In CTR fpECAs, treatment with low concentrations of HCQ alone (1 µg/mL) reduced basal levels of IL-8 and VCAM-1 mRNA and secretion of IL-8, while in EO-PE fpECAs, a higher (10µg/mL) HCQ concentration slightly reduced the gene expression of IL-8. Conclusion: These results provide additional support for the safety of HCQ, as it did not adversely affect endothelial functionality in control fpECAs at the tested concentration. Furthermore, the observed limited effects on IL-8 secretion in EO-PE fpECAs warrant further investigation, highlighting the need for clinical trials to assess the potential therapeutic effects of HCQ in preeclampsia. Conducting clinical trials would offer a more comprehensive understanding of HCQ's efficacy and safety, allowing us to explore its potential benefits and limitations in a real-world clinical setting.

Antiphospholipid syndrome management: a 2023 update and practical algorithm-based approach

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is an acquired thrombo-inflammatory disease that has morbid and sometimes devastating effects on patients and their families. This review will discuss the most recent international societal treatment guidelines and propose practical management algorithms for various APS sub-types.

RECENT FINDINGS

APS represents a disease spectrum. Although thrombosis and pregnancy morbidities are traditional hallmarks of APS, a variety of extra-criteria clinical phenotypes can often be seen, which makes clinical management more challenging. Primary APS thrombosis prophylaxis should take a risk-stratified approach. Although vitamin K antagonists (VKAs) or heparin/low molecular weight heparin (LMWH) remain the preferred treatment for secondary APS thrombosis prophylaxis, some international society guidelines support the use of direct oral anticoagulants (DOACs) in certain circumstances. Careful monitoring and individualized obstetric care with the use of aspirin and heparin/LMWH will improve pregnancy outcomes among pregnant individuals with APS. Treatment of microvascular and catastrophic APS remains challenging. While the addition of various immunosuppressive agents is often utilized, further systemic evaluations of their use are warranted before definitive recommendations can be made. Several new therapeutic strategies are on the horizon that might enable more personalized and targeted APS management in the near future.

SUMMARY

Although the knowledge of APS pathogenesis has grown in recent years, the management principles and strategies are largely unchanged. There is an unmet need for evaluating pharmacological agents, beyond anticoagulants, that target diverse thromboinflammatory pathways.

Hydroxychloroquine as an Immunomodulatory and Antithrombotic Treatment in Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an acquired highly prothrombotic disorder in which thrombo-inflammatory antiphospholipid antibodies (aPL) cause thrombosis via multiple mechanisms, including endothelial damage and activation. Obstetric complications in APS are caused by placental thrombosis, inflammation and complement activation. Anticoagulation is poorly effective in some patients especially those with triple positive aPL who are at ~30% risk of thrombosis recurrence within 10 years. Increasing therapeutic anticoagulation intensity may be beneficial but leads to excess bleeding with serious complications, such as intracerebral haemorrhage. Nonetheless, anticoagulation is still the mainstay of treatment despite the autoimmune nature of APS. The antimalarial immunomodulatory drug hydroxychloroquine (HCQ) has been used for many years for the treatment of inflammatory rheumatic diseases. HCQ has complex pleiotropic mechanisms of action upon multiple cell types. The proposed biological processes that HCQ regulates support the hypothesis that it may be a successful adjunctive treatment in the prevention of recurrent thrombosis and pregnancy complications.

SAMD1 attenuates antiphospholipid syndrome-induced vascular injury and pregnancy complications

OBJECTIVE

This study was intended to investigate the effect of SAMD1 on antiphospholipid syndrome (APS)-induced vascular injury in human umbilical vein endothelial cells (HUVECs) and pregnancy complications in mice.

METHODS

The expression of SAMD1 in APS patients and healthy controls was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Anti-B₂ GPI and anticardiolipin antibody (ACA) levels were tested by enzyme-linked immunosorbent assay, MMP-9, iNOS, ICAM-1, and MCP-1 mRNA and protein levels determined by qRT-PCR and Western blot, cellular senescence detected by β-galactosidase staining, cell proliferation ability detected by CCK-8 assay, cell viability detected by trypan blue staining, cell mobility detected by Transwell, and cell angiogenesis ability detected by matrigel tube formation assay. An APS pregnant mouse model was constructed, and the embryo absorption rate was calculated.

RESULTS

SAMD1 expression was low in serum of APS patients, which was correlated with the history of thrombosis and the number of adverse pregnancies. Anti-B₂ GPI and ACA levels were increased in APS. The expressions of MMP-9, iNOS, ICAM-1, and MCP-1 were also significantly upregulated in HUVECs treated with APS serum. APS promoted HUVEC senescence and inhibited cell proliferation, migration, and angiogenesis. Overexpression of SAMD1 reversed the above results. Experiments on the APS pregnant mouse model confirmed that overexpression of SAMD1 reduced the rate of fetal loss.

CONCLUSION

SAMD1 may reduce APS-induced vascular injury and embryo loss by regulating cellular senescence, proliferation, migration, and angiogenesis.

The Potential Benefit of Hydroxychloroquine in Chronic Placental Inflammation of Unknown Etiology Associated with Adverse Pregnancy Outcomes

The placenta is the site of connection between maternal and fetal circulation, and the liaison is established early in pregnancy. A large variety of pregnancy complications such as preterm birth, fetal growth restriction, or pregnancy loss have placental expression and can be accompanied in some cases of acute or chronic identifiable placental inflamatory lesions. Chronic placental inflammatory (CPI) lesions include chronic villitis of unknow etiology (CVUE), chronic intervillositis of unknown etiology, CIUE (also described as chronic histiocytic intervillositis, CHI), and chronic deciduits. Hydroxychloroquine (HCQ) has been prescribed with good results during pregnancy to prevent adverse perinatal outcomes in maternal autoimmune conditions. Its success has paved the way to its use in CPI as CIUE/CHI; however, to date, there are no prospective, informatively designed, controlled studies on its value in these setting. This review aims to explore the potential role of HCQ in CPI of unknown etiology. Ideally, properly designed, probably multicentric studies should be undertaken to fully understand HCQ's role for prevention of adverse pregnancy outcomes after a chronic placental inflammation.