IgA Antiphospholipid Antibodies in Antiphospholipid Syndrome and Systemic Lupus Erythematosus

The autoimmune landscape of Porto-sinusoidal vascular disorder: What the rheumatologist needs to know

Porto-sinusoidal vascular disorder (PSVD) encompasses a group of vascular disorders characterized by lesions of the portal venules and sinusoids with clinical manifestations ranging from non-specific abnormalities in serum liver enzymes to clinically overt portal hypertension and related complications. Several reports have documented cases of PSVD in patients with systemic autoimmune conditions, such as systemic lupus erythematosus, systemic sclerosis, and rheumatoid arthritis. It is of note that these diseases share specific pathophysiological features with PSVD, including endothelial dysfunction, vascular inflammation, and molecular signatures. This narrative review aims to summarize the current knowledge on the association between PSVD and systemic autoimmune diseases, emphasizing the importance of promptly recognizing this condition in the rheumatological practice, and highlighting the key aspects where further research is necessary from both pathogenic and clinical perspectives.

Updates in diagnosis and treatment of pediatric antiphospholipid syndrome

PURPOSE OF REVIEW

This review offers an overview of the most important recent articles on pediatric APS.

RECENT FINDINGS

Non-thrombotic extra criteria manifestations were prevalent in pediatric APS. Pregnancy morbidity has been described as the first manifestation of APS at youth age, impairing gestational outcomes. The 2023 APS criteria were developed for adult APS patients, and there is still a lack of pediatric-specific APS criteria. Catastrophic APS was more commonly reported as the initial manifestation of pediatric APS than in adults. Regarding treatment, direct oral anticoagulants have been recently approval for pediatric patients with venous thrombosis. New approaches have been proposed for severe cases, for arterial thrombosis, and rituximab for refractory cases. Recurrences typically occurred early and were associated with older age at diagnosis. Current studies highlighted the multifaceted nature of pediatric APS. Further large prospective multicenter studies evaluating new medications capable of reducing recurrence risk and improving prognosis in this population will be required.

The impact of antiphospholipid antibodies/antiphospholipid syndrome on systemic lupus erythematosus

aPLs are a major determinant of the increased cardiovascular risk in patients with SLE. They adversely affect clinical manifestations, damage accrual and prognosis. Apart from the antibodies included in the 2006 revised classification criteria for APS, other non-classical aPLs might help in identifying SLE patients at increased risk of thrombotic events. The best studied are IgA anti-β2-glycoprotein I, anti-domain I β2-glycoprotein I and aPS-PT. Major organ involvement includes kidney and neuropsychiatric systems. aPL/APS severely impacts pregnancy outcomes. Due to increased thrombotic risk, these patients require aggressive cardiovascular risk factor control. Primary prophylaxis is based on low-dose aspirin in high-risk patients. Warfarin is the gold-standard drug for secondary prophylaxis.

Viewpoint: The value of non-criteria antiphospholipid antibodies

In 2006, at a meeting in Sydney, Australia, consensus was reached by an international group of specialists to establish a number of serological criteria that identify patients with a history of thrombosis or pregnancy complications as having antiphospholipid syndrome (APS). These criteria were originally formulated for research purposes and to compare clinical trials in different centres. However, these same criteria are now generally used and accepted for the diagnosis and treatment of patients. The practice of using these criteria for direct patient care requires that these criteria are based on sound scientific evidence. Indeed, for all the autoantibodies that are officially included in the serological criteria, it has been shown that they induce thrombosis and fetal loss when infused into mice. There are also a number of additional autoantibodies that have been identified in these patients but for these antibodies there was not enough evidence to meet the official APS criteria in 2006. Seventeen years have now passed since the consensus meeting, therefore, this review examines whether additional studies performed with these 'non-criteria' autoantibodies have provided sufficient results to suggest the inclusion of these autoantibodies in the official serological criteria of APS.

Antiphospholipid Syndrome in Pregnancy: New and Old Pathogenetic Mechanisms

The antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized, according to the Sydney criteria, by the persistent presence of autoantibodies directed against phospholipid-binding proteins associated with thrombosis and/or obstetrical complications. The most frequent complications in obstetric antiphospholipid syndrome are recurrent pregnancy losses and premature birth due to placental insufficiency or severe preeclampsia. In recent years, vascular APS (VAPS) and obstetric APS (OAPS) have been described as two different clinical entities. In VAPS, antiphospholipid antibodies (aPL) interfere with the mechanisms of coagulation cascade and the 'two hit hypothesis' has been suggested to explain why aPL positivity does not always lead to thrombosis. OAPS seems to involve additional mechanisms, such as the direct action of anti-β2 glycoprotein-I on trophoblast cells that can lead to a direct placental functional damage. Furthermore, new actors seem to play a role in the pathogenesis of OAPS, including extracellular vesicles, micro-RNAs and the release of neutrophil extracellular traps. The aim of this review is to investigate the state-of-the-art antiphospholipid syndrome pathogenesis in pregnancy, in order to provide a comprehensive overview of both old and new pathogenetic mechanisms involved in this complex disease.

Anticardiolipin and anti-beta 2-glycoprotein I antibodies in patients with unexplained articular manifestations

OBJECTIVE

To determine the frequency of antiphospholipid antibodies (aPL) in patients with unexplained articular manifestations.

MATERIAL AND METHODS

Three hundred thirteen patients suffering from arthritis or arthralgia without evident cause and 266 healthy blood donors (HBD) were included in the study. Anticardiolipin antibodies (aCL) and anti-beta 2-glycoprotein I antibodies (aβ2GPI) were measured by ELISA.

RESULT

Out of the 313 patients, 250 were females and 63 were males. The mean age of patients was 49 ± 14 years (17-87 years). One hundred eleven patients have arthralgia and 202 have arthritis. The frequency of aCL and/or aβ₂ GPI (24.9%) was significantly higher in patients than in HBD (10.9%). The frequency of aβ2GPI was 23.6% in patients and 9.4% in the control group (p < 10^-3 ). aβ2GPI-IgA was significantly more frequent in patients than in the control group (20.4% vs. 7.5%, p < 10^-3 ). aβ2GPI was most commonly observed than aCL in patients (23.6% vs. 6.4%, p < 10^-6 ). IgA isotype of aβ2GPI was the most frequent in 20.4% of patients while IgG and IgM were detected in 5.4% and 2.9% respectively.

CONCLUSION

This study showed that aPL were common in patients with articular manifestations and were mainly directed against β₂ GPI. The role of these antibodies remains to be specified.

Research trends and frontiers on antiphospholipid syndrome: A 10-year bibliometric analysis (2012-2021)

Objectives: A growing body of studies related to antiphospholipid syndrome (APS) have been published in recent years. Nevertheless, there is a lack of visualized and systematic analysis in the literature on APS. Hence, this study sought to conduct a bibliometric analysis to identify research status and discover frontiers in the field. Methods: Articles and reviews concerning APS were acquired from the Web of Science Core Collection (WoSCC) database. CiteSpace, VOSviewer and a bibliometric online analysis platform were employed to conduct a visualization and knowledge-map analysis. Results: A total of 1,390 publications regarding APS were identified. Globally, Italy contributed the most publications. The University of Padua was the most productive institution. Lupus ranked first in both the most published and most co-cited journals. Savino Sciascia and Spiros Miyakis were the most prolific and most co-cited authors, respectively. "Vitamin K antagonists (VKA)" and "immunoglobulin A (IgA)" were current research foci. Burst analysis of keywords suggested that "neutrophil extracellular trap (NET)," "direct oral anticoagulant (DOAC)," "open label," "outcome," "hydroxychloroquine (HCQ)," and "arterial thrombosis (AT)" were significant future research frontiers. Conclusion: The scientific literature on APS has increased steadily in the past 10 years. The clinical studies on the treatment and mechanism research of APS are recognized as promising research hotspots in the domain of APS. The research status and trends of APS publications from the bibliometric perspective can provide a practical guide and important reference for subsequent studies by researchers and physicians in the domain.