Presence of Extra-Criteria Antiphospholipid Antibodies Is an Independent Risk Factor for Ischemic Stroke

Current status and value of testing antiphospholipid antibody in patients with acute ischemic stroke: a retrospective single-center study in China

BACKGROUND AND PURPOSE

Testing for antiphospholipid antibodies (aPL) is useful to determine the cause of ischemic stroke in young and female patients. However, the clinical relevance of aPL in older patients with ischemic stroke remains unclear. We aimed to explore the status and diagnostic value of initial aPL testing in all patients with acute ischemic stroke.

METHODS

We retrospectively analyzed patients with acute ischemic stroke who were consecutively hospitalized in our hospital between June 2012 and January 2022 and investigated the factors associated with performing aPL screening in real-world clinical practice. Furthermore, factors associated with initial aPL positivity were evaluated by comparing the demographic, etiological, and therapeutic characteristics.

RESULTS

Of 1209 patients, 287 (23.7%) were tested for aPL and 58 (20.2%) tested positive. Physicians tended to conduct aPL testing on female patients (P<0.001), younger patients (P<0.001), patients with fewer vascular risk factors (P<0.001), and multiple infarctions in the multivascular blood supply area (P<0.001). Multivariate logistic regression analysis showed that only stroke of other determined etiology type was a significant influencing factor for positive aPL results (OR 2.97, 95% CI 1.137, 7.774, P=0.026), adjusting for sex, age, and causes of stroke, etc. CONCLUSION: Approximately one-quarter of the patients with acute ischemic stroke were tested for aPL. Age, sex, number of vascular risk factors, and neuroimaging features affected the discretion in performing aPL testing. aPL testing may be appropriate in older patients with no identified cause of ischemic stroke and may provide additional diagnostic opportunities for acute ischemic stroke.

Epidemiology of antiphospholipid syndrome: macro- and microvascular manifestations

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombotic and non-thrombotic macro- and microvascular manifestations and pregnancy complications in the setting of persistent antiphospholipid antibodies (aPL), namely anticardiolipin antibodies, anti-β2 glycoprotein-I antibodies and lupus anticoagulant. Four decades after its first description, APS prevalence and incidence are still not completely understood due to the limited number of well-designed, population-based multi-ethnic studies. Furthermore, despite decades of efforts to standardise aPL immunoassays, considerable intraassay and interlaboratory variances in aPL measures still exist. Large multicentre APS cohorts have shown a 10-year survival of ∼91% and the presence of catastrophic APS occurs in about 1% of the entire population, associated with a 50% mortality rate. Clinically, any organ can be affected in the context of large, medium or small vessel (artery and/or vein) thrombosis. Macrovascular thrombosis is the hallmark of the disease and veins are more frequently affected than arteries. Deep vein thrombosis/pulmonary embolism thromboembolic disease is the most common APS manifestation, while stroke and transient ischaemic attack are the most frequent arterial thrombosis events. Myocardial infarction can also occur and contributes to increased mortality in APS. A minority of patients present with thrombosis affecting the intraabdominal organs, including the liver, spleen, small and large bowel, and the kidneys. Microvascular thrombosis, including APS nephropathy, chronic skin ulcers and livedoid vasculopathy represent a diagnostic challenge requiring histologic confirmation. In this narrative review we summarize the available evidence on APS epidemiology, focusing on the description of the prevalence of macro- and microvascular manifestations of the disease.

Belimumab therapy for refractory immune thrombocytopenia in systemic lupus erythematosus patients with anti-phospholipid antibodies

OBJECTIVE

To observe the effect of belimumab treatment in refractory anti-phospholipid antibody-associated immune thrombocytopenia with systemic lupus erythematosus (SLE).

METHOD

Four SLE patients with refractory anti-phospholipid antibody-associated immune thrombocytopenia were included in this one-arm observational study. Inclusion criteria were a diagnosis of SLE according to 1997 American College of Rheumatology criteria, severe immune thrombocytopenia (platelets <30 × 109/L), no bleeding symptoms, lack of satisfactory response to traditional treatment, and high-titre anti-phospholipid antibodies. All patients received belimumab (Benlysta®) for 6 months.

RESULTS

The mean platelet count was 21.8 × 109 cells/L, ranging between 16 and 29 × 109/L at baseline, 123.3 × 109/L at 1 month, and 172.5 × 109/L at the end of 6 months after belimumab treatment. No bleeding complications occurred during the entire follow-up period.

CONCLUSION

In this study, belimumab reduced the anti-phospholipid antibodies while increasing the platelet count in SLE patients with anti-phospholipid antibody-associated immune thrombocytopenia.

Neurological damages in COVID-19 patients: Mechanisms and preventive interventions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, causes coronavirus disease 2019 (COVID-19) which led to neurological damage and increased mortality worldwide in its second and third waves. It is associated with systemic inflammation, myocardial infarction, neurological illness including ischemic strokes (e.g., cardiac and cerebral ischemia), and even death through multi-organ failure. At the early stage, the virus infects the lung epithelial cells and is slowly transmitted to the other organs including the gastrointestinal tract, blood vessels, kidneys, heart, and brain. The neurological effect of the virus is mainly due to hypoxia-driven reactive oxygen species (ROS) and generated cytokine storm. Internalization of SARS-CoV-2 triggers ROS production and modulation of the immunological cascade which ultimately initiates the hypercoagulable state and vascular thrombosis. Suppression of immunological machinery and inhibition of ROS play an important role in neurological disturbances. So, COVID-19 associated damage to the central nervous system, patients need special care to prevent multi-organ failure at later stages of disease progression. Here in this review, we are selectively discussing these issues and possible antioxidant-based prevention therapies for COVID-19-associated neurological damage that leads to multi-organ failure.

Lupus, antiphospholipid syndrome, and stroke: An attempt to crossmatch

Cerebrovascular accidents (CVAs) or strokes are part of the common thrombotic manifestations of Systemic Lupus Erythematosus (SLEs) and Antiphospholipid syndrome (APS). Such neurological thrombotic events tend to occur in patients with SLE at a higher frequency when Antiphospholipid antibodies (aPLs) are present, and tend to involve the large cerebral vessels. The mechanism of stroke in SLE can be driven by complement deposition and neuroinflammation involving the blood-brain barrier although the traditional cardiovascular risk factors remain major contributing factors. Primary prevention with antiplatelet therapy and disease activity controlling agent is the basis of the management. Anticoagulation via warfarin had been a tool for secondary prevention, especially in stroke recurrence, although the debate continues regarding the target international normalized ratio (INR). The presence of either of the three criteria antiphospholipid antibodies (aPLs) and certain non-criteria aPL can be an independent risk factor for stroke. The exact mechanism for the involvement of the large cerebral arteries, especially in lupus anticoagulant (LAC) positive cases, is still to be deciphered. The data on the role of non-criteria aPL remain very limited and heterogenous, but IgA antibodies against β2GPI and the D4/5 subunit as well as aPS/PT IgG might have a contribution. Anticoagulation with warfarin has been recommended although the optimal dosing or the utility of combination with antiplatelet agents is still unknown. Minimal data is available for direct oral anticoagulants (DOACs).

COVID-19 and the antiphospholipid syndrome

Coronavirus disease 2019 (COVID-19) has resulted in a global pandemic. Most COVID-19 patients are asymptomatic or have flu-like symptoms. However, around 15% of the patients may have severe disease, including unilateral or bilateral pneumonia with acute respiratory distress syndrome and progressive hypoxemia that may require mechanical ventilation assistance. A systemic inflammatory response syndrome occurs in the most severe forms of COVID-19, with multiorgan involvement which can be life threatening caused by a cytokine storm. Although what best characterizes COVID-19 are the manifestations of the respiratory system, it has been shown that it also acts at the cardiovascular level, producing coagulation abnormalities, which causes thrombotic events mainly in the arteries/arterioles, microcirculation and venous system, and potentially increased mortality risk. This multiorgan vascular disease overlaps with other known microangiopathies, such as thrombotic microangiopathy or paroxysmal nocturnal hemoglobinuria, where complement overactivation plays an important role in the pathophysiology of thrombosis. Furthermore, coagulopathy secondary to COVID-19 occurs in the context of an uncontrolled inflammatory response, reminiscent of APS, especially in its catastrophic form. This review summarizes the current knowledge regarding the relationship between COVID-19 and the APS.

Exploring the risk factors for ischemic cerebrovascular disease in systemic lupus erythematosus: A single-center case-control study

Objectives

Ischemic cerebrovascular disease (ICVD) is one of the most common and severe complications in systemic lupus erythematosus (SLE). We aim to explore the risk factors for ICVD in SLE and to assess their associated clinical characteristics.

Methods

In this study, 44 lupus patients with ICVD (ICVD-SLE) and 80 age- and sex-matched lupus patients without ICVD (non-ICVD-SLE) who were hospitalized in our center between 2014 and 2021 were enrolled. A comprehensive set of clinical and socio-demographic data was recorded. In the ICVD-SLE group, the modified Rankin score (mRS) at 90 days after the occurrence of ICVD, the brain MRI, and arterial ultrasonography findings were collected. Group comparisons were made with continuous variables using an independent t-test or the Mann–Whitney test, and with categorical variables using the chi-square test or Fisher exact test. Multivariate logistic regression analysis was performed to identify the risk factors for ICVD in SLE. Patients with ICVD-SLE were divided into three subgroups according to the gradations of intracranial arterial stenosis (ICAS). The subgroup comparisons were performed by one-way ANOVA test or Kruskal–Wallis test.

Results

Of the 44 patients with ICVD, 45% had a large-vessel ischemic stroke, 50% had a symptomatic lacunar stroke, and 9% had a transient ischemic attack. 2 (4.5%) had both large-vessel ischemic stroke and symptomatic lacunar stroke. Multivariate logistic regression analysis showed that cutaneous vasculitis (OR=7.36, 95% CI=2.11–25.65), anticardiolipin antibody (aCL) (OR=4.38, 95% CI=1.435–13.350), and lupus anticoagulant (LA) (OR=7.543,95% CI=1.789–31.808) were the risk factors, and hydroxychloroquine (HCQ) therapy (OR=0.198, 95% CI=0.078–0.502) was the protective factor, after controlling for confounders. During the analysis of the subgroups, no significant difference was observed between the patients in the group without internal carotid arterial occlusion (ICAS) and those with severe ICAS except for diagnostic delay. However, patients in the moderate ICAS group were older when SLE occurred (P&lt;0.01), had a longer diagnostic delay (P&lt;0.01), a lower percentage of hypocomplementemia (P=0.05) and steroids and HCQ therapy (P=0.01, P=0.05, respectively), a trend toward lower mRS score, but a higher incidence of carotid atherosclerotic plaque (P&lt;0.01), when compared with the other two subgroups.

Conclusion

Cutaneous vasculitis and antiphospholipid antibodies (aPLs) are associated with an increased risk of ICVD, while HCQ therapy may provide protection against ICVD in SLE. The ICVD in younger lupus patients is associated with complement-mediated inflammation and poorer outcome, and require immunosuppressive therapy, whereas the ICVD in elderly patients are characterized by moderate ICAS and carotid atherosclerotic plaques.

A Cryptogenic Stroke Associated With Infective Endocarditis and Antiphospholipid Antibody Syndrome: Case Report and Literature Review

Introduction

Accurate definition of stroke etiology is crucial, as this will guide effective targets for treatment. Both antiphospholipid antibody syndrome (APS) and infective endocarditis (IE) can be independent risk factors for ischemic stroke in young adults. When an embolic stroke occurs with IE and APS simultaneously, the origin of the embolic source is difficult to identify.

Case Report

A 19-year-old man was admitted to the hospital for the onset of stroke. A diagnosis of APS accompanied by IE was made after a series of examinations. We identified aortic valve vegetation as the embolic source. Although both APS and IE can induce valve vegetation, we considered IE to be the primary cause according to the infective clues. Despite treatment with ampicillin, the patient's fever persisted, and surgical aortic valve replacement was performed urgently. The patient recovered without recurrence of stroke during the 1-year follow-up.

Conclusion

A considerable challenge for physicians is evaluating all the signs suggestive of embolic sources in acute stroke and identifying the primary etiology when there are multiple causes. Early diagnosis and surgical intervention for bicuspid aortic valve (BAV) vegetation complicated by acute stroke may yield favorable clinical results.

Antigens and Antibodies of the Antiphospholipid Syndrome as New Allies in the Pathogenesis of COVID-19 Coagulopathy

High prevalence of both criteria and extra-criteria antiphospholipid antibodies (aPL) has been reported in COVID-19 patients. However, the differences in aPL prevalence decreased when an age-matched control group was included. The association of aPL with thrombotic events in COVID-19 is very heterogeneous. This could be influenced by the fact that most of the studies carried out were conducted on small populations enriched with elderly patients in which aPL was measured only at a single point and they were performed with non-standardized assays. The few studies that confirmed aPL in a second measurement showed that aPL levels hardly changed, with the exception of the lupus anticoagulant that commonly reduced. COVID-19 coagulopathy is an aPL-independent phenomenon closely associated with the onset of the disease. Thrombosis occurs later in patients with aPL presence, which is likely an additional prothrombotic factor. B2-glycoprotein deficiency (mainly aPL antigen caused both by low production and consumption) is very common during the SARS-CoV2 infection and has been associated with a greater predisposition to COVID-19 complications. This could be a new prothrombotic mechanism that may be caused by the blockage of its physiological functions, the anticoagulant state being the most important.

Evidence of Thrombogenesis Recurrence Induced by IgA Antiphospholipid Antibody β2 Glycoprotein I-Dependent in Early Adulthood

Antiphospholipid antibodies (aPLs) against Beta-2 glycoprotein-I (β₂GPI) are considered to be the center of pathogenesis of antiphospholipid syndrome (APS). Autoimmune aPLs are pathogenic as patients are at increased risk of enhancing thrombin generation at a young age. There are only three aPLs considered as diagnostic laboratory markers for APS - IgM, IgG, and IgA isotypes. However, the association of the IgA isotypes with clinical thrombosis remains highly controversial.

A 30-year-old male with a past medical history of childhood asthma initially presented to the hospital with acute left middle cerebral artery ischemic stroke, which did not get resolved with tissue plasminogen activator (tPA) but was successfully resolved with thromboembolectomy. It was speculated to be associated with a clot from mitral valve prolapse found subsequently on echocardiogram. Twenty-eight days later, the patient presented again with a high-grade luminal narrowing of his mid- and distal left internal carotid artery with 80% narrowing and an acute dissection of his left internal carotid artery. The recurrence of thrombosis was evaluated through hypercoagulable state workup, which demonstrated evidence of antiphospholipid syndrome with elevated beta-2 glycoprotein IgA antibody titers of more than 150 U/mL. This is one of the first cases reported nationwide as evidence of thrombogenesis recurrence induced by IgA antiphospholipid antibody β₂ glycoprotein I-dependent in early adulthood.

IgA anti- β₂GPI antibodies are found to have an association with many clinical manifestations of antiphospholipid syndrome and thrombotic events, particularly arterial thrombosis. To determine the link between the IgA-aβ₂GPI antibodies and APS-events in asymptomatic individuals before recommending preventive treatments, there needs to be a broader intention to standardize IgA-aβ₂GPI assays as a diagnostic criterion for APS.

Risk of Thrombosis, Pregnancy Morbidity or Death in Antiphospholipid Syndrome

The antiphospholipid syndrome is an autoimmune disease characterized by thrombosis and pregnancy morbidity. The manifestations are caused by antibodies targeting cell membrane phospholipids and/or associated proteins. The triggers leading to these antibodies' production are unknown but recent work suggests cross-reactivity between the autoantigens and peptides produced by the intestinal microbiome. Work on how the autoantibodies could cause clinical manifestations implicates different mechanisms. Binding to surface proteins of different cell types can induce intracellular signaling leading to cell activation and tissue factor expression. Complement activation and neutrophil extracellular-traps are also involved, and recent evidence implicates endothelial protein C receptor-lysobisphosphatidic acid complex. Pregnancy is a high-risk situation for antiphospholipid syndrome patients due to the increased risk of thrombosis and obstetric complications. Epidemiological and clinical research on APS is hampered by heterogeneity in populations, testing and treatment strategies. About one in 10 to one in fifty APS pregnancies is complicated by thrombosis, despite treatment. Pregnant patients with prior thrombosis are prescribed therapeutic dose heparins and low dose aspirin. Without prior thrombosis a prophylactic dose is used. The most frequent obstetrical manifestation is recurrent early pregnancy loss. The association of APS antibodies with late pregnancy loss is stronger, however. Prevention of recurrence is achieved with aspirin and prophylactic dose heparin, although the evidence is of low certainty. The third obstetrical classifying manifestation comprises preterm delivery due to placenta-mediated complications and is treated in subsequent pregnancies with aspirin with or without prophylactic dose heparin, again based on low quality evidence. New therapies are under investigation.

Anti-Phospholipid Antibodies and COVID-19 Thrombosis: A Co-Star, Not a Supporting Actor

Background: COVID-19 clinical features include a hypercoagulable state that resembles the antiphospholipid syndrome (APS), a disease characterized by thrombosis and presence of antiphospholipid antibodies (aPL). The relationship between aPL-presence and the appearance of thrombi as well as the transience or permanence of aPL in COVID-19 patients is not sufficiently clear. Methods: A group of 360 COVID-19 patients were followed-up for 6 months. Classic aPL, anti-B2GPI IgA, anti-phosphatidylserine/prothrombin IgG/M and anti-SARS-CoV-2 antibodies were determined at acute phase and >12 weeks later. The reference group included 143 healthy volunteers of the same age-range distribution. Results: aPL prevalence was similar in COVID-19 patients and the reference population. aPL presence in both determinations was significantly associated with thrombosis (OR: 2.33 and 3.71), strong agreement being found for classic aPL and anti-B2GPI IgA (Weighted kappa: 0.85–0.91). Thrombosis-associated aPL occurred a median of 17 days after hospital admission (IQR: 6–28) vs. 4 days for the rest (IQR: 3–7). Although anti-SARS-CoV-2 antibodies levels increased during convalescence, aPL hardly changed. Conclusions: Most COVID-19 patients would carry these aPL before the infection. At least two mechanisms could be behind thrombosis, early immune-dysregulation-mediated thrombosis after infection and belated-aPL-mediated thrombosis, with SARS-CoV-2 behaving as a second hit.