Neurologic manifestations of the antiphospholipid syndrome

Risk Factors for Antiphospholipid Antibodies and Antiphospholipid Syndrome

Persistence of serum antiphospholipid antibodies (aPL) is associated with a high thrombotic risk, both arterial and venous, and with pregnancy complications. Due to the potential morbidity and mortality associated with the presence of aPL, identifying and recognizing risk factors for the development of aPL and thrombosis in aPL carriers may help to prevent and reduce the burden of disease. Multiple elements are involved in the pathomechanism of aPL development and aPL-related thrombosis such as genetics, malignancy, and infections. This review will address the role of both well-known risk factors and their evolution, and of emerging risk factors, including COVID-19, in the development of aPL and thrombosis in aPL carriers.

Neurovascular Issues in Antiphospholipid Syndrome: Arterial Vasculopathy from Small to Large Vessels in a Neuroradiological Perspective

Antiphospholipid syndrome (APS) is an autoimmune prothrombotic condition characterized by venous thromboembolism, arterial thrombosis, and pregnancy morbidity. Among neurological manifestations, arterial thrombosis is only one of the possible associated clinical and neuroradiological features. The aim of this review is to address from a neurovascular point of view the multifaceted range of the arterial side of APS. A modern neurovascular approach was proposed, dividing the CNS involvement on the basis of the size of affected arteries, from large to small arteries, and corresponding clinical and neuroradiological issues. Both large-vessel and small-vessel involvement in APS were detailed, highlighting the limitations of the available literature in the attempt to derive some pathomechanisms. APS is a complex disease, and its neurological involvement appears multifaceted and not yet fully characterized, within and outside the diagnostic criteria. The involvement of intracranial large and small vessels appears poorly characterized, and the overlapping with the previously proposed inflammatory manifestations is consistent.

Neurologic Manifestations of the Antiphospholipid Syndrome - an Update

PURPOSE OF REVIEW

In recent years, the spectrum of neurological manifestations of antiphospholipid syndrome (APS) has been growing. We provide a critical review of the literature with special emphasis on presentation, proposed mechanisms of disease, and treatment of neurological involvement in APS.

RECENT FINDINGS

Although stroke is the most common cause of neurological manifestations in patients with APS, other neurological disorders have been increasingly associated with the disease, including cognitive dysfunction, headache, and epilepsy. Direct oral anticoagulants have failed to show non-inferiority compared to vitamin K antagonists for the prevention of major thrombotic events. Antiphospholipid antibodies are often found in patients with acute COVID-19 but clear evidence supporting an association between these antibodies and the risk of thrombotic events, including stroke and cerebral venous thrombosis, is still lacking. APS patients may present with several distinct neurological manifestations. New criteria will facilitate the classification of patients presenting with increasingly recognized non-criteria neurological manifestations.

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

Background: Ischemic stroke is the most common and severe arterial thrombotic event in Antiphospholipid syndrome (APS). APS is an autoimmune disease characterized by the presence of thrombosis and antiphospholipid antibodies (aPL), which provide a pro-coagulant state. The aPL included in the classification criteria are lupus anticoagulant, anti-cardiolipin (aCL) and anti-β2-glycoprotein-I antibodies (aB2GPI) of IgG and IgM isotypes. Extra-criteria aPL, especially IgA aB2GPI and IgG/IgM anti-phosphatidylserine/prothrombin antibodies (aPS/PT), have been strongly associated with thrombosis. However, their role in the general population suffering from stroke is unknown. We aim (1) to evaluate the aPL prevalence in ischemic stroke patients, (2) to determine the role of aPL as a risk factor for stroke, and (3) to create an easy-to-use tool to stratify the risk of ischemic stroke occurrence considering the presence of aPL and other risk factors.

Materials and Methods: A cohort of 245 consecutive ischemic stroke patients was evaluated in the first 24 h after the acute event for the presence of classic aPL, extra-criteria aPL (IgA aB2GPI, IgG, and IgM aPS/PT) and conventional cardiovascular risk factors. These patients were followed-up for 2-years. A group of 121 healthy volunteers of the same age range and representative of the general population was used as reference population. The study was approved by the Ethics Committee for Clinical Research (Reference numbers CEIC-14/354 and CEIC-18/182).

Results: The overall aPL prevalence in stroke patients was 28% and IgA aB2GPI were the most prevalent (20%). In the multivariant analysis, the presence of IgA aB2GPI (OR 2.40, 95% CI: 1.03–5.53), dyslipidemia (OR 1.70, 95% CI: 1.01–2.84), arterial hypertension (OR 1.82, 95% CI: 1.03–3.22), atrial fibrillation (OR 4.31, 95% CI: 1.90–9.78), and active smoking (OR 3.47, 95% CI: 1.72–6.99) were identified as independent risk factors for ischemic stroke. A risk stratification tool for stroke was created based on these factors (AUC: 0.75).

Conclusions: IgA aB2GPI are an important independent risk factor for ischemic stroke. Evaluation of aPL (including extra-criteria) in cardiovascular risk factor assessment for stroke can potentially increase the identification of patients at risk of thrombotic event, facilitating a decision on preventive treatments.

Risk factors for ischemic antiphospholipid syndrome: A case-control study

OBJECTIVE

The objective of this study was to identify clinical and laboratory risk factors for ischemic stroke (IS) in primary antiphospholipid syndrome (APS) patients.

MATERIALS AND METHODS

We performed a case-control study with consecutive primary APS patients divided into two groups, those who presented with IS, vs. those with no history of stroke. Demographics, vascular risk factors, therapeutic approaches, laboratory, imaging and functional outcomes were recorded.

RESULTS

Fifty-three confirmed primary APS patients with IS and sixty-six non-stroke primary APS controls were recruited. Most patients were female (65.5 %), with a median age of 33 years. The main vascular risk factors for primary APS-associated stroke were hypertension (11.3 %), diabetes (11.3 %) and hypercholesterolemia (9.4 %). Among patients with stroke, median NIHSS score was 6; 15.1 % of these patients presented a recurrent stroke, and 88.8 % had a good functional outcome at the final follow-up. Positive lupus anticoagulant (OR = 6.1, 95 %CI 2.7-13.5), anti-β2 glycoprotein IgG (OR = 3.6, 95 %CI 1.7-7.9), and anticardiolipin IgG (OR = 2.8, 95 %CI 1.3-5.9) were more prevalent in non-stroke primary APS, with a triple-positive antibody presence in 46.4 % of controls vs. 22.2 % of patients with stroke (OR = 3.0, 95 %CI 1.3-6.7). At the time of the index event (arterial or venous), 14 known primary APS patients were using vitamin K antagonists, but only 35.7 % of them had achieved therapeutic INR.

CONCLUSION

Patients with primary APS and IS have similar vascular risk factors and lower antibody positivity than those with extracranial thrombosis.

Seronegative antiphospholipid syndrome: refining the value of "non-criteria" antibodies for diagnosis and clinical management

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial and venous thrombotic manifestations and/or pregnancy-related complications in patients with persistently high antiphospholipid antibodies (aPL), the most common being represented by anticardiolipin antibodies (aCL), anti-beta 2 glycoprotein-I (aβ2GPI), and lupus anticoagulant (LAC). A growing number of studies have showed that, in some cases, patients may present with clinical features of APS but with temporary positive or persistently negative titers of aPL. For these patients, the definition of seronegative APS (SN-APS) has been proposed. Nevertheless, the negativity to classic aPL criteria does not imply that other antibodies may be present or involved in the onset of thrombosis. The diagnosis of SN-APS is usually made by exclusion, but its recognition is important to adopt the most appropriate anti-thrombotic strategy to reduce the rate of recurrences. This research is in continuous development as the clinical relevance of these antibodies is far from being completely clarified. The most studied antibodies are those against phosphatidylethanolamine, phosphatidic acid, phosphatidylserine, phosphatidylinositol, vimentin/cardiolipin complex, and annexin A5. Moreover, the assays to measure the levels of these antibodies have not yet been standardized. In this review, we will summarize the evidence on the most studied non-criteria aPL, their potential clinical relevance, and the antithrombotic therapeutic strategies available in the setting of APS and SN-APS.

Infectious encephalitis: mimics and chameleons

Click here to listen to the Podcast 'Query encephalitis' is a common neurological consultation in hospitalised patients. Identifying the syndrome is only part of the puzzle. Although historically encephalitis has been almost synonymous with infection, we increasingly recognise parainfectious or postinfectious as well as other immune-mediated causes. We must also distinguish encephalitis from other causes of encephalopathy, including systemic infection, metabolic derangements, toxins, inherited metabolic disorders, hypoxia, trauma and vasculopathies. Here, we review the most important differential diagnoses (mimics) of patients presenting with an encephalitic syndrome and highlight some unusual presentations (chameleons) of infectious encephalitis.

Antiphospholipid Syndrome and the Neurologist: From Pathogenesis to Therapy

Antiphospholipid syndrome (APS) is an autoimmune antibody-mediated condition characterized by thrombotic events and/or pregnancy morbidity in association with persistent positivity to antiphospholipid antibodies (aPL). The nervous system is frequently affected, as intracranial vessels are the most frequent site of arterial pathology. Over the course of years, many other neurological conditions not included in the diagnostic criteria, have been associated with APS. The pathogenic mechanisms behind the syndrome are complex and not fully elucidated. aPL enhance thrombosis, interfering with different pathways. Nevertheless, ischemic injury is not always sufficient to explain clinical features of the syndrome and immune-mediated damage has been advocated. This may be particularly relevant in the context of neurological complications. The reason why only a subgroup of patients develop non-criteria nervous system disorders and what determines the clinical phenotype are questions that remain open. The double nature, thrombotic and immunologic, of APS is also reflected by therapeutic strategies. In this review we summarize known neurological manifestations of APS, revisiting pathogenesis and current treatment options.

Increased heterogeneity of brain perfusion is an early marker of central nervous system involvement in antiphospholipid antibody carriers

Objective

The non-criteria neuropsychiatric manifestations of antiphospholipid syndrome include headache, dizziness, vertigo, seizure, depression and psychosis. There were still no objective methods qualified to detect the early central nervous system involvement in non-criteria antiphospholipid syndrome. We evaluated the effectiveness of Tc-99m ECD SPECT in assessing circulatory insufficiency in the brains of patients with antiphospholipid antibodies and neuropsychiatric symptoms but without thromboembolism.

Materials and methods

Patients with a history of positive antiphospholipid antibodies and neuropsychiatric symptoms composed the case group; patients without antiphospholipid antibody served as the control group. Subjects with a history of thromboembolism or autoantibodies to extractable nuclear antigens were excluded. All patients received Tc-99m ECD SPECT studies and were classified by the number of positive antiphospholipid antibodies they carried. The heterogeneity of brain perfusion was defined as the coefficient of variation of the SPECT signals. Analysis of variance (ANOVA) was applied to evaluate the differences between the groups.

Results

Total 60 adult patients were included in this study. There were 54 patients in the case group and 6 patients in the control group. The mean age was 38.3 ± 11.5 years. There were 52 women and 8 men. There was no significant difference in the mean brain perfusion between groups (P = 0.69). However, Tc-99m ECD SPECT demonstrated significant heterogeneity of brain perfusion in relation to the number of antiphospholipid antibodies (P = 0.01).

Conclusions

This is the first study demonstrating that Tc-99m ECD SPECT can early detect the increased heterogeneity of brain circulation in non-criteria antiphospholipid antibody carriers.

A model for lupus brain disease

Systemic lupus erythematosus is an autoimmune disease characterized by antibodies that bind target autoantigens in multiple organs in the body. In peripheral organs, immune complexes engage the complement cascade, recruiting blood-borne inflammatory cells and initiating tissue inflammation. Immune complex-mediated activation of Fc receptors on infiltrating blood-borne cells and tissue resident cells amplifies an inflammatory cascade with resulting damage to tissue function, ultimately leading to tissue destruction. This pathophysiology appears to explain tissue injury throughout the body, except in the central nervous system. This review addresses a paradigm we have developed for autoantibody-mediated brain damage. This paradigm suggests that antibody-mediated brain disease does not depend on immune complex formation but rather on antibody-mediated alterations in neuronal activation and survival. Moreover, antibodies only access brain tissue when blood-brain barrier integrity is impaired, leading to a lack of concurrence of brain disease and tissue injury in other organs. We discuss the implications of this model for lupus and for identifying other antibodies that may contribute to brain disease.

Neurological manifestations of antiphospholipid syndrome

BACKGROUND

Neurologic disorders are among the most common and important clinical manifestations associated with the antiphospholipid syndrome (APS). It is characterized by diverse neurological manifestations. These include stroke, transient ischaemic attack, Sneddon's syndrome, convulsions/epilepsy, dementia, cognitive deficits, headaches/migraine, chorea, multiple sclerosis-like, transverse myelitis, ocular symptoms and Guillain-Barré syndrome.

MATERIAL AND METHODS

We review the latest data about neurologic disorders and APS.

RESULTS

In patients under 45 years of age, 20% of strokes are potentially associated with APS. Our study group recently reported a correlation between primary APS and peripheral neuropathy. Only one study investigated the occurrence of peripheral neuropathy in patients diagnosed with PAPS through electrophysiological study and showed alterations in 35% of patients. The mechanism of nervous system involvement in APS is considered to be primarily thrombotic. However, other mechanisms have been described, such as antiphospholipid antibodies that bind to the neural tissue, deregulating their functions and having an immediate pathogenic effect.

CONCLUSIONS

This review summarizes the latest data regarding the clinical aspects, radiological and therapeutic of major neurologic manifestations associated with antiphospholipid antibodies.