Cognitive impairment in antiphospholipid syndrome: evidence from animal models

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.

Unveiling the Link Between Antiphospholipid Antibodies and Cognitive Dysfunction in the Almenara Lupus Cohort

OBJECTIVE

Cognitive dysfunction is a prevalent manifestation of systemic lupus erythematosus (SLE). There is evidence for the role of antiphospholipid (aPL) antibodies on its etiopathogenesis. Our objective was to identify the association between aPL antibodies and cognitive dysfunction in SLE patients.

METHODS

This cross-sectional study included 135 patients evaluated from March 2015 to October 2017 at one center. Cognitive deficit was measured using the NEUROPSI test. Disease activity and damage were ascertained using the SLEDAI-2K (SLE Disease Activity Index 2000) and the SDI (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index), respectively; aPL antibodies were measured by enzyme-linked immunosorbent assay. The association between cognitive dysfunction and aPL antibodies was evaluated using univariable and multivariable linear regression models adjusted for age, sex, education, socioeconomic status, disease duration, SLEDAI-2K, SDI, mean current dose of prednisone, time of exposure to glucocorticoids, and drug use (immunosuppressants, hydroxychloroquine, aspirin, and warfarin).

RESULTS

One hundred thirty-one patients (97.1%) were women; their mean (SD) age was 46.6 (12.5) years; 59 patients (43.7%) had positivity for at least 1 aPL antibody. IgM anticardiolipin (aCL) was positive in 24.5%, IgG in 13.5%, IgM aβ2GP1 in 16.8%, IgG anti-β2 glycoprotein in 24.6%, and the lupus anticoagulant in 5.3%. Ninety patients (66.7%) had some cognitive dysfunction. In the univariable analysis, a significant correlation between the NEUROPSI score and IgM aCL antibodies was found (B = -20.87 [SE, 3.2]; p < 0.001), which remained significant in the multivariable model (B = -13.89 [SE, 3.14]; p < 0.001).

CONCLUSIONS

IgM aCL antibodies are associated with cognitive dysfunction in patients with SLE. Larger and longitudinal studies are needed to assess the impact of these findings.

Neurologic Manifestations of Catastrophic Antiphospholipid Syndrome

PURPOSE OF REVIEW

Understanding of antiphospholipid antibody syndrome (APS), associated neurological manifestations, and disease-directed treatment has grown considerably over the last decade. Herein, we critically review the current and high-yield literature related to the pathophysiology, neurological presentations, and management of APS with particular emphasis on the rare and more fatal subset of APS, catastrophic antiphospholipid syndrome (CAPS).

RECENT FINDINGS

APS may manifest with a variety of neurologic syndromes, with cerebrovascular disease representing the most commonly encountered presentation. Diagnostic evaluation and treatment are often tailored to the specific presentation, with suspicion and testing for antiphospholipid antibodies recommended when neurologic presentations occur atypically or in younger individuals. In CAPS, which is more rapidly progressive with multiorgan involvement, potential alternative microangiopathic syndromes should be carefully considered in the differential diagnosis. To date, anticoagulation with vitamin K antagonists remains the mainstay of therapy in APS while triple therapy with anticoagulation, corticosteroids, and plasma exchange is standard of care in CAPS. Immunotherapy has shown early promise in refractory cases. APS is an autoimmune clinical syndrome with neurologic presentations classically characterized by vascular thrombosis, though recent understandings suggest additional direct immune-mediated phenomena. Our understanding of the underlying pathogenic mechanisms of APS continues to grow and will continue to influence our therapeutic approaches.

Cognitive dysfunction and serum levels of brain-derived neurotrophic factor (BDNF) in primary anti-phospholipid syndrome (PAPS)

OBJECTIVES

Cognitive dysfunction (CD) is a poorly understood non-stroke central neurological manifestation in anti-phospholipid syndrome (APS). Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays an important role in neural plasticity and could potentially be a biomarker of CD in primary APS (PAPS). The aim of the study is to assess CD in PAPS patients and to evaluate its association with clinical data, anti-phospholipid antibodies and serum BDNF levels.

METHODS

This cross-sectional study compared 44 PAPS patients and 20 healthy controls matched for age, gender and education. PAPS patients and controls underwent a standardized cognitive examination. The demographic, clinical and laboratory characteristics of patients were recorded. Serum BDNF was measured by Enzyme Linked Immunosorbent.

RESULTS

Fourteen (31.8%) of the 44 patients with PAPS had CD compared with only one (5%) healthy control (P =0.019). PAPS patients presented lower serum BDNF levels when compared with controls (P =0.007). Lower levels of BDNF were associated with CD in PAPS patients (P =0.032). In the univariate analysis, a positive association was found between CD and livedo reticularis, deep vein thrombosis, stroke, seizure, smoking as well as a negative association with Mini Mental State Examination and serum BDNF. According to multivariate analysis, the only independent predictor of CD in PAPS was stroke (OR 137.06; 95% CI: 4.73, 3974.32; P =0.004).

CONCLUSIONS

CD is commonly reported in PAPS patients; however, its assessment lacks in standards and objective screening tests. The association between CD and low serum BDNF suggests that this neurotrophin can be a promising biomarker for PAPS cognitive impairment.

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.

Neurologic manifestations of antiphospholipid syndrome

Neurological involvement in antiphospholipid antibody syndrome (APS) is common, and its occurrence increases morbidity and mortality. Patients may present variable neurological involvement, such as cerebrovascular disease, cognitive dysfunction, headache, seizures, movement disorders, multiple sclerosis-like syndrome, transverse myelitis and ocular symptoms. Most neurological manifestations are associated with thrombosis of the microcirculation or of large vessels; nonetheless, there is compelling evidence suggesting that, in some cases, symptoms are secondary to an immune-mediated pathogenesis, with direct binding of aPL on neurons and glia. Herein we describe clinical characteristics and management of neurological APS manifestations.

A role for tissue plasminogen activator in thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease characterized by generalized microvascular occlusion. TTP has been related to severe deficiency of ADAMTS13, an enzyme that cleaves von Willebrand factor multimers into less adhesive molecules. However, ADAMTS13 deficiency correlates poorly with severity of thrombocytopenia or microangiopathic hemolysis, with the frequency of neurologic complications or the response to plasma exchange. Also, some patients with severe hereditary ADAMTS13 deficiency consistently relapse every few weeks, whereas others remain asymptomatic into their forties. Taken together, these findings suggest that an additional element is missing in the pathophysiology of TTP. We postulate that both low ADAMTS13 activity and low tissue-plasminogen activator activity are required to trigger TTP attacks. Tissue-plasminogen activator end product, plasmin, extensively degrades von Willebrand factor, breaking-down the bonds between platelets and the blood vessel wall, so that low tissue-plasminogen activator activity prevents a mechanism similar to that of ADAMTS13. The hypothesis that low tissue-plasminogen activator activity plays an important role in TTP pathogenesis is further substantiated by TTP comorbidity. Problems prevalent in patients with TTP attacks or with long-term TTP remission, including increased body mass index, major depression, cognitive abnormalities, hypertension, and premature death, are somehow associated with low tissue-plasminogen activator activity.