Decreased hippocampal cell proliferation in mice with experimental antiphospholipid syndrome

Antiphospholipid Antibodies in Mental Disorders

Thrombotic events striking the central nervous system are clinical criteria for the antiphospholipid syndrome (APS). Besides these, neuropsychiatric non-APS criteria manifestations are increasingly described in patients with persistently positive antiphospholipid antibodies (aPL). Among these are psychiatric manifestations. Animal models mainly describe hyperactive behavior and anxiety associated with hippocampal abnormalities. Cases of associations with psychosis, mood disorders, bipolarity, anxiety, obsessive-compulsive behavior, and depression have been reported but are still rare. Systematic human clinical association studies are concordant with a risk of psychosis, depression (simple to major), and anxiety disorders, but these are limited and of inconstant methodological quality. Brain imaging in patients, also insufficiently investigated, shows early signs of hypoperfusion and of subtle diffuse white matter changes compatible with an alteration of the axonal structure and changes in the myelin sheath. Direct interactions of aPL with the brain cells, both on cell lines and on animal and human brain biopsies, targeting both glial cells, astrocytes, and neurons, can be demonstrated. These clusters of arguments make the association between psychiatric diseases and aPL increasingly plausible. However, a considerable amount of clinical research must still be performed in accordance with the highest standards of methodological quality. The therapeutic management of this association, in terms of both prevention and cure, currently remains unresolved.

Cognitive dysfunction in SLE: An understudied clinical manifestation

Neuropsychiatric lupus (NPSLE) is a debilitating manifestation of SLE which occurs in a majority of SLE patients and has a variety of clinical manifestations. In the central nervous system, NPSLE may result from ischemia or penetration of inflammatory mediators and neurotoxic antibodies through the blood brain barrier (BBB). Here we focus on cognitive dysfunction (CD) as an NPSLE manifestation; it is common, underdiagnosed, and without specific therapy. For a very long time, clinicians ignored cognitive dysfunction and researchers who might be interested in the question struggled to find an approach to understanding mechanisms for this manifestation. Recent years, however, propelled by a more patient-centric approach to disease, have seen remarkable progress in our understanding of CD pathogenesis. This has been enabled through the use of novel imaging modalities and numerous mouse models. Overall, these studies point to a pivotal role of an impaired BBB and microglial activation in leading to neuronal injury. These insights suggest potential therapeutic modalities and make possible clinical trials for cognitive impairment.

Teriflunomide normalizes anti-anxiety effect in anti-ANXA2 APS mice model teriflunomide in anti-ANXA2 mice model

Antiphospholipid syndrome (APS) affects the brain by both hypercoagulation and immunological mechanisms. APS is characterized by several autoantibodies binding to a thrombolytic complex including beta-2-glycoprotein I (β2-GPI) and annexin A2 (ANXA2). Teriflunomide, an oral drug for the treatment of multiple sclerosis (MS), has a cytostatic effect on B cells and is therefore a potential antibody-targeting treatment for APS. In this study, we assessed the effect of teriflunomide in two APS mouse models by inducing autoantibody formation against β2-GPI and ANXA2 in female BALB/c mice. The ANXA2 model displayed a behavioral change suggesting an anti-anxiety effect in open field and forced swim tests, early in the course of the disease. This effect was normalized following teriflunomide treatment. Conversely, behavioral tests done later during the study demonstrated depression-like behavior in the ANXA2 model. No behavioral changes were seen in the β2-GPI model. Total brain IgG levels were significantly elevated in the ANXA2 model but not in the teriflunomide treated group. No such change was noted in the brains of the β2-GPI model. High levels of serum autoantibodies were induced in both models, and their levels were not lowered by teriflunomide treatment. Teriflunomide ameliorated behavioral changes in mice immunized with ANXA2 without a concomitant change in serum antibody levels. These findings are compatible with the effect of teriflunomide on neuroinflammation.Teriflunomide ameliorated behavioral and brain IgG levels in mice immunized with ANXA2 without a concomitant change in serum antibody levels. These findings are compatible with an effect of teriflunomide on the IgG permeability to the brain and neuroinflammation.

Neuropsychiatric Manifestations of Antiphospholipid Syndrome—A Narrative Review

Antiphospholipid syndrome (APS) is a common autoimmune pro-thrombotic condition characterised by thrombosis and pregnancy morbidity. There are a broad range of neuropsychiatric manifestations associated with APS, from focal symptoms to more global dysfunction. Patients commonly present with transient ischaemic attacks and ischaemic strokes, with identifiable lesions on brain imaging. However, the underlying pathogenesis remains uncertain in other manifestations, such as cognitive dysfunction, seizures, headache and chorea. The aim is to provide a comprehensive review of the various neuropsychiatric manifestations associated with APS. A detailed literature search was applied to PubMed, including citations from 1983 to December 2021.

From Systemic Inflammation to Neuroinflammation: The Case of Neurolupus

It took decades to arrive at the general consensus dismissing the notion that the immune system is independent of the central nervous system. In the case of uncontrolled systemic inflammation, the relationship between the two systems is thrown off balance and results in cognitive and emotional impairment. It is specifically true for autoimmune pathologies where the central nervous system is affected as a result of systemic inflammation. Along with boosting circulating cytokine levels, systemic inflammation can lead to aberrant brain-resident immune cell activation, leakage of the blood⁻brain barrier, and the production of circulating antibodies that cross-react with brain antigens. One of the most disabling autoimmune pathologies known to have an effect on the central nervous system secondary to the systemic disease is systemic lupus erythematosus. Its neuropsychiatric expression has been extensively studied in lupus-like disease murine models that develop an autoimmunity-associated behavioral syndrome. These models are very useful for studying how the peripheral immune system and systemic inflammation can influence brain functions. In this review, we summarize the experimental data reported on murine models developing autoimmune diseases and systemic inflammation, and we explore the underlying mechanisms explaining how systemic inflammation can result in behavioral deficits, with a special focus on in vivo neuroimaging techniques.