The Pathogenesis of Neural Injury in Animal Models of the 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.

Inflammation and Coagulation in Neurologic and Psychiatric Disorders

Coagulation factors are intrinsically expressed in various brain cells, including astrocytes and microglia. Their interaction with the inflammatory system is important for the well-being of the brain, but they are also crucial in the development of many diseases in the brain such as stroke and traumatic brain injury. The cellular effects of coagulation are mediated mainly by protease-activated receptors. In this review, we sum up the role of the coagulation cascade in the development of different diseases including psychiatric disorders. In inflammatory diseases such as multiple sclerosis, fibrinogen activates microglia and suppresses the differentiation of oligodendrocytes, leading to axonal damage and suppression of remyelination. In ischemic stroke, thrombin activity is associated with the size of infarction, and the inhibition of either thrombin- or protease-activated receptor 1 promotes neuronal survival and reduces the size of infarction. Patients suffering from Alzheimer's disease express higher levels of thrombin, which in turn damages the endothelium, increases blood-brain barrier permeability, and induces cell apoptosis. In major depressive disorder, a positive correlation is present between prothrombotic states and suicidality. Moreover, both protein S deficiency and antiphospholipid antibodies are associated with schizophrenia and there is an effect of warfarin on psychosis-free intervals. Studying the coagulation in the brain could open a new door in understanding and treating neurological and psychiatric disorders, and extensive research should be conducted in this field.

Autoimmune-related movement disorders

Movement disorders (MDs) are common symptoms of autoimmune diseases. However, the clinical spectrum of MDs in autoimmune diseases remains poorly characterized, largely due to the scarcity of large-scale clinical surveys and trials. Most available data are derived from case reports and small case series. Here, we review the 123 currently reported cases of patients with autoimmune-related MDs and evaluate the demographic and clinical characteristics, pathophysiologies, and treatments. Autoimmune MDs were observed in various diseases involving autoimmune processes, including autoimmune encephalitis (AE), central nervous system infections, and systemic autoimmune diseases; even some typical autoimmune diseases of the peripheral nervous system may also cause MDs. Owing to the diversity of aetiologies and pathophysiologies of these diseases, the clinical characteristics and prognoses of these autoimmune-related MDs are highly variable. The mechanisms underlying MDs in autoimmune diseases involve abnormalities in neuronal signalling pathways, including neurotransmitter and receptor dysfunction, as well as direct antibody-mediated attacks on neuronal structures.

Cardiolipin Antibody: A Potential Biomarker for Depression

Background: Inflammation plays a pivotal role in the etiopathology of Major Depressive Disorder (MDD), at least in a subset of patients. It is crucial to first establish which specific inflammatory biomarkers are of clinical utility. Anti-cardiolipin antibody (aCL IgM) is an inflammatory marker that has the potential to be such a candidate but there are insufficient studies to confirm this potential. Objective: To investigate the baseline titer level and the longitudinal progression of plasma titers of aCL IgM in MDD subjects receiving antidepressant therapy in comparison to healthy control (HC) subjects; to determine if changes in aCL IgM plasma titers correlate to changes in depressive symptoms; and, to ascertain if baseline aCL IgM plasma titers could predict treatment response. Methods: Forty-eight medically healthy outpatients diagnosed with MDD were enrolled in one of two groups in two sequentially conducted clinical trials. In Group-E, patients received a 12-week regimen of escitalopram (n = 20). Those in Group-Q received a 12-week regimen of quetiapine (n = 28). The main outcome measure was plasma aCL IgM titers, the Hamilton Rating Scale for Depression (HAM-D17) and the Hamilton Rating Scale for Anxiety (HAM-A). There were 16 HC subjects. Results: When Group-Q and Group-E participants were grouped together (n = 48), MDD subjects had an elevated baseline aCL IgM (19.9 μg/mL) compared to HC subjects (8.32 μg/mL) (p = 0.006). aCL IgM correlated significantly with HAM-D17 scores at baseline in MDD subjects (p = 0.0185, r = 0.296). Examining the individual groups, Group-Q MDD patients had a significantly elevated baseline aCL IgM (p = 0.008) while Group-E's MDD patients did not. On the other hand, only Group-E MDD patients showed a significant correlation at baseline between aCL IgM and HAM-A score (p = 0.0392, r = 0.4327); they also showed a significant inverse correlation between week 12 HAMD-17 Item #10 (Anxiety, Psychic) and week 12 aCL IgM titer (p = 0.0268, r = -0.5516). Conclusions: MDD patients had significantly higher plasma titers of aCL IgM when compared to HC subjects. Moreover, at baseline, the higher the aCL IgM titer, the higher the depression severity, as measured by HAMD-17 score. However, this study did not demonstrate that aCL IgM titers changed significantly throughout a 12-week course of antidepressant treatment and revealed no correlation between changes in depressive symptoms and changes in aCL IgM titers. Baseline aCL IgM could not predict treatment response. We conclude that, despite lacking predictive ability as regards treatment response, plasma titers of aCL IgM have a diagnostic potential in MDD that necessitates further exploration.

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.

The Endocannabinoid System: A Potential Target for the Treatment of Various Diseases

The Endocannabinoid System (ECS) is primarily responsible for maintaining homeostasis, a balance in internal environment (temperature, mood, and immune system) and energy input and output in living, biological systems. In addition to regulating physiological processes, the ECS directly influences anxiety, feeding behaviour/appetite, emotional behaviour, depression, nervous functions, neurogenesis, neuroprotection, reward, cognition, learning, memory, pain sensation, fertility, pregnancy, and pre-and post-natal development. The ECS is also involved in several pathophysiological diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases. In recent years, genetic and pharmacological manipulation of the ECS has gained significant interest in medicine, research, and drug discovery and development. The distribution of the components of the ECS system throughout the body, and the physiological/pathophysiological role of the ECS-signalling pathways in many diseases, all offer promising opportunities for the development of novel cannabinergic, cannabimimetic, and cannabinoid-based therapeutic drugs that genetically or pharmacologically modulate the ECS via inhibition of metabolic pathways and/or agonism or antagonism of the receptors of the ECS. This modulation results in the differential expression/activity of the components of the ECS that may be beneficial in the treatment of a number of diseases. This manuscript in-depth review will investigate the potential of the ECS in the treatment of various diseases, and to put forth the suggestion that many of these secondary metabolites of Cannabis sativa L. (hereafter referred to as "C. sativa L." or "medical cannabis"), may also have potential as lead compounds in the development of cannabinoid-based pharmaceuticals for a variety of diseases.

Non-Criteria Manifestations of Juvenile Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder mainly characterised by increased risks of thrombosis and pregnancy morbidity and persistent positive test results for antiphospholipid antibodies (aPLs). The criteria for diagnosing juvenile APS have yet to be validated, while the Sydney classification criteria do not contain several non-thrombotic clinical manifestations associated with the presence of aPLs. As such, difficulties have been encountered in the diagnosis of patients who have no certain thrombotic occlusions. Moreover, extra-criteria manifestations (i.e., clinical manifestations not listed in the classification criteria), including neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease have been reported, which suggests that the clinical spectrum of aPL-related manifestations extends beyond that indicated in the classification criteria. Studies have demonstrated that more than 40% of children with aPLs demonstrated non-thrombotic aPL-related clinical manifestations alone. Moreover, our results showed that the pathogenesis of non-criteria manifestations is characterised by “APS vasculopathy”. The present review introduces the characteristics and findings of non-criteria manifestations observed in juvenile APS.

Association between dementia and systemic rheumatic disease: A nationwide population-based study

Objectives

Systemic rheumatic disease is characterized by autoimmunity and systemic inflammation and affects multiple organs. Few studies have investigated whether autoimmune diseases increase the risk of dementia. Herein, we evaluate the relationship between systemic rheumatic disease and dementia through a population-based study using the Korean National Health Insurance Service (NHIS) claims database.

Methods

We conducted a nationwide population-based study using the Korean NHIS database, consisting of individuals who submitted medical claims from 2002–2013. Dementia was defined as having an acetylcholinesterase inhibitors (AChEIs) prescription along with symptoms satisfying the Alzhemier’s disease (AD) International Classification of Diseases (ICD)-10 codes (F00 or G30), or vascular dementia (VaD; ICD-10 or F01) criteria. Control subjects were matched to the dementia patients by age and sex. The study group was limited to those diagnosed with rheumatic disease at least 6 months prior to diagnosis of dementia. Rheumatic disease was defined by the following ICD-10 codes: Rheumatoid arthritis (RA: M05), Sjögren’s syndrome (SS: M35), systemic lupus erythematosus (SLE: M32), and Behcet’s disease (BD: M35.2).

Results

Of the 6,028 dementia patients, 261 (4.3%) had RA, 108 (1.6%) had SS, 12 (0.2%) had SLE, and 6 (0.1%) had BD. SLE history was significantly higher in dementia patients (0.2%) than in controls (0.1%) and was associated with dementia (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.19–5.15). In subgroup analysis, SLE significantly increased dementia risk, regardless of dementia type (AD: OR, 2.29; 95% CI, 1.06–4.91; VaD: OR, 4.54; 95% CI, 1.36–15.14). However, these associations were not sustained in the mild CCI or elderly group.

Conclusion

SLE was independently associated with a higher risk of dementia, including AD and VaD when compared to the control group, even after adjustment. SLE patients (<65 years old) are a high-risk group for early vascular dementia and require screening for early detection and active prevention.

Antiphospholipid syndrome: a case report with an unusual wide spectrum of clinical manifestations

Background

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of venous and/or arterial thrombosis, and the detection of circulating antiphospholipid antibodies. The classification criteria for definite APS are actually met when at least one clinical criterion (thrombosis or pregnancy morbidity) is present in association of one laboratory criterion (LAC, aCL antibody or aβ2GPI antibody present on two or more occasions, at least 12 weeks a part), and thrombosis should be confirmed by objective validated criteria. The average age of primary APS patients has been reported to be about 35–40 years and the disease is more common in women than in men.

Case presentation

In this report, we described a rare case of an adult male who presented over a period of 9 years with a wide spectrum of clinical manifestations involving different organs that were not initially diagnosed as APS. Dizziness and syncope were his first clinical symptoms, and a non-bacterial thrombotic endocarditis (NBTE) involving the mitral valve was at first diagnosed. Subsequently, the patient also presented with generalized seizures and subsequent head injury. When the patient was admitted to our clinic with bilateral epistaxis and fever, thrombocytopenia was revealed. Moreover, laboratory examinations showed acute pancreatitis with an increase of levels of inflammation markers.

Conclusion

Based on the patient’s medical history and all the examination results, it was possible to make a diagnosis of primary APS and, starting from diagnosis of thrombocytopenia, we were allowed to conclude that all of manifestation were epi-phenomena of a unique clinical entity, rather than unrelated diseases. Though APS is one of the most common thrombocytophilias, unfortunately, it is not recognized often enough. The lack of prevention in undiagnosed patients may cause severe complications which can in turn result in the death of those patients.

Management of Psychosis in Neuropsychiatric Lupus

Manifestations of neuropsychiatric systemic lupus erythematosus (NPSLE) are heterogeneous. Acute psychosis is an uncommon but well-recognized manifestation of NPSLE. With no specific biomarkers to date, the diagnosis of NPSLE relies on clinical acumen for circumstantial evidence and exclusion of important differential diagnoses. The attribution of psychosis to NPSLE is facilitated by the application attribution models. In particular, the American College of Rheumatology nomenclature, Systemic Lupus International Collaborating Clinics attribution models and Italian algorithm for the attribution of psychosis to NPSLE are revisited. The mainstay of treatment for psychosis attributable to NPSLE is immunosuppression and symptomatic control. In refractory cases, immunomodulatory and emerging biological agents may be considered. This article reviews the diagnostic dilemma, pathogenic mechanisms and treatment of psychosis in SLE patients.

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.

Diagnostic approach to neuropsychiatric lupus erythematosus: what should we do?

Neuropsychiatric systemic lupus erythematosus is a diagnostic challenge due to the multifarious neurological and psychiatric manifestations that define it but, when suspected, diagnostic imaging can give a fundamental help. The advancements and variety of neuroimaging techniques allow us to perform more and more accurate evaluations of structure, perfusion, and metabolism of the brain and to detect cerebral and spinal lesions. Moreover, vascular districts of the neck and the brain, as well as the electrical brain and peripheral muscle activity may be accurately investigated, thus giving us a wide panoramic view. Although magnetic resonance is recognized as a fundamental neuroimaging technique to reach a correct diagnosis, the juxtaposition of other diagnostic techniques has improved the possibility to make diagnoses but has also increased the confusion about deciding which of them to use and when. Our aim was to combine the number of available techniques with the need to simplify the diagnostic path. Therefore, through the construction of an algorithm from an evidence based approach, we believe we are providing some added improvements to facilitate and expedite the diagnosis of NPSLE.

Antiphospholipid syndrome, "the best prophet of the future"

The antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the occurrence of venous and arterial thromboses, often multiple, and obstetric-related adverse events in the presence of antiphospholipid antibodies (aPL). APS, first described in 1983, as thrombosis, abortion and cerebral disease, is nowadays recognised as a systemic disease with a wide constellation of clinical manifestations related to acute and chronic vascular lesions. The presence of aPL is the serological hallmark of APS representing a heterogeneous population of autoantibodies with many antigenic specificities directed to phospholipid-binding proteins, either alone or in combination with phospholipids. Many assays have been developed for aPL detection. Particularly, anticardiolipin antibodies, anti-β2-glycoprotein I antibodies and lupus anticoagulant are essential tools for APS diagnosis. The cumulative evidence indicates that aPL are pathogenic autoantibodies binding to target cells and promoting thrombosis and pregnancy complications through a wide range of pathological mechanisms not yet fully understood. Finally, the recognition of the important role of aPL to assess the individual risk of thrombosis or pregnancy complications has expanded the concept of aPL, and currently aPL profile is regarded as a major risk factor for clinical thrombotic events.

Presence of Anticardiolipin Antibodies in Patients with Dementia: A Systematic Review and Meta-Analysis

Growing evidences are supporting towards the involvement of antiphospholipid antibodies [aPLs e.g., lupus anticoagulant (LA), anticardiolipin (aCL) and anti-β2-glycoprotein I (anti-β2-GPI) antibodies] in various neurological manifestations including migraine, epilepsy and dementia in the presence or absence of autoimmune diseases such as antiphospholipid syndrome or systemic lupus erythematosus. The aim of this systematic review and meta-analysis was to assess the presence of aPLs in dementia patients without a diagnosis of any autoimmune disease. Electronic databases (e.g., PubMed, Web of Science, Scopus, ScienceDirect and Google Scholar) were searched without any year or language restrictions and based on the inclusion criteria, nine prospective case-control studies assessing only aCL were included involving 372 dementia patients and 337 healthy controls. No studies were found to assess the presence of both LA or anti-β2-GPI. The study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects model. We observed the prevalence of aCL in dementia was higher (32.80%) than that of controls (9.50%) e.g., 3.45 times higher risk of presenting with dementia than the controls, and significant presence of aCL antibodies was detected in dementia patients compared to controls (OR: 4.94, 95% CI: 2.66 - 9.16, p < 0.00001; I² = 32%, p = 0.16). Publication bias was not observed from Egger's (p = 0.081) and Begg's tests (p = 0.180). Based on the study quality assessment using modified Newcastle-Ottawa Scale for case-control studies, seven of nine studies were of high methodological quality scoring ≥ 7 (median value). In summary, aCL antibodies were significantly present in dementia patients suggesting that aCL antibodies are generated due to the autoimmune-derived effects of dementia or there might be a potential causative role of this autoantibody in dementia pathogenesis.

Comorbid association of antiphospholipid antibodies and migraine: A systematic review and meta-analysis

BACKGROUND

Antiphospholipid antibodies (aPLs) namely anticardiolipin (aCL) antibody, anti-β2-glycoprotein I (β2GPI) antibody and lupus anticoagulant (LA) are autoantibodies produced against anionic phospholipids and proteins on plasma membranes. Migraine is a primary headache disorder which has growing evidences of autoimmune-mediated pathogenesis and previous studies suggested the presence of aPLs in migraine patients.

AIMS

The aim of this study was to evaluate the comorbid association between aPLs (aCL, anti-β2GPI and LA) and migraine compared to healthy controls.

METHODS

Studies were searched through PubMed, ISI Web of Science and Google Scholar databases without restricting the languages and year (up to October 2016) and were selected based on the inclusion criteria. Two authors independently extracted data from the included studies. All analyses were conducted by using random effects model to calculate the odds ratio (OR) and 95% confidence interval (CI). Quality assessment was carried out by using the modified Newcastle-Ottawa Scale (NOS). Publication bias was evaluated via visualization of funnel plots, Begg's and Egger's tests.

RESULTS

The database searches produced 1995 articles, 13 of which were selected (912 migraineurs and 822 healthy controls). 8.59%, 15.21% and 4.11% of the migraineurs exhibited aCL, anti-β2GPI and LA which was 4.83, 1.63 and 3.03 times higher, respectively, than healthy controls. A significant presence of aCL (OR: 3.55, 95% CI: 1.59-7.95; p=0.002) or anti-β2GPI antibodies (OR: 2.02, 95% CI: 1.20-3.42; p=0.008) was observed in migraine patients, however, LA was not significantly associated (OR: 2.02, 95% CI: 0.50-8.37; p=0.320). Majority of the studies (n=10 of 13) demonstrated NOS score of 7 or above and no significant publication bias was observed.

CONCLUSION

Migraine might be an autoimmune-associated neurologic disorder. The presence of aCL or anti-β2GPI antibodies was significant in migraine patients compared to healthy controls, suggesting an involvement of these autoantibodies in migraine attack.

Biomarkers for CNS involvement in pediatric lupus

CNS disease, or central neuropsychiatric lupus erythematosus (cNPSLE), occurs frequently in pediatric lupus, leading to significant morbidity and poor long-term outcomes. Diagnosing cNPSLE is especially difficult in pediatrics; many current diagnostic tools are invasive and/or costly, and there are no current accepted screening mechanisms. The most complicated aspect of diagnosis is differentiating primary disease from other etiologies; research to discover new biomarkers is attempting to address this dilemma. With many mechanisms involved in the pathogenesis of cNPSLE, biomarker profiles across several modalities (molecular, psychometric and neuroimaging) will need to be used. For the care of children with lupus, the challenge will be to develop biomarkers that are accessible by noninvasive measures and reliable in a pediatric population.

The effects of lupus and antiphospholipid antibody syndrome on foetal outcomes

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease that primarily affects women of childbearing-age. Antiphospholipid syndrome (APS) is a systemic autoimmune disorder defined by the occurrence of venous and arterial thrombosis, often multiple, and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). Recently, the long-term outcome of children born to patients with lupus and APS has become a major topic of interest both to patients and physicians. One of the major problems related to maternal disease is preterm delivery with all the consequences that this condition may bring. Prematurity may also be due to the presence of aPL; however, aPL do not generally display any thrombotic potential on neonates. Another complication may be neonatal lupus (NL), mediated by the presence of maternal antibodies (anti-Ro/SSA and anti-La/SSB). In addition, behaviour and neuropsychological outcomes have also been a matter of interest, but there are currently few data available. Beyond the biological influence of both maternal disease and autoimmune background, it is important to focus on the possible influence of maternal chronic illness on the neuropsychological development of her children. Whether aPL exposure could have a direct effect on brain development is still being debated. In children of mothers with APS, language delays have been noted and learning disabilities were described with a higher rate than the general age-school population. Several studies were performed on children born to lupus mothers: even if maternal lupus does not seem to impair intelligence levels, it may increase the occurrence of learning disabilities and particularly dyslexia in male children. To the best of our knowledge, no studies are available on the long-term outcome of children born to mothers with lupus or APS and particularly regarding the development of autoimmune diseases. Nevertheless, common experience of experts in the field is that these children do not show a significantly increased risk of displaying the same autoimmune disease as their mothers. The purpose of this paper is to answer the frequently asked questions of patients with lupus and APS who desire to become mothers, based on the little information available.

Altered receptor binding densities in experimental antiphospholipid syndrome despite only moderately enhanced autoantibody levels and absence of behavioral features

Experimental antiphospholipid syndrome (eAPS) in Balb/c mice causes neuropsychiatric abnormalities including hyperactivity, increased explorative behavior and cognitive deficits. Recently, we have demonstrated that these behavioral changes were linked to an upregulation of serotonergic 5-HT1A receptor binding densities in cortical and hippocampal regions while excitatory and inhibitory neurotransmitter receptors remain largely unchanged. To examine whether the observed behavioral features depend on a critical antibody concentration, mice with only moderately enhanced antiphospholipid antibodies (aPL), about 50-80% of high levels, were analyzed and compared to controls. The staircase test was used to test animals for hyperactivity and explorative behavior. The brains were analyzed for tissue integrity and inflammation. Ligand binding densities of NMDA, AMPA, GABAA, 5-HT1A, M1 and M2 muscarinic acetylcholine receptors, respectively, were analyzed by in vitro receptor autoradiography and compared to brains of mice from our previous study with high levels of aPL. Mice with only moderately enhanced aPL did not develop significant behavioral changes. Brain parenchyma remained intact and neither inflammation nor glial activation was detectable. However, there was a significant decrease of NMDA receptor binding densities in the motor cortex as well as an increase in M1 binding densities in cortical and hippocampal regions, whereas the other receptors analyzed were not altered. Lack of neuropsychiatric symptoms may be due to modulations of receptors resulting in normal behavior. In conclusion, our results support the hypothesis that high levels of aPL are required for the manifestation of neuropsychiatric involvement while at lower antibody levels compensatory mechanisms may preserve normal behavior.

Coagulopathy triggered autoimmunity: experimental antiphospholipid syndrome in factor V Leiden mice

BACKGROUND

We investigated interactions between genetically and autoimmune-mediated coagulopathies by inducing experimental antiphospholipid syndrome (eAPS) in mice carrying the factor V Leiden (FVL) mutation.

METHODS

eAPS was induced in heterozygous and homozygous FVL transgenic mice (C57BL/6 background) by immunization with β(2)-glycoprotein I (β(2)-GPI). Autoantibody levels were measured at 1 and 5 months post-immunization. Mice were tested at 4 months post-immunization for behavior and cognitive function in the staircase, elevated plus-maze, and swim T-maze tests. Brains were removed and analyzed by immunohistochemistry for inflammatory markers and neurodegenerative processes.

RESULTS

A single immunization with β(2)-GPI induced significantly higher and longer-lasting immune responses, and this was dependent on the number of FVL alleles. At 1 and 5 months post-immunization, levels of antibodies rose from 1.17 ± 0.07 to 1.62 ± 0.17 (optical density units; ODU) in homozygous FVL mice, compared with stable levels of 0.59 ± 0.17 and 0.48 ± 0.16 ODU in heterozygous FVL mice and a drop from 1.62 ± 0.21 to 0.61 ± 0.13 ODU in wild-type mice. Behavioral and cognitive clinical features of eAPS were also correlated with FVL allele load, as assessed by the elevated plus-maze (altered anxiety), staircase (hyperactivity and higher exploration), and swim T-maze (impaired learning) tests. Histological studies identified significant neurodegenerative changes in both grey and white matter in the eAPS-FVL brains. In spite of the potential interaction of two prothrombotic disease states, there were no ischemic lesions seen in this group.

CONCLUSIONS

The results indicate that genetically mediated coagulopathies increase the risk of developing coagulation-targeted autoimmune responses, and suggest the importance of antibody-mediated neurodegenerative processes in the brain in APS.

Antiphospholipid-related chorea

Chorea is a movement disorder which may be associated with immunologic diseases, in particular in the presence of antiphospholipid antibodies (aPL). Choreic movements have been linked to the isolated presence of plasmatic aPL, or to primary, or secondary antiphospholipid syndrome. The highest incidence of aPL-related chorea is detected in children and females. The presentation of chorea is usually subacute and the course monophasic. Choreic movements can be focal, unilateral, or generalized. High plasmatic titers of aPL in a choreic patient can suggest the diagnosis of aPL-related chorea; neuroimaging investigation does not provide much additional diagnostic information. The most relevant target of aPL is β2-glycoprotein I, probably responsible for the thrombotic manifestations of antiphospholipid syndrome. Etiology of the movement disorder is not well understood but a neurotoxic effect of aPL has been hypothesized, leading to impaired basal ganglia cell function and development of neuroinflammation. Patients affected by aPL-related chorea have an increased risk of thrombosis and should receive antiplatelet or anticoagulant treatment.

The future of autoimmunity

There have been enormous strides in our understanding of autoimmunity. These strides have come under the umbrellas of epidemiology, immunological phenotype and function, disease definitions and classification and especially new therapeutic reagents. However, while these advances have been herculean, there remains enormous voids. Some of these voids include genetic susceptibility and the interaction of genes and environment. The voids include induction of tolerance in preclinical disease and definitions of host susceptibility and responses to the expensive biologic agents. The voids include the so-called clustering of human autoimmune diseases and the issues of whether the incidence is rising in our western society. Other voids include the relationships between microbiology, vaccination, gut flora, overzealous use of antibiotics, and the role of nanoparticles and environmental pollution in either the induction or the natural history of disease. One cannot even begin to address even a fraction of these issues. However, in this special issue, we are attempting to discuss clinical issues in autoimmunity that are not usually found in generic reviews. The goal is to bring to the readership provocative articles that ultimately will lead to improvement in patient care.

Neurological impairment in experimental antiphospholipid syndrome is associated with increased ligand binding to hippocampal and cortical serotonergic 5-HT1A receptors

The antiphospholipid syndrome (APS) is an autoimmune disease where the presence of high titers of circulating autoantibodies causes thrombosis with consecutive infarcts. In experimental APS (eAPS), a mouse model of APS, behavioral abnormalities develop in the absence of vessel occlusion or infarcts. Using brain hemispheres of control and eAPS mice with documented neurological and cognitive deficits, we checked for lymphocytic infiltration, activation of glia and macrophages, as well as alterations of ligand binding densities of various neurotransmitter receptors to unravel the molecular basis of this abnormal behavior. Lymphocytic infiltrates were immunohistochemically characterized using antibodies against CD3, CD4, CD8 and forkhead box P3 (Foxp3), respectively. GFAP, Iba1 and CD68-immunohistochemistry was performed, to check for activation of astrocytes, microglia and macrophages. Ligand binding densities of NMDA, AMPA, GABAA and 5-HT1A receptors were analyzed by in vitro receptor autoradiography. No significant inflammatory reaction occurred in eAPS mice. There was neither activation of astrocytes or microglia nor accumulation of macrophages. Binding values of excitatory and inhibitory neurotransmitter receptors were largely unchanged. However, ligand binding densities of the modulatory serotonergic 5-HT1A receptors in the hippocampus and in the primary somatosensory cortex of eAPS mice were significantly upregulated which is suggested to induce the behavioral abnormalities observed.

Secondary hypertrophic pachymeningitis in antiphospholipid syndrome

This report describes a rare case of hypertrophic pachymeningitis secondary to antiphospholipid syndrome in a 37-year-old woman. The patient had a history of antiphospholipid syndrome and developed hypertrophic pachymeningitis subsequently. Pathological examination of the dura mater showed not only fibrous thickening, the typical finding of hypertrophic pachymeningitis, but also thrombosis in the dural microvessels and T cell infiltration without B cell or plasma cell infiltration, suggesting cell-mediated immunity. The dural thickening spontaneously improved and did not deteriorate during corticosteroid therapy. The histological findings and spontaneous remission observed in this case might be characteristic of secondary hypertrophic pachymeningitis with antiphospholipid syndrome. Further investigations are necessary to elucidate the pathophysiology of this novel type of hypertrophic pachymeningitis.

Cutting-edge issues in organ-specific autoimmunity

There have been numerous methods and ways to classify autoimmune diseases. By far, the most traditional has been to separate immune-mediated pathology into organ-specific and organ-non-specific diseases. The classic systemic autoimmune diseases are, of course, rheumatoid arthritis and systemic lupus. The classic organ-specific autoimmune diseases have been autoimmune thyroiditis and autoimmune gastritis. However, as our understanding of the loss of tolerance has expanded, so has the long list of autoimmune diseases. In many cases, the distinction between organ-specific and organ-non-specific or systemic autoimmunity becomes a blur. In this issue, we discuss recent concepts in autoimmune pancreatitis, primary sclerosing cholangitis, Goodpasture's syndrome, myofasciitis, type I diabetes, polymyositis, autoimmune thyroid disease, IgA nephropathy, autoimmune uveitis, and ANCA-associated vasculitis. Common themes on both etiology and effector mechanisms are described throughout these papers with an attempt to provide a cutting-edge overview.

Cognitive impairment in antiphospholipid syndrome: evidence from animal models

Although antiphospholipid syndrome (APS) is a multisystem prothrombotic condition, its inflammatory nature has been increasingly recognized in recent years. Stroke and transitory ischemic attacks are the neurological manifestations included in APS criteria, however many other neurological involvements have been attributed to antiphospholipid antibodies (aPL), such as seizures, transverse myelitis, and cognitive impairment. In this article we will review evidence from animal model that explain the role of aPL in cognition.

Anatomical localization of protease-activated receptor-1 and protease-mediated neuroglial crosstalk on peri-synaptic astrocytic endfeet

We studied the localization, activation and function of protease-activated receptor 1 (PAR-1) at the CNS synapse utilizing rat brain synaptosomes and slices. Confocal immunofluoresence and transmission electron microscopy in brain slices with pre-embedding diaminobenzidine (DAB) immunostaining found PAR-1 predominantly localized to the peri-synaptic astrocytic endfeet. Structural confocal immunofluorescence microscopy studies of isolated synaptosomes revealed spherical structures stained with anti-PAR-1 antibody which co-stained mainly for glial-filament acidic protein compared with the neuronal markers synaptophysin and PSD-95. Immunoblot studies of synaptosomes demonstrated an appropriate major band corresponding to PAR-1 and activation of the receptor by a specific agonist peptide (SFLLRN) significantly modulated phosphorylated extracellular signal-regulated kinase. A significant membrane potential depolarization was produced by thrombin (1 U/mL) and the PAR-1 agonist (100 μM) and depolarization by high K(+) elevated extracellular thrombin-like activity in the synaptosomes preparation. The results indicate PAR-1 localized to the peri-synaptic astrocytic endfeet is most likely activated by synaptic proteases and induces cellular signaling and modulation of synaptic electrophysiology. A protease mediated neuron-glia pathway may be important in both physiological and pathological regulation of the synapse.

Devic’s syndrome and primary APS: a new immunological overlap

Neuromyelitis optica (NMO or Devic’s syndrome) is a rare autoimmune disease, previously considered a multiple sclerosis variant. The most important laboratory and clinical features are optic myelitis and transverse myelitis, associated with neuromyelitis optica-IgG antibody (NMO-IgG) positivity. Subsequent to this immunological test being available, different groups have described the not-so-rare comorbidity of neuromyelitis optica with other systemic autoimmune diseases, systemic lupus erythematosus with secondary anti-phospholipid syndrome (APS) in particular. We describe a patient meeting both the classification criteria for primary APS and the new diagnostic criteria for neuromyelitis optica. It’s important to diagnose NMO syndrome as both optic neuritis and transverse myelitis were also considered neurological complications of antiphospholipid syndrome. NMO-IgG is a new and fundamental test to decide if immunosuppressant therapy is warranted for such patients.