High prevalence of antiphospholipid antibodies in children with epilepsy: a controlled study of 50 cases

Pediatric APS: State of the Art

PURPOSE OF REVIEW

The purpose of this report is to review recent research findings on APS in children and neonates.

RECENT FINDINGS

European evidence-based recommendations for diagnosis and treatment of pediatric APS has recently been published by the SHARE Initiative. Recent studies have shown a high prevalence of non-thrombotic manifestations in children with aPL, domains 4/5 specificity of 'innocent' anti-β2GPI antibodies in infants, and a higher risk for developmental delays and learning disabilities, hence, the need for neurodevelopmental monitoring in children born to mothers with APS. An International effort on creating a new diagnostic criteria for APS is underway. Pediatric APS is a rare disease with significant differences from the APS in adults. Majority of the children with persistently positive aPL do not develop thrombotic events; however, relatively higher proportion of thrombosis in children is related to aPL positivity compared to adults; this may partly be due to the absence of common pro-thrombotic "second-hit" risk factors of adults such as atherosclerosis and cigarette smoking. Diagnosis of APS in children may be delayed or missed when adult APS criteria are used, because in pediatric APS, non-thrombotic clinical manifestations such as thrombocytopenia, hemolytic anemia, and neurological disorders such as migraine, epilepsy, and chorea may precede thrombotic manifestations. Around 20% of the children initially diagnosed with primary APS eventually develop SLE. Neonatal APS is rare; however, the offspring of mothers with APS are at a higher risk for developmental delays and learning disabilities; prematurity and IUGR may increase this risk. Regular assessment of neurodevelopmental status of these children should be performed. Thrombosis is a rare event in the offspring of mothers with APS; anticoagulation of such infants is not recommended. An international effort to create a new diagnostic criteria for APS is underway.

Antiphospholipid and Antinuclear Antibodies in Children with Idiopathic Epilepsy: A 2-Year Prospective Study

BACKGROUND AND PURPOSE

The high prevalence of antiphospholipid antibodies (aPL) and antinuclear antibodies (ANA) in patients with epilepsy may be associated with either the disease itself or the antiepileptic treatment. The purpose of this prospective study was to determine the prevalence of aPL and ANA in children with idiopathic epilepsy before and during treatment with antiepileptic drugs.

METHODS

aPL, including both anticardiolipin and anti-β2-glycoprotein I antibodies, and ANA statuses were determined in 40 healthy children, 30 children treated with sodium valproate (VPA) monotherapy, and 20 children treated with carbamazepine (CBZ) monotherapy before and at 6, 12, and 24 months after treatment initiation.

RESULTS

Fifteen children (50%) in the VPA-treated group and 7 (35%) in the CBZ-treated group showed positivity for aPL before treatment initiation, compared with only 4 of the 40 controls. Nine children (30%) in the VPA-treated group and 4 (20%) in the CBZ-treated group showed positivity for ANA before treatment initiation, compared with only 2 of the 40 controls. The subgroup analysis found nonsignificant associations at the different time points regarding the positivity of all of the autoantibodies. Only patients treated with VPA had a significantly decreased risk of aPL positivity after 6 months of treatment.

CONCLUSIONS

The increased prevalence of autoantibodies in children with idiopathic epilepsy is strongly associated with the disease itself.

Antiphospholipid antibodies in epilepsy: A systematic review and meta-analysis

BACKGROUND

Autoimmunity is believed to play an important causative role in the pathogenesis of epilepsy. There are evidences for the presence of autoantibodies in patients with epilepsy. To date, many studies have assessed the presence of antiphospholipid antibodies (aPLs) in epilepsy patients, though the relationship has been inconclusive.

AIMS

The aim of this systematic review and meta-analysis was to evaluate the presence of aPLs in epileptic patients as compared to healthy controls.

METHODS

Five electronic databases (PubMed, Web of Science, Embase, Scopus and Google Scholar) were searched systematically. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects model. Quality assessment was carried out by using the modified 9-star Newcastle-Ottawa Scale (NOS). L'Abbé plots were generated to visually inspect heterogeneity while publication bias was evaluated via visualization of contour- enhanced funnel plots, and Begg's and Egger's tests.

RESULTS

Based on the inclusion criteria, 14 studies were selected involving 1248 epilepsy patients and 800 healthy controls. The majority of epilepsy was categorised as generalised or partial and none had comorbidity with autoimmune diseases. Significant presence of both anticardiolipin (aCL) antibodies (OR: 5.16, 95% CI: 3.21-8.28, p < 0.00001) and anti-β2- glycoprotein I (anti-β2-GPI) antibodies (OR: 2.95, 95% CI: 1.07-8.11, p = 0.04) exhibited comorbid association with epilepsy patients as compared to healthy controls. Subgroup analyses revealed that presence of aCL antibodies was more specifically observed in paediatrics (OR: 4.57, 95% CI: 2.57-8.15, p < 0.00001) than adults (OR: 4.24, 95% CI: 1.80-10.01, p = 0.001). The odds of aCL antibody presence was higher in partial epilepsy patients (OR: 7.88, 95% CI: 3.23-19.24, p < 0.00001) than that of generalised (OR: 3.76, 95% CI: 2.15-6.59, p < 0.00001) and in Asian epileptic patients (OR: 9.56, 95% CI: 2.69-33.95, p = 0.0005) than Europeans (OR: 4.35, 95% CI: 2.74-6.92, p < 0.00001). The presence of anti-β2-GPI antibodies was significant in paediatric (OR: 6.44, 95% CI: 1.39-29.89, p = 0.02) and African population with epilepsies (OR: 10.59, 95% CI: 1.22-92.25, p = 0.03). NOS of the majority of the studies (11/14) indicated a high methodological quality. No substantial heterogeneity was observed either from the quantitative analysis or from the L'Abbé plots while no significant publication bias was detected from funnel plots; Begg's and Egger's tests.

CONCLUSION

Since none of the epilepsy subjects exhibited any comorbid autoimmune disorders, significant presence of aCL and anti-β2-GPI antibodies indicate towards their contribution in immune-mediated general pathogenesis of epilepsy.

Subtypes of Antiphospholipid Antibodies in Neurologic Disorders: An Observational Study

BACKGROUND AND OBJECTIVES

Concomitant neurologic manifestations and positive antiphospholipid antibodies (APAs) have been investigated in different manners. The present study aimed to investigate the association between neurologic manifestations and APAs.

MATERIALS AND METHODS

This cross-sectional descriptive study was conducted on 100 consecutive patients with selected neurological manifestations and at least one positive APAs within the age range of 20-50 years, referred to the Rheumatic Diseases Research Center from the Northeast Central Neurology Department of Iran during August 2012 to March 2014.

RESULTS

According to the results, 89% of the participants were persistently positive for APAs, including lupus anticoagulant, IgG anticardiolipin (aCL), IgM aCL, IgG β-2 glycoprotein 1 (β2- GP1), and IgM β2-GP1, observed in 16%, 41%, 42%, 17%, and 15% of the patients, respectively. Furthermore, 10% of the patients had concomitant lupus manifestations, and 37% of them showed anti-DNA. The IgG and IgM aCL were the most prevalent antibodies. Cerebral vascular accident (33%), retinal artery/vein occlusion (21%), and seizure (20%) were the most frequent presentations among the patients. In addition, the patients with multiple sclerosis (composing 3% of the subjects) were 100% positive for IgG and IgM aCL, as well as lupus anticoagulant. In addition, IgM anti-β2- GP1 was 100% positive in optic neuritis patients (composing 5% of the subjects) and was significantly associated with this neurologic disorder. IgM anti-β2-GP1 was also prevalent in the cases with Guillain-Barré syndrome. The most prevalent persistently positive antibody in the patients with cerebrovascular accident was IgM aCL.

CONCLUSION

The findings of this study revealed some associations between the subtypes of APAs and incidence of neurologic disorders. However, the exact correlation between those symptoms and APAs needs further investigations.

Seizures and risk of epilepsy in autoimmune and other inflammatory encephalitis

PURPOSE OF REVIEW

The aim of this study was to assess the seizure manifestations and risk of epilepsy in encephalitis associated with antibodies against neuronal cell-surface (autoimmune encephalitis) or myelin-associated antigens, and to review several chronic epileptic disorders, including Rasmussen's encephalitis, fever-induced refractory epileptic syndromes (FIRES) and new-onset refractory status epilepticus (NORSE).

RECENT FINDINGS

Seizures are a frequent manifestation of autoimmune encephalitis. Some autoimmune encephalitis may associate with characteristic features: faciobrachial dystonic seizures (anti-LGI1 encephalitis), electroencephalogram extreme delta brush (anti-NMDAR) or multifocal FLAIR-MRI abnormalities (anti-GABAAR). In anti-LGI1 encephalitis, cortical, limbic and basal ganglia dysfunction results in different types of seizures. Autoimmune encephalitis or myelin-antibody associated syndromes are often immunotherapy-responsive and appear to have a low risk for chronic epilepsy. In contrast patients with seizures related to GAD65-antibodies (an intracellular antigen) frequently develop epilepsy and have suboptimal response to treatment (including surgery). Rasmussen's encephalitis or FIRES may occur with autoantibodies of unclear significance and rarely respond to immunotherapy. A study of patients with NORSE showed that 30% developed chronic epilepsy.

SUMMARY

Although seizures are frequent in all types of autoimmune encephalitis, the risk for chronic epilepsy is dependent on the antigen: lower if located on the cell-surface, and higher if intracellular. For other disorders (Rasmussen's encephalitis, FIRES, NORSE), the prognosis remains poor.

Hughes syndrome and epilepsy: when to test for antiphospholipid antibodies?

Epilepsy and seizures are reported among the neurological manifestations of antiphospholipid syndrome (APS) at a prevalence rate of approximately 8%, which is nearly 10 times the prevalence of epilepsy in the general population. The association of seizures with antiphospholipid antibodies (aPL) is even more significant in the presence of systemic lupus erythematosus (SLE). In this review, we discuss the epidemiological, pathophysiological, laboratory, clinical, and radiological aspects of this association, and derive suggestions on when to consider testing for aPL in epileptic patients and how to manage seizures secondary to APS based on literature data. Epilepsy due to APS should be considered in young patients presenting with seizures of unknown origin. Temporal lobe epilepsy seems to be particularly prevalent in APS patients. The pathogenesis is complex and may not only involve micro-thrombosis, but also a possible immune-mediated neuronal damage. Patients with seizures and positive aPL tend to develop thrombocytopenia and livedo racemosa more frequently compared with those without aPL. Magnetic resonance imaging (MRI) remains the imaging modality of choice in these patients. The presence of SLE and the presence of neurological symptoms significantly correlate with the presence of white matter changes on MRI. In contrast, the correlation between aPL positivity and the presence of white matter changes is very weak. Furthermore, MRI can be normal in more than 30–40% of neuropsychiatric lupus patients with or without aPL. aPL testing is recommended in young patients presenting with atypical seizures and multiple hyper-intensity lesions on brain MRI in the absence of other possible conditions. New MRI techniques can better understand the pathology of brain damage in neuro-APS. The therapeutic management of epileptic APS patients relies on anti-epileptic treatment and anticoagulant agents when there is evidence of a thrombotic event. In the absence of consensual recommendations, the decision of lifelong anticoagulation is discussed on a case-by-case basis. The anti-thrombotic benefit of hydroxychloroquine and statins is supported by several studies.

Epilepsy as part of systemic lupus erythematosus and systemic antiphospholipid syndrome (Hughes syndrome)

The antiphospholipid syndrome (APS) is defined by the presence of antiphospholipid antibodies (aPL), demonstrated by ELISAs for antibodies against phospholipids and associated phospholipid-binding cofactor proteins and/or a circulating lupus anticoagulant (LA) together with diverse systemic clinical manifestations such as thrombosis, and recurrent spontaneous abortions. According to the criteria set out in Sydney1 the only neurological manifestations that can be suitable as APS classification criteria are ischemic events (stroke and transient ischemic attacks). However, other neurological manifestations, including seizures in particular, have been repeatedly reported in APS patients.2

The present review will summarize recent research on the association of aPL, as well as other autoantibodies, with seizure disorders, with or without concomitant SLE.

Antithyroid Antibodies Are Implicated in Epileptogenesis of Adult Patients With Epilepsy

Antithyroid antibodies (Abs) are associated with epilepsy in steroid-responsive encephalopathy, but have been rarely studied in unselected epilepsy patients. This study aimed to characterize the prevalence and associated factors of antithyroid Abs and other auto-Abs in adult patients with epilepsy.Epilepsy patients without autoimmune disorders were surveyed for antinuclear antibody (ANA), anti-β2 glycoprotein 1 antibody (aβ2GP1), anticardiolipin IgG Ab, antimicrosomal antibody (AMA), antithyroglobulin antibody (ATA), and thyroid function test.Of 319 patients, 75 (23.5%) were positive for at least 1 Ab. The most common Ab was anticardiolipin antibody (aCL) (30/319, 9.4%), followed by AMA (24/319, 7.5%), ANA (18/319, 5.6%), aβ2GP1 (18/319, 6.5%), and ATA (6/319, 3.25%). Antimicrosomal Abs were significantly more frequent in patients who were female, older at disease onset, older at the time of study, and had unknown seizure etiology. The presence of aCL was significantly associated with more frequent seizures. Most patients with antithyroid Ab were female and had focal seizures with unknown etiology.The association of different auto-Abs with different factors suggests that they may have different roles in adult patients with epilepsy. Recurrent seizures and certain antiepileptic medications may cause the production of aCL. The role of antithyroid Abs in adult focal epilepsy with unknown cause, especially in females, warrants further evaluation because of the potential implications on treatment.

Epilepsy in systemic autoimmune disorders

Autoimmunity and inflammation have been implicated as causative factors of seizures and epilepsy. Autoimmune disorders can affect the central nervous system as an isolated syndrome or be part of a systemic disease. Examples of systemic autoimmune disorders include systemic lupus erythematosus, antiphospholipid syndrome, rheumatic arthritis, and Sjögren syndrome. Overall, there is a 5-fold increased risk of seizures and epilepsy in children with systemic autoimmune disorders. Various etiologic factors have been implicated in causing the seizures in these patients, including direct inflammation, effect on blood vessels (vasculitis), and production of autoantibodies. Potential treatments for this autoimmune injury include steroids, immunoglobulins, and other immune-modulatory therapies. A better understanding of the mechanisms of epileptogenesis in patients with systemic autoimmune diseases could lead to targeted treatments and better outcomes.

Immunological perspectives of temporal lobe seizures

The temporal lobes are affected in many different neurological disorders, such as neurodegenerative diseases, viral and immunological encephalitides, and epilepsy. Both experimental and clinical evidence suggests a different inflammatory response to seizures in patients with temporal lobe epilepsy (TLE) in comparison to those with extra-TLE (XTLE). Proinflammatory cytokines and several autoantibodies have been shown to be associated with TLE compared to other epilepsy types suggesting the specific role and structure of the temporal lobe. Abundant experience suggests that activation of both innate and adaptive immunity is associated with epilepsy, particularly refractory focal epilepsy. Limbic encephalitis often triggers temporal lobe seizures, and a proportion of these disorders are immune-mediated. Histological evidence shows activation of specific inflammatory pathways in resected temporal lobes of epileptic patients, and certain epileptic disorders have shown increased incidence in patients with autoimmune diseases. Rapid activation of proinflammatory cytokines is observed after single seizures, but there is also evidence of chronic overproduction of cytokines and other inflammatory mediators in patients with TLE, suggesting a neuromodulatory role of inflammation in epilepsy. In this review we summarize current data on the presence and the role of immunological factors in temporal lobe seizures, and their possible involvement in epileptogenesis.

Intracellular and circulating neuronal antinuclear antibodies in human epilepsy

There are overwhelming data supporting the inflammatory origin of some epilepsies (e.g., Rasmussen's encephalitis and limbic encephalitis). Inflammatory epilepsies with an autoimmune component are characterized by autoantibodies against membrane-bound, intracellular or secreted proteins (e.g., voltage gated potassium channels). Comparably, little is known regarding autoantibodies targeting nuclear antigen. We tested the hypothesis that in addition to known epilepsy-related autoantigens, the human brain tissue and serum from patients with epilepsy contain autoantibodies recognizing nuclear targets. We also determined the specific nuclear proteins acting as autoantigen in patients with epilepsy. Brain tissue samples were obtained from patients undergoing brain resections to treat refractory seizures, from the brain with arteriovenous malformations or from post-mortem multiple sclerosis brain. Patients with epilepsy had no known history of autoimmune disease and were not diagnosed with autoimmune epilepsy. Tissue was processed for immunohistochemical staining. We also obtained subcellular fractions to extract intracellular IgGs. After separating nuclear antibody-antigen complexes, the purified autoantigen was analyzed by mass spectrometry. Western blots using autoantigen or total histones were probed to detect the presence of antinuclear antibodies in the serum of patients with epilepsy. Additionally, HEp-2 assays and antinuclear antibody ELISA were used to detect the staining pattern and specific presence of antinuclear antibodies in the serum of patients with epilepsy. Brain regions from patients with epilepsy characterized by blood-brain barrier disruption (visualized by extravasated albumin) contained extravasated IgGs. Intracellular antibodies were found in epilepsy (n=13/13) but not in multiple sclerosis brain (n=4/4). In the brain from patients with epilepsy, neurons displayed higher levels of nuclear IgGs compared to glia. IgG colocalized with extravasated albumin. All subcellular fractions from brain resections of patients with epilepsy contained extravasated IgGs (n=10/10), but epileptogenic cortex, where seizures originated from, displayed the highest levels of chromatin-bound IgGs. In the nuclear IgG pool, anti-histone autoantibodies were identified by two independent immunodetection methods. HEp-2 assay and ELISA confirmed the presence of anti-histone (n=5/8) and anti-chromatin antibodies in the serum from patients with epilepsy. We developed a multi-step approach to unmask autoantigens in the brain and sera of patients with epilepsy. This approach revealed antigen-bound antinuclear antibodies in neurons and free antinuclear IgGs in the serum of patients with epilepsy. Conditions with blood-brain barrier disruption but not seizures, were characterized by extravasated but not chromatin-bound IgGs. Our results show that the pool of intracellular IgG in the brain of patients with epilepsy consists of nucleus-specific autoantibodies targeting chromatin and histones. Seizures may be the trigger of neuronal uptake of antinuclear antibodies.

Can Immune Disorders Influence Therapeutical Approach in Treatment of Epilepsy among Neurologists? A First Co-Operative National Recognition in Italy

Functional disturbances of the immune system have been detected more often among persons affected by epilepsy than in the general population. In the February-July period of 2007 a specific questionnaire on the relationship between epilepsy and immunological response was sent to 27 specialized Centres for Epilepsy in nine Italian regions. 15,388 epileptic patients attended twenty-seven Centers during this six-month period. 3.3% (n=502) of these patients suffered an immune disease. This is the first national survey on the relationship between epilepsy and immunological response in current clinical practice.

Do helminths cause epilepsy?

Both helminthiases and epilepsy occur globally, and are particularly prevalent in developing regions of the world. Studies have suggested an association between epilepsy and helminth infection, but a causal relationship is not established in many helminths, except perhaps with neurocysticercosis. We review the available literature on the global burden of helminths, and the epidemiological evidence linking helminths to epilepsy. We discuss possible routes that helminths affect the central nervous system (CNS) of humans and the immunological response to helminth infection in the CNS, looking at possible mechanisms of epileptogenesis. Finally, we discuss the current gaps in knowledge about the interaction between helminths and epilepsy.

Role of brain inflammation in epileptogenesis

Inflammation is known to participate in the mediation of a growing number of acute and chronic neurological disorders. Even so, the involvement of inflammation in the pathogenesis of epilepsy and seizure-induced brain damage has only recently been appreciated. Inflammatory processes, including activation of microglia and astrocytes and production of proinflammatory cytokines and related molecules, have been described in human epilepsy patients as well as in experimental models of epilepsy. For many decades, a functional role for brain inflammation has been implied by the effective use of anti-inflammatory treatments, such as steroids, in treating intractable pediatric epilepsy of diverse causes. Conversely, common pediatric infectious or autoimmune diseases are often accompanied by seizures during the course of illness. In addition, genetic susceptibility to inflammation correlated with an increased risk of epilepsy. Mounting evidence thus supports the hypothesis that inflammation may contribute to epileptogenesis and cause neuronal injury in epilepsy. We provide an overview of the current knowledge that implicates brain inflammation as a common predisposing factor in epilepsy, particularly childhood epilepsy.

Pediatric antiphospholipid syndrome

APS is rare in the pediatric age, but it represents an interesting phenomenon because most of the known "second hit" risk factors such as atherosclerosis, smoking, hypertension, contraceptive hormonal treatment, and pregnancy are not present in childhood. This could also be the reason for the prevalence of some clinical manifestations rather than others in PAPS. On the other hand, the increased frequency of infectious processes in the childhood age is likely responsible for the relatively high prevalence of non-pathogenic and transient aPL. Such points raise the problem of a different diagnosis or monitoring approach in pediatric APS. Of particular interest is the special entity of neonatal APS, which represents an in vivo model of acquired autoimmune disease, in which transplacentally acquired aPL cause thrombosis in the newborn. International registries for pediatric and neonatal APS are currently in place; epidemiologic, clinical, and laboratory re-search will help to shed light on all the still obscure aspects of this fascinating but rare disorder in the very young. Finally, treatment is less aggressive overall in pediatric APS, given the reluctance to anticoagulate children over the long term. Studies on the outcome of pediatric APS and the relative risks of prolonged anticoagulation in children are necessary to determine the type and duration of anticoagulation therapy.

Cerebral Manifestations in the Antiphospholipid (Hughes) Syndrome

The importance of cerebral disease in patients with the Hughes syndrome is now becoming more widely recognized. The range of neuropsychiatric manifestations of APS is comprehensive, and includes focal symptoms attributable to lesions in a specific area of the brain as well as diffuse or global dysfunction. Patients with APS frequently present with strokes and TIA, but a wide spectrum of other neurologic features-also including non thrombotic neurologic syndromes-has been described in association with the presence of aPL. The recognition of APS has had a profound impact on the understanding and management of the treatment of CNS manifestations associated with connective tissue diseases, in particular, SLE. Many patients with focal neurologic manifestations and aPL, who a few years ago would have received high-dose corticosteroids or immunosuppression, are often successfully treated with anticoagulation. In our opinion, testing for aPL may have a major diagnostic and therapeutic impact not only in patients with autoimmune diseases and neuropsychiatric manifestations, but also in young individuals who develop cerebral ischemia, in those with atypical multiple sclerosis, transverse myelitis, and atypical seizures. We would also recommend testing for aPL for young individuals found with multiple hyperintensity lesions on brain MRI in the absence of other possible causes,especially when under the age of 40 years. It is our practice to anticoagulate patients with aPL suffering from cerebral ischemia with a target INR of 3.0 to prevent recurrences. Low-dose aspirin alone (with occasional exceptions)does not seem helpful to prevent recurrent thrombosis in these patients. Our recommendation, once the patient has had a proven thrombosis associated with aPL, is long-term (possibly life-long) warfarin therapy. Oral anti coagulation carries a risk of hemorrhage, but in our experience the risk of serious bleeding in patients with APS and previous thrombosis treated with oral anticoagulation to a target INR of 3.5 was similar to that in groups of patients treated with lower target ratios. Although a double-blind crossover trial comparing low molecular weight heparin with placebo in patients with aPL and chronic headaches did not show a significant difference in the beneficial effect of low molecular weight heparin versus placebo, in our experience selected patients with aPL and neuropsychiatric manifestations such as seizures, severe cognitive dys-function, and intractable headaches unresponsive to conventional treatment may respond to anticoagulant treatment. The neurologic ramifications of Hughes syndrome are extensive, and it behoves clinicians in all specialties to be aware of this syndrome because treatment with anticoagulation may profoundly change the outlook for these patients.

Hughes syndrome, the antiphospholipid syndrome: a new chapter in neurology

The importance of cerebral disease in patients with the antiphospholipid (Hughes) syndrome (APS) is now becoming more widely recognized. The range of neuropsychiatric manifestations of APS is comprehensive and includes focal symptoms attributable to lesions in a specific area of the brain as well as diffuse or global dysfunction. Patients with APS frequently present with strokes and transient ischemic attacks, but a wide spectrum of other neurologic features, also including nonthrombotic neurological syndromes, has been described in association with the presence of antiphospholipid antibodies. In this review, we attempt to highlight the large variety of the neurological features of APS.

Antiglial Cell Autoantibodies and Childhood Epilepsy: A Case Report

We report the case of a patient with severe partial epilepsy associated with a focal rolandic, pathologically proven, cortical dysplasia. By measuring intracellular calcium concentrations, functional antiglial non-glutamate receptor 3 (GluR3) autoantibodies were identified in the serum of this patient. Antineuronal autoantibodies, which interfere with GluR3-receptor function, also were detected. This observation provides new clues about the involvement of immunologic mechanisms in epileptic disorders.

Antimitochondrial antibodies in patients with epilepsy

Immune mechanisms have been implicated in the pathogenesis of epilepsy. An increased prevalence of autoantibodies, as well as changes in serum immunoglobulin concentrations, has been reported in patients with epilepsy. The presence of unspecific antimitochondrial antibodies (AMAs) and their possible associations with other immunological markers were evaluated in a cohort of 1386 adult patients with epilepsy and population-based reference subjects. Unspecific AMAs were more frequent in epilepsy patients than in the reference group. Thirty-seven epilepsy patients (3.9%) and eleven control subjects (1.9%) had unspecific AMAs (RR 2.1, CI 1.05-4.1, P=0.03). These antibodies were associated with long duration of epilepsy and old age at the onset of epilepsy among patients with epilepsy. Their presence was independent of other immunological markers, comorbidity, and epilepsy medications.

Antibodies and clinical features of the antiphospholipid syndrome as criteria for systemic lupus erythematosus

The antiphospholipid syndrome (APS) can occur as a primary diagnosis or as a prominent feature of other diseases, predominantly systemic lupus erythematosus (SLE). The 1982 revised criteria for SLE were published prior to many of the studies which have illuminated current understanding of the antiphospholipid syndrome and several current clinical criteria for SLE, when arising from thrombotic damage to different organ systems, could be attributed to APS, leading to some confusion about where the diagnoses of these two disorders should begin and end. Additionally, APS is a significant generalized risk factor for irreversible organ damage and overall mortality in SLE patients and genetic linkages to HLA in APS hold up whether the disorder is primary or linked to SLE. It is increasingly recognized that APS itself is a complex, heterogenous disorder, involving a spectrum of autoantibodies to phospholipid-binding proteins, many of which have known coagulation-regulating functions. Although the combination of more than one antiphospholipid-related antibody might indicate a more severe phenotype, it is not suggested here that additive criteria for the diagnosis of SLE be accumulated with more than one of these pathologically related autoantibodies. Patients with multiple criteria for APS should be considered to have severe APS but it would be recommended to restrict APS-attributed criteria for SLE to a maximal of two: one immunologic and one clinical. Thus people meeting the Sapporo criteria for APS could gain only a maximum of two criteria for SLE, regardless of how many autoantibodies were detected or how severe the clinical syndrome might be. This would allow manifestations of fullblown APS an appropriate impact towards the diagnosis of SLE without leading to a premature diagnosis of SLE for people who might better be considered to have moderate to severe primary APS.

Serum IgA, IgG, and IgM concentrations in patients with epilepsy and matched controls: a cohort-based cross-sectional study

Conflicting reports have been published on serum immunoglobulin (Ig) concentrations in patients with epilepsy. Serum IgA, IgG, and IgM concentrations were determined in a cohort of 958 patients and in a reference population of 581 subjects. Overall, 8.2% of patients with epilepsy and 1.9% of control subjects had low serum IgA concentrations. Low serum IgA levels were measured in 19.1% of patients currently on phenytoin therapy and in 11.9% of patients who had previously been treated with phenytoin, whereas only 3.8% of patients who had never been on phenytoin therapy had low serum IgA. In multivariate analysis low serum IgA concentrations were associated with phenytoin medication and female gender. No differences in serum IgG and IgM concentrations were observed between patients and control subjects. However, in patients with epilepsy, low serum IgG concentrations were associated with concomitant autoimmune diseases, and low IgM levels with older age at the onset of epilepsy, long duration of epilepsy, and autoimmune diseases. In conclusion, the prevalence of low serum IgA concentrations was increased in patients with epilepsy, but serum IgG and IgM concentrations were similar in patients with epilepsy and reference subjects. The low serum IgA concentrations were associated with phenytoin medication. In addition to current phenytoin medication, previous phenytoin therapy also was associated with low serum IgA concentrations. This implies that phenytoin medication may have permanent immunological effects in some patients.

Epilepsy and the immune system: is there a link?

The concept that the immune system plays a role in the epileptogenic process of some epileptic syndromes was first proposed more than 20 years ago. Since then, numerous studies have reported on the existence of a variety of immunological alterations in epileptic patients, on the observation of favourable responses of refractory epilepsy syndromes to immunomodulatory treatment, and on the association of certain well-known immune-mediated disease states with epilepsy. This review comprehensively recapitulates the currently available evidence supporting or arguing against the possible involvement of the immune system in the pathogenesis of certain types of epilepsy. It is concluded that an abundance of facts is in support of this concept and that further studies should be directed at substantiating the pathogenic significance of (auto)immune responses in certain types of epilepsy. Current progress in the functional and molecular immunological research techniques will indisputably contribute to the elucidation of this link.

Frequency of anticardiolipin, antinuclear and anti β2GP1 antibodies is not increased in unselected epileptic patients: a case-control study

In order to determine whether auto antibodies were restricted to some subtypes of epilepsy, we included 81 unselected epileptic patients and 81 controls, studied clinical data, EEG, neuroimaging, measured antinuclear (ANA), anticardiolipin (aCL) and beta2GP1 antibodies.

RESULTS

Epilepsy was active in 74 patients, generalised in 78 and partial in 9. Auto antibodies were positive at the same frequency and the same level among patients and controls (ANA+ 17% vs. 11%; aCL+ 4% vs. 7%; beta2GP1 antibodies+ 5% vs. 6%). There was no increased frequency of auto antibodies among subgroups of epileptic patients except ANA which were more frequent when patients had more than 10 seizures per year.

CONCLUSIONS

Positivity of ANA, aCL and beta2GP1 antibodies is not increased in all types of epilepsy and further studies are needed to determine exactly which kind of seizure is immune-mediated.

Anticardiolipin and antinuclear antibodies in epilepsy—a population-based cross-sectional study

Increased prevalence of autoantibodies has been suggested in patients with epilepsy. This study determined the presence of autoantibodies in a representative cohort of 960 patients with epilepsy. The frequency of antinuclear antibodies (ANA), immunoglobulin G class anticardiolipin antibodies (aCL) and anti-B2-glycoprotein I antibodies were studied in 960 consenting adult patients with epilepsy and in 580 population-based reference subjects identified from the Finnish Population Registry. Overall the frequencies of the autoantibodies studied did not differ between patients with epilepsy and reference subjects. aCL were present in 4.5% of the patients and in 5.0% of the reference subjects and 17% of both the patients and the reference subjects had antinuclear antibodies. However, patients with partial epilepsy for > or =30 years were three times more likely to have aCL than patients with partial epilepsy for <10 years. Patients with partial epilepsy and > or=1 seizure per month were 2.2 times more likely to have aCL than patients with partial epilepsy with <1 seizure per month. Moreover, ANA tended to be more frequent among patients with > or =1 seizure per month. No association was found between the major antiepileptic drugs and autoantibodies. Overall the frequencies of the autoantobodies studied were similar in the large epilepsy cohort and in matched reference subjects from the general population. However, a long duration of epilepsy and poor seizure control were associated with an increased presence of aCL in patients with partial epilepsy.

Immunologic aspects of West syndrome and evidence of plasma inhibitory effects on T cell function

STUDY OBJECTIVE: The purpose of this study was to assess the extent of immune dysfunction in a well-defined group of epileptic patients: children with diagnosis of West syndrome (WS) or with transitions to another age-related EEG patterns, the multifocal independent spikes (MIS), and the slow spike-wave complexes (Lennox-Gastaut syndrome - LGS). Thus, WS was studied at different points of the natural evolutive history of the disease. METHOD: A group of 50 patients (33 with WS, 10 with LGS and 7 with MIS) and 20 age-matched healthy controls were submitted to enumeration of T lymphocyte subsets: CD1, CD3, CD4, CD8, CD4/CD8 ratio and lymphocyte proliferation assay to phytohaemagglutinin (PHA), in the presence of autologous and AB, homologous plasma. Dinitrochlorobenzene (DNCB) skin test sensitization was performed only in patients. Determinations of IgG, IgA, and IgM serum levels were compared to standard values for Brazilian population in different age ranges. RESULTS: Sensitization to DNCB showed absent or low skin reactions in 76% of the patients. High levels of IgG (45.7%) and IgM (61.4%), and lower levels of IgA (23.9%) were detected in the serum of the patients. Enumeration of lymphocyte subsets in peripheral blood showed: low CD3+ (p<0.05), low CD4+ (p<0.05), high CD8+ (p<0.01) and low CD4+ / CD8+ ratio (p<0.001). The proportion of CD1+ cells in the control group was less than 3%, while ranged between 6 and 11 % in 18% of the patients. The in vitro PHA-induced T cell proliferation showed significantly low blastogenic indices only when patients, cells were cultured in presence of their own plasma. No differences in blastogenic indices were observed when the cells of patients and controls were cultured with human AB plasma. CONCLUSION: The immunodeficiency in WS was mainly characterized by anergy, impaired cell-mediated immunity, altered levels of immunoglobulins, presence of immature thymocytes in peripheral blood and functional impairment of T lymphocytes induced by plasma inhibitory factors.

Virological and immunological aspects of seizure disorders

The brain is a symptom-producing organ, and one of the symptoms due to a basic brain dysfunction is epilepsy. The pathophysiologic background is in most epilepsies multifactorial, as different pre-, peri-, and postnatal triggers or environmental conditions influence one or several genetic factors, where also gender is of importance. One of the genetic factors is immunodysfunction, and the trigger mechanism may be a virus infection. Viruses are the most common agents to which the human being is exposed throughout life. The herpes virus group is of special interest with respect to complications of the central nervous system. Herpes viruses, especially herpes simplex virus type 1 (HSV-1), human herpes virus type 6 (HHV-6), cytomegalovirus (CMV) and Epstein-Barr virus (EBV), are capable of establishing latent infection and reactivating under a variety of stimuli. In this review especially HHV-6 will be emphasized, as well as CMV in relation to Rasmussen's syndrome. The immunological aspects will focus on immunoglobulins, antibodies, especially the glutamate receptors, human leukocyte antigens, T- and B-lymphocytes, and their respective interaction with the antigen presenting cell. This course of events concerns the 'immunological synapse'. Finally, reports on herpes virus genomes in the human brain are discussed. A study on herpes viral DNA in brain tissue from patients operated for focal epilepsy is briefly mentioned.