Antiphospholipid antibodies permeabilize and depolarize brain synaptoneurosomes

Genetic and immunological factors interact in a mouse model of CNS antiphospholipid syndrome

The antiphospholipid syndrome (APS) includes systemic and central nervous system (CNS) pathology associated with antibodies to a complex of phospholipids and beta(2)-glycoprotein I (beta(2)-GPI). We have recently reported the induction of APS associated with behavioral and cognitive deficits in BALB/c female mice that developed 4-5 months after immunization with beta(2)-GPI. In the present study, we examined the influence of genetic factors on the ability to induce experimental APS with CNS involvement by testing several mouse strains immunized with beta(2)-GPI. Female mice from five strains were immunized once with beta(2)-GPI in complete Freund's adjuvant (CFA) or with CFA alone (controls). Autoantibody levels were examined at 1 and 5 months after immunization. Neurological assessment in a staircase test was performed 4-5 months following the immunization. Induction of APS resulted in elevated levels of antibodies against negatively charged phospholipids and beta(2)-GPI in all five mouse strains. Autoantibody levels were significantly higher in Balb/c, ICR, and C57BL/6 mouse strains compared to AKR and C3H. aPL levels dropped significantly more in the C57BL/6 compared to Balb/c mice over a period of 4 months. Hyperactivity reflected by higher number of stairs climbed in 3 min, was induced by APS in the Balb/c and ICR, mouse strains. Exploratory behavior reflected by more frequent rears, was seen in the APS-Balb/c and AKR mice. Hypoactivity and less exploration were seen in the APS-C57BL/6 and C3H mice. The study supports a link between high levels of aPL and behavioral changes in a mouse APS model. Qualitative differences in behavioral patterns may be due to nervous system as well as immune genetic factors. The minimal effect of APS in C57BL/6 mice may provide a suitable background for the study of transgenes in these mice.

Antiphospholipid antibodies bind ATP: a putative mechanism for the pathogenesis of neuronal dysfunction

Antiphospholipid antibodies (aPL) generated in experimental animals cross-react with ATP. We therefore examined the possibility that aPL IgG from human subjects bind to ATP by affinity column and an enzyme linked immunosorbent assay (ELISA). Sera with high levels of aPL IgG were collected from 12 patients with the antiphospholipid syndrome (APS). IgG fractions from 10 of 12 APS patients contained aPL that could be affinity-bound to an ATP column and completely eluted with NaCl 0.5 M. A significant (>50%) inhibition of aPL IgG binding by ATP 5 mM was found in the majority. Similar inhibition was obtained with ADP but not with AMP or cAMP. All the affinity purified anti-ATP antibodies also bound β₂-glycoprotein-I (β₂-GPI, also known as apolipoprotein H) suggesting that, similar to most pathogenic aPL, their binding depends on this serum cofactor. We further investigated this possibility and found that the binding of β₂-GPI to the ATP column was similar to that of aPL IgG in that most was reversed by NaCl 0.5 M. Furthermore, addition of β₂-GPI to aPL IgG significantly increased the amount of aPL binding to an ATP column. We conclude that aPL IgG bind ATP, probably through β₂-GPI. This binding could interfere with the normal extracellular function of ATP and similar neurotransmitters.

Predictive role of hs-C-reactive protein in patients with antiphospholipid syndrome

High-sensitive C-reactive protein (hs-CRP) is a marker of inflammation which has been shown in several prospective studies to independently predict myocardial infarction, stroke and peripheral artery disease. Patients with antiphospholipid antibodies (aPL) are at increased risk of recurrent thromboembolic events, but the possibility of predicting this risk seems rather limited. Similarities were recently found between aPL and CRP in the pathology of thrombosis. The current study investigated the predictive role of hs-CRP in a cohort of patients with neurological manifestations. A follow-up investigation was done in a cohort of 55 aPL-positive patients with acute manifestations of neurological disease. hs-CRP levels were measured in all patients at enrollment and were compared to the patients' condition after a median period of 32 months. Lupus anticoagulants were detected according to the Standardization of Lupus Anticoagulants (SSC) of the ISTH. Anticardiolipin tests were performed by a beta2-glycoprotein I-dependent enzyme-linked immunsorbent assay (Pharmacia ELISA). hs-CRP was measured by latex-enhanced turbidometry (dimension RXL, Dade Behring). Cerebral infarctions and transient ischemic attacks were the most frequent cerebral events. In patients with aPL, elevated levels of hs-CRP were closely associated with an increased rate of recurrent or residual symptoms (OR, 12.5; 95% CI, 3.72-41.94) and were not related to other risk factors, except smoking (p<0.05). The rate at which a given patient's condition deteriorated was also related to the level of hs-CRP. In patients with antiphospholipid syndrome (APS), elevated levels of hs-CRP may identify a group of patients which is at high risk of recurrent or residual neurological symptoms and which may benefit from more careful follow-up and from antithrombotic therapy.

Management of neuropsychiatric lupus

Nervous system disease in systemic lupus erythematosus (SLE) is manifested by a wide variety of clinical manifestations. Despite the development of a universal classification for neuropsychiatric (NP) lupus in 1999, there continues to be considerable variability in the reported prevalence of NP syndromes between different lupus cohorts. Due to the lack of specificity of individual NP manifestations, non-SLE causes such as complications of therapy and co-morbidities must be considered in advance of attributing the event to one or more primary immunopathogenic mechanisms. These include intracranial microangiopathy, autoantibodies to neuronal and non-neuronal antigens, and the generation of proinflammatory cytokines and mediators. The diagnosis of NP-SLE remains largely one of exclusion and is approached in individual patients by thorough clinical evaluation, supported when necessary by autoantibody profiles, diagnostic imaging, electrophysiologic studies and objective assessment of cognitive performance. Given the diversity in clinical manifestations, the management is tailored to the specific needs of individual patients. In the absence of controlled studies, the use of symptomatic therapies, immunosuppressives, anticoagulants and non-pharmacologic interventions is supported by case series and clinical experience.

Evoked potential studies in the antiphospholipid syndrome: differential diagnosis from multiple sclerosis

BACKGROUND

The CNS manifestations of the antiphospholipid syndrome (APS) can mimic multiple sclerosis both clinically and radiologically.

OBJECTIVE

To compare evoked potential studies in APS patients and patients with multiple sclerosis with similar neurological disability.

METHODS

30 APS patients with CNS manifestations and 33 patients with definite multiple sclerosis and similar neurological disability underwent studies of visual evoked potentials (VEP), somatosensory evoked potentials (SSEP) in the upper and lower limbs (UL, LL), and sympathetic skin responses (SSR) in the upper and lower limbs.

RESULTS

The neurological manifestations in the APS patients included stroke (n = 17), transient ischaemic attacks (n = 10), and severe headache with multiple white matter lesions on brain MRI (n = 3). Abnormal SSEP (LL), and SSR (UL; LL) were seen in APS patients (37%, 27%, and 30%, respectively) but VEP and UL SSEP were rarely abnormal (10% and 6%, respectively in APS v 58% and 33% in multiple sclerosis; p = 0.0005, p = 0.008). Mean VEP latencies were more prolonged in multiple sclerosis (116 ms v 101 ms, p<0.001). Only one APS patient had abnormal findings in all three evoked potential studies, compared with seven patients in the multiple sclerosis group (p = 0.04)

CONCLUSIONS

Abnormal VEPs are uncommon in APS in contrast to multiple sclerosis. Coexisting abnormalities in all other evoked potentials were similarly rare in APS. In patients with brain MRI findings compatible either with multiple sclerosis or APS, normal evoked potential tests, and especially a normal VEP, may support the diagnosis of APS.

Antiphospholipid Syndrome: Review

Antiphospholipid syndrome spans many medical disciplines. Classic criteria include the presence of anticardiolipin antibody or lupus anticoagulant with typical complications of thrombosis or pregnancy loss. Other common associated manifestations include livedo reticularis, thrombocytopenia, valvular heart disease, and nephropathy with renal insufficiency, hypertension, and proteinuria. Treatment of serious complications with anticoagulation is standard; generally warfarin for thrombosis and aspirin/heparin for pregnancy prophylaxis. Detailed recommendations regarding precise intensity and duration of anticoagulation are still a subject of debate.

Neuropsychiatric Lupus

Nervous system disease in patients who have systemic lupus erythematosus (SLE) spans a wide spectrum of neurologic (N) and psychiatric (P) features that may be attributed to a primary manifestation of SLE, complications of the disease or its therapy, or a coincidental disease process. The etiology of primary NP disease is multifactorial and includes vascular injury of intracranial vessels, autoantibodies to neuronal antigens, ribosomes and phospholipid-associated proteins, and the intracranial generation of cytokines. In the absence of a diagnostic gold standard for most of the NP-SLE syndromes, a range of investigations are employed to support the clinical diagnosis and determine the severity of NP disease. Treatment remains largely empiric in the absence of controlled studies, and current strategies include the use of immunosuppressive therapies, appropriate symptomatic interventions, and the treatment of non-SLE factors.

Prevalence of antiphospholipid antibodies in patients with neurological symptoms

OBJECTIVE AND PURPOSE

Neurological involvement is a common feature of the antiphospholipid syndrome (APS). A variety of thrombotic and non-thrombotic manifestations may accompany the presence of antiphospholipid antibodies (aPL).

PATIENTS AND METHODS

We retrospectively reviewed the prevalence of aPL in a cohort of over 350 unselected patients from a neurological clinic and studied the neurological manifestations of APS.

RESULTS

We found that within this cohort the prevalence of aPL was about 15%. Most of the patients with aPL suffered from strokes and transient ischemic attacks (TIA). One patient died from spinal infarction. Non-thrombotic manifestations also occurred in 40% of these patients, such as multiple sclerosis, chorea, seizures or cerebral malignancies. No significant correlations of the titres or different types of aPL and the type of the neurological symptoms could be found. In comparison to age and sex matched patients of the cohort where the presence of aPL could be excluded, the occurrence of non-thrombotic manifestations was significantly more frequent and varied in the group of patients with aPL. The higher incidence of stroke in the non-APS group could be explained by the significantly higher presence of other laboratory risk factors, mainly hypercholesterinemia.

CONCLUSION

This investigation indicates that aPL may play an important role in the etiology of various neurological syndromes.

Budding, vesiculation and permeabilization of phospholipid membranes—evidence for a feasible physiologic role of β2-glycoprotein I and pathogenic actions of anti-β2-glycoprotein I antibodies

The in vivo physiologic role of beta2-glycoprotein I (beta2GPI) is presumed to be related to its interactions with negatively charged phospholipid membranes. Increased quantities of procoagulant microparticles derived by the vesiculation of blood cells have been detected in patients with antiphospholipid syndrome (APS) frequently associated with antibodies against beta2GPI (anti-beta2GPI). We investigated the influence of beta2GPI and anti-beta2GPI on giant phospholipid vesicles (GPVs). GPVs composed of phosphatidylserine and phosphatidylcholine were formed in an aqueous medium and individually transferred to a compartment containing either beta2GPI, anti-beta2GPI, or beta2GPI along with anti-beta2GPI. Shape changes of a single GPV were observed by a phase contrast microscope. Most GPVs transferred to the solution containing only beta2GPI budded moderately. Upon the transfer of GPVs to the solution containing beta2GPI and anti-beta2GPI either from patient with APS or mouse monoclonal anti-beta2GPI Cof-22, the budding was much more pronounced, generating also daughter vesicles. No such effects were seen when GPV was transferred to the solution containing anti-beta2GPI without beta2GPI. Our results suggest a significant physiologic role of beta2GPI in the budding of phospholipid membranes, which may be explained by the insertion of the C-terminal loop of beta2GPI into membranes, thus increasing the surface of the outer layer of a phospholipid bilayer. Anti-beta2GPI, recognizing domains I to IV of beta2GPI, enhanced the budding and vesiculation of GPVs in the presence of beta2GPI. This might be a novel pathogenic mechanism of anti-beta2GPI, promoting in vivo the expression of proadhesive and procoagulant phospholipid surfaces in APS.

Close association between valvar heart disease and central nervous system manifestations in the antiphospholipid syndrome

BACKGROUND

Heart valves lesions and central nervous system involvement are among the most common manifestations of the antiphospholipid syndrome (APS).

OBJECTIVE

To evaluate possible interrelations between these manifestations in a large group of APS patients.

METHODS

284 APS patients were evaluated retrospectively, 159 of whom had primary APS. Cardiac-CNS associations were determined for the entire study population, and for subgroups of patients with primary APS or APS associated with systemic lupus erythematosus (SLE).

RESULTS

Significant associations where found between cardiac vegetations and epilepsy (p < 0.02), and between cardiac valve thickening or dysfunction and migraine (p = 0.002). Borderline association was found between valvar vegetations and migraine (p = 0.09). A significant association was also found between all valvar lesions and stroke or transient ischaemic attacks. Subanalyses showed that patients with primary APS had significant associations between cardiac valve pathology and all CNS manifestations, while patients with APS associated with SLE had no such associations.

CONCLUSIONS

The study suggests potential differences in biological behaviour between primary APS and APS associated with SLE. The presence of cardiac valve pathology may be a risk factor for several types of CNS involvement in PAPS.

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.

The antiphospholipid (Hughes') syndrome: changing the face of neurology

Hughes' syndrome (the antiphospholipid syndrome (APS)) presents with recurrent thrombosis, recurrent miscarriage and neurological disease. The major pathogenic mechanism of the syndrome is vascular obstruction (both venous and arterial) due to hypercoagulability. Neurological manifestations are prominent and are often the dominant feature. Headache, migraine and cognitive dysfunction are common while other manifestations such as dementia, epilepsy, chorea, multiple sclerosis (MS), psychiatric disease, transverse myelitis, ocular syndromes, sensorineural hearing loss and movement disorders are also associated with the syndrome. Anticoagulation therapy (either aspirin or oral anticoagulants) can lead to significant improvement.

Non-stroke neurological syndromes associated with antiphospholipid antibodies: evaluation of clinical and experimental studies

Although many types of neurological disorders and events have been described in association with antiphospholipid antibodies (aPL) and the antiphospholipid syndrome (APS), only ischaemic stroke is reasonably well established and accepted as a diagnostic criterion for the syndrome. We propose to evaluate, classify and rank the association of other neurological manifestations as possible, probable, or definite according to the data available from clinical studies and animal models. By these criteria, none of the neurological disorders or events such as epilepsy, psychiatric disease, dementia, transverse myelitis, multiple sclerosis-like disease, chorea, migraine, Guillian-Barrè syndrome, and sensory-neural hearing loss, can be definitely associated with aPL or APS.

Neuronal-binding antibodies from patients with antiphospholipid syndrome induce cognitive deficits following intrathecal passive transfer

Antiphospholipid antibodies (aPL) have been suggested to play a role in causing cognitive and behavioral impairments. In the present study we investigated the pathogenic potential of aPL by intracerebro-ventricular (ICV) administration of immunoglobulins (IgG) from patients with antiphospholipid syndrome (APS). IgG, purified from the sera of four APS patients, was tested for binding to normal mouse brain by immunohistological staining. These IgG (7.5 microg) were injected ICV unilaterally to male C3H mice. Mice injected with IgG purified from pooled sera derived from healthy subjects served as controls. The mice were examined neurologically for motor function and coordination, and cognitively in a Morris water maze. The cognitive tests were performed with the experimenter blinded to the treatment. The performance of the mice in four separate experiments was compared by analysis of variance with repeated measures. IgG from one APS patient was found to bind best to neuronal structures in the hippocampus and cerebral cortex. Mice (n = 43) injected with this IgG performed worse in the water maze compared to the controls (n = 45) with significant effects of the aPL IgG on the overall performance of the mice (treatment, P < 0.03), on learning throughout the experiment (treatment x day, P < 0.02) and on short term memory (treatment x day xtrial, P < 0.002). IgG injected from two of the three other patients also bound specifically to mouse brain neurons and produced an impairment in performance of the water maze. These results support the hypothesis that aPL that gain access to the central nervous system may play a direct role in the pathogenesis of neurological manifestations of APS.

Behavioral and cognitive deficits occur only after prolonged exposure of mice to antiphospholipid antibodies

The antiphospholipid (Hughes) syndrome (APS) includes systemic and central nervous system (CNS) pathology associated with antibodies to a complex of phospholipids and beta2-glycoprotein I (beta2-GPI). Beta2-GPI immunized mice develop systemic manifestations of APS and we presently examined CNS manifestations in this APS model. Female BALB/c mice were immunized once with beta2-GPI in complete Freund's adjuvant (CFA) or with CFA alone (controls). A staircase test and a T-maze alternation test were performed to test behavior and cognition in independent groups of mice 6, 12 and 18 weeks following the immunization. The APS mice developed elevated levels of antibodies against negatively charged phospholipids and beta2-GPI. Neurological impairment was detected only 18 weeks after the induction of the APS and consisted of both cognitive (53 +/- 4 vs 71 +/- 3% correct choices in the T-maze alternation for APS vs control mice, P < 0.001) and behavioral changes (higher number of rears (18 +/- 2 vs 11 +/- 1, P < 0.006) and higher number of stairs climbed (12 +/- 2 vs 7 +/- 1, P < 0.02). This is the first report of cognitive deficits in this APS model and demonstrates the time course for the development of previously described behavioral changes. The mechanism involved in these CNS manifestations remains to be elucidated.

Prevalence and clinical features of dementia associated with the antiphospholipid syndrome and circulating anticoagulants

The increasing prevalence with age of antiphospholipid antibodies (aPL), of dementia and of stroke complicates the study of a causal relationship between antiphospholipid syndrome (APS) and dementia. Prolonged aPTT due to circulating anticoagulants (CAC) may serve as a more specific laboratory marker of APS. In a hospital-based study, we examined all patients with CAC and included 23 who fulfilled standard criteria for primary APS. These patients were assessed for dementia, vascular brain disease, autoimmune disease activity and dementia risk factors. Among CAC-positive APS patients, 13 of the 23 (56%) were demented and these were significantly older (mean age+/-S.E., 68+/-3 years) than the nondemented APS group (n=10, 51+/-4 years; p<0.01, Student's t-test). The demented patients had significantly more pathology on computerized brain tomography (CT) and electroencephalography (EEG) studies but six of them had no clinical or CT evidence of vascular brain disease. Erythrocyte sedimentation rate was significantly lower in the dementia group, in which there was also a significant negative correlation between levels of aPL and age. CAC-positive APS patients seem to be at risk for developing dementia with age, suggesting a pathogenic role for prolonged exposure to elevated aPL.

Neurological and neuroendocrine-cytokine inter-relationship in the antiphospholipid syndrome

Although many neurological deficits have been described in the antiphospholipid syndrome (APS), only stroke is well established and accepted as a diagnostic criterion in the disease. We presently review clinical data obtained from large series of cases regarding stroke, dementia, epilepsy, chorea, migraine, white-matter disease, and behavioral changes in APS, or linked-to-laboratory criteria such as antiphospholipid antibodies (aPL). The contribution of animal models to our understanding of these manifestations of APS is stressed, especially regarding the cognitive and behavioral aspects for which we have established model systems in the mouse. These models utilize immunization of mice with beta(2)-glycoprotein1, a central autoantigen in APS, which induces persistent high levels of aPLs. These mice develop hyperactive behavior after a period of four months, as well as deficits in learning and memory, and are potentially valuable as a system in which to study the pathogenesis and treatment of cognitive and behavioral aspects of APS. We have developed another model, in which IgGs from APS patients induce depolarization of brain synaptoneurosomes, and which may serve as a model for the pathogenesis of epilepsy in APS. Hormonal changes are another potential CNS manifestation of APS and this may be potentially linked to the systemic and central effects of cytokines such as interleukin-3. Better understanding of the link between APS and neurological or neuroendocrine manifestations other than stroke will reveal whether they can be used as clinical criteria for the diagnosis of APS and, it is hoped, lead to better treatment.

Epilepsy associated with lupus anticoagulant

INTRODUCTION

Lupus anticoagulant (LA) is commonly present in patients with systemic lupus erythematosus (SLE) who present with an ischemic cerebral stroke. Reports have noted the presence of LA in patients with epilepsy who do not have SLE. These patients are usually elderly, and it has been postulated that their epilepsy is due to subclinical ischemic infarcts.

METHODS

Two cases are presented in young patients (age < 35 years) who developed epileptic seizures and were LA positive. These patients did not have SLE or have cerebral infarcts that could explain the presence of their seizures.

RESULTS

A 28-year-old woman was admitted for aortic insufficiency and new onset seizures. The clinical history, physical examination and magnetic resonance imaging did not reveal an antecedent cortical ischemic event. Serological testing revealed the presence of LA. The second patient was a 33-year-old man with medically intractable epilepsy in whom serological testing revealed the presence of LA. The clinical history, physical examination, and MRI did not reveal any evidence of an antecedent ischemic event. Neither patient had SLE.

CONCLUSIONS

In young patients without SLE and cerebral infarcts, LA may be associated with epileptic seizures.

Neuropsychiatric lupus

Neuropsychiatric (NP) manifestations of systemic lupus erythematosus (SLE) have been recognized for more than 100 years but continue to pose a diagnostic and therapeutic challenge for rheumatologists and other physicians involved in the care of SLE patients. NP-SLE includes a plethora of clinical manifestations and the reported prevalence has varied widely between 14% and 75%. The recent introduction of a standard nomenclature, case definitions, and diagnostic criteria for 19 NP-SLE syndromes should facilitate a more consistent approach to the classification of patients and to the execution of large multicenter clinical studies. The etiology of NP-SLE is likely multifactorial and includes microangiopathy, autoantibody production, and the intrathecal production of proinflammatory cytokines. Newer imaging modalities of brain structure and function provide novel ways of understanding pathogenic mechanisms. The use of standardized neuropsychometric techniques to evaluate cognitive function has identified a high prevalence of cognitive impairment in SLE patients. The management of patients with NP-SLE includes symptomatic and immunosuppressive therapies, evidence for which is largely limited to uncontrolled clinical trials and anecdotal experience. Multicenter initiatives are required to address important issues on prognosis and management.

Prevalence of anti-cardiolipin, anti-beta2 glycoprotein I, and anti-prothrombin antibodies in young patients with epilepsy

PURPOSE

To measure anti-cardiolipin (aCL), anti-beta2 glycoprotein I (anti-beta2GPI), and anti-prothrombin (aPT) antibodies in young patients with epilepsy, and to correlate their presence with demographic data, clinical diagnoses, laboratory and neuroradiologic findings, and antiepileptic drugs (AEDs).

METHODS

Sera from one hundred forty-two consecutive patients with epilepsy with a median age of 10 years were tested for aCL and anti-beta2GPI autoantibodies by solid-phase assays. aPT antibodies also were assayed in sera from 90 patients. Positive results were confirmed after a minimum of 6 weeks. Antinuclear antibodies (ANAs) and antibodies against extractable nuclear antigens (ENAs) also were tested.

RESULTS

An overall positivity of 41 (28.8%) of 142 sera was found. Fifteen patients were positive for aCL, 25 for anti-beta2GPI, and 18 for aPT antibodies. Several patients (12%) displayed more than one specificity in their serum. Only one of these patients had a concurrent positivity for ANAs and ENAs. A predominance of younger patients was found in the antibody-positive group. All types of epilepsy were represented in the positive group. No relation between antibody positivity and AEDs was found. Diffuse ischemic lesions at computed tomography (CT)/magnetic resonance imaging (MRI) scans were present in higher percentages in patients who were antibody positive. No positive patient had a history of previous thrombosis or other features related to systemic lupus erythematosus (SLE), and no patient was born of a mother with SLE.

CONCLUSIONS

Our study suggests a relation between epilepsy and aPL in young patients. A pathogenetic role for these autoantibodies cannot be excluded, and their determination might prove useful even from a therapeutic point of view.

Hughes (antiphospholipid) syndrome. Clinical features

Hughes (antiphospholipid) syndrome is a noninflammatory autoimmune disease. The most critical pathologic process is thrombosis, which results in most of the clinical features suffered by these patients. Recurrent thrombosis together with an adverse pregnancy history and the presence of antiphospholipid antibodies defines the syndrome.

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

Evidence of immune system aberrations in patients with epilepsy includes antiphospholipid antibody positivity in adult patients with epilepsy with a prevalence of 19-26% and in 13% of children with partial epilepsy. Also immunoglobulin A deficiency has been reported to exist in up to 25% of epilepsy patients. The possible role of immune mechanisms in the pathogenesis of childhood epilepsy is clinically supported by the effectiveness of immunomodulatory treatments in cases with catastrophic childhood epilepsies. We analyzed a set of various autoantibodies in 50 consecutive children with epilepsy and in 20 healthy control subjects. None of the children had any clinical signs of immune system disorders. The main result was a significantly (P=0.011) higher prevalence of antiphospholipid antibodies in the study group (44%) compared with controls (10%). These antibodies were unexpectedly common (71-80%) in children with multiple seizure types associated often with symptomatic etiology, early onset and high frequency of seizures. There was no evidence of the antiphospholipid positivity being induced by certain AEDs (e.g. phenytoin or carbamazepine). Even though the significance of these autoantibodies remains unknown, their increased prevalence indicates that immune system mediated mechanisms may have a role in the manifestation of epilepsy in some children.

Prevalence of positive anticardiolipin antibody in benign infantile convulsion

We report six anticardiolipin antibody (aCL)-positive cases among 18 children with epilepsy showing various seizure types in our initial study. These six cases revealed normal coagulation tests. As three of these six cases involved benign infantile convulsion (BIC), we further investigated the high frequency of positive aCL-Immunoglobulin (Ig) G in BIC in our subsequent study of nine cases that included three cases from the previous study and an additional six BIC cases followed and/or diagnosed by co-author (T.K.). As a result, eight of nine BIC cases were positive for aCL-IgG and the values of aCL-IgG decreased over long-term observation in three of these cases. The frequency of positivity for aCL-IgG in BIC was obviously higher than that of controls. Based on these results, we suggest that some immunological responses may be responsible for the pathogenesis of BIC.

Increased levels of proinflammatory cytokines and nitric oxide metabolites in neuropsychiatric lupus erythematosus

OBJECTIVE

To investigate systemic and intrathecal production of proinflammatory cytokines in relation to cerebrospinal fluid (CSF) nitric oxide (NO) release in patients with neuropsychiatric lupus erythematosus (NPLE).

METHODS

Thirty patients with NPLE rated as mild, moderate, or severe were studied and CSF was obtained from 21 of these. Cytokine mRNA expressing cells were detected by in situ hybridisation. Soluble cytokines were assessed by enzyme linked immunosorbent assay (ELISA). Nitrite and nitrate were determined by capillary electrophoresis.

RESULTS

Patients with NPLE had high numbers of lymphocytes expressing mRNA for tumour necrosis factor alpha (TNFalpha), interferon gamma, and interleukin 10 in blood. The number of peripheral blood TNFalpha mRNA positive cells correlated strongly with the level of NO metabolites in the CSF (r(2)=0.69). Both the number of peripheral blood mononuclear cells expressing mRNA for TNFalpha as well as the CSF level of NO metabolites correlated with NPLE disease severity.

CONCLUSION

These data suggest that increased peripheral production of proinflammatory cytokines such as TNFalpha may contribute both to an increased production of NO in the central nervous system and to generation of clinical NPLE. The data also support the possibility that measurements of NO metabolites in CSF may be of value in the diagnosis of neurological symptoms related to SLE.

Differential diagnosis of central nervous system manifestations of the antiphospholipid antibody syndrome

Anti-phospholipid antibodies (aPL) have been associated with a variety of neurologic manifestations. The evidence for an association between aPL and most of these is weak because (1) no association actually exists, (2) the manifestation is rare or (3) sufficiently powered studies have not been performed. The only neurologic manifestation that is considered to have sufficient evidence to justify it being a part of the criteria for the diagnosis of Anti-phospholipid Antibody Syndrome (APS) is cerebral ischemia. In this mini-review, most of the neurologic syndromes with an actual or suspected association with aPL are considered. The role of aPL in the differential diagnosis of these syndromes is considered as well.

Antiphospholipid syndrome: insights from animal models

Animal models of the relatively new antiphospholipid syndrome (APS) enabled researchers to understand disease pathogenesis and to test novel experimental therapeutic modalities. Animal models of APS include spontaneous genetic models and experimental induced models. The latter test more reliably the pathogenicity of antiphospholipid antibodies because the syndrome is induced in normal mice rather than being secondary to a preexisting autoimmune disease. Reports about animal models of APS in the recent year provide new insights into the pathogenesis of antiphospholipid antibodies and beta2-glycoprotein-I in reproductive failure, neurologic manifestations, thrombosis, and atherosclerosis. In addition, novel therapies that were successful in experimental APS included anti-idiotypes, oral tolerance, and specific peptides that bind to beta2-glycoprotein-I. Animal models provide the first step in development of novel therapies for patients with APS.