Endothelium and the brain in CNS lupus

Posterior reversible encephalopathy syndrome: another manifestation of CNS SLE?

A variety of neuropsychiatric findings may complicate systemic lupus erythematosus (SLE) and pose diagnostic and therapeutic dilemmas. We describe the clinical and radiographic features of posterior reversible encephalopathy syndrome (PRES) and distinguish PRES from other conditions seen in SLE. Patient charts and magnetic resonance imaging (MRI) findings of four patients with SLE on immunosuppressive therapy with acute or subacute neurologic changes initially suggesting cerebritis or stroke were reviewed. The English language literature was reviewed using the Medline databases from 1996-2006 for other reports of PRES with SLE. Literature review yielded 26 other SLE cases reported with PRES. SLE patients with PRES were more commonly on immunosuppressive drugs, had episodes of relative hypertension, and had renal involvement. Characteristic findings are seen on MRI, which differentiate PRES from other CNS complications of SLE. Clinical and radiographic resolution of abnormalities within 1-4 weeks is typically seen. PRES has been increasingly recognized. Reversible changes are found on brain MRI accompanied by sometimes dramatic signs and symptoms. The therapeutic implications for separating PRES from stroke or cerebritis are important. We propose that PRES should be considered in the differential diagnosis in SLE patients with new-onset neurologic signs and symptoms.

Assessment of cerebral blood volume in schizophrenia: A magnetic resonance imaging study

Brain atrophy has consistently been observed in schizophrenia, representing a 'gross' evidence of anatomical abnormalities. Reduced cerebral blood volume (CBV) may accompany brain size decrement in schizophrenia, as suggested by prior small SPECT studies. In this study, we non-invasively investigated the hemisphere CBV in a large sample of patients suffering from schizophrenia with perfusion-weighted imaging (PWI). PWI images were obtained, following intravenous injection of paramagnetic contrast agent (Gadolinium-DTPA), for 54 DSM-IV patients with schizophrenia (mean age+/-SD=39.19+/-12.20 years; 34 males, 20 females) and 24 normal controls (mean age+/-SD=44.63+/-10.43 years; 9 males, 15 females) with a 1.5T Siemens magnet using an echo-planar sequence (TR=2160 ms, TE=47 ms, slice thickness=5mm). The contrast of enhancement (CE), a semi-quantitative parameter inversely estimating the CBV, were calculated pixel by pixel as the ratio of the maximum signal intensity drop during the passage of contrast agent (Sm) by the baseline pre-bolus signal intensity (So) (CE=Sm/Sox100) for right and left hemisphere on two axial images. Specifically, higher CE values correspond to lower CBV and viceversa Compared to normal controls, patients with schizophrenia had significantly higher bilateral hemisphere CE values (p=0.02) and inverse CE laterality index (p=0.02). This study showed abnormally reduced and inverse hemisphere CBV in a large population of patients with schizophrenia. Hypothetically, chronic low CBV may sustain neural hypoactivation and concomitant increase of free radicals, ultimately resulting in neuronal loss and cognitive impairments. Thus, altered intracranial hemodynamics may accompany brain atrophy and cognitive deficits, being a crucial factor in the pathophysiology of schizophrenia.

Comparison of the clinical manifestations, brain MRI and prognosis between neuroBeçhet's disease and neuropsychiatric lupus

BACKGROUND

Neuropsychiatric systemic lupus erythematosus (NPSLE) shows some similarities to neuroBeçhet disease (NBD) in that both conditions have some analogous clinical features and they are both pathologically associated cerebral vasculopathy. This study compared the clinical manifestations, brain MRI findings and prognosis of NPSLE and NBD patients.

METHODS

Forty three patients with NPSLE (n = 25) or NBD (n = 18), who were monitored at a single center, were enrolled in this study. We retrospectively analyzed the clinical and brain MRI data. The neuropsychiatric manifestations were classified in both groups according to the new American College of Rheumatology nomenclature for NPSLE.

RESULTS

The diffuse symptoms that included mood disorders, psychosis, confusion, cognitive dysfunctions, generalized seizures and headaches other than migraine or cluster headaches were more commonly observed in the NPSLE patients, while the frequency of focal diseases such as cranial neuropathy tended to be higher in the NBD patients. The brain MRI revealed that the NBD patients had more abnormalities in the brain stem than did the NPSLE patients. Most of the patients improved, at least partially, after being treated with glucocorticoid and/or immune suppressants. However, the disease course differed significantly between the two groups. There were more episodic cases in the NPSLE group of patients, while there were more remittent cases in the NBD group of patients.

CONCLUSION

NPSLE had a tendency to cause diffuse neuropsychiatric manifestations, and it has a different predilection of brain lesions compared with NBD. The NBD patients showed a poorer outcome than did the NPSLE patients, suggesting that different therapeutic strategies for the two diseases need to be considered.

Neuroimmunopathology in a murine model of neuropsychiatric lupus

Animal models are extremely useful tools in defining pathogenesis and treatment of human disease. For many years researchers believed that structural damage to the brain of neuropsychiatric (NP) patients lead to abnormal mental function, but this possibility was not extensively explored until recently. Imaging studies of NP-systemic lupus erythematosus (SLE) support the notion that brain cell death accounts for the emergence of neurologic and psychiatric symptoms, and evidence suggests that it is an autoimmunity-induced brain disorder characterized by profound metabolic alterations and progressive neuronal loss. While there are a number of murine models of SLE, this article reviews recent literature on the immunological connections to neurodegeneration and behavioral dysfunction in the Fas-deficient MRL model of NP-SLE. Probable links between spontaneous peripheral immune activation, the subsequent central autoimmune/inflammatory responses in MRL/MpJ-Tnfrsf6(lpr) (MRL-lpr) mice and the sequential mode of events leading to Fas-independent neurodegenerative autoimmune-induced encephalitis will be reviewed. The role of hormones, alternative mechanisms of cell death, the impact of central dopaminergic degeneration on behavior, and germinal layer lesions on developmental/regenerative capacity of MRL-lpr brains will also be explored. This model can provide direction for future therapeutic interventions in patients with this complex neuroimmunological syndrome.

Pathogenic mechanisms of anti-endothelial cell antibodies (AECA): their prevalence and clinical relevance

Anti‐endothelial cell antibodies (AECA) represent a heterogeneous family of autoantibodies directed against structural endothelial proteins, as well as antigens adhering to endothelial cells. Although AECA immunoassays still show a high‐interlaboratory variability, several findings suggest a pathogenic role of these autoantibodies in diseases characterized by endothelial damage. In this chapter, we analyze the knowledge about AECA prevalence, clinical relevance, and their pathogenic role in autoimmune diseases focusing in particular on systemic lupus erythematosus, antiphospholipid syndrome, systemic sclerosis (SSc), and systemic vasculitis.

Antiphospholipid syndrome and pregnancy

Since the 1960s, antiphospholipid antibodies have been known to be associated with repeated miscarriages and fetal losses. Other complications of pregnancy, such as preterm birth, with pre-eclampsia or severe placental insufficiency were also frequently reported and are included in the current classification criteria of the antiphospholipid syndrome. The titer, isotype or antigen specificity of the antibodies may be important in risk determination. The pathogenesis of pregnancy failures is not only linked to the thrombophilic effect of antiphospholipid antibodies but also to a direct effect of antibodies on trophoblast differentiation and invasion. The study of experimental animal models provided sound evidence of the pathogenic role of antiphospholipid antibodies both in lupus-prone and -naive mice. The classification of pregnant antiphospholipid syndrome patients as being at a 'high risk' has completely changed their prognosis due to obstetric monitoring and the application of effective therapy. In fact, despite the high rates of complications and preterm delivery, a successful outcome can now be achieved in a large majority of cases.

Microcirculatory Hemodynamics and Endothelial Dysfunction in Systemic Lupus Erythematosus

Objective— Impaired flow-mediated dilation (FMD) occurs in disease states associated with atherosclerosis, including SLE. The primary hemodynamic determinant of FMD is wall shear stress, which is critically dependent on the forearm microcirculation. We explored the relationship between FMD, diastolic shear stress (DSS), and the forearm microcirculation in 32 patients with SLE and 19 controls.

Methods and Results— DSS was calculated using (mean diastolic velocity×8×blood viscosity)/baseline brachial artery diameter. Doppler velocity envelopes from the first 15 seconds of reactive hyperemia were analyzed for resistive index (RI), and interrogated in the frequency domain to assess forearm microvascular hemodynamics. FMD was significantly impaired in SLE patients (median, 2.4%; range, −2.1% to 10.7% versus median 5.8%; range, 1.9% to 14%; P <0.001). DSS (dyne/cm 2 ) was significantly reduced in SLE patients (median, 18.5; range, 3.9 to 34.0 versus median 21.8; range, 14.1 to 58.7; P =0.037). A strong correlation between FMD and DSS, r s =0.65, P =0.01 was found. Postischemic RI was not significantly different between the 2 groups; however, there were significant differences in the power-frequency spectrums of the Doppler velocity envelopes ( P <0.05).

Conclusions— These data suggest that in SLE, altered structure and function of the forearm microcirculation contributes to impaired FMD through a reduction in shear stress stimulus.

Anti-endothelial antibodies and neuropsychiatric systemic lupus erythematosus

The pathogenesis of neuropsychiatric systemic lupus erythematosus (NPSLE) has been attributed to autoantibody-mediated neural dysfunction, vasculopathy, and coagulopathy. Several autoantibodies specificities have been reported in serum and cerebrospinal fluid of NPSLE patients (i.e., antineuronal, antiribosomal P proteins, antiglial fibrillary acidic proteins, antiphospholipid, and anti-endothelial antibodies). We have recently demonstrated an association between serum anti-endothelial antibodies and psychosis or depression in patients with SLE. Subsequently, by screening a cDNA library from human umbilical artery endothelial cells with serum from a SLE patient with psychosis, one positive strongly reactive clone was identified encoding the C-terminal region (C-ter) of Nedd5, an intracytoplasmatic protein of the septin family. Anti-Nedd5 antibodies have been found significantly associated with psychiatric manifestations in SLE patients, strengthening the view of a possible implication of autoantibodies in the development of psychiatric disorders.

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.

Autoantibodies against the fibrinolytic receptor, annexin 2, in antiphospholipid syndrome

The association of thrombosis and gestational morbidity with antiphospholipid antibodies is termed antiphospholipid syndrome (APS). Annexin 2 (A2) is a profibrinolytic endothelial cell surface receptor that binds plasminogen, its tissue activator (tPA), and beta(2)-glycoprotein I (beta2GPI), the main antigen for antiphospholipid antibodies. Here, we evaluate A2 as a target antigen in APS. Serum samples from 434 individuals (206 patients with systemic lupus erythematosus without thrombosis, 62 with APS, 21 with nonautoimmune thrombosis, and 145 healthy individuals) were analyzed by enzyme-linked immunosorbent assay (ELISA) and immunoblot for antiphospholipid and A2 antibodies. Anti-A2 antibodies (titer > 3 SDs) were significantly more prevalent in patients with APS (22.6%; venous, 17.5%; arterial, 34.3%; and mixed thrombosis, 40.4%) than in healthy individuals (2.1%, P < .001), patients with nonautoimmune thrombosis (0%, P = .017), or patients with lupus without thrombosis (6.3%, P < .001). Anti-A2 IgG enhanced the expression of tissue factor on endothelial cells (6.4-fold +/- 0.13-fold SE), blocked A2-supported plasmin generation in a tPA-dependent generation assay (19%-71%) independently of beta2GPI, and inhibited cell surface plasmin generation on human umbilical vein endothelial cells (HUVECs) by 34% to 83%. We propose that anti-A2 antibodies contribute to the prothrombotic diathesis in antiphospholipid syndrome.

Association between microscopic brain damage as indicated by magnetization transfer imaging and anticardiolipin antibodies in neuropsychiatric lupus

The pathogenetic role of anticardiolipin antibodies (aCLs) in patients with neuropsychiatric systemic lupus erythematosus (NPSLE) without cerebral infarcts remains elusive. Magnetization transfer imaging (MTI) has proved to be a sensitive tool for detecting diffuse microscopic brain damage in NPSLE patients. In this study we examined the correlation between grey and white matter magnetization transfer ratio (MTR) parameters and the presence of IgM and IgG aCLs and lupus anticoagulant in 18 patients with systemic lupus erythematosus and a history of NPSLE but without cerebral infarcts on conventional magnetic resonance imaging. Lower grey matter mean MTR (P < 0.05), white matter mean MTR (P < 0.05), white matter peak location (P < 0.05) and grey matter peak location (trend toward statistical significance) were observed in IgM aCL-positive patients than in IgM aCL-negative patients. No significant differences were found in MTR histogram parameters with respect to IgG aCL and lupus anticoagulant status, nor with respect to anti-dsDNA or anti-ENA (extractable nuclear antigen) status. This is the first report of an association between the presence of aCLs and cerebral damage in grey and white matter in NPSLE. Our findings suggest that aCLs are associated with diffuse brain involvement in NPSLE patients.

Antiphospholipid antibodies, thrombin and LPS activate brain endothelial cells and Ras-dependent pathways through distinct mechanisms

BACKGROUND

The antiphospholipid syndrome (APS) commonly affects the central nervous system through mechanisms that may include small vessel pathology and activation of thrombin. Antiphospholipid antibodies (aPL) activate endothelial cells but the specific activation of brain vascular endothelial cells (BVEC) and the receptors and signaling pathways involved have not been fully characterized.

OBJECTIVE

To examine whether aPL, the inflammatory stimulant lipopolysacharide (LPS) and thrombin activate BVECs through a Ras-dependent pathway.

METHODS

Rat BVEC (G8) were grown to confluence on 24-well plates. IgG was purified from 8 APS patients on a protein G column. Phosphorylation of ERK in the BVEC was measured by immunoblot utilizing a specific antibody.

RESULTS

Significant phosphorylation of ERK was measured following exposure of the cells to LPS and thrombin and this was blocked by the Ras inhibitor farnesylthiosalicylate (FTS). aPL IgG (1:100 relative to serum) from 7/8 patients also induced phosphorylation of ERK.

CONCLUSIONS

Activation of the Ras-ERK pathway is an effect of both APS IgG and thrombin. This pathway is potentially amenable to drugs such as FTS and may serve as a therapeutic target in APS.

Pregnancy and autoimmunity: Maternal treatment and maternal disease influence on pregnancy outcome

If a woman suffers from autoimmune disease (AD), several factors can affect pregnancy or neonatal outcome: repeated spontaneous pregnancy losses (frequently related to antiphospholipid antibodies (aPL)), neonatal lupus with complete congenital heart block (CHB) (linked to transplacental passage of IgG anti Ro/SS-A antibodies) and the disease activity itself that can affect the mother, the pregnancy and fetal outcome. If appropriately managed, the antiphospholipid syndrome (APS) is "one of the few tractable causes of pregnancy losses." A recent case control study, on babies from APS-mothers and healthy mothers, did not show any difference in the occurrence of neonatal complications. There are few data about the long-term outcome of babies born to patients with AD. We recently reported increased occurrence of learning disabilities in children born to aPL positive mothers with systemic lupus erythematosus (SLE). The modern management of pregnancy in patients with AD includes the treatment of disease flares, using drugs effective but safe for fetus. Corticosteroids and some immunosuppressive drugs can be used in pregnancy to control maternal disease. A prolonged fetal exposure to dexamethasone was reported to impair cerebral development, but we recently studied 6 children, born to patients treated with dexamathasone because of CHB, showing a normal intelligence quotient. The last 10-year experience shows that fetal exposure to antimalarial drugs should not be regarded as an important risk factor for gestational nor neonatal complications. However, information about long-term outcome of children exposed to immunosuppressive drugs "in utero" are still lacking and more efforts are needed in this research area.

Controlled clinical trial of IV cyclophosphamide versus IV methylprednisolone in severe neurological manifestations in systemic lupus erythematosus

BACKGROUND

Severe neurological involvement in systemic lupus erythematosus (NPSLE) is one of the most dreadful complications of the disease.

OBJECTIVE

To identify the best drug, dose, and treatment.

PATIENTS AND METHODS

The study was a controlled clinical trial at two tertiary care centres of patients with SLE according to the ACR criteria, with incident (no more than 15 days) onset of severe NP manifestations such as seizures, optic neuritis, peripheral or cranial neuropathy, coma, brainstem disease, or transverse myelitis. Induction treatment with 3 g of IV methylprednisolone (MP) followed by either IV monthly cyclophosphamide (Cy) versus IV MP bimonthly every 4 months for 1 year and then IV Cy or IV MP every 3 months for another year. The primary end point was response to treatment: at least 20% improvement from basal conditions on clinical, laboratory, or specific neurological testing variables.

RESULTS

Overall, a response rate of 75% was observed. Of the 32 patients studied, 18/19 receiving Cy and 7/13 receiving MP responded to treatment (p<0.03).

CONCLUSIONS

Cy seems to be more effective than MP in the treatment of acute, severe NPSLE.

Innate immunity in the antiphospholipid syndrome: role of toll-like receptors in endothelial cell activation by antiphospholipid antibodies

Antiphospholipid antibodies are mainly directed against beta 2 glycoprotein I (beta2GPI), a plasma phospholipid-binding protein expressed on endothelial cells of different anatomical localizations. Anti-beta2GPI antibodies recognize the molecule on endothelial monolayers in vitro, and, once bound, might activate the cells both in vitro and in vivo experimental models inducing a proinflammatory and a procoagulant phenotype. Cell activation is associated with nuclear factor-kappaB (NF-kappaB) translocation and with a signaling cascade comparable to that triggered by the toll-like receptors (TLRs)-4. The cell membrane receptor(s) for beta2GPI adhesion is still under investigation. It has been suggested that beta2GPI might adhere through electrostatic interaction between its cationic phospholipid binding site and anionic structures on the cell membrane; however, binding to annexin II-the endothelial cell receptor for tissue plasminogen activator-plays also a role. Because annexin II does not display any transmembrane protein, it has been suggested that it requires a yet unknown "adaptor" protein to signal the cells. Because of the molecular mimicry between beta2GPI and viral/bacterial structures-the natural ligands for TLRs-antibodies might cross-link the molecule associated to annexin II and TLR-4 eventually triggering the signaling.

Inflammatory response and the endothelium

Antiphospholipid-mediated endothelium perturbation plays a role in antiphospholipid syndrome (APS)-associated vasculopathy. Antiphospholipid antibodies activate endothelium both in vitro and in vivo experimental models by inducing a pro-inflammatory/-coagulant phenotype; the antibodies recognize beta2 glycoprotein I (beta2GPI) on human endothelial cells (EC) from different parts of the vasculature. In spite of such large in vitro evidence, few studies have addressed the issue whether or not a comparable endothelial perturbation might be detectable in vivo. We investigated several indirect ex vivo parameters of endothelial dysfunction: plasma levels of soluble adhesion molecules (sADM), soluble thrombomodulin (sTM), von Willebrand factor (vWF) and tissue plasminogen activator (t-PA) by solid-phase assays. The study included: patients with primary antiphospholipid syndrome (n=32), with the syndrome secondary to non-active systemic lupus erythematosus (SLE, n=10), six patients with persistent antiphospholipid positivity at medium/high titre without any clinical manifestation of the syndrome. Fifty-two age and sex matched healthy subjects have been enrolled as controls. In addition, circulating endothelial cells identified by flow cytometry and the brachial artery flow-mediated vasodilation (FMV) were evaluated in 26 patients (20 primary and 6 lupus syndromes) and 30 healthy controls. Plasma levels of soluble adhesion molecules did not differ from controls, while a significant increase in von Willebrand factor titres (P<0.05) was found. No significant difference was found regarding the number of circulating endothelial cells and flow-mediated vasodilation. As a whole, these findings do suggest that antiphospholipid antibodies per se are not able to support a full-blown endothelial perturbation in vivo. As shown in antiphospholipid syndrome experimental animal models, a two-hit hypothesis is suggested.

How to diagnose and treat secondary forms of vasculitis

Vasculitis is considered to be secondary when it arises either in the context of a pre-existing connective tissue disease, as a result of direct infection with a limited range of organisms, especially viruses, or when it arises in response to exposure to a number of medications. Rheumatoid vasculitis is probably the most widely recognised form of secondary vasculitis, and in this article we review the incidence, clinical features and management of this condition. Infections may either trigger or cause some types of vasculitis. Drug therapy is a common cause of limited forms of vasculitis and may enhance our understanding of the mechanism of these diseases. The premature development of atherosclerosis in patients with existing connective tissue diseases or indeed primary vasculitis has been recognised for some time, and the underlying mechanisms are currently being studied. An appreciation of the complex and varied pathophysiology of secondary vasculitis may further our understanding of primary vasculitis.

Endothelial cell activation by antiphospholipid antibodies

Antiphospholipid antibodies are mainly directed against beta 2 glycoprotein I, a phospholipid-binding protein expressed on endothelial cell membranes of different anatomical localizations and recognized by the specific autoantibodies. Antibody binding induces an endothelial activation both in in vitro and in vivo experimental models that might contribute to the prothrombotic state. Endothelial beta 2 glycoprotein I adhesion is mediated by the electrostatic interaction between its cationic phospholipid binding site and anionic structures on the cell membrane; however, binding to annexin II--the endothelial cell receptor for tissue plasminogen activator--plays also a role. Anti-beta-2 glycoprotein I antibodies up-regulate mRNA expression of pro-inflammatory mediators through NF-kappaB translocation and the signaling cascade triggered by Toll-like receptors. Because of the molecular mimicry between beta 2 glycoprotein I and viral/bacterial structures-the natural ligands for Toll-like receptors (TLR)-antibodies might cross-link the molecule associated to the receptors eventually triggering their signaling.

Autoantibody profile in systemic lupus erythematosus with psychiatric manifestations: a role for anti-endothelial-cell antibodies

This study was performed to determine the correlation between psychiatric manifestations and several autoantibodies that might participate in the pathogenesis of psychiatric disorders in the course of systemic lupus erythematosus (SLE). Fifty-one unselected outpatients with SLE were enrolled. Psychiatric evaluation was performed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. The prevalence of antibodies against endothelial cells (AECA), cardiolipin, β2 glycoprotein I, Ro, Ro52, La, glial fibrillary acidic protein, ribosomal P protein, dsDNA, and nucleosomes was assessed by experimental and commercial enzyme-linked immunosorbent assays. According to the cutoff value, AECA were present in 11 of 17 (64.7%) SLE patients with psychosis and mood disorders and in 10 of 34 (29.4%) patients without psychiatric manifestations other than anxiety (P = 0.03). Moreover, the AECA binding index was significantly higher in the first group (P = 0.03). Conversely, no significant correlation was found between the presence of the other autoantibodies studied and psychiatric involvement. The results of this study suggest a relationship between AECA and psychosis and mood disorders in SLE, supporting the hypothesis of a biological origin of these disturbances.

The blood-brain barrier in systemic lupus erythematosus

Central nervous system (CNS) involvement may occur in 20-70% of systemic lupus erythematosus (SLE) patients where neurological symptoms are overt; this is termed neuropsychiatric lupus or NPSLE. This review summarizes evidence that damage to the brain endothelium forming the blood-brain barrier (BBB) is a contributory factor in NPSLE. The normal CNS is protected by blood-tissue barriers at three sites, the brain endothelium (BBB), the choroid plexus epithelium (blood-CSF barrier) and the arachnoid epithelium. The tight junctions of the barrier layers severely restrict entry of plasma constituents including proteins, so that the CSF and brain interstitial fluid contain low levels of protein. Methods for diagnosing BBB damage include imaging (CT, MRI) using contrast agents, and analysing protein content and profiles of CSF Changes in the albumin quotient Qalbumin show evidence for barrier damage, while changes in the immunoglobulin (Ig) index can indicate intrathecal antibody production. However, BBB damage may be transient, and hence undetected or underestimated. Few mechanistic studies exist, but the two main candidate mechanisms for BBB damage are microthrombi in cerebral vessels leading to ischaemia, and immune-mediated attack and activation of the endothelium leading to local cytokine production. Both can result in barrier breakdown. Neurological syndromes could then be secondary to damage to the BBB. The implications for treatment of NPSLE are discussed.

Endothelium activation in the anti-phospholipid syndrome

Anti-phospholipid syndrome is an autoimmune systemic disease characterized by the persistent presence of anti-phospholipid antibodies and by the occurrence of thrombosis, fetal loss and thrombocytopenia. Anti-phospholipid antibodies are widely accepted as pathogenic antibodies mainly directed against the phospholipid-binding protein beta 2 glycoprotein I. Beta 2 glycoprotein I can be expressed on the endothelial cell membranes of different anatomical localizations and recognized by the autoantibodies. The antibody binding might induce an endothelial activation both in vitro and in vivo experimental models, that was suggested to represent one of the pathogenic mechanisms leading to the prothrombotic state of the syndrome. Beta 2 glycoprotein I endothelial adhesion was found to take place through the interaction of the cationic phospholipid binding site of the molecule with anionic endothelial structures and through annexin II, the endothelial cell receptor for tissue plasminogen activator. Anti-beta 2 glycoprotein I antibodies can directly activate the cells via NF-kB translocation and the signaling cascade triggered by toll like receptors. It has been suggested that beta 2 glycoprotein I might be associated with toll like receptors because of its molecular mimicry with bacterial structures, the natural ligands of toll like receptors. The binding of the antibodies is thought to cross-link beta 2 glycoprotein I and the toll like receptors, eventually switching their signaling pathway.