Lymphocyte antigens in neuropsychiatric systemic lupus erythematosus. Relationship of lymphocyte antibody specificities to clinical disease

Cognitive dysfunction and associated neuroimaging biomarkers in antiphospholipid syndrome: a systematic review

Objectives

Cognitive dysfunction is common in patients with aPL (including primary APS or APS associated with SLE). Neuroimaging biomarkers may contribute to our understanding of mechanisms of cognitive dysfunction in these cohorts. This review aimed to investigate: (i) the prevalence of cognitive dysfunction in studies including neuroimaging biomarkers; and (ii) associations between cognition and neuroimaging biomarkers in patients with APS/aPL.

Methods

We conducted a systematic search of electronic databases PubMed, Science Direct, Scopus and PsycINFO, and included studies with descriptions of neuroimaging findings, cognitive dysfunction or both, in patients with aPL positivity (LA, IgG and IgM aCL and anti-β2 glycoprotein-I antibodies).

Results

Of 120 search results we included 20 eligible studies (6 APS, 4 SLE with APS/aPL and 10 NPSLE). We identified a medium risk of bias in 6/11 (54%) of cohort studies and 44% of case–control studies, as well as marked heterogeneity in cognitive assessment batteries, APS and aPL definitions, and neuroimaging modalities and protocols. The prevalence of cognitive dysfunction ranged between 11 and 60.5%. Structural MRI was the most common imaging modality, reporting cognitive dysfunction to be associated with white matter hyperintensities, ischaemic lesions and cortical atrophy (four with cerebral atrophy, two with white matter hyperintensities and two with cerebral infarcts).

Conclusion

Our findings confirm that cognitive impairment is commonly found in patients with aPL (including APS, SLE and NPSLE). The risk of bias, and heterogeneity in the cognitive and neuroimaging biomarkers reported does not allow for definitive conclusions.

The immunologic etiology of psychiatric manifestations in systemic lupus erythematosus: A narrative review on the role of the blood brain barrier, antibodies, cytokines and chemokines

INTRODUCTION

The aim of this narrative review is to provide an overview of the literature on the possible immunologic pathophysiology of psychiatric manifestations of neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

A systematic search on PubMed was conducted. English studies with full text availability that investigated the correlation between blood-brain barrier (BBB) dysfunction, intrathecal synthesis of antibodies, antibodies, cytokines, chemokines, metalloproteinases, complement and psychiatric NPSLE manifestations in adults were included.

RESULTS

Both transient BBB-dysfunction with consequent access of antibodies to the cerebrospinal fluid (CSF) and intrathecal synthesis of antibodies could occur in psychiatric NPSLE. Anti-phospholipid antibodies, anti-NMDA antibodies and anti-ribosomal protein p antibodies seem to mediate concentration dependent neuronal dysfunction. Interferon-α may induce microglial engulfment of neurons, direct neuronal damage and production of cytokines and chemokines in psychiatric NPSLE. Several cytokines, chemokines and matrix metalloproteinase-9 may contribute to the pathophysiology of psychiatric NPSLE by attracting and activating Th1-cells and B-cells.

DISCUSSION

This potential pathophysiology may help understand NPSLE and may have implications for the diagnostic management and therapy of psychiatric NPSLE. However, the presented pathophysiological model is based on correlations between potential immunologic etiologies and psychiatric NPSLE that remain questionable. More research on this topic is necessary to further elucidate the pathophysiology of NPSLE.

Adjunctive plasma exchanges to treat neuropsychiatric lupus: a retrospective study on 10 patients

Neuropsychiatric manifestations of systemic lupus erythematosus (NPSLE) are among the main causes of morbidity and mortality attributed to lupus activity. Conventional NPSLE treatment combines CS and immunosuppressants, but some symptoms do not respond. We retrospectively evaluated the adjunction of plasma exchanges (PE) to treat 13 NPSLE flares occurring in 10 patients (mean age, 30 years) between 1989 and 2002. NP manifestations were the first SLE symptoms for seven patients, with a mean of 3.2 NP manifestations/flare. All patients received CS and cyclophosphamide pulses. A mean of 15 PE/flare were performed. All patients improved within a mean of 3 (median: 2.5; range: 1.5—8) weeks thereafter. Complete remissions of 7/13 flares were obtained within a mean of 7 (median: 4; range: 2—22) weeks. Partial remissions were achieved for the remaining six flares, characterized by new NP manifestations during three and insufficient control of the others. Other SLE manifestations regressed for all patients with the mean European consensus lupus activity measurement score declining from pretreatment 6.9 to 1.2. A regimen combining CS, cyclophosphamide and PE is effective against severe NPSLE, with acceptable toxicity. Lupus (2007) 16, 817—822.

Antilymphocyte antibodies in systemic lupus erythematosus: association with disease activity and lymphopenia

PURPOSE

We analyzed the prevalence, clinical correlation, and the functional significance of ALA in patients with systemic lupus erythematosus (SLE).

METHODS

ALA IgG was detected by indirect immunofluorescence in the serum of 130 SLE patients, 75 patients with various rheumatic diseases, and 45 healthy controls (HC).

RESULTS

The sensitivity and specificity of ALA IgG in SLE were 42.3% and 96.7%, respectively. ALA was observed in 55.6% (50/90) of patients with lymphopenia, which was significantly higher than in patients with normal lymphocytes (5/40, 12.5%; P<0.001). Patients with active SLE showed higher ALA positivity (60.9%) than those with inactive disease (24.2%; χ2=17.925; P<0.001). ALA correlated significantly with hypocomplementemia, anti-dsDNA antibodies, and higher SLEDAI scores. The incidences of ALA in SLE patients who were seronegative for anti-dsDNA, anti-Sm, or both antibodies were 32.9% (26/79), 41.0% (43/105), and 32.4% (22/68), respectively. The ALA-positive group also had higher incidences of neuropsychiatric SLE (NPSLE) and lupus nephritis (LN). In multivariate analyses, ALA was independently associated with lymphopenia, higher SLEDAI scores, and increased risk for LN. ALA titers significantly decreased as clinical disease was ameliorated following treatment.

CONCLUSIONS

ALA occurred more frequently in patients with active SLE and was independently associated with lymphopenia, disease activity, and LN.

Tumor necrosis factor-alpha and neuropsychiatric lupus erythematosus: relation to single photon emission computed tomography findings

Abstract This study was designed to highlight the relation of tumor necrosis factor-α (TNF-α) to neuropsychiatric lupus (NPLE) manifestations. The relation of TNF-α to the type of single photon emission computed tomography (SPECT) findings in this context was also studied. Twenty-one systemic lupus erythematosus (SLE) females, mean age 27.57 ± 9.89 years, and twenty age-matched normal females (controls), were subjected to TNF-α assessment. Different clinical and neuropsychiatric manifestations were evaluated. SPECT was carried out for all patients. The results showed that the mean TNF-α level (pg/ml) was significantly raised in patients compared with controls (167.8 ± 102.5 versus 64 ± 50.2, respectively, P < 0.005). Thirteen patients (69.1%) had NPLE manifestations. NPLE patients had a significantly higher mean TNF-α than patients without NPLE (203 ± 102.8 versus 109 ± 47.3, respectively, P < 0.03). Positive SPECT findings were found in 18 lupus patients (85.7%), including all 13 patients with NPLE (100% sensitivity), with a multiple focal pattern of hypoperfusion being the most frequent type (9/13), followed by diffuse (3/13), and then single focal pattern (1/13). The mean TNF-α was significantly higher in patients with multiple focal pattern (P < 0.001). In conclusion, results of this work support the hypothesis that TNF-α could be involved in the pathogenesis of NPLE, and hence, it could be speculated that the evolving anti-TNF therapy can play a potential role in the management of this disease.

Lymphocytotoxic antibodies in systemic lupus erythematosus are associated with disease activity irrespective of the presence of neuropsychiatric manifestations

OBJECTIVES

To evaluate the association of the presence of lymphocytotoxic, anti-beta2-glycoprotein I (anti-beta2-GPI) and anti-ribosomal P (anti-P) antibodies in patients with systemic lupus erythematosus (SLE), presenting or not neuropsychiatric (NP) manifestations, stratified according to the activity of the disease.

METHODS

A total of 138 patients with SLE (59 with active NPSLE, 49 with active non-NPSLE, and 30 with inactive disease) and 57 healthy controls were studied. Disease activity was assessed by the SLE Disease Activity Index (SLEDAI). The presence of lymphocytotoxic antibodies was assessed using a complement-dependent lymphocytotoxicity assay. The presence of anti-beta2-GPI and anti-P antibodies was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Lymphocytotoxic antibodies were detected primarily in patients with active disease, that is in 35 out of 59 (59.3%) NPSLE and 23 out of 49 (46.9%) non-NPSLE patients, whereas only four out of 30 (13.3%) inactive SLE patients and none of the healthy controls exhibited the autoantibody. The frequency of lymphocytotoxic antibodies in active SLE patients, considered as a whole or stratified into NPSLE or non-NPSLE, was significantly increased in relation to inactive SLE patients (p<0.001 for each comparison). No significant difference was observed when comparing active NPSLE with non-NPSLE patients. No associations were observed between the presence of anti-beta2-GPI or anti-P antibodies and the activity of SLE or the presence of lymphocytotoxic antibodies.

CONCLUSIONS

Lymphocytotoxic antibodies occurred more frequently in patients with active SLE than in patients with inactive disease, irrespective of the presence of NP manifestations, a finding that is similar to classical biomarkers of lupus activity (anti-dsDNA and complement). These results indicate that the assessment of the presence of lymphocytotoxic antibodies may be an additional useful tool for the evaluation of SLE activity.

Brain diffusivity in patients with neuropsychiatric systemic lupus erythematosus with new acute neurological symptoms

PURPOSE

To investigate the source of significant difference in apparent diffusion coefficient (ADC) between patients with acute symptoms of neuropsychiatric (NP) systematic lupus erythematosus (SLE) (NPSLE) and normal controls.

MATERIALS AND METHODS

Diffusion-weighted echo-planar imaging was performed on 1.5-T scanners in 17 female and four male NPSLE patients with acute neurological symptoms (23-76 years, mean = 42.7 years), and in 21 aged-matched healthy controls (16 female, five male, 26-63 years, mean = 41.1 years). ADC histograms were calculated for whole brain, gray matter tissue, and white matter tissue.

RESULTS

Of the 17 NPSLE patients, 13 (72%) had abnormal findings on MR imaging. The NPSLE patients had a mean ADC value of (1105.1 +/- 23.6) x 10(-6) mm(2)/second and the control had a mean ADC value of (1012.5 +/- 9.4) x 10(-6) mm(2)/second (P < or = 0.0012). Significant differences were also found in white matter (P < or = 0.0020) and gray matter (P < or = 0.0022).

CONCLUSION

ADC histogram analysis demonstrated increased general diffusivity in the brain in NPSLE patients with acute symptoms compared with healthy normal controls. This finding suggests that in the brain parenchyma of NPSLE patients a loss of tissue integrity occurs facilitating motility of free-water protons.

Autoantibodies Involved in Neuropsychiatric SLE and Antiphospholipid Syndrome

OBJECTIVE

We sought (1) to identify and (2) to define the association of all reported antibodies (Abs) with neuropsychiatric lupus (NPSLE), (3) to search for possible mechanisms that are involved in NPSLE, and (4) to determine whether we can recognize a panel of Abs associated with specific neuropsychiatric (NP) manifestations.

METHODS

A MEDLINE search (1975 to 2005) was performed utilizing the following terms: neuropsychiatric lupus, antiphospholipid syndrome, or central nervous system systemic lupus erythematosus matched with the term antibodies.

RESULTS

Twenty Abs (11 brain-specific and 9 systemic) were described in NPSLE patients. These include Abs that target brain-specific antigens (neuronal, ganglioside, synaptosomes, glia, methyl-d-aspartate receptors, lymphocytotoxic) and systemic antigens (nuclear, cytoplasmic, phospholipid, endothelial cells). Cognitive impairment, psychosis, and depression were associated with many Abs. Elevated titers of anticardiolipin Abs (aCL) were reported most often and found in patients with cognitive impairment, psychosis, depression, seizures, chorea, and migraine. No specificity was encountered among brain-specific or systemic Abs for any single NP manifestation. No studies evaluated a specific NP manifestation with the full panel of 20 Abs. A panel of brain-specific and systemic Abs may be helpful in establishing the diagnosis of NPSLE. Postulated mechanisms in experimental models included vascular occlusion and injury by pathogenic Abs in a disrupted blood brain barrier.

CONCLUSIONS

NPSLE is associated with brain-specific and systemic Abs. Cognitive impairment, psychosis, and depression were associated with many Abs, including aCL Abs. Possible mechanisms include vascular occlusion and injury by pathogenic Abs in a disrupted blood brain barrier.

Cognitive dysfunction in the patient with antiphospholipid antibodies: considerations for cause and treatment

The evidence supporting a causal relationship between antiphospholipid (aPL) antibodies and cognitive dysfunction is very limited despite a general impression that one exists. Patients with aPL antibodies may complain of cognitive difficulties in their everyday lives, forcing the clinician to examine this issue. As with other non-thrombotic antiphospholipid syndrome (APS) manifestations, cognitive dysfunction in this population should be approached as a diagnosis of exclusion. The complexity in diagnosing and treating various manifestations of rheumatic disease holds true for identifying and addressing cognitive decline in these patients.

Magnetic Resonance Spectroscopy

Magnetic resonance spectroscopy (MRS) complements magnetic resonance imaging (MRI) as a non-invasive means for the characterization of tissue. While MRI uses the signal from hydrogen protons to form anatomic images, proton MRS uses this information to determine the concentration of brain metabolites such as N-acetyl aspartate (NAA), choline (Cho), creatine (Cr) and lactate in the tissue examined. The most widely used clinical application of MRS has been in the evaluation of central nervous system disorders.MRS has its limitations and is not always specific but, with good technique and in combination with clinical information and conventional MRI, can be very helpful in diagnosing certain entities. For example, a specific pattern of metabolites can be seen in disorders such as Canavan's disease, creatine deficiency, and untreated bacterial brain abscess. MRS may also be helpful in the differentiation of high grade from low grade brain tumors, and perhaps in separating recurrent brain neoplasm from radiation injury.

MRI and 2D-CSI MR spectroscopy of the brain in the evaluation of patients with acute onset of neuropsychiatric systemic lupus erythematosus

MRI and 2D-CSI spectroscopy were performed in eight patients with systemic lupus erythematosus who presented with acute onset of neuropsychiatric lupus (NP-SLE), and in seven normal controls to evaluate for differences in metabolic peaks and metabolic ratios between the two groups. Also, the interval change of the metabolic peaks and their ratios during treatment in the NP-SLE patient group was evaluated. Metabolic peaks for N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), and lactate/lipids (LL) and their ratios (NAA/Cr, NAA/Cho, Cho/Cr, LL/Cr) were determined at initial presentation and 3 and 6 months later. In the eight lupus patients compared to the seven normal controls, NAA/Cho ratios were lower at presentation (1.05 vs 1.25; p = 0.004) and decreased even further at the three month follow-up (0.92 vs 1.05; p = 0.008). In contrast, both Cho/Cr (1.42 vs 1.26; p = 0.026) and LL/Cr ratios (0.26 vs 0.19; p = 0.002) were higher in the lupus patients at presentation compared to the controls and did not significantly change at three and six months follow-up. The NAA/Cr ratios were lower in the lupus patients compared to the controls at presentation but the difference was not statistically significant. However, the mean NAA/Cr significantly decreased from the initial examination to the three month follow-up (1.42 vs 1.32; p = 0.049) but did not significantly change from the three to the six month follow-up examinations. The NAA/Cr, Cho/Cr, and NAA/Cho ratios varied significantly (p < 0.05, p < 0.05, p < 0.05, respectively) between the 17 different locations measured in the brain in all eight patients and seven controls. Both the NAA/Cr ratios and the Cho/Cr ratios were also significantly lower in the gray matter than in the white matter (p < 0.0001) in both patients and controls, whereas the LL/Cr and NAA/Cho ratios were not significantly different. In conclusion, 2D-CSI MR spectroscopy may be useful in the early detection of metabolic CNS changes in NP-SLE patients with acute onset of new neurological symptoms as well as in the follow-up after treatment to assess presence and changes in metabolic brain injury. However, although there are detectable differences between normal individuals and lupus patients it is currently unclear whether these relate to the acute episode. Future studies are needed comparing NP-SLE patients with active CNS involvement with those inactive disease.

Autoimmune-induced damage of the midbrain dopaminergic system in lupus-prone mice

Spontaneous development of lupus-like disease is accompanied by impaired dopamine catabolism and degenerating axon terminals in the mesencephalon of MRL-lpr mice. We presently examine the hypothesis that systemic autoimmunity affects the central dopaminergic system in behaviorally impaired animals. The functional damage of the nigrostriatal pathway was assessed from rotational behavior after a single injection of the D1/D2-receptor agonist apomorphine. Neurodegeneration in the midbrain was estimated by Fluoro Jade B (FJB) staining. The causal role of autoimmunity was tested by comparing asymptomatic and diseased MRL-lpr mice, and by employing the immunosuppressive drug cyclophosphamide. Damage of dopaminergic neurons was assessed by tyrosine-hydroxylase (TH) staining of the midbrain. Apomorphine induced significant asymmetry in limb use, which lead to increased circling in the diseased MRL-lpr group. While FJB-positive somas were not seen in the striatum, increased staining in the substantia nigra (SN) and ventral tegmental area (VTA) were detected in behaviorally impaired MRL-lpr mice, but not in age-matched controls. Reduced brain mass and increased levels of TNF-alpha in their cerebrospinal fluid (CSF) suggested cerebral atrophy and inflammation. In addition, CSF was neurotoxic to a dopaminergic progenitor cell line. Immunosuppression attenuated CSF cytotoxicity, TNF-alpha levels, and midbrain neurodegeneration. Supportive of the notion that dying neurons were dopaminergic, the SN of autoimmune mice showed approximately a 35% reduction in the number of TH-positive cells. A three-fold increase in serum brain-reactive antibodies accompanied this loss. Although the source of toxic mediator(s) remains unknown, present results are consistent with the hypothesis that autoimmunity-induced destruction of mesonigral and mesolimbic dopaminergic pathways contributes to the etiology of aberrant behavior in an animal model of neuropsychiatric lupus.

Neurodegeneration in autoimmune MRL-lpr mice as revealed by Fluoro Jade B staining

As in many humans suffering from lupus erythematosus, the development of systemic autoimmunity and inflammation in Fas-deficient MRL-lpr mice is accompanied by CNS dysfunction of unknown etiology. Experimental studies revealed infiltration of lymphoid cells into the choroid plexus, reduced neuronal complexity, retarded brain growth, and enlargement of cerebral ventricles. Moreover, an increased presence of cells with nicked-DNA (TUNEL+ cells) in the periventricular areas suggested accelerated apoptosis in brain cells of MRL-lpr mice. However, direct evidence that the dying cells were neurons was lacking. For this purpose, we presently use Fluoro-Jade B (FJB), a novel fluorescent dye which has high affinity for dying neurons (both apoptotic and necrotic). As expected, in comparison to the control groups, the brains of diseased, 5-month-old MRL-lpr mice showed increased numbers of FJB-positive (+) cells in cortical and periventricular regions. The FJB+ cells were significantly more numerous than TUNEL+ cells, and only approximately 7% co-localized with TUNEL. Immunostaining for CD4 and CD8 markers did not correlate with the number of FJB+ cells, suggesting that T-lymphocyte infiltration into the brain tissue is not a reliable predictor of neuronal demise. Conversely, indices of systemic autoimmunity (splenomegaly and high serum anti-nuclear antibody levels) were associated with increased FJB+ cell numbers in brains of autoimmune MRL-lpr mice, supporting the causal link between autoimmunity and neurodegeneration. Taken together, the above results suggest that factors other than T-cell infiltration and cell death mechanisms other than Fas-mediated apoptosis dominate neuronal degeneration in lupus-prone MRL-lpr mice.

Anti-adenosine deaminase antibodies in lupus erythematosus

Adenosine deaminase (ADA) is an enzyme involved in purine metabolism and has a major role in the development and function of lymphoid cells. Congenital deficiency of ADA results in severe immunodeficiency. Patients with congenital ADA deficiency treated with polyethylene glycol-conjugated bovine ADA develop antibodies to ADA. This leads us to investigate the role of anti-ADA antibodies in patients with systemic rheumatic diseases. Commercially available ADA was used in ELISA and immunoblots for detection of anti-ADA antibodies. Four out of 100 patients examined were positive for anti-ADA antibodies. Two of them had peripheral blood lymphopenia but the antibody levels did not appear to correlate with the lymphocyte counts. Immunoblotting revealed that the antibodies recognized a 40 kDa peptide of ADA, corresponding to ADA1, the major component of ADA. Affinity-purified antibodies were used to locate the distribution of ADA on Hep-2 cells and lymphocytes by indirect immunofluorescence. Anti-ADA antibodies gave a distinct nuclear speckled pattern on acetone-fixed cells. With viable cell immunofluorescence, anti-ADA antibodies also stained the cell surface of HEp-2 cells and lymphocytes, indicating surface expression of ADA. The anti-ADA antibodies failed to gain access into the cytoplasm or nuclei when added to the cultures of HEp-2 cells. In summary, this is the first report of detection of anti-ADA1 autoantibody which is a new type of ANA with discrete, speckled nuclear staining, but which may not be associated with lymphopenia.

Systemic Lupus Erythematosus Presenting as Subacute Delirium in an 82‐Year‐Old Woman

OBJECTIVES

To describe an older patient with delirium attributed to systemic lupus erythematosus (SLE) and to review the literature on neuropsychiatric manifestations of SLE in older people.

DESIGN

Case report and literature review. MEDLINE search using terms systemic lupus erythematosus, neurologic, psychiatric, neuropsychiatric, autoantibodies (anti-nuclear antibody (ANA), antiphospholipid, anticardiolipin, anti-double stranded deoxyribonucleic acid (anti-dsDNA), anti-Smith), and elderly. Additional articles obtained from hand-searched references and through experts.

SETTING

Hospital (case report).

PARTICIPANTS

Case report and literature cases.

MEASUREMENTS

None.

RESULTS

SLE is increasingly diagnosed in older adults. Onset is insidious and diagnosis is delayed because of a different clinical spectrum and immunological profile than in younger adults. Autoantibodies have an important role in the pathogenesis of neuropsychiatric manifestations, while vasculitis is less common. Aggressive immunosuppressive therapy is typically indicated, although recent case reports suggest that lower doses may suffice. The American College of Rheumatology 1982 revised criteria may be inadequate to diagnose neuropsychiatric lupus in older persons.

CONCLUSION

Neuropsychiatric symptoms can be prominent in older people, presenting features of SLE. This case illustrates the lowest dose of corticosteroids shown to be effective in an older patient with delirium due to SLE.

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.

Central nervous system involvement in systemic lupus erythematosus: cerebral imaging and serological profile in patients with and without overt neuropsychiatric manifestations

The aim of this study was to evaluate morphological and functional abnormalities by cerebral imaging in a series of systemic lupus erythematosus (SLE) patients with and without overt central nervous system (CNS) manifestations, and to detect possible relationships with clinical parameters and a large panel of autoantibodies, including those reactive against neurotypic and gliotypic antigens. 68 patients with SLE were investigated in a cross-sectional study which included clinical evaluation of symptoms, cerebral magnetic resonance imaging (MRI) and brain single photon emission tomography (SPECT) analysis, electroencephalography (EEG), and serological tests for antibodies directed against nuclear, cytoplasmic neuronal and glial cell-related antigens. The results of this study showed: (1) a significant positive association of (a) anti-glial fibrillary acidic protein (GFAP) serum antibodies with neuropsychiatric (NP) manifestations and (b) anti-serin proteinase 3 (anti-PR3/c-ANCA) serum antibodies with pathological cerebral SPECT; (2) the presence of significantly higher values of (a) SLICC organ damage index in patients with abnormal MRI and (b) SLAM activity index in patients with abnormal SPECT; and (3) the association of (a) abnormal MRI with nonactive NP manifestations and (b) combined abnormality of brain SPECT and MRI with the occurrence of overall overt NP manifestations and with those of the organic/major type. Neuropsychiatric manifestations, namely those of the organic/major type, appeared to be significantly associated to the presence of a serum antibody against GFAP, a gliotypic antigen. There was also evidence of an association between SPECT abnormality and the presence of anti-PR3 (c-ANCA). Furthermore, brain imaging by MRI and SPECT applied to SLE patients appears to express CNS involvement significantly related to specific categories of NP manifestations. The abnormalities detected by the two tests seem to be preferentially associated with different activity phases of the NP disorder or of the lupus disease.

Sensitivity of quantitative (1)H magnetic resonance spectroscopy of the brain in detecting early neuronal damage in systemic lupus erythematosus

OBJECTIVE

To quantify N-acetylaspartate (NAA), total creatines (tCr), total cholines (tCho), and myo-inositol (mI) levels in normal and abnormal appearing white matter of patients with neuropsychiatric systemic lupus erythematosus (NPSLE) in order to determine the specific changes in metabolite concentrations.

METHODS

Axial proton density and T(2) weighted magnetic resonance images, and short echo time (TE 30 ms) (1)H spectra were acquired with a GE SIGNA 1.5 T magnetic resonance system. Concentrations of NAA, tCr, tCho, and mI were determined, using brain tissue water as a reference, from nine patients (seven female, mean age 40.3 years, range 16-65) with NPSLE and eight healthy women (mean age 43 years, range 31-65).

RESULTS

A significant rise of tCho (12.4%, p<0.05) and mI (31.4%, p<0.005) and a significant reduction in NAA (-12%, p<0.05) was found in normal appearing white matter compared with controls. Analysis according to severity of the clinical NPSLE features (subgrouped as major or minor) showed that SLE major had reduced NAA compared with SLE minor (-18.4%, p<0.05) and controls (-20%, p<0.005). The SLE major group showed a significant rise of mI (32%, p<0.01) and the SLE minor group a significant increase in tCho (18.6%, p<0.05) compared with controls. Longitudinal analysis of brain metabolites in normal appearing white matter showed consistent abnormalities in NAA, tCho, and mI in a patient with stable clinical features and a constant rise of tCho, but transient rise of mI was seen during a flare of disease in another patient.

CONCLUSION

Quantitative (1)H magnetic resonance spectroscopy (MRS) suggests a particular course of neurometabolite changes that precedes irreversible reductions in NAA and permanent neuronal loss. Initially, in patients with SLE minor, there is a significant rise in tCho and a trend (reversible) for mI also to be raised. In patients with SLE major the NAA is significantly and permanently reduced and mI is significantly raised, whereas the tCho levels are near normal. Further investigations are needed to determine how specific MRS is as a clinical marker for brain disturbance in SLE.

Evaluation of cerebrospinal anticardiolipin antibodies in lupus patients with neuropsychiatric manifestations

To evaluate the role of cerebrospinal fluid (CSF) anticardiolipin antibody (aCL) in lupus patients with neuropsychiatric manifestations, paired measurements of aCL, in the serum and CSF, were performed using the ELISA method in lupus patients (n=31) and controls with other medical diseases (n=8). High titers of CSF IgG-aCL were detected in cerebral lupus patients with lupus headache, acute psychosis, cognitive impairment, high cortical dysfunction, and altered consciousness. Intrathecal synthesis, rather than the diffusion of IgG-aCL from serum to compartment of the central nervous system, occurred in these NPLE patients. The binding of aCL to brain components might play a role in the development of neuropsychiatric manifestations in cerebral lupus patients.

The association between the antiphospholipid antibody syndrome and neuropsychological impairment in SLE

OBJECTIVE

To examine the relationship between neuropsychological impairment and antiphospholipid antibody syndrome (aPL syndrome) in patients with systemic lupus erythermatosus (SLE).

PATIENTS

Sixty-nine patients satisfying ACR criteria were studied. Sixteen patients with the aPL syndrome and 53 patients without the syndrome were subjected to eight neuropsychological tests, a physical examination and serological investigations. No patients with other pathology, known to cause acute or chronic impairment of neuropsychological function, were included. Sixty-five underwent MRI scans.

RESULTS

There were no significant differences in age, level of education, incidence of hypertension or disease activity in the two groups. Pearson's correlation coefficients revealed a significant negative correlation with duration of disease in six out of eight tests in the aPL positive group and one out of eight in the aPL negative group. This suggests that aPL syndrome may be involved in the psychological impairment in SLE patients. A larger cohort needs to be studied to confirm this observation.

The American College of Rheumatology nomenclature and case definitions for neuropsychiatric lupus syndromes

OBJECTIVE

To develop a standardized nomenclature system for the neuropsychiatric syndromes of systemic lupus erythematosus (NPSLE).

METHODS

An international, multidisciplinary committee representing rheumatology, neurology, psychiatry, neuropsychology, and hematology developed case definitions, reporting standards, and diagnostic testing recommendations. Before and after the meeting, clinician committee members assigned diagnoses to sets of vignettes randomly generated from a pool of 108 NPSLE patients. To assess whether the nomenclature system improved diagnostic agreement, a consensus index was developed and pre- and postmeeting scores were compared by t-tests.

RESULTS

Case definitions including diagnostic criteria, important exclusions, and methods of ascertainment were developed for 19 NPSLE syndromes. Recommendations for standard reporting requirements, minimum laboratory evaluation, and imaging techniques were formulated. A short neuropsychological test battery for the diagnosis of cognitive deficits was proposed. In the postmeeting exercise, a statistically significant improvement in diagnostic agreement was observed.

CONCLUSION

The American College of Rheumatology (ACR) Nomenclature for NPSLE provides case definitions for 19 neuropsychiatric syndromes seen in SLE, with reporting standards and recommendations for laboratory and imaging tests. It is intended to facilitate and enhance clinical research, particularly multicenter studies, and reporting. In clinical settings, consultation with other specialists may be required. It should be useful for didactic purposes but should not be used uncritically or as a substitute for a clinical diagnosis. The complete case definitions are available on the ACR World Wide Web site: http://www.rheumatology .org/ar/ar.html.

The immune system can affect learning: chronic immune complex disease in a rat model

Evidence is presented that the immune system can affect central nervous system functioning, leading to changes in learning. Immune complex disease is induced in rats and their behavior tested using a Lashley maze. Significant differences in behavior were found between the animals with high disease activity and those with low disease activity and the non-disease controls. These changes were not due to uremia and are most likely due to the immune response. There is some evidence immune complex deposits in the choroid plexus may play some role, but not the sole or major role in the behavioral changes. This provides a model by which immunologic processes can cause neuropsychiatric manifestations in autoimmune diseases like lupus, as well as showing that immune processes can affect behavioral functioning.

Cognition and mood in systemic lupus erythematosus. Evaluation and pathogenesis

Cognitive dysfunction is frequent in SLE, probably related to primary underlying immune/inflammatory mechanisms operating in the brain. Longitudinal studies relating patterns of cognitive impairment to putative pathogenetic factors would provide evidence for this hypothesis. Such studies could also lead to more specific therapeutic interventions to ameliorate or reverse brain compromise in SLE.

Human CD4-reactive antibodies from SLE patients induce reversible inhibition of polyclonal T lymphocyte proliferation

We report on isolation of human polyclonal CD4-reactive antibodies of IgM and/or IgG isotypes from several SLE patients. These antibodies bound specifically to CD4-expressing cell lines and to rCD4 in ELISA and immunoblots. Saturation of CD4-binding sites occurred at antibody concentrations between 5 and 15 micrograms/ml. Anti-CD4 antibodies, in a dose-dependent manner, suppressed the proliferative responses of human peripheral blood mononuclear cells (PBMC) to superantigens (Staphylococcal enterotoxins A and B), anti-CD3 antibodies, and mitogens (PWM and Con A, but not PHA). They could also inhibit the proliferation of highly purified human T cells induced by immobilized anti-CD3 antibodies. To promote their effects on T cells, human anti-CD4 antibodies had to be present at lymphocyte cultures before or at the time of priming. There was no significant inhibition when antibodies were added more than 24 h following T cell activation. Substantial evidence that the immunosuppression induced by anti-CD4 antibodies was due to their direct effect on T cells was obtained. Down-regulatory effect of anti-CD4 antibodies could be significantly reversed by addition of exogenous IL-2 and by preincubation with soluble recombinant (r)CD4. Interestingly, at least one affinity-purified anti-CD4 antibody could costimulate the T cell proliferation induced by superantigens or anti-CD3 antibodies, especially when used at subsaturating concentrations (1-4 micrograms/ml) and when added subsequently to the initiation of cultures.

CD4-reactive antibodies in systemic lupus erythematosus

An important place in the immune network is reserved for specific interactions between regulatory antibodies (Ab) and their ligands on T and B lymphocytes. Several lines of evidence indicate that the CD4 glycoprotein may be recognized by such Ab. High levels of CD4-reactive Ab occur in approximately 10-20% of HIV-infected patients. Moreover, between 20 and 30% SLE patients have Ab preferentially reactive with the CD4+ T cells. In relation to this, we have done studies aimed at demonstrating the existence and characteristics of Ab directly targeting CD4 in patients with SLE in comparison with rheumatoid arthritis and normal controls. Assessment of the CD4-reactive Ab by different approaches revealed a several-fold increase in serum concentration of anti-CD4 Ab restricted to a subset of SLE patients (n = 15/87, 17.2%). Enhanced binding was shown to occur specifically both on native CD4 (by immunofluorescence) and on recombinant CD4 (by ELISA and Western blot). Anti-CD4 Ab belonged to IgM and/or IgG isotypes. The overall binding of immunoglobulins to the CD4 molecule was not significantly contributed by DNA/anti-DNA and other circulating immune complexes, and there was no restriction in the usage of kappa and lambda light chains. Clinically, high CD4 reactivity occurred in SLE patients with active disease, as measured by the SLEDAI, and was associated with particular clinical manifestations, including neuropsychiatric disease and lymphopenia.

Psychoneuroimmunology of autoimmune disorders

The interactions between the immune system and psychological states are both intricate and intriguing. Research at a molecular level has thrown considerable light on the previously ill-defined area of psychoneuroimmunology. In this report, we explore the psychoneuroimmunology of autoimmune disorders, particularly rheumatoid arthritis and lupus erythematosus. Animal models of these diseases have provided a particularly useful window on complex psychoneuroimmunological interactions. Observations about the effect of stress on the onset and course of autoimmune disorders has added to our understanding of psychoneuroimmunological interactions. These interactions are bi-directional, as reflected in the autoimmune-mediated neuropsychiatric manifestations of systemic lupus. Exploring the role of various neurotransmitters and neuromodulators in the stress response may have important therapeutic implications for autoimmune disorders.

Anti-neuronal antibodies in antiphospholipid syndrome with central nervous system involvement: the difference from systemic lupus erythematosus

The presence of antineuronal antibodies was compared in 43 patients with primary aPLS and 57 patients with neuropsychiatric SLE. Fifty-eight patients with Guillain-Barré syndrome and 72 normal healthy donors served as control groups. Seventeen patients in the study group had aPLS associated with CNS involvement. Antineuronal antibodies were studied in the sera employing a novel flow cytometric assay. The frequency of antineuronal antibodies in patients with aPLS and CNS involvement was not significantly different from that of patients with aPLS without CNS disease or from that found in the control groups (12%, 19% and 7%, respectively). However, it was significantly different from that found in SLE patients with CNS involvement (60%) (P < 0.001). Our results provide further evidence that unlike CNS-SLE, the major mechanism of CNS involvement in patients with primary aPLS might not be autoantibody (antineuronal) mediated, but rather 'thrombotic' in origin, or due to yet unknown factors.

Controversies in lupus: nervous system involvement

What have we learned about CNS lupus in recent years? An enormous amount of knowledge on pathophysiology of antiphospholipid antibodies, in particular, has been gathered. Although hard evidence of a direct pathogenetic role of these antibodies in cerebral lupus is still lacking, it is generally felt that the multiple microinfarctions found in the brains of lupus patients are related to their presence. Better understanding of the pathogenesis of cerebral lupus will come from the study of experimental models, as it has been possible to develop an antiphospholipid antibody syndrome in mice. Because no specific laboratory test for CNS lupus is yet available, diagnosing the condition remains a challenge to every clinician. Techniques including neuropsychometric testing, quantitative EEG, and SPECT scans have taught us more about cognitive dysfunction and psychosis in patients with SLE. These categories remain the most difficult to define. The concept of hypercoagulability in SLE patients has diverted the direction of therapy from immunosuppression towards anticoagulation. It is of utmost importance that randomised trials are commenced in order to determine the optimal mode of anticoagulation for various groups of lupus patients. It will be necessary to conduct such trials under strict inclusion criteria, based on well defined patient categories. Such an enterprise will require international co-operation of investigators.

[Neurologic manifestations associated with antiphospholipid antibodies. Or what remains of neurolupus?]

Antiphospholipid antibody is associated with a clinical syndrome of vascular thrombosis, thrombocytopenia, recurrent fetal loss and livedo reticularis, whether or not a clinical diagnosis of systemic lupus erythematosus (SLE) coexists. Central nervous system involvement in SLE is multifactorial, thrombotic events, antineuronal antibodies, hypertension, infection, side effects of drugs etc. Antiphospholipid antibodies may play a role in focal neurological manifestations in SLE. In the absence of SLE, different neurological symptoms are well associated with antiphospholipid antibodies including stroke, seizures, dementia, migraine, ocular ischemia, chorea, transverse myelopathy, cerebral phlebitis. Other association are more controversal like Guillain Barré syndrome, motor neuron disease, communicating hydrocephalus. In all patients with antiphospholipid antibodies with neurological involvement, cerebral MRI may be performed with an echocardiographic study because a possible association with Libman and Sacks endocarditis, valve dysfunction or cardiac thrombus source of cerebral ischemia.

Nervous system lupus: pathogenesis and rationale for therapy

Several different pathogenic mechanisms appear to be involved in CNS lupus. These include: B-cell/autoantibody-mediated nervous system compromise; immune complex deposition and vasculitis; microthrombosis and vasculopathy; aberrant MHC Class II antigen expression with T-cell mediated disease (multiple-sclerosis model); and, cytokine-induced brain inflammation. These processes are not mutually exclusive: there exist in vitro and in vivo models for each of these. A number of autoantibodies, especially those with specificities for shared neuronal/lymphocyte antigens, are associated with certain forms of cognitive dysfunction or overt nervous system manifestations. In MRL/lpr mice, lymphoid infiltrates in the brain parenchyma are related to a neurobehavioural dysfunction which develops very early in the course of autoimmune disease. Recent results, both in animal models and in human studies on the therapeutic effects of corticosteroids, immunosuppressive drugs or anticoagulants on clinical and subclinical manifestations of CNS lupus are highlighted in an attempt to develop a rationale for intervention based upon presumed pathogenesis.

Psychiatric disorder and cognitive impairment in SLE

Poor performance on cognitive testing is common in SLE but it is not progressive in the majority of patients and may fluctuate or resolve without specific treatment. Cognitive impairment in patients without overt CNS-SLE may result from generalised disease activity or psychiatric disorder which reduce speed, concentration and motivation. This emphasises once again the importance of recognising and treating psychiatric disorder in these patients. Although mean cognitive scores are lower in SLE patients with overt CNS involvement than those without, an individual's cognitive score is a poor predictor of the presence of CNS involvement because of considerable overlap between groups. It has been suggested that the pattern of cognitive impairment, rather than simply whether it is present or absent, may be more helpful in identifying patients with CNS involvement but this requires further investigation in prospective studies. Cognitive impairment at one point in time is not predictive of future CNS events during 1 or 2 years of follow-up. Routine cognitive testing in SLE does not therefore appear to be helpful either for identifying patients with current CNS involvement or for identifying those at future risk of this complication. In the absence of double-blind randomised controlled trials, treatment of neuropsychiatric SLE is based on clinical experience and anecdotal case reports. Aggressive immunosuppression with high-dose corticosteroids in conjunction with either azathioprine or cyclophosphamide may be indicated in patients with life-threatening CNS-SLE but, on the basis of current evidence, is not justified in those with lone subtle cognitive abnormalities.