Neuropsychiatric Lupus

Functional outcome after stroke in patients with rheumatoid arthritis and systemic lupus erythematosus

OBJECTIVE

To compare outcomes following stroke rehabilitation among patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) versus patients with neither RA nor SLE (non-RA/SLE).

METHODS

We conducted a retrospective analysis using a national database of patients with stroke admitted to inpatient rehabilitation between 1994 and 2001. Primary outcomes were discharge disposition and functional status, rated by the Functional Independence Measure (FIM) Instrument, at discharge and at followup. The independent variable was RA or SLE. Covariates were age, sex, race/ethnicity, admission FIM ratings, additional comorbidities (none, 1-3, and >3), type of stroke, and length of stay.

RESULTS

We studied 47,853 patients with stroke, 368 with RA, and 119 with SLE. Discharge dispositions were similar for patients with RA and non-RA/SLE (81% discharged home). At discharge, the average FIM rating for patients with RA was 85.8, compared with 87.8 for non-RA/SLE patients. At followup, the average FIM rating for patients with RA was 95.9, compared with 99.6 for non-RA/SLE patients. RA was associated with lower FIM ratings at discharge and followup in multivariate analyses. SLE was associated with younger age (17.5 years). However, patients with SLE had similar discharge dispositions and FIM ratings to non-RA/SLE patients.

CONCLUSION

RA was associated with lower functional status ratings at discharge and followup. Outpatient therapy for patients with RA may reduce long-term assistance. Patients with SLE were younger, but had similar functional outcomes to patients without RA/SLE, suggesting early morbidity from stroke among patients with SLE.

Autoantibodies and neuropsychiatric events at the time of systemic lupus erythematosus diagnosis: results from an international inception cohort study

OBJECTIVE

To examine, in an inception cohort of systemic lupus erythematosus (SLE) patients, the association between neuropsychiatric (NP) events and anti-ribosomal P (anti-P), antiphospholipid (lupus anticoagulant [LAC], anticardiolipin), anti-beta2-glycoprotein I, and anti-NR2 glutamate receptor antibodies.

METHODS

NP events were identified using the American College of Rheumatology case definitions and clustered into central/peripheral and diffuse/focal events. Attribution of NP events to SLE was determined using decision rules of differing stringency. Autoantibodies were measured without knowledge of NP events or their attribution.

RESULTS

Four hundred twelve patients were studied (87.4% female; mean +/- SD age 34.9 +/- 13.5 years, mean +/- SD disease duration 5.0 +/- 4.2 months). There were 214 NP events in 133 patients (32.3%). The proportion of NP events attributed to SLE varied from 15% to 36%. There was no association between autoantibodies and NP events overall. However, the frequency of anti-P antibodies in patients with central NP events attributed to SLE was 4 of 20 (20%), versus 3 of 107 (2.8%) in patients with other NP events and 24 of 279 (8.6%) in those with no NP events (P = 0.04). Among patients with diffuse NP events, 3 of 11 had anti-P antibodies (27%), compared with 4 of 111 patients with other NP events (3.6%) and 24 of 279 of those with no NP events (8.6%) (P = 0.02). Specific clinical-serologic associations were found between anti-P and psychosis attributed to SLE (P = 0.02) and between LAC and cerebrovascular disease attributed to SLE (P = 0.038). There was no significant association between other autoantibodies and NP events.

CONCLUSION

Clinically distinct NP events attributed to SLE and occurring around the time of diagnosis were found to be associated with anti-P antibodies and LAC. This suggests that there are different autoimmune pathogenetic mechanisms, although low sensitivity limits the clinical application of testing for these antibodies.

Antiribosomal-P autoantibodies from psychiatric lupus target a novel neuronal surface protein causing calcium influx and apoptosis

The interesting observation was made 20 years ago that psychotic manifestations in patients with systemic lupus erythematosus are associated with the production of antiribosomal-P protein (anti-P) autoantibodies. Since then, the pathogenic role of anti-P antibodies has attracted considerable attention, giving rise to long-term controversies as evidence has either contradicted or confirmed their clinical association with lupus psychosis. Furthermore, a plausible mechanism supporting an anti-P-mediated neuronal dysfunction is still lacking. We show that anti-P antibodies recognize a new integral membrane protein of the neuronal cell surface. In the brain, this neuronal surface P antigen (NSPA) is preferentially distributed in areas involved in memory, cognition, and emotion. When added to brain cellular cultures, anti-P antibodies caused a rapid and sustained increase in calcium influx in neurons, resulting in apoptotic cell death. In contrast, astrocytes, which do not express NSPA, were not affected. Injection of anti-P antibodies into the brain of living rats also triggered neuronal death by apoptosis. These results demonstrate a neuropathogenic potential of anti-P antibodies and contribute a mechanistic basis for psychiatric lupus. They also provide a molecular target for future exploration of this and other psychiatric diseases.

Regional cerebral blood flow between primary and concomitant fibromyalgia patients: a possible way to differentiate concomitant fibromyalgia from the primary disease

OBJECTIVES

Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) has been used to detect abnormal regional cerebral blood flow (rCBF) in women with primary fibromyalgia (FM). The main aim of this study was to investigate the rCBF deficit in concomitant FM patients and compare it with primary FM.

METHODS

An observational study was designed to analyse the SPECT findings in 92 female patients recruited from January 2002 to January 2004. Differences in the rCBF hypoperfusive areas between 49 primary and 29 concomitant FM patients were assessed in different areas of the brain using the chi(2)-test for statistical significance.

RESULTS

Tc-99m ECD brain SPECT in 71 FM patients revealed heterogeneous rCBF in comparison to the homogeneous scan in 14 control patients. The most prominent rCBF hypoperfusive region in both primary and concomitant FM groups was the left temporoparietal area, followed by the thalamus, right temporoparietal, frontal, and basal ganglia areas. Differences in rCBF hypoperfusion in these areas for both FM groups were not significant (all p>0.5).

CONCLUSIONS

Reduced rCBF at cortical regions, in addition to previously reported areas at the thalamus and the subcortical nucleus, in FM patients was demonstrated in this study. The perfusion deficit areas were similar between primary and concomitant FM when the underlying disease activity was quiescent. The feasibility of using this neuroimaging study to differentiate FM from the primary disease, such as rheumatoid arthritis (RA)-associated depression and neuropsychiatric lupus, should be considered.

New insights into central nervous system lupus: A clinical perspective

Patients with systemic lupus erythematosus (SLE) experience a wide array of neurologic (N) and psychiatric (P) events, some of which are directly attributable to lupus. Regardless of attribution, NP events have a significant impact on individual patient's health-related quality of life. Primary immunopathogenic mechanisms of NP-SLE include vasculopathy, autoantibody production, and intrathecal inflammatory mediators. The recently described anti-NR2 glutamate receptor antibodies have been implicated in animal models of neuronal injury, but their role in the pathogenesis of human NP-SLE is unclear. The diagnosis of NP-SLE remains largely one of exclusion, although the detection of select autoantibodies, CSF analysis, and appropriate use of neuroimaging and neuropsychometric testing may provide support in the evaluation of individual patients. Therapeutic options include symptomatic therapies, immunosuppression, and anticoagulation.

Mortality related to cerebrovascular disease in systemic lupus erythematosus

The objective of this study was to examine mortality rates related to cerebrovascular disease in systemic lupus erythematosus (SLE) compared to the general population. Our sample was a multisite Canadian SLE cohort (10 centres, n = 2688 patients). Deaths due to cerebrovascular disease were ascertained by vital statistics registry linkage using ICD diagnostic codes. Standardized mortality ratio (SMR, ratio of deaths observed to expected) estimates were calculated. The total SMR for death due to cerebrovascular disease was 2.0 (95% confidence interval [CI] 1.0, 3.7). When considering specific types of events, the category with the greatest increased risk was that of ill-defined cerebrovascular events (SMR 44.9 95% CI 9.3, 131.3) and other cerebrovascular disease (SMR 8.4, 95% CI 2.3, 21.6). Deaths due to cerebral infarctions appeared to be less common than hemorrhages and other types of cerebrovascular events. Our data suggest an increase in mortality related to cerebrovascular disease in SLE patients compared to the general population. The large increase in ill-defined cerebrovascular events may represent cases of cerebral vasculitis or other rare forms of nervous system disease; alternately, it may reflect diagnostic uncertainty regarding the etiology of some clinical presentations in SLE patients. The suggestion that more deaths are attributed to cerebral hemorrhage, as opposed to infarction, indicates that inherent or iatrogenic factors (eg, thrombocytopenia or anticoagulation) may be important. In view of the paucity of large-scale studies of mortality attributed to neuropsychiatric outcomes in SLE, our findings highlight the need for additional research in large SLE cohorts.

Elderly-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus is an autoimmune multi-system disease of uncertain aetiology with highly variable clinical manifestations. Women of child-bearing age are most often affected; however, approximately 10-20% of cases occur in older patients. Elderly-onset lupus has been defined in various studies as onset of lupus after age 50-65 years. Menopause and changes in cellular immunity with aging may contribute to development of lupus in older adults. Many studies suggest that the clinical and serological features of elderly-onset lupus differ from those of lupus in younger patients. Arthritis, fever, serositis, sicca symptoms, Raynaud's syndrome, lung disease and neuropsychiatric symptoms are more common in patients with elderly-onset lupus, while malar rash, discoid lupus and glomerulonephritis are less common in elderly-onset patients compared with younger lupus patients. Most elderly-onset lupus patients have a positive anti-nuclear antibody test, but the prevalence of anti-double-stranded DNA and hypocomplementaemia is lower in elderly-onset patients than in younger patients. Rheumatoid factor, anti-Ro/Sjögren's syndrome (SS) A and anti-La/SSB are more often positive in elderly-onset patients. The diagnosis of elderly-onset lupus may be delayed for many months: insidious onset, low prevalence and similarity to other more common disorders make the diagnosis of lupus challenging in this population. Treatment of lupus in the elderly may be complicated by co-morbidities and increased risk of toxicities from usual treatments. Optimal management of elderly-onset lupus is empiric because of a lack of randomised controlled studies. However, the approach to treatment is similar regardless of the age of the patient. This article discusses the prevalence, clinical course, serological features, prognosis and treatment of elderly-onset systemic lupus erythematosus.

Human lupus autoantibodies against NMDA receptors mediate cognitive impairment

Neuropsychiatric systemic lupus erythematosus, which often entails cognitive disturbances and memory loss, has become a major complication for lupus patients. Previously, we developed a murine model of neuropsychiatric lupus based on Abs that cross-react with dsDNA and the NMDA receptor (NMDAR). We showed that these murine Abs impair cognition when they access the CNS through a breach in the blood-brain barrier (BBB) triggered by lipopolysaccharide. Because studies show that lupus patients possess anti-NMDAR Abs in their serum and cerebrospinal fluid, we decided to investigate whether these human Abs contribute to cognitive dysfunction. Here, we show that serum with reactivity to DNA and NMDAR extracted from lupus patients elicited cognitive impairment in mice receiving the serum intravenously and given lipopolysaccharide to compromise the BBB integrity. Brain histopathology showed hippocampal neuron damage, and behavioral testing revealed hippocampus-dependent memory impairment. To determine whether anti-NMDAR Abs exist in the brains of systemic lupus erythematosus patients, we eluted IgG from a patient's brain. The IgG bound DNA and NMDAR and caused neuronal apoptosis when injected into mouse brains. We examined four more brains of patients with neuropsychiatric lupus and found that they displayed endogenous IgG colocalizing with anti-NMDAR Abs. Our results indicate that lupus patients have circulating anti-NMDAR Abs capable of causing neuronal damage and memory deficit, if they breach the BBB, and that the Abs exist within patients' brains. Which aspects of neuropsychiatric lupus may be mediated by anti-NMDAR Abs, how often, and in which patients are now important clinical questions.

The role of autoantibodies in pediatric neuropsychiatric systemic lupus erythematosus

Neuropsychiatric syndromes are prevalent in pediatric patients with systemic lupus erythematosus (SLE) and often manifest early in disease course and with significant associated morbidity. Postulated pathogenic mechanisms of peripheral and central nervous system events include vasculopathy, autoantibody effects and systemic inflammation. The pathogenic roles of anti-phospholipid, anti-ribosomal-P and anti-neuronal autoantibodies have been examined in both focal and diffuse adult neuropsychiatric syndromes. Few studies have probed associations between these autoantibodies and pediatric neuropsychiatric SLE (NP-SLE). Retrospective review of a large ethnically diverse pediatric SLE cohort revealed anti-phospholipid, anti-ribosomal P, and anti-neuronal antibodies to be more prevalent than in many adult studies. Rates of anti-phospholipid and anti-ribosomal P antibody positivity were similar to those of other pediatric reports. Association between anti-neuronal antibodies and NP-SLE events appeared statistically significant in this cohort. Prospective inception cohort studies will need to be undertaken to investigate the significance and utility of autoantibody testing in pediatric NP-SLE.

Update on the treatment of systemic lupus erythematosus

The improving prognosis in patients with systemic lupus erythematosus is due in no small part to refinements in treatment. One idea is to tailor the treatment to the specific clinical features. For example, the treatment of cutaneous lupus may require antimalarial and topical agents initially, with more severe cases requiring dapsone or even thalidomide. Conversely, renal involvement in systemic lupus erythematosus is better treated with corticosteroids and immunosuppressive agents such as intravenous cyclophosphamide, mycophenolate mofetil or azathioprine. It is very clear that comorbidities such as steroid-induced diabetes mellitus, hypertension and osteonecrosis have been responsible for a great deal of the morbidity associated with systemic lupus erythematosus and must be aggressively managed. In addition to 'traditional' agents, newer medications such as rituximab, abatacept and B-lymphocyte stimulator antagonists are showing great promise and will probably be an an important part of the management of severe lupus in the future.

Neuropsychiatric events at the time of diagnosis of systemic lupus erythematosus: An international inception cohort study

OBJECTIVE

To describe the prevalence, characteristics, attribution, and clinical significance of neuropsychiatric (NP) events in an international inception cohort of systemic lupus erythematosus (SLE) patients.

METHODS

The study was conducted by the Systemic Lupus International Collaborating Clinics (SLICC). Patients were enrolled within 15 months of fulfilling the American College of Rheumatology (ACR) SLE classification criteria. All NP events within a predefined enrollment window were identified using the ACR case definitions of 19 NP syndromes. Decision rules were derived to determine the proportion of NP disease attributable to SLE. Clinical significance was determined using the Short Form 36 (SF-36) Health Survey and the SLICC/ACR Damage Index (SDI).

RESULTS

A total of 572 patients (88% female) were recruited, with a mean +/- SD age of 35 +/- 14 years. The mean +/- SD disease duration was 5.2 +/- 4.2 months. Within the enrollment window, 158 of 572 patients (28%) had at least 1 NP event. In total, there were 242 NP events that encompassed 15 of 19 NP syndromes. The proportion of NP events attributed to SLE varied from 19% to 38% using alternate attribution models and occurred in 6.1-11.7% of patients. Those with NP events, regardless of attribution, had lower scores on the SF-36 and higher SDI scores compared with patients with no NP events.

CONCLUSION

Twenty-eight percent of SLE patients experienced at least 1 NP event around the time of diagnosis of SLE, of which only a minority were attributed to SLE. Regardless of attribution, the occurrence of NP events was associated with reduced quality of life and increased organ damage.

SLE: translating lessons from model systems to human disease

Systemic lupus erythematosus (SLE, lupus) results from immune-mediated damage to multiple organs. Its pathogenesis should be viewed as a series of steps, beginning with impaired immune regulation that permits self-reactive T-B-cell activation, which results in the production of autoantibodies. Activated T and B cells then infiltrate tissues, which along with autoantibody and immune complex deposition, triggering local events that ultimately cause organ damage. Although improved understanding of early autoimmune events might open up avenues for disease prevention, future investigations must focus on the mechanisms of end-organ damage in model systems and how to translate this knowledge into human disease. Understanding the mechanisms of each pathogenetic step would provide a rational basis for the development of disease stage-specific diagnostic markers and treatments.