Pathogenesis of neuropsychiatric systemic lupus erythematosus and potential biomarkers

Acute Encephalopathy Workup for a Patient With a History of Lupus Cerebritis and Unremarkable Inflammatory Markers: A Case Report

Lupus is a relatively rare disease; however, many of the patients diagnosed with lupus experience an acute confusional state. Despite the prevalence, lupus cerebritis remains a diagnosis of exclusion due to the number of differential diagnoses of the cause of acute confusional state and unreliable clinical markers. This case report highlights the significant duration it takes to work up a broad differential before initiating treatment for lupus. Our case involves a 65-year-old woman with a documented history of lupus, who presented with acute encephalopathy. Following the comprehensive diagnostic investigation, the patient was treated with high-dose steroids that resolved the patient's symptoms. This report considers the option of empiric steroid treatment in the setting of acute encephalopathy in individuals with a history of lupus cerebritis with inconclusive test results.

Prevalence of neuropsychiatric disorders in patients with systemic lupus erythematosus in Pakistan: A systematic review and meta-analysis

INTRODUCTION

By conducting a systematic review and meta-analysis, we investigated the prevalence of neuropsychiatric (NP) symptoms among systemic lupus erythematosus (SLE) patients in Pakistan.

METHODS

In this review work, three electronic databases (Web of Science, MEDLINE, and Google Scholar) and local databases were screened for 20 years from 1 January 2002 to 30 September 2022, to identify the articles evaluating the prevalence of NP symptoms in SLE patients in Pakistan. We performed a random-effects meta-analysis to estimate the prevalence of NPSLE. Statistical heterogeneity was measured by the I2 index, and subgroup meta-analyses were used to access the statistical heterogeneity. Furthermore, meta-regression models were used to examine the associations between prevalence estimates and study characteristics of interest. Three independent authors reviewed existing studies, extracted data, and rated the qualities of selected studies. This review was registered on PROSPERO (Registration no. CRD42022361798).

RESULTS

Thirteen studies met the inclusion criteria out of the 322 studies with a total of 2,003 SLE patients for this systematic review and meta-analysis. The prevalence of NP disorders in SLE patients was estimated to be 30.42% (95% CI:18.26-44.11%), with cognitive dysfunction being the most common (31.51%; 95% CI:1.28-76.27%), followed by headache (10.22%; 95% CI: 0.00-33.43%), seizures (5.96%; 95% CI: 3.80-8.53%), psychosis (3.64%; 95% CI: 2.38-5.13%), and neuropathy is the least common (0.86%; 95% CI: 0.00-2.74%). The heterogeneity between studies was significant (p < 0.01). The pooled prevalence of NP disorders among SLE patients was found highest in Punjab (41.21%) and lowest in Sindh (17.60%).

CONCLUSION

Findings from this study revealed that SLE patients have a high prevalence of NP disorders. The most common symptoms were cognitive dysfunctions, headaches, seizures, psychosis, and neuropathy. Clinicians can manage these potentially deadly and disabling diseases more effectively if they understand the incidence of each NP symptom in SLE patients. NP symptoms among SLE patients are at their peak in Pakistan; policymakers should devise preventive strategies to curb the disease.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record. php?RecordID=361798, identifier CRD42022361798.

White-matter integrity in patients with systemic lupus erythematosus and memory deficits

PURPOSE

Cognitive dysfunction is common in neuropsychiatric systemic lupus erythematosus (SLE). Memory is a commonly affected cognitive domain. Clinically, however, it is difficult to detect memory deficits. The objective of this study is to evaluate whether normal controls and SLE patients with and without memory deficit differ in terms of white-matter integrity.

METHODS

Twenty SLE patients with memory deficit were compared to 47 SLE patients without memory deficit and 22 sex-, age-, and education-matched control individuals. Diffusion tensor imaging (DTI) was performed in a 1.5-Tesla scanner. For tract-based spatial statistics analysis, a white-matter skeleton was created. A permutation-based inference with 5000 permutations with a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD) were also projected onto the mean FA skeleton.

RESULTS

Compared to controls, SLE patients with and without memory deficit had decreased FA in: bilateral anterior thalamic radiation, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, uncinate fasciculus, corticospinal tract, genu, and body of the corpus callosum. SLE patients with and without memory deficit also presented increased MD and RD values compared to controls in these areas. Comparison between SLE patients with and without memory deficit did not present significant differences in DTI parameters.

CONCLUSION

DTI can detect extensive abnormalities in the normal-appearing white matter of SLE patients with and without memory deficit, compared to controls. However, there was no difference, in terms of white-matter integrity, between the groups of SLE patients.

Depression and anxiety in systemic lupus erythematosus: The crosstalk between immunological, clinical, and psychosocial factors

Depression and anxiety cause severe loss of quality of life for patients with systemic lupus erythematosus. The causes and factors that contribute to these psychological manifestations in lupus are difficult to disentangle. This study compared clinical, psychological, and demographic factors between lupus patients, depressed patients, and rheumatoid arthritis patients to discover lupus-specific contributors to depression. Lupus-specific manifestations of depression were also investigated.Physiological, clinical, and psychosocial data were collected from 77 patients. ELISA was used to measure cytokine levels. Univariate and Multivariate analyses were used to compare the patient populations and identify correlations between key physical and psychological indicators.The prevalence of depression in the SLE cohort was 6 times greater than the healthy control subjects. Pain, IL-6, and Pittsburgh Sleep Quality index values were all significantly higher in SLE patients compared with the healthy control group (P < .001, P = .038, and P = .005, respectively). Anxiety levels were significantly higher in SLE patients compared to healthy and RA control patients (P = .020 and .011, respectively). Serum IL-10 concentrations, relationship assessment scale, and fatigue severity scale values were found to be correlated with depression among the SLE patients (P = .036, P = .007, and P = .001, respectively). Relationship assessment and fatigue severity scale scores were found to be the best indicators of depression for the SLE patients (P = .042 and .028, respectively).Fatigue Severity, relationship satisfaction, and IL-10 concentrations are indicators of depression in lupus patients. Despite also suffering from the pain and disability that accompanies chronic autoimmune disease, the rheumatoid arthritis patients had less anxiety and better relationship scores.

Effects of sustained i.c.v. infusion of lupus CSF and autoantibodies on behavioral phenotype and neuronal calcium signaling

Systemic lupus erythematosus (SLE) is a potentially fatal autoimmune disease that is often accompanied by brain atrophy and diverse neuropsychiatric manifestations of unknown origin. More recently, it was observed that cerebrospinal fluid (CSF) from patients and lupus-prone mice can be neurotoxic and that acute administration of specific brain-reactive autoantibodies (BRAs) can induce deficits in isolated behavioral tasks. Given the chronic and complex nature of CNS SLE, the current study examines broad behavioral performance and neuronal Ca²⁺ signaling in mice receiving a sustained infusion of cerebrospinal fluid (CSF) from CNS SLE patients and putative BRAs (anti-NR2A, anti-ribosomal P, and anti-α-tubulin). A 2-week intracerebroventricular (i.c.v.) infusion of CSF altered home-cage behavior and induced olfactory dysfunction, excessive immobility in the forced swim test, and perseveration in a learning task. Conversely, sustained administration of purified BRAs produced relatively mild, both inhibitory and stimulatory effects on olfaction, spatial learning/memory, and home-cage behavior. In vitro studies revealed that administration of some CSF samples induces a rapid influx of extracellular Ca²⁺ into murine neurons, an effect that could be partially mimicked with the commercial anti-NR2A antibody and blocked with selective N-methyl-D-aspartate (NMDA) receptor antagonists. The current findings confirm that the CSF from CNS SLE patients can be neuroactive and support the hypothesis that intrathecal BRAs induce synergistically diverse effects on all domains of behavior. In addition, anti-NMDA receptor antibodies may alter Ca²⁺ homeostasis of central neurons, thus accounting for excitotoxicity and contributing to the heterogeneity of psychiatric manifestations in CNS SLE and other autoantibody-related brain disorders.

Neuropsychiatric manifestations in patients with systemic lupus erythematosus: A study from Iran

Background:

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious and well-known complication of systemic lupus erythematosus (SLE). There is limited evidence about the prevalence of NPSLE and its manifestations in Iran. The aim of this study was to study clinical and demographic characteristics of patients with NPSLE in an Iranian population.

Materials and Methods:

This was a cross-sectional study that was undertaken in two referral Clinics of Neurological and Rheumatological Disorders in Alzahra Hospital, Isfahan, Iran. Between March 2004 and June 2010, medical records of registered patients with SLE were examined. NPSLE was characterized using the American College of Rheumatology case definitions. Descriptive statistics and logistic regression were performed for statistical assessment.

Results:

Among 556 patients with SLE, 121 (21.7%) patients were diagnosed as NPSLE and enrolled in the study. Of whom, 94 patients were female (77.7%) and 27 patients were male (22.3%) with a female to male ratio of 3.48:1. The most common NPSLE manifestations were headache (38.8%), cerebrovascular disease (CVD) (38.8%) and seizure (26.4%). Thirty-nine patients have psychiatric disorders. Among them, 32 patients (26.4%) have periods of psychosis and mood disorder was found in 6 patients (5%).

Conclusions:

We identified NPSLE manifestations in 21.7% of patients; headache and CVD were the most frequent neurological manifestations. Continued studies into the pathogenesis of neurological involvement in patients with SLE are warranted.

Immunoinflammatory diseases of the central nervous system - the tale of two cytokines

Cytokines are potent mediators of cellular communication that have crucial roles in the regulation of innate and adaptive immunoinflammatory responses. Clear evidence has emerged in recent years that the dysregulated production of cytokines may in itself be causative in the pathogenesis of certain immunoinflammatory disorders. Here we review current evidence for the involvement of two different cytokines, IFN-α and IL-6, as principal mediators of specific immunoinflammatory disorders of the CNS. IFN-α belongs to the type I IFN family and is causally linked to the development of inflammatory encephalopathy exemplified by the genetic disorder, Aicardi-Goutières syndrome. IL-6 belongs to the gp130 family of cytokines and is causally linked to a number of immunoinflammatory disorders of the CNS including neuromyelitis optica, idiopathic transverse myelitis and genetically linked autoinflammatory neurological disease. In addition to clinical evidence, experimental studies, particularly in genetically engineered mouse models with astrocyte-targeted, CNS-restricted production of IFN-α or IL-6 replicate many of the cardinal neuropathological features of these human cytokine-linked immunoinflammatory neurological disorders giving crucial evidence for a direct causative role of these cytokines and providing further rationale for the therapeutic targeting of these cytokines in neurological diseases where indicated.

Neuropsychiatric systemic lupus erythematosus persists despite attenuation of systemic disease in MRL/lpr mice

Background

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease marked by both B and T cell hyperactivity which commonly affects the joints, skin, kidneys, and brain. Neuropsychiatric disease affects about 40 % of SLE patients, most frequently manifesting as depression, memory deficits, and general cognitive decline. One important and yet unresolved question is whether neuropsychiatric SLE (NPSLE) is a complication of systemic autoimmunity or whether it is primarily driven by brain-intrinsic factors.

Methods

To dissect the relative contributions of the central nervous system from those of the hematopoietic compartment, we generated bone marrow chimeras between healthy control (MRL/+) and lupus-prone MRL/Tnfrsf6^lpr/lpr mice (MRL/+ → MRL/lpr), as well as control chimeras. After bone marrow reconstitution, mice underwent extensive behavioral testing, analysis of brain tissue, and histological assessment.

Results

Despite transfer of healthy MRL/+ bone marrow and marked attenuation of systemic disease, we found that MRL/+ → MRL/lpr mice had a behavioral phenotype consisting of depressive-like behavior and visuospatial memory deficits, comparable to MRL/lpr → MRL/lpr control transplanted mice and the behavioral profile previously established in MRL/lpr mice. Moreover, MRL/+ → MRL/lpr chimeric mice displayed increased brain RANTES expression, neurodegeneration, and cellular infiltration in the choroid plexus, as well as blood brain barrier disruption, all in the absence of significant systemic autoimmunity.

Conclusions

Chimeric MRL/+ → MRL/lpr mice displayed no attenuation of the behavioral phenotype found in MRL/lpr mice, despite normalized serum autoantibodies and conserved renal function. Therefore, neuropsychiatric disease in the MRL/lpr lupus-prone strain of mice can occur absent any major contributions from systemic autoimmunity.

Behavioral Deficits Are Accompanied by Immunological and Neurochemical Changes in a Mouse Model for Neuropsychiatric Lupus (NP-SLE)

Neuropsychiatric symptoms of systemic lupus erythematosus (NP-SLE) have been understudied compared to end-organ failure and peripheral pathology. Neuropsychiatric symptoms, particularly affective and cognitive indications, may be among the earliest manifestations of SLE. Among the potential pathophysiological mechanisms responsible for NP-SLE are increased peripheral pro-inflammatory cytokines, subsequent induction of indoleamine-2,3-dioxygenase (IDO) and activation of the kynurenine pathway. In the MRL/MpJ-Faslpr (MRL/lpr) murine model of lupus, depression-like behavior and cognitive dysfunction is evident before significant levels of autoantibody titers and nephritis are present. We examined the behavioral profile of MRL/lpr mice and their congenic controls, a comprehensive plasma cytokine and chemokine profile, and brain levels of serotonin and kynurenine pathway metabolites. Consistent with previous studies, MRL/lpr mice had increased depression-like behavior and visuospatial memory impairment. Plasma levels of different inflammatory molecules (Haptoglobin, interleukin 10 (IL-10), interferon γ-inducible protein 10 (IP-10/CXCL10), lymphotactin, macrophage inhibitory protein 3β (MIP-3β/CCL19), monocyte chemotactic protein 1, 3 and 5 (MCP-1/CCL2, MCP-3/CCL7, MCP-5/CCL12), vascular cell adhesion molecule 1 (VCAM-1), lymphotactin and interferon γ (IFN-γ)) were increased in MRL/lpr mice. In cortex and hippocampus, MRL/lpr mice had increased levels of kynurenine pathway metabolites (kynurenine, 3-hydroxykynurenine, 3-hydroxynthranilic acid and quinolinic acid). Therefore, our study suggests that increased cytokine expression may be critical in the regulation subtle aspects of brain function in NP-SLE via induction of IDO and tryptophan/kynurenine metabolism.

Novel nanometer scaffolds regulate the biological behaviors of neural stem cells

Ideal tissue-engineered scaffold materials regulate proliferation, apoptosis and differentiation of cells seeded on them by regulating gene expression. In this study, aligned and randomly oriented collagen nanofiber scaffolds were prepared using electronic spinning technology. Their diameters and appearance reached the standards of tissue-engineered nanometer scaffolds. The nanofiber scaffolds were characterized by a high swelling ratio, high porosity and good mechanical properties. The proliferation of spinal cord-derived neural stem cells on novel nanofiber scaffolds was obviously enhanced. The proportions of cells in the S and G2/M phases noticeably increased. Moreover, the proliferation rate of neural stem cells on the aligned collagen nanofiber scaffolds was high. The expression levels of cyclin D1 and cyclin-dependent kinase 2 were increased. Bcl-2 expression was significantly increased, but Bax and caspase-3 gene expressions were obviously decreased. There was no significant difference in the differentiation of neural stem cells into neurons on aligned and randomly oriented collagen nanofiber scaffolds. These results indicate that novel nanofiber scaffolds could promote the proliferation of spinal cord-derived neural stem cells and inhibit apoptosis without inducing differentiation. Nanofiber scaffolds regulate apoptosis and proliferation in neural stem cells by altering gene expression.

Libman-Sacks endocarditis and embolic cerebrovascular disease

OBJECTIVES

The aim of this study was to determine whether Libman-Sacks endocarditis is a pathogenic factor for cerebrovascular disease (CVD) in systemic lupus erythematosus (SLE).

BACKGROUND

A cardioembolic pathogenesis of SLE CVD manifested as: 1) neuropsychiatric systemic lupus erythematosus (NPSLE), including stroke and transient ischemic attacks (TIA); 2) neurocognitive dysfunction; and 3) magnetic resonance imaging of focal brain lesions has not been established.

METHODS

A 6-year study of 30 patients with acute NPSLE (27 women, 38 ± 12 years of age), 46 age- and sex-matched SLE controls without NPSLE (42 women, 36 ± 12 years of age), and 26 age- and sex-matched healthy controls (22 women, 34 ± 11 years of age) who underwent clinical and laboratory evaluations, transesophageal echocardiography, carotid duplex ultrasound, transcranial Doppler ultrasound, neurocognitive testing, and brain magnetic resonance imaging/magnetic resonance angiography. Patients with NPSLE were re-evaluated after 4.5 months of therapy. All patients were followed clinically for a median of 52 months.

RESULTS

Libman-Sacks vegetations (87%), cerebromicroembolism (27% with 2.5 times more events per hour), neurocognitive dysfunction (60%), and cerebral infarcts (47%) were more common in NPSLE than in SLE (28%, 20%, 33%, and 0%) and healthy controls (8%, 0%, 4%, and 0%, respectively) (all p ≤ 0.009). Patients with vegetations had 3 times more cerebromicroemboli per hour, lower cerebral blood flow, more strokes/TIA and overall NPSLE events, neurocognitive dysfunction, cerebral infarcts, and brain lesion load than those without (all p ≤ 0.01). Libman-Sacks vegetations were independent risk factors of NPSLE (odds ratio [OR]: 13.4; p < 0.001), neurocognitive dysfunction (OR: 8.0; p = 0.01), brain lesions (OR: 5.6; p = 0.004), and all 3 outcomes combined (OR: 7.5; p < 0.001). Follow-up re-evaluations in 18 of 23 (78%) surviving patients with NPSLE demonstrated improvement of vegetations, microembolism, brain perfusion, neurocognitive dysfunction, and lesion load (all p ≤ 0.04). Finally, patients with vegetations had reduced event-free survival time to stroke/TIA, cognitive disability, or death (p = 0.007).

CONCLUSIONS

The presence of Libman-Sacks endocarditis in patients with SLE was associated with a higher risk for embolic CVD. This suggests that Libman-Sacks endocarditis may be a source of cerebral emboli.

Blood-brain barrier damages and intrathecal synthesis of anti-N-methyl-D-aspartate receptor NR2 antibodies in diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematosus

Introduction

Although neuropsychiatric systemic lupus erythematosus (NPSLE) is one of the recalcitrant complications of the disease, its pathogenesis still remains unclear. Previous studies revealed that antibodies reactive with NMDA (N-methyl-D-aspartate) receptor NR2 (anti-NR2) are elevated in cerebrospinal fluid (CSF) of patients with diffuse psychiatric/neuropsychological syndromes (diffuse NPSLE), which is usually more recalcitrant than neurologic syndromes of NPSLE (focal NPSLE). Two mechanisms have been implicated for the elevation of CSF IgG, including intrathecal synthesis and transudation through the damaged blood-brain barrier (BBB). The present study was designed in order to elucidate the roles of BBB function and intrathecal synthesis of anti-NR2 in the elevation of CSF anti-NR2 with regard to the severity in NPSLE.

Methods

Paired serum and CSF samples were obtained from 81 systemic lupus erythematosus (SLE) patients when they presented active neuropsychiatric manifestations, and from 22 non-SLE control patients with non-inflammatory neurological diseases. The 81 SLE patients consisted of 55 patients with diffuse NPSLE, including 23 patients with acute confusional state (ACS), the severest form of diffuse NPSLE, and 26 patients with neurologic syndromes or peripheral nervous system involvement (focal NPSLE). IgG anti-NR2 and albumin were measured by ELISA. BBB function and intrathecal synthesis of anti-NR2 were evaluated by Q albumin and by CSF anti-NR2 index, respectively.

Results

CSF anti-NR2 levels, Q albumin and CSF anti-NR2 index were significantly higher in NPSLE than in non-SLE control. CSF anti-NR2 levels and Q albumin were significantly higher in ACS than in non-ACS diffuse NPSLE (anxiety disorder, cognitive dysfunction, mood disorder and psychosis) or in focal NPSLE, whereas there was no significant difference in CSF anti-NR2 index among the 3 groups. CSF anti-NR2 levels were significantly correlated with Q albumin in diffuse NPSLE (r = 0.3754, P = 0.0053).

Conclusions

These results demonstrate that the severity of BBB damages plays a crucial role in the development of ACS, the severest form of diffuse NPSLE, through the accelerated entry of larger amounts of anti-NR2 into the central nervous system.

A systemic sclerosis and systemic lupus erythematosus pan-meta-GWAS reveals new shared susceptibility loci

Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are two archetypal systemic autoimmune diseases which have been shown to share multiple genetic susceptibility loci. In order to gain insight into the genetic basis of these diseases, we performed a pan-meta-analysis of two genome-wide association studies (GWASs) together with a replication stage including additional SSc and SLE cohorts. This increased the sample size to a total of 21,109 (6835 cases and 14,274 controls). We selected for replication 19 SNPs from the GWAS data. We were able to validate KIAA0319L (P = 3.31 × 10(-11), OR = 1.49) as novel susceptibility loci for SSc and SLE. Furthermore, we also determined that the previously described SLE susceptibility loci PXK (P = 3.27 × 10(-11), OR = 1.20) and JAZF1 (P = 1.11 × 10(-8), OR = 1.13) are shared with SSc. Supporting these new discoveries, we observed that KIAA0319L was overexpressed in peripheral blood cells of SSc and SLE patients compared with healthy controls. With these, we add three (KIAA0319L, PXK and JAZF1) and one (KIAA0319L) new susceptibility loci for SSc and SLE, respectively, increasing significantly the knowledge of the genetic basis of autoimmunity.

Therapeutic potential of SIGIRR in systemic lupus erythematosus

Single immunoglobulin IL-1-related receptor (SIGIRR), which is also known as Toll/interleukin-1 receptor 8, is a member of the interleukin-1 receptor (IL-1R) family. Different from other typical IL-1R superfamily members, SIGIRR seems to exert negatively modulates in immune responses. Several previous studies demonstrated that SIGIRR influences chronic inflammatory or autoimmune diseases, such as intestinal inflammation, rheumatoid arthritis and psoriatic arthritis. Recent work has explored the role of SIGIRR in systemic lupus erythematosus (SLE), for example, the role of SIGIRR protects the mice from hydrocarbon oil-induced lupus has been reported. These results indicate that SIGIRR may represent a novel target for the treatment of SLE. In this review, we will discuss the SIGIRR and the therapeutic potential of modulating the pathway in SLE.

Type I interferon in neurological disease-the devil from within

The members of the type I interferon (IFN-I) family of cytokines are pleiotropic factors that have seminal roles in host defence, acting as antimicrobial and antitumor mediators as well as potent immunomodulatory factors that bridge the innate and adaptive immune responses. Despite these beneficial actions there is mounting evidence that link inappropriate or chronic production of IFN-I in the CNS to the development of a number of severe neuroinflammatory disorders. The most persuasive example is the genetically determined inflammatory encephalopathy, Aicardi-Goutières syndrome (AGS) in which patients have chronically elevated IFN-α production in the CNS. The presentation of AGS can often mimic congenital viral infection, however, molecular genetic studies have identified mutations in six genes that can cause AGS, most likely via dysregulated nucleic acid metabolism and activation of the innate immune response leading to increased intrathecal production of IFN-α. The role of IFN-α as a pathogenic factor in AGS and other neurological disorders has gained considerable support from experimental studies. In particular, a transgenic mouse model with CNS-restricted production of IFN-α replicates many of the cardinal neuropathologic features of AGS and reveal IFN-I to be the "devil from within", mediating molecular and cellular damage within the CNS. Thus, targeting IFN-I may be an effective strategy for the treatment of AGS as well as some other autoimmune and infectious neurological "interferonopathies".

Impaired DNA methylation and its mechanisms in CD4(+)T cells of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by production of autoantibodies against a series of nuclear antigens. Although the exact cause of SLE is still unknown, the influence of environment, which is largely reflected by the epigenetic mechanisms, with DNA methylation changes in particular, are generally considered as key players in the pathogenesis of SLE. As an important post-translational modification, DNA methylation mainly suppresses the expression of relevant genes. Accumulating evidence has indicated that abnormal DNA hypomethylation in T cells is an important epigenetic hallmark in SLE. Apart from those classic methylation-sensitive autoimmunity-related genes in lupus, such as CD11a (ITGAL), Perforin (PRF1), CD70 (TNFSF7), CD40 ligand (TNFSF5) and PP2Acα, the genome-wide methylation pattern has also been explored recently, providing us a more and more full-scale picture of the abnormal status of DNA methylation in SLE. On the other hand, certain miRNAs, RFX1, defective ERK pathway signaling, Gadd45α and DNA hydroxymethylation have been proposed as potential mechanisms leading to DNA hypomethylation in lupus. In this review, we summarize current understanding of T cell DNA methylation changes and the consequently altered gene expressions in lupus, and how they contribute to the development of SLE. Possible mechanisms underlying these aberrancies are also discussed based on the reported literature and our own findings.

Prospective study of clinical phenotypes in neuropsychiatric systemic lupus erythematosus; multidisciplinary approach to diagnosis and therapy

OBJECTIVE

To describe clinical phenotypes in neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

Data were prospectively collected in the Leiden NPSLE referral clinic, where patients suspected of having NPSLE are assessed in a standardized multidisciplinary manner. In consensus meetings, all medical specialists agreed on therapeutic strategy based on the suspected pathogenetic mechanism of NPSLE in the individual patient. An algorithm illustrates the process of decision-making during the consensus meeting. Clinical phenotypes are described, classified by pathogenetic mechanism.

RESULTS

One hundred consecutive patients were evaluated, of whom 71 had SLE (29 patients did not fulfill ≥ 4 American College of Rheumatology criteria) and 46 had NPSLE. Primary NPSLE was diagnosed in 38 patients (53%) and could be differentiated in 21 patients (55%) with inflammatory NPSLE who were advised on immunosuppressive therapy, 12 patients (32%) with ischemic NPSLE who were advised on anticoagulant therapy, and 5 patients (13%) with undefined NPSLE who were advised symptomatic treatment only. Cognitive dysfunction and higher level of disease activity were associated with inflammatory NPSLE. Although presence of immunoglobulin G anticardiolipin antibodies and abnormalities on magnetic resonance imaging (MRI) were associated with ischemic NPSLE, abnormalities on MRI lacked specificity to distinguish phenotypes. A history of renal disease and use of corticosteroids were associated with secondary NPSLE.

CONCLUSION

We describe multidisciplinary consensus as a standard for diagnosing and defining phenotypes in NPSLE. These phenotypes show specific characteristics, which can be used to support diagnosis and guide therapeutic decisions. Clinical phenotyping and selection of patients becomes increasingly important when advances in experimental science lead to new targets for therapy in NPSLE.

Serum antibodies against the 70k polypeptides of the U1 ribonucleoprotein complex are associated with psychiatric syndromes in systemic lupus erythematosus: a retrospective study

OBJECTIVES

We assessed the association between serum autoantibodies against the 70-kDa polypeptide of the U1-ribonucleoprotein (RNP) complex (U1-70k) and the central nervous system (CNS) syndromes in systemic lupus erythematosus (SLE) patients.

METHODS

We studied 106 hospitalized patients with active SLE, comparing those with (n = 32) and without (n = 74) CNS syndromes. CNS syndromes were further classified into neurologic (n = 21) and psychiatric (n = 15) disorders. Immunoglobulin G (IgG) anti-U1-70k antibodies were measured by enzyme-linked immunosorbent assay (ELISA) using recombinant antigens. IgG antibodies against whole U1-RNP were measured using commercial ELISA kits.

RESULTS

Although there was no significant difference in the levels of serum anti-U1-70k antibodies in SLE patients with or without CNS syndromes (p = 0.83), the levels were significantly elevated in SLE patients compared with patients without psychiatric syndromes (p = 0.030). In contrast, no significant difference was observed in the levels of serum anti-U1-RNP antibodies in SLE patients with or without psychiatric syndromes (p = 0.555).

CONCLUSIONS

These results indicate that serum anti-U1-70k antibodies are associated with psychiatric syndromes in SLE but that they are not associated with CNS syndromes as a whole or with neurologic syndromes. The anti-U1-70k antibodies might be involved in the pathological mechanisms of psychiatric syndromes in SLE.

Measurement of autoantibodies in pediatric-onset systemic lupus erythematosus and their relationship with disease-associated manifestations

OBJECTIVE

To evaluate an autoantibody profile in pediatric-onset systemic lupus erythematosus (SLE) patients to determine clinical and statistical associations with disease-associated manifestations.

METHODS

Sera from 53 SLE patients and 22 healthy individuals were collected. Antibodies to C1q, histone, chromatin, ribosomal P, dsDNA, and high-avidity dsDNA were measured by enzyme-linked immunosorbent assays. Patient records were evaluated for clinical and laboratory associations.

RESULTS

The most prevalent autoantibodies found in the SLE cohort were anti-C1q antibodies (n = 32, 60%), which correlated significantly with proteinuria and decreased complement levels (P < 0.05). Anti-C1q and antihistone antibodies were significantly elevated in patients with class III/IV nephritis compared with class I/II/V nephritis (P = 0.041). SLE patients with active nephritis at the time of sample collection demonstrated significantly elevated levels of anti-C1q antibodies compared with those without active nephritis, also exhibiting 100% sensitivity for active nephritis, proteinuria, and urinary casts. Antibodies to C1q, dsDNA, histone, and chromatin were significantly elevated in patients with active disease (P < 0.01). Chart-documented anti-dsDNA antibodies were positive in 28 SLE patients, INOVA anti-dsDNA antibodies in 25 patients, and high-avidity anti-dsDNA antibodies in 8 patients. Antihistone correlated significantly with leukopenia and hemolytic anemia (P < 0.05).

CONCLUSIONS

This study indicates the importance of measuring anti-C1q antibodies in pediatric-onset SLE patients because elevated anti-C1q antibodies may be more indicative of renal disease activity, showing significant correlation with proteinuria, urinary casts, and active nephritis. Antibodies to C1q, histone, chromatin, and dsDNA exhibited the strongest association with clinical features, indicating the importance of measuring all of these antibodies in pediatric-onset SLE patients.

Autoantibodies as biomarkers for the prediction of neuropsychiatric events in systemic lupus erythematosus

OBJECTIVE

Neuropsychiatric events occur unpredictably in systemic lupus erythematosus (SLE) and most biomarker associations remain to be prospectively validated. This study examined a disease inception cohort of 1047 SLE patients to determine which autoantibodies at enrolment predicted subsequent neuropsychiatric events.

METHODS

Patients with a recent SLE diagnosis were assessed prospectively for up to 10 years for neuropsychiatric events using the American College of Rheumatology case definitions. Decision rules of graded stringency determined whether neuropsychiatric events were attributable to SLE. Associations between the first neuropsychiatric event and baseline autoantibodies (lupus anticoagulant (LA), anticardiolipin, anti-β(2) glycoprotein-I, anti-ribosomal P and anti-NR2 glutamate receptor) were tested by Cox proportional hazards regression.

RESULTS

Disease duration at enrolment was 5.4 ± 4.2 months, follow-up was 3.6 ± 2.6 years. Patients were 89.1% female with mean (±SD) age 35.2 ± 13.7 years. 495/1047 (47.3%) developed one or more neuropsychiatric event (total 917 events). Neuropsychiatric events attributed to SLE were 15.4% (model A) and 28.2% (model B). At enrolment 21.9% of patients had LA, 13.4% anticardiolipin, 15.1% anti-β(2) glycoprotein-I, 9.2% anti-ribosomal P and 13.7% anti-NR2 antibodies. LA at baseline was associated with subsequent intracranial thrombosis (total n=22) attributed to SLE (model B) (HR 2.54, 95% CI 1.08 to 5.94). Anti-ribosomal P antibody was associated with subsequent psychosis (total n=14) attributed to SLE (model B) (HR 3.92, 95% CI 1.23 to 12.5, p=0.02). Other autoantibodies did not predict neuropsychiatric events.

CONCLUSION

In a prospective study of 1047 recently diagnosed SLE patients, LA and anti-ribosomal P antibodies are associated with an increased future risk of intracranial thrombosis and lupus psychosis, respectively.

Neuropsychiatric manifestations in systemic lupus erythematosus: epidemiology, pathophysiology and management

Systemic lupus erythematosus (SLE) is a relapsing-remitting autoimmune disease with CNS involvement occurring in up to 75% of patients. However, the frequency of neuropsychiatric manifestations in SLE studies varies widely, depending on the type of manifestations included and the method used for evaluation. CNS involvement may be considered primary if directly related to SLE activity in the CNS or secondary when related to treatment, infections, metabolic abnormalities or other systemic manifestations such as uraemia and hypertension. The pathogenesis of neuropsychiatric SLE is as yet unknown, though numerous autoantibodies and cytokines have been suggested as possible mediators. However, independent of the aetiology of the insult, the final common pathway in neuropsychiatric SLE is the involvement of the cerebral microvasculature. The diagnosis of primary CNS involvement by SLE is often difficult, as both focal and diffuse manifestations may occur and there is no gold standard for diagnosis. A high index of clinical suspicion, in addition to laboratory and neuroimaging findings may support the diagnosis. Treatment is mostly empirical, although one randomized controlled trial has shown that cyclophosphamide in addition to methylprednisolone is superior to methylprednisolone alone in severe neuropsychiatric SLE.

Gene expression profiles in a rabbit model of systemic lupus erythematosus autoantibody production

We previously reported the establishment of a rabbit (Oryctolagus cuniculus) model in which peptide immunization led to production of lupus-like autoantibodies including anti-Sm, -RNP, -SS-A, -SS-B, and -dsDNA characteristic of those produced in systemic lupus erythematosus (SLE) patients. Some neurologic symptoms in the form of seizures and nystagmus were observed. The animals used in the previous and in the current study were from a National Institute of Allergy and Infectious Diseases colony of rabbits that were pedigreed, Ig-allotype defined, but not inbred. Their genetic heterogeneity may correspond to that found among patients of a given ethnicity. We extended the information about this rabbit model by microarray-based expression profiling. We first demonstrated that human expression arrays could be used with rabbit RNA to yield information on molecular pathways. We then designed a study evaluating gene expression profiles in eight groups of control and treated rabbits (47 rabbits in total). Genes significantly upregulated in treated rabbits were associated with NK cytotoxicity, Ag presentation, leukocyte migration, cytokine activity, protein kinases, RNA spliceosomal ribonucleoproteins, intracellular signaling cascades, and glutamate receptor activity. These results link increased immune activation with upregulation of components associated with neurologic and anti-RNP responses, demonstrating the utility of the rabbit model to uncover biological pathways related to SLE-induced clinical symptoms, including neuropsychiatric lupus. Our finding of distinct gene expression patterns in rabbits that made anti-dsDNA compared with those that only made other anti-nuclear Abs should be further investigated in subsets of SLE patients with different autoantibody profiles.

Biomarkers in lupus nephritis

Biomarkers have the potential to be useful tools for noninvasively evaluating and managing patients with lupus nephritis. Many candidate biomarkers have been identified, but they require validation in larger cohorts. It is likely that combinations or biomarker profiles, rather than individual markers, will emerge to help better predict the severity of inflammation, the extent of fibrosis, degree of drug responsiveness, and other variables. This approach has the potential to reduce the use of the renal biopsy, improve therapeutic efficacy, and limit toxicity. We predict algorithms based on genotype and biomarkers combined with clinical presentation will emerge to help guide physicians in management. Assays that show the most potential include serum erythrocyte bound complement C4d, interleukin 17, interleukin 23, interferon score/chemokine score ratio, and anti-C1q antibodies. Such urinary biomarkers as fractional excretion of endothelial-1, monocyte chemoattractant protein-1, vascular cell adhesion molecule-1, and TWEAK (tumor necrosis factor-like weak inducer of apoptosis) may also be useful but require validations.