Role of Serum IL-6 in Neuropsychiatric Systemic lupus Erythematosus

Neuropsychiatric manifestations in systemic lupus erythematosus and Sjogren's disease

INTRODUCTION

Autoimmune diseases often present in a systemic manner, affecting various organs and tissues. Involvement of the central and peripheral nervous system is not uncommon in these conditions and is associated with high morbidity and mortality. Therefore, early recognition of the neuropsychiatric manifestations associated with rheumatologic diseases is essential for the introduction of appropriate therapies with the objective of providing a better quality of life for individuals.

OBJECTIVE

To provide a literature review of the neuropsychiatric manifestations related to Systemic Lupus Erythematosus (SLE) and primary Sjögren's Disease (pSD), through the description of signs, symptoms, and immunological variables associated with these conditions.

METHODS

A literature review was conducted by searching for national and international articles available in the SciELO and PubMed databases related to the description of neurological and psychiatric manifestations in patients with the rheumatologic diseases of interest in this study.

RESULTS

The main NP manifestations presented in SLE and pSD are discussed, focusing on clinical presentation and etiology. Treatment option are, however, mainly based on expert opinion, since a few randomized controlled trials have been done.

CONCLUSIONS

There is a high prevalence of neuropsychiatric manifestations associated with SLE and pSD. The variety of physiopathology pathways may explain the variety of symptoms, however pathological findings are rare. Multicenter studies on attribution protocols and treatment are necessary to address the current gaps.

Elevated serum neurofilament light chain levels in patients with neuropsychiatric systemic lupus erythematosus: a cross-sectional study

BACKGROUND

The neurofilament light chain (NfL) in cerebrospinal fluid (CSF) and serum as a marker of neuronal damage may be a potential biomarker of neuropsychiatric involvement in SLE (NPSLE).

METHODS

80 patients with SLE were included.We obtained paired serum and CSF samples from 48 patients (NPSLE n=32, non-NPSLE n=16) and 31 controls. The serum and CSF levels of NfL were determined using ELISA.

RESULTS

Patients with NPSLE demonstrated significantly higher levels of serum NfL compared with the non-NPSLE group (mean 31.68±36.63 pg/mL vs mean 16.75±12.48 pg/mL, respectively, p<0.05) and with controls (mean 10.74±4.36 pg/mL, p<0.01). Notably, CSF NfL concentrations in patients with NPSLE showed an upward trend (mean 1600±2852 pg/mL) in contrast to non-NPSLE patients (mean 393.4±191.9 pg/mL) and controls (mean 509.7±358.5 pg/mL). Furthermore, a positive correlation was observed between serum and CSF NfL levels in patients with NPSLE (R=0.8686, p<0.01). Elevated serum triacylglycerol concentrations, C reactive protein and organ damage were linked to increased serum (p=0.002; p<0.001; p=0.036) and CSF (p=0.008; p=0.007; p<0.001) NfL concentrations. In addition, we established a significant correlation between intrathecal NfL concentrations and interleukin-6 levels in the CSF of patients with NPSLE (R=0.5118, p<0.05).

CONCLUSION

The serum NfL levels may be a readily available marker of neuropsychiatric involvement in SLE.

Changes in immuno-inflammatory and antioxidant biomarkers in serum and cerebrospinal fluid of dogs with distemper

Canine distemper virus (CDV) causes a multisystemic disease with central nervous system involvement in dogs. Little is known about the role of immuno-inflammatory and redox-state biomarkers in the pathogenesis and diagnosis of naturally occurring CDV infection. Thus, the objectives of this study were: 1) to evaluate the potential differences in a profile of cytokines/chemokines, and inflammatory and redox-status biomarkers in serum between dogs with CDV-infection and healthy dogs, and 2) possible correlations between serum/blood and cerebrospinal fluid (CSF) of these biomarkers in dogs with CDV-infection. Two groups of dogs were designed: 10 with CDV-infection, and 10 healthy. A total of 13 cytokines/chemokines, 3 inflammatory (C-reactive protein [CRP], haptoglobin [Hp], and butyrylcholinesterase [BChE]) and 3 antioxidants of redox status (cupric reducing antioxidant capacity [CUPRAC], Thiol, and ferric reducing ability of plasma [FRAP]) were analyzed in serum and CSF samples. Serum IL-7, IL-8, MCP-1, CRP, Hp, FRAP and Thiol levels were higher (P < 0.05) in dogs with CDV compared to controls. There were significant (P < 0.05) correlations only in IL-6 and MCP-1 between CSF and serum. In conclusion, deregulated immune response, raised inflammation, and imbalances of redox homeostasis and antioxidant defense status may play role in the pathophysiological mechanism of neurological form of CDV-infection. The combination of clinical features and cytokine biomarkers (IL-7, IL-8 and MCP-1) might facilitate clinical diagnosis for neural involvement in dogs with CDV. Some cytokine/chemokine (IL-6 and MCP-1) in CSF are highly correlated with those of serum, indicating that serum samples could reflect the possible changes of these analytes in CSF.

[Formula: see text] Cognitive dysfunction in pediatric systemic lupus erythematosus: current knowledge and future directions

Cognitive dysfunction (CD) is a neurologic complication of pediatric systemic lupus erythematosus (SLE) that remains poorly understood and understudied, despite the potential negative effects of CD on long-term socioeconomic status and quality of life. Data regarding the prevalence and risk factors for CD in pediatric SLE as well as the optimal screening, treatment, and long-term outcomes for CD are lacking. In this review, we present current knowledge on CD in pediatric SLE with a focus on the application to clinical practice. We discuss the challenges in diagnosis, clinical screening methods, potential impacts, and interventions for this complication. Finally, we discuss the remaining gaps in our knowledge of CD in pediatric SLE, and avenues for future research efforts.

Constitutive knockout of interleukin-6 ameliorates memory deficits and entorhinal astrocytosis in the MRL/lpr mouse model of neuropsychiatric lupus

BACKGROUND

Neuropsychiatric lupus (NPSLE) describes the cognitive, memory, and affective emotional burdens faced by many lupus patients. While NPSLE's pathogenesis has not been fully elucidated, clinical imaging studies and cerebrospinal fluid (CSF) findings, namely elevated interleukin-6 (IL-6) levels, point to ongoing neuroinflammation in affected patients. Not only linked to systemic autoimmunity, IL-6 can also activate neurotoxic glial cells the brain. A prior pre-clinical study demonstrated that IL-6 can acutely induce a loss of sucrose preference; the present study sought to assess the necessity of chronic IL-6 exposure in the NPSLE-like disease of MRL/lpr lupus mice.

METHODS

We quantified 1308 proteins in individual serum or pooled CSF samples from MRL/lpr and control MRL/mpj mice using protein microarrays. Serum IL-6 levels were plotted against characteristic NPSLE neurobehavioral deficits. Next, IL-6 knockout MRL/lpr (IL-6 KO; n = 15) and IL-6 wildtype MRL/lpr mice (IL-6 WT; n = 15) underwent behavioral testing, focusing on murine correlates of learning and memory deficits, depression, and anxiety. Using qPCR, we quantified the expression of inflammatory genes in the cortex and hippocampus of MRL/lpr IL-6 KO and WT mice. Immunofluorescent staining was performed to quantify numbers of microglia (Iba1 +) and astrocytes (GFAP +) in multiple cortical regions, the hippocampus, and the amygdala.

RESULTS

MRL/lpr CSF analyses revealed increases in IL-17, MCP-1, TNF-α, and IL-6 (a priori p-value < 0.1). Serum levels of IL-6 correlated with learning and memory performance (R2 = 0.58; p = 0.03), but not motivated behavior, in MRL/lpr mice. Compared to MRL/lpr IL-6 WT, IL-6 KO mice exhibited improved novelty preference on object placement (45.4% vs 60.2%, p < 0.0001) and object recognition (48.9% vs 67.9%, p = 0.002) but equivalent performance in tests for anxiety-like disease and depression-like behavior. IL-6 KO mice displayed decreased cortical expression of aif1 (microglia; p = 0.049) and gfap (astrocytes; p = 0.044). Correspondingly, IL-6 KO mice exhibited decreased density of GFAP + cells compared to IL-6 WT in the entorhinal cortex (89 vs 148 cells/mm2, p = 0.037), an area vital to memory.

CONCLUSIONS

The inflammatory composition of MRL/lpr CSF resembles that of human NPSLE patients. Increased in the CNS, IL-6 is necessary to the development of learning and memory deficits in the MRL/lpr model of NPSLE. Furthermore, the stimulation of entorhinal astrocytosis appears to be a key mechanism by which IL-6 promotes these behavioral deficits.

Serum S100A8/A9 and MMP-9 levels are elevated in systemic lupus erythematosus patients with cognitive impairment

Objective

Cognitive impairment (CI) is one of the most common manifestations of Neuropsychiatric Systemic Lupus Erythematosus (NPSLE). Despite its frequency, we have a limited understanding of the underlying immune mechanisms, resulting in a lack of pathways to target. This study aims to bridge this gap by investigating differences in serum analyte levels in SLE patients based on their cognitive performance, independently from the attribution to SLE, and exploring the potential for various serum analytes to differentiate between SLE patients with and without CI.

Methods

Two hundred ninety individuals aged 18-65 years who met the 2019-EULAR/ACR classification criteria for SLE were included. Cognitive function was measured utilizing the adapted ACR-Neuropsychological Battery (ACR-NB). CI was defined as a z-score of ≤-1.5 in two or more domains. The serum levels of nine analytes were measured using ELISA. The data were randomly partitioned into a training (70%) and a test (30%) sets. Differences in the analyte levels between patients with and without CI were determined; and their ability to discriminate CI from non-CI was evaluated.

Results

Of 290 patients, 40% (n=116) had CI. Serum levels of S100A8/A9 and MMP-9, were significantly higher in patients with CI (p=0.006 and p=0.036, respectively). For most domains of the ACR-NB, patients with CI had higher S100A8/A9 serum levels than those without. Similarly, S100A8/A9 had a negative relationship with multiple CI tests and the highest AUC (0.74, 95%CI: 0.66-0.88) to differentiate between patients with and without CI.

Conclusion

In this large cohort of well-characterized SLE patients, serum S100A8/A9 and MMP-9 were elevated in patients with CI. S100A8/A9 had the greatest discriminatory ability in differentiating between patients with and without CI.

Cognitive dysfunction in systemic lupus erythematosus is associated with disease activity and oxidative stress: a comparative study with rheumatoid arthritis for identifying biomarkers

BACKGROUND

The prevalence and pathophysiological mechanisms of cognitive deficits (CD) Systemic Lupus Erythematosus (SLE) and Rheumatoid arthritis (RA) are very heterogeneous and poorly understood. We characterized CD in patients with SLE compared with RA patients and healthy controls. We compared the neuropsychological profile of SLE and RA with patients' oxidative/inflammatory biomarkers for CD.

METHODS

We performed a cross-sectional study, including 50 SLE patients, 29 RA patients, and 32 healthy controls. SLEDAI and DAS28 assessed disease activity. SF-36 questionnaire and a battery of cognitive tests were applied to all participants. Blood samples were collected to determine IL-6, S100ß, myeloperoxidase (MPO), malondialdehyde and reduced glutathione (GSH) alterations.

RESULTS

In the SLE group, higher GSH was associated with the absence of CD (With CD = 69 ± 49, Without CD = 112 ± 81, p = 0.030), while higher IL-6 was associated with the presence of CD in the RA group (With CD = 603 ± 173, Without CD = 431 ± 162, p = 0.032). Regarding specific cognitive domains, in SLE higher MPO was associated with poor performance in reasoning and abstraction (p = 0.039), higher IL-6 was associated with poor performance in inhibitory control and attention (p = 0.031), and higher GSH was associated with better performance in memory(p = 0.021). Higher SLEDAI was associated with poor performance in semantic fluency(p = 0.031), inhibitory control, and attention in the SLE group(p = 0.037). In the RA group, higher DAS-28 was associated with poor performance in executive functions(p = 0.016) and phonemic fluency (p = 0.003).

CONCLUSION

SLE patients' disease activity, inflammatory state, and oxidative stress were associated with CD. In RA patients, CD was associated with disease activity and inflammatory state. These results encourage further studies with larger samples aiming to confirm oxidative stress parameters as biomarkers of CD in SLE patients.

Role of IL-6 and IL-6 targeted therapy in systemic lupus erythematosus

Interleukin-6 (IL-6) is one of the cytokines implicated in murine and human SLE. Only a few small studies have investigated IL-6 inhibition in human SLE. Currently, there are no studies registered in clinicaltrials.gov to assess the IL-6 targeted therapy in SLE, yet its role in the future remains to be defined. This narrative review analyses these and potential areas of future studies with IL-6 targeted therapy in SLE.

Interleukin 6: at the interface of human health and disease

Interleukin 6 (IL-6) is a pleiotropic cytokine executing a diverse number of functions, ranging from its effects on acute phase reactant pathways, B and T lymphocytes, blood brain barrier permeability, synovial inflammation, hematopoiesis, and embryonic development. This cytokine empowers the transition between innate and adaptive immune responses and helps recruit macrophages and lymphocytes to the sites of injury or infection. Given that IL-6 is involved both in the immune homeostasis and pathogenesis of several autoimmune diseases, research into therapeutic modulation of IL-6 axis resulted in the approval of a number of effective treatments for several autoimmune disorders like neuromyelitis optica spectrum disorder (NMOSD), rheumatoid arthritis, juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis (GCA), and cytokine release syndrome, associated with SARS-CoV2 pneumonia. This review discusses downstream inflammatory pathways of IL-6 expression and therapeutic applications of IL-6 blockade, currently investigated for the treatment of several other autoimmune conditions such as autoimmune encephalitis, autoimmune epilepsy, as well as myelin oligodendrocyte glycoprotein associated demyelination (MOGAD). This review further highlights the need for clinical trials to evaluate IL-6 blockade in disorders such neuropsychiatric lupus erythematosus (SLE), sarcoidosis and Behcet's.

Relationship between Disease Characteristics and Circulating Interleukin 6 in a Well-Characterized Cohort of Patients with Systemic Lupus Erythematosus

Interleukin-6 (IL-6) is a proinflammatory cytokine that mediates pleiotropic functions in immune responses and inflammatory diseases. The literature lacks studies, with a clinical perspective, on the relationship between IL-6 serum levels and the characteristics of the disease in patients with systemic lupus erythematosus (SLE). In the present work, we aimed to analyze the association between circulating IL-6 and disease manifestations in a well-characterized series of patients with SLE. Serum IL-6 levels and disease activity (SLEDAI-2K), severity (Katz) and damage index (SLICC-DI), complete lipid profile, and subclinical carotid atherosclerosis were evaluated in 284 patients with SLE. In addition, a complete characterization of the complement system was performed in samples from patients with SLE. A multivariate linear regression analysis was carried out to study the relationship between clinical and laboratory characteristics of the disease and IL-6 levels. Age (beta coef. 0.07 [95%CI 0.01-0.1] pg/mL, p = 0.014), C-reactive protein (beta coef. 0.21 [95%CI 0.16-0.25] pg/mL, p < 0.01), and male gender (beta coef. 2 [95%CI 0.3-0.5] pg/mL, p = 0.024), were positively associated with higher IL-6 levels in SLE patients. Most disease characteristics and damage and activity indices did not show significant relationships with IL-6. However, after multivariate analysis, IL-6 was associated with lower serum levels of HDL cholesterol (beta coef. -0.04 [95%CI -0.08-(-0.1)] pg/mL, p = 0.011), and apolipoprotein A1 (beta coef. -0.02 [95%CI -0.04-(-0.001)] pg/mL, p = 0.035). In contrast, the alternative complement cascade, C1inh, and C3a were all positively and independently associated with higher serum levels of IL-6. Moreover, stratification of the Systematic Coronary Risk Assessment 2 (SCORE2) results according to different categories of cardiovascular risk was associated with higher circulating serum IL-6 levels (beta coef. 0.2 [95%CI 0.02-0.4], pg/mL, p = 0.028). In conclusion, in a large series of SLE patients, IL-6 was not associated with disease-related features of SLE, including damage, severity, or activity indices. However, an association was found between serum IL-6 levels and circulating C3a and cardiovascular risk. Our study emphasizes the importance that IL-6 could have in cardiovascular disease and complement system disruption of SLE patients. Therapies targeting IL-6 could have a role in these two clinical manifestations of patients with SLE.

A Framework to Overcome Challenges in the Management of Infections in Patients with Systemic Lupus Erythematosus

Infections remain one of the leading causes of death in systemic lupus erythematosus (SLE), despite awareness of factors contributing to increased susceptibility to infectious diseases in SLE. Clinicians report challenges and barriers when encountering infection in SLE as certain infections may mimic a lupus flare. There are no evidence-based practice guidelines in the management of fever in SLE, with suboptimal implementations of evidence-based benefits related to infectious disease control and/or prevention strategies in SLE. Vigilance in identifying an opportunistic infection must be stressed when confronted by a diagnostic challenge during a presentation with a febrile illness in SLE. A balanced approach must focus on management of infections in SLE, and reduction in the glucocorticoids dose, given the need to control lupus disease activity to avoid lupus related organ damage and mortality. Clinical judgement and application of biomarkers of lupus flares could reduce false positives and overdiagnosis and improve differentiation of infections from lupus flares. Further precision-based risk and screening measures must identify individuals who would benefit most from low dose immunosuppressive therapy, targeted immune therapy, and vaccination programs.

The association between inflammatory markers in blood and cerebrospinal fluid: a systematic review and meta-analysis

BACKGROUND

Neuroinflammatory processes have been hypothesized to play a role in the pathogenesis of psychiatric and neurological diseases. Studies on this topic often rely on analysis of inflammatory biomarkers in peripheral blood. Unfortunately, the extent to which these peripheral markers reflect inflammatory processes in the central nervous system (CNS) is unclear.

METHODS

We performed a systematic review and found 29 studies examining the association between inflammatory marker levels in blood and cerebrospinal (CSF) samples. We performed a random effects meta-analysis of 21 studies (pooled n = 1679 paired samples) that reported the correlation of inflammatory markers in paired blood-CSF samples.

RESULTS

A qualitative review revealed moderate to high quality of included studies with the majority of studies reporting no significant correlation of inflammatory markers between paired blood-CSF. Meta-analyses revealed a significant low pooled correlation between peripheral and CSF biomarkers (r = 0.21). Meta-analyses of individual cytokines revealed a significant pooled correlation for IL-6 (r = 0.26) and TNFα (r = 0.3) after excluding outlier studies, but not for other cytokines. Sensitivity analyses showed that correlations were highest among participants with a median age above 50 (r = 0.46) and among autoimmune disorder patients (r = 0.35).

CONCLUSION

This systematic review and meta-analysis revealed poor correlation between peripheral and central inflammatory markers in paired blood-CSF samples, with increased correlations in certain study populations. Based on the current findings, peripheral inflammatory markers are a poor reflection of the neuroinflammatory profile.

The pathogenic role of lupus-specific autoantibodies and Interleukin-6 on demyelination of the brainstem and spinal cord in systemic lupus erythematosus

OBJECTIVES

Demyelinating syndromes that result in brainstem and/or spinal cord lesions similar to those observed in neuromyelitis optica spectrum disorder (NMOSD) as neuropsychiatric syndromes in systemic lupus erythematosus (NPSLE) occasionally develop in patients with SLE. Cerebrospinal fluid (CSF) interleukin (IL)-6 is a known biomarker for NMOSD; however, its application in patients with SLE with brainstem and/or spinal cord lesions is unknown. Additionally, the breakdown of blood-brain barrier (BBB) integrity by autoantibodies is another mechanism of NMOSD; however, it is not elucidated in SLE. Therefore, this study was designed to clarify the use of CSF IL-6 and investigate whether autoantibodies contribute to BBB breaches and the development of brainstem and/or spinal cord lesions.

METHODS

Data from patients with NPSLE who had NMOSD-like demyelinating lesions in the central nervous system (CNS), including brainstem and/or spinal cord lesions, were retrospectively analyzed. We retrospectively investigated the interval changes in CSF IL-6 and clinical and serological factors related to BBB permeability using CSF/serum albumin ratio (QAlb).

RESULTS

Twelve patients with NPSLE who had demyelinating lesions in the brainstem and/or spinal cord were recruited. Before treatment, CSF IL-6 levels were 29.1 pg/mL and significantly decreased to 3.8 pg/mL by treatment (p = 0.008). Before treatment, CSF IL-6 was significantly correlated with the anti-dsDNA antibody titer (p = 0.027). Furthermore, before treatment, QAlb was significantly correlated with the serum anti-Smith antibody titer. In patients with atypical NMOSD who had specific lesions defined in the NMOSD diagnostic criteria but were negative for antiaquaporin four antibody, a significant correlation was observed between the serum anti-Smith antibody titer and CSF IL-6 (p = 0.025) and QAlb (p = 0.033) values before treatment.

CONCLUSION

CSF IL-6 could be a surrogating marker for disease activity, and serum anti-Smith antibody permeabilizes the BBB in patients with NPSLE, supporting the development of NMOSD-like CNS lesions.

Inhibitor of NF-κB Kinase Subunit ε Contributes to Neuropsychiatric Manifestations in Lupus-Prone Mice Through Microglial Activation

OBJECTIVE

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiorgan dysfunction. Neuropsychiatric SLE (NPSLE) occurs in 30-40% of lupus patients and is the most severe presentation of SLE, frequently resulting in limitation of daily life. Recent studies have shown that microglia, tissue-resident macrophages in the central nervous system, are involved in the pathogenesis of NPSLE. This study was undertaken to explore new therapeutic targets for NPSLE focusing on microglia.

METHODS

RNA sequencing of microglia in MRL/lpr, lupus-prone mice, as well as that of microglia cultured in vitro with cytokines were performed. A candidate gene, which could be a therapeutic target for NPSLE, was identified, and its role in microglial activation and phagocytosis was investigated using specific inhibitors and small interfering RNA. The effect of intracerebroventricular administration of the inhibitor on the behavioral abnormalities of MRL/lpr was also evaluated.

RESULTS

Transcriptome analysis revealed the up-regulation of Ikbke, which encodes the inhibitor of NF-κB kinase subunit ɛ (IKBKε) in both microglia from MRL/lpr mice and cytokine-stimulated microglia in vitro. Intracerebroventricular administration of an IKBKε inhibitor ameliorated cognitive function and suppressed microglial activation in MRL/lpr mice. Mechanistically, IKBKε inhibition reduced glycolysis, which dampened microglial activation and phagocytosis.

CONCLUSION

These findings suggest that IKBKε plays a vital role in the pathogenesis of NPSLE via microglial activation, and it could serve as a therapeutic target for NPSLE.

Gut microbiome and fecal metabolic alteration in systemic lupus erythematosus patients with depression

Background

Mental health disorders in systemic lupus erythematosus (SLE) are gradually getting recognized; however, less is known regarding the actual structure and compositional alterations in gut microbiome and metabolism and the mechanisms of how they affect depression development in SLE patients.

Methods

Twenty-one SLE patients with depression (SLE-d), 17 SLE patients without depression (SLE-nd), and 32 healthy controls (HC) were included in this study. Fecal samples were collected for 16S rRNA gene sequencing and ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) based metabolomics.

Results

The structure of gut microbiome in the SLE-d group changed compared with that in the other two groups. The microbiome composition of SLE-d group showed decreased species richness indices, characterized by low ACE and Chao1 indices, a decrease in the ratio of phylum Firmicutes to Bacteroidetes, genus Faecalibacterium and Roseburia. A downregulation of the metabolite fexofenadine involved in bile secretion was positively correlated with the genus Faecalibacterium, Subdoligranulum and Agathobacter. Compared with the SLE-nd group, the SLE-d group had elevated serum levels of IL-2 and IL-6 and decreased BDNF. Interestingly, abundance of the genus Faecalibacterium and Roseburia was negatively correlated with IL-6, abundance of the genus Roseburia was negatively correlated with IL-2, and abundance of the genus Bacteroides was positively correlated with IL-2.

Conclusion

This study identified specific fecal microbes and their metabolites that may participate in the development of SLE-d. Our findings provide a new perspective for improving depression in SLE patients by regulating the gut-brain axis.

Cognitive dysfunction in SLE: An understudied clinical manifestation

Neuropsychiatric lupus (NPSLE) is a debilitating manifestation of SLE which occurs in a majority of SLE patients and has a variety of clinical manifestations. In the central nervous system, NPSLE may result from ischemia or penetration of inflammatory mediators and neurotoxic antibodies through the blood brain barrier (BBB). Here we focus on cognitive dysfunction (CD) as an NPSLE manifestation; it is common, underdiagnosed, and without specific therapy. For a very long time, clinicians ignored cognitive dysfunction and researchers who might be interested in the question struggled to find an approach to understanding mechanisms for this manifestation. Recent years, however, propelled by a more patient-centric approach to disease, have seen remarkable progress in our understanding of CD pathogenesis. This has been enabled through the use of novel imaging modalities and numerous mouse models. Overall, these studies point to a pivotal role of an impaired BBB and microglial activation in leading to neuronal injury. These insights suggest potential therapeutic modalities and make possible clinical trials for cognitive impairment.

Pathogenesis and treatment of neuropsychiatric systemic lupus erythematosus: A review

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease with a complex pathogenesis. Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious complication of SLE that involves the nervous system and produces neurological or psychiatric symptoms. After decades of research, it is now believed that the diverse clinical manifestations of NPSLE are associated with intricate mechanisms, and that genetic factors, blood-brain barrier dysfunction, vascular lesions, multiple autoimmune antibodies, cytokines, and neuronal cell death may all contribute to the development of NPSLE. The complexity and diversity of NPSLE manifestations and the clinical overlap with other related neurological or psychiatric disorders make its accurate diagnosis difficult and time-consuming. Therefore, in this review, we describe the known pathogenesis and potential causative factors of NPSLE and briefly outline its treatment that may help in the diagnosis and treatment of NPSLE.

Jak Inhibitors for Treatment of Autoimmune Diseases: Lessons from Systemic Sclerosis and Systemic Lupus Erythematosus

Systemic sclerosis and systemic lupus erythematosus represent two distinct autoimmune diseases belonging to the group of connective tissue disorders. Despite the great progress in the basic science, this progress has not been translated to the development of novel therapeutic approaches that can radically change the face of these diseases. The discovery of JAK kinases, which are tyrosine kinases coupled with cytokine receptors, may open a new chapter in the treatment of so far untreatable diseases. Small synthetic compounds that can block Janus kinases and interact directly with cytokine signalling may provide therapeutic potential in these diseases. In this review, we discuss the therapeutic potential of Jak kinases in light of the cytokine network that JAK kinases are able to interact with. We also provide the theoretical background for the rationale of blocking cytokines with specific JAK inhibitors.

Acute encephalitis in primary Sjögren's syndrome: A case report and literature review

Acute encephalitis is an extremely rare condition in primary Sjogren's syndrome (pSS), and its characteristics and prognosis remain unclear. Here, we report the case of pSS presented with acute encephalitis. She was admitted to our hospital for acute disturbance of consciousness. Acute encephalitis was diagnosed based on the results of the cerebrospinal fluid test (the increase of leucocyte counts, proteins, and interleukin-6 levels), magnetic resonance imaging, and single-photon emission computed tomography with 99mTc. The infectious aetiologies and underlying malignancies were excluded. Serum anti-Sjogren's syndrome-related antigen A autoantibody was positive with extremely high titre. The biopsy specimen of her labial salivary gland revealed a focal lymphocytic sialadenitis with a score of grade 4 in the Greenspan grade. She also developed diffuse alveolar haemorrhage during the clinical course. She was diagnosed with pSS complicated with acute encephalitis followed by diffuse alveolar haemorrhage and successfully treated with pulse steroids, high dose of prednisolone and intravenous cyclophosphamide. Our present case and literature review suggest that acute encephalitis associated with pSS can be treatable with the immunosuppressive therapy, and thus early recognition and treatment initiation are important for this life-threatening condition. Thus, pSS should be included in the differential diagnosis of unexplained encephalitis. Notably, our case characteristically showed diffuse alveolar haemorrhage, adding new insights into the pathogenesis of acute encephalitis associated with pSS that capillaritis might be the underlying cause of this condition.

Role of interleukin-6 and interferon-α in systemic lupus erythematosus: A case-control study and meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disorder affecting various organ systems with unknown etiology. Interleukin-6 (IL-6) and interferon-alpha (IFN-α) have been shown to have a major role in disease pathogenesis, and they correlate with SLE disease activity, but reports in the literature are conflicting. The present study aims to investigate the significance of IL-6 and IFN-α levels in SLE pathogenesis in an eastern Indian cohort.

MATERIAL AND METHODS

70 SLE patients fulfilled SLICC 2012 criteria, and 40 age- and gender-matched healthy controls (HC) were enrolled. Baseline characteristics along with disease activity were recorded for all patients. Levels of IL-6 and IFN-α were measured by using ELISA. For the meta-analysis, published articles were searched through different databases. Two independent researchers extracted data, and the meta-analysis was performed with CMA v3.1.

RESULTS

The plasma levels of IL-6 and IFN-α in SLE patients were significantly elevated compared to HC (IL-6: p < .0001, IFN-α: p = 0.01). SLEDAI score correlated positively with plasma IL-6 (p < .0001, r = 0.46) and IFN-α levels (p < .0001; r = 0.47). Meta-analysis of previous reports, including our case-control data, revealed higher IL-6 (p < .0001) and IFN-α (p = .005) in SLE patients compared to HC. Furthermore, IL-6 (p < .0001, r = 0.526) and IFN-α (p < .0001; r = 0.371) levels positively correlated with the disease activity.

CONCLUSION

IL-6 and IFN-α levels are elevated in SLE and they correlate with disease activity. Further studies with a larger sample size in different populations are required to validate our findings.

Neuropsychiatric Systemic Lupus Erythematosus: a remaining challenge

Systemic Lupus Erythematosus (SLE) is an autoimmune disease, which affects a wide range of organs with variable clinical features. Involvement of the nervous system is a challenging and multifaceted manifestation of the disease, presenting with a broad range of symptoms. Neuropsychiatric lupus (NPSLE) encompasses seven syndromes of the peripheral and 12 of the central nervous system, associated with a high disease burden. Despite advances in the management of SLE, NP manifestations still pose a challenge to clinicians. First, diagnosis and attribution to SLE is difficult due to the lack of specific biomarkers or imaging modalities. Second, therapeutic options are limited, and evidence is mainly based on case reports and expert consensus, as clinical trials are sparse. Moreover, no validated outcome measure on disease activity exists. Current recommendations for treatment include supportive as well as immunosuppressive medication, depending on the type and severity of manifestations. As NPSLE manifestations are increasingly recognized, a broader spectrum of therapeutic options can be expected.

An update on the pathogenic role of IL-6 in rheumatic diseases

Interleukin (IL)-6 is a pleiotropic cytokine that is involved in the pathogenesis of various rheumatic diseases. Direct inhibition of the IL-6 pathway by an anti-IL-6 receptor or inhibiting the ligand itself has proved to be efficacious in the treatment of these diseases. Juvenile idiopathic arthritis, adult-onset Still's disease, large vessel vasculitis including giant cell arteritis and Takayasu disease, systemic sclerosis, and polymyalgia rheumatica respond well to IL-6 inhibition as expected. However, no clinically meaningful effect has been observed with regard to IL-6 blockade in ankylosing spondylitis, psoriatic arthritis, and systemic lupus erythematosus. This review discusses the current state of IL-6 targeting approaches in various rheumatic diseases other than rheumatoid arthritis.

Cognitive Dysfunction in Systemic Lupus Erythematosus: Immunopathology, Clinical Manifestations, Neuroimaging and Management

Cognitive dysfunction (CD) is a common yet often clinically subtle manifestation that considerably impacts the health-related quality of life in patients with systemic lupus erythaematosus (SLE). Given the inconsistencies in CD assessment and challenges in its attribution to SLE, the reported prevalence of CD differs widely, ranging from 3 to 88%. The clinical presentation of CD in SLE is non-specific and may manifest concurrently with overt neuropsychiatric illness such as psychosis or mood disorders or as isolated impairment of attention, working memory, executive dysfunction or processing speed. Despite the lack of standardized and sensitive neuropsychological tests and validated diagnostic biomarkers of CD in SLE, significant progress has been made in identifying pathogenic neural pathways and neuroimaging. Furthermore, several autoantibodies, cytokines, pro-inflammatory mediators and metabolic factors have been implicated in the pathogenesis of CD in SLE. Abrogation of the integrity of the blood-brain barrier (BBB) and ensuing autoantibody-mediated neurotoxicity, complement and microglial activation remains the widely accepted mechanism of SLE-related CD. Although several functional neuroimaging modalities have consistently demonstrated abnormalities that correlate with CD in SLE patients, a consensus remains to be reached as to their clinical utility in diagnosing CD. Given the multifactorial aetiology of CD, a multi-domain interventional approach that addresses the risk factors and disease mechanisms of CD in a concurrent fashion is the favourable therapeutic direction. While cognitive rehabilitation and exercise training remain important, specific pharmacological agents that target microglial activation and maintain the BBB integrity are potential candidates for the treatment of SLE-related CD.