Distinguishing the cerebrospinal fluid cytokine profile in neuropsychiatric systemic lupus erythematosus from other autoimmune neurological diseases

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.

Biomarkers for systemic lupus erythematosus - a focus on organ damage

INTRODUCTION

Systemic lupus erythematosus (SLE) is complex autoimmune disease with heterogenous manifestations, unpredictable disease course and response to treatment. One of the critical needs in SLE management is the identification of reliable biomarkers that can aid in early diagnosis, accurate monitoring of disease activity, and assessment of treatment response.

AREAS COVERED

In the current review, we focus on the commonly affected organs (skin, kidney, and nervous system) in SLE to summarize the emerging biomarkers that show promise in disease diagnosis, monitoring and treatment response assessment. The subtitles within each organ domain were determined based on the most relevant and promising biomarkers for that specific organ damage.

EXPERT OPINION

Biomarkers have the potential to significantly benefit the management of SLE by aiding in diagnosis, disease activity monitoring, prognosis, and treatment response assessment. However, despite decades of research, none has been validated and implemented for routine clinical use. Novel biomarkers could lead to the development of precision medicine for SLE, guide personalized treatment, and improve patient outcomes. Challenges in biomarker research in SLE include defining clear and clinically relevant questions, accounting for the heterogeneity of SLE, and confirming initial findings in larger, multi-center, multi-ethnic, independent cohorts that reflect real-world clinical scenarios.

Is Th17-Targeted Therapy Effective in Systemic Lupus Erythematosus?

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a broad spectrum of clinical manifestations. The proposed pathophysiological hypotheses of SLE are numerous, involving both innate and adaptive abnormal immune responses. SLE is characterized by the overproduction of different autoantibodies that form immune complexes, which cause damage in different organs. Current therapeutic modalities are anti-inflammatory and immunosuppressive. In the last decade, we have witnessed the development of many biologicals targeting different cytokines and other molecules. One of them is interleukin-17 (IL-17), a central cytokine of a proinflammatory process that is mediated by a group of helper T cells called Th17. Direct inhibitors of IL-17 are used in psoriatic arthritis, spondyloarthritis, and other diseases. Evidence about the therapeutic potential of Th17-targeted therapies in SLE is scarce, and probably the most promising is related to lupus nephritis. As SLE is a complex heterogeneous disease with different cytokines involved in its pathogenesis, it is highly unlikely that inhibition of only one molecule, such as IL-17, will be effective in the treatment of all clinical manifestations. Future studies should identify SLE patients that are eligible for Th17-targeted therapy.

Cerebrospinal Fluid Biomarkers in Differential Diagnosis of Multiple Sclerosis and Systemic Inflammatory Diseases with Central Nervous System Involvement

BACKGROUND

Diagnosis of multiple sclerosis (MS) is established on criteria according to clinical and radiological manifestation. Cerebrospinal fluid (CSF) analysis is an important part of differential diagnosis of MS and other inflammatory processes in the central nervous system (CNS).

METHODS

In total, 242 CSF samples were collected from patients undergoing differential MS diagnosis because of the presence of T2-hyperintensive lesions on brain MRI. The non-MS patients were subdivided into systemic inflammatory diseases with CNS involvement (SID) or cerebrovascular diseases (CVD) or other non-inflammatory diseases (NID). All samples were analyzed for the presence of oligoclonal bands and ELISA was performed for detection of: INF gamma, IL-6, neurofilaments light chain (NF-L), GFAP, CHI3L1, CXCL13, and osteopontin.

RESULTS

The level of IL-6 (p = 0.024), osteopontin (p = 0.0002), and NF-L (p = 0.002) was significantly different among groups. IL-6 (p = 0.0350) and NF-L (p = 0.0015) level was significantly higher in SID compared to NID patients. A significantly higher level of osteopontin (p = 0.00026) and NF-L (p = 0.002) in MS compared to NID population was noted. ROC analysis found weak diagnostic power for osteopontin and NFL-L.

CONCLUSIONS

The classical and non-standard markers of inflammatory process and neurodegeneration do not allow for sufficient differentiation between MS and non-MS inflammatory CNS disorders. Weak diagnostic power observed for the osteopontin and NF-L needs to be further investigated.

Biomarkers in Neuropsychiatric Systemic Lupus Erythematosus: A Systematic Literature Review of the Last Decade

Nervous system involvement in patients with SLE, termed neuropsychiatric SLE (NPSLE), constitutes a diagnostic challenge, and its management is still poorly optimised. This review summarises recent insights over the past decade in laboratory biomarkers of diagnosis, monitoring, and prognosis of NPSLE. An initial systematic search in the Medline and Web of Science was conducted to guide the selection of articles. Emerging diagnostic biomarkers in NPSLE that displayed satisfactory ability to discriminate between NPSLE and controls include serum interleukin (IL)-6, microRNA (miR)-23a, miR-155, and cerebrospinal fluid (CSF) α-Klotho. CSF lipocalin-2, macrophage colony-stimulating factor (M-CSF), and immunoglobulin (Ig)M also displayed such ability in two ethnically diverse cohorts. Serum interferon (IFN)-α and neuron specific enolase (NSE) were recently reported to moderately correlate with disease activity in patients with active NPSLE. CSF IL-8, IL-13, and granulocyte colony-stimulating factor (G-CSF) exhibited excellent sensitivity, yet poorer specificity, as predictors of response to therapy in patients with NPSLE. The overall lack of validation studies across multiple and diverse cohorts necessitates further and well-concerted investigations. Nevertheless, we propound CSF lipocalin 2 among molecules that hold promise as reliable diagnostic biomarkers in NPSLE.

Association between senescence of T cells and disease activity in patients with systemic lupus erythematosus

Objectives

Systemic lupus erythematosus (SLE) patients are predisposed to chronic immune activation, leading to accelerated immunosenescence. The aging of the immune system causes the T cells to express several senescence markers such as CD57 and KLRG1, which produce pro-inflammatory cytokine interferon γ (IFN-γ). Immunosenescence was associated with high morbidity and mortality in other diseases. This research was conducted to prove the association between senescent T cells and SLE disease activity.

Material and methods

This research was an observational cross-sectional study on 53 women aged 16–45 years diagnosed with SLE based on SLICC 2012 criteria. All subjects were recorded for demographic and clinical data, and their SLE disease activity index (SLEDAI) score was measured to evaluate disease activity. Active disease was defined as SLEDAI score ≥ 3. The CD57 antigen and KLRG1 expression on CD4+ and CD8+ T cells were calculated from peripheral blood mononuclear cells (PBMC) by flow cytometry. Interferon γ was measured from serum using ELISA. The comparison was done using the Mann-Whitney U test, and correlation was tested using the Spearman test. Associations between variables were calculated using linear regression models.

Results

Systemic lupus erythematosus patients with active disease had markedly higher CD4+KLRG1+ (3.1 [1.3–5.5]% vs. 0.3 [0.1–0.5]%), CD8+CD57+ (11.6 ±7.1% vs. 2.4 ±2.0%, p = 0.000), and CD8+KLRG1+ T cell percentages (13.7 ±7.5% vs. 0.3 ±0.1%, p = 0.000), and IFN- γ levels (208.9 [148.3–233.8] vs. 146.7 [130.2–210.8] pg/ml, p = 0.048), compared to the inactive patients. Positive correlation and association was found between the CD8+CD57+ and CD8+KLRG1+ percentages with the SLEDAI score (p = 0.007 and p = 0.007, for the linear regression analysis, respectively).

Conclusions

Systemic lupus erythematosus patients showed significantly higher senescence T cell markers compared to controls, and the increase of T cell senescence, especially in the CD8 compartment, has some association with increased disease activity in patients with SLE.

A Comprehensive Review on the Role of Genetic Factors in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorders (NMOSD) comprise a variety of disorders being described by optic neuritis and myelitis. This disorder is mostly observed in sporadic form, yet 3% of cases are familial NMO. Different series of familial NMO cases have been reported up to now, with some of them being associated with certain HLA haplotypes. Assessment of HLA allele and haplotypes has also revealed association between some alleles within HLA-DRB1 or other loci and sporadic NMO. More recently, genome-wide SNP arrays have shown some susceptibility loci for NMO. In the current manuscript, we review available information about the role of genetic factors in NMO.

The Th17/IL-17 Axis and Kidney Diseases, With Focus on Lupus Nephritis

Systemic lupus erythematosus (SLE) is a disease characterized by dysregulation and hyperreactivity of the immune response at various levels, including hyperactivation of effector cell subtypes, autoantibodies production, immune complex formation, and deposition in tissues. The consequences of hyperreactivity to the self are systemic and local inflammation and tissue damage in multiple organs. Lupus nephritis (LN) is one of the most worrying manifestations of SLE, and most patients have this involvement at some point in the course of the disease. Among the effector cells involved, the Th17, a subtype of T helper cells (CD4+), has shown significant hyperactivation and participates in kidney damage and many other organs. Th17 cells have IL-17A and IL-17F as main cytokines with receptors expressed in most renal cells, being involved in the activation of many proinflammatory and profibrotic pathways. The Th17/IL-17 axis promotes and maintains repetitive tissue damage and maladaptive repair; leading to fibrosis, loss of organ architecture and function. In the podocytes, the Th17/IL-17 axis effects include changes of the cytoskeleton with increased motility, decreased expression of health proteins, increased oxidative stress, and activation of the inflammasome and caspases resulting in podocytes apoptosis. In renal tubular epithelial cells, the Th17/IL-17 axis promotes the activation of profibrotic pathways such as increased TGF-β expression and epithelial-mesenchymal transition (EMT) with consequent increase of extracellular matrix proteins. In addition, the IL-17 promotes a proinflammatory environment by stimulating the synthesis of inflammatory cytokines by intrinsic renal cells and immune cells, and the synthesis of growth factors and chemokines, which together result in granulopoiesis/myelopoiesis, and further recruitment of immune cells to the kidney. The purpose of this work is to present the prognostic and immunopathologic role of the Th17/IL-17 axis in Kidney diseases, with a special focus on LN, including its exploration as a potential immunotherapeutic target in this complication.

Association of anti-NR2 and U1RNP antibodies with neurotoxic inflammatory mediators in cerebrospinal fluid from patients with neuropsychiatric systemic lupus erythematosus

BACKGROUND

Autoantibodies (auto Abs) and inflammatory mediators (IMs) in cerebrospinal fluid (CSF) may be involved in the pathogenesis of neuropsychiatric systemic lupus erythematosus (NPSLE). It is suggested that anti-N-methyl D-aspartate receptor NR2 subunit (NR2) Ab can develop NP manifestation after blood-brain barrier (BBB) abruption. We also reported the association between NPSLE and CSF anti-U1RNP Ab. In the present study, combined effects of CSF anti-NR2 and anti-U1RNP Abs on IMs in patients with NPSLE were examined.

METHODS

CSF samples were collected from 69 patients with NPSLE and 13 non-NPSLE controls. CSF anti-NR2 and anti-U1RNP Abs were determined using ELISA. Levels of IL-6, IL-8, and monokine induced by IFN-γ (MIG) in CSF were measured by quantitative multiplex cytokine analysis.

RESULTS

CSF IL-6 levels were higher in CSF anti-NR2-positive than in CSF anti-NR2-negative patients (p = 0.003) and non-NPSLE controls (p = 0.015) and were positively correlated with anti-NR2 titer (r = 0.42). CSF IL-8 levels were higher in CSF anti-U1RNP-positive than in CSF anti-U1RNP-negative patients (p = 0.041). CSF MIG levels were more elevated in CSF anti-NR2-positive (p = 0.043) and anti-U1RNP-positive patients (p = 0.029) than in non-NPSLE controls. Additionally, in double positive (DP; both anti-NR2 and U1RNP Ab positive) group, CSF IL-6 and MIG levels were significantly higher than in the double negative (DN; both anti-NR2 and U1RNP Ab negative) group. However, combined effect of both Abs on IM elevation and clinical manifestation was not clear.

CONCLUSIONS

CSF anti-NR2 and anti-U1RNP Abs have different effects on the elevation of CSF IM levels in patients with NPSLE. Additional effect of anti-U1RNP Abs on anti-NR2 Ab-mediated NP manifestation, however, was not recognized in our study.

Accelerated immune aging was correlated with lupus-associated brain fog in reproductive-age systemic lupus erythematosus patients

AIMS

Cognitive impairment is common in systemic lupus erythematosus (SLE) patients with substantial adverse effects on function and quality of life. One hypothesis to understand the mechanisms of cognitive impairment in SLE is accelerated immunosenescence. The aim of this study is to observe the correlation between immunosenescence with cognitive impairment in patients with SLE.

METHODS

Sixty-one female SLE patient were measured for CD4 and CD8 T cell-associated senescence markers, including percentage of end-stage differentiated T cells (CD4 and CD8 T cells expressing CD57⁺ or loss of CD28 expression), of naïve T cells (CD4⁺ CD45RA⁺ and CD8⁺ CD45RA⁺ ), memory T cells (CD4⁺ CD45RO⁺ and CD8⁺ CD45RO⁺ ), and antigen-experienced T cells (CD4⁺ KLRG1⁺ and CD8⁺ KLRG1⁺ ) which were measured using flow cytometry. One hallmark of immunosenescence called immune risk profile (IRP) was defined by an inverted ratio of CD4 and CD8. Cognitive functions were measured by Mini-Mental State Examination (MMSE) and Montréal Cognitive Assessment (MOCA) questionnaire.

RESULTS

Thirty-six (59.1%) SLE patients who had IRP develop significantly lower attention and recall from both MMSE (P = .005 and P = .000) and MOCA (P = .017 and P = .000) examinations. Decreased visuospatial ability was also found in patients with IRP measured by MOCA (P = .046). There was a negative correlation between memory CD4⁺ CD45RO⁺ T cells with recall and visuospatial domain (R = -0.204, P = .039 and R = -0.250, P = .033; respectively), and negative correlation between CD8⁺ CD28^- T cells with recall and attention domain (R = -0.249, P = .027 and R = -0.145, P = .048, respectively).

CONCLUSION

Systemic lupus erythematosus patients develop an accelerated immunosenescence which contributes to cognitive dysfunction, especially in attention, recall, and visuospatial domains.

Neuropsychiatric lupus: new mechanistic insights and future treatment directions

Patients with systemic lupus erythematosus (SLE) frequently show symptoms of central nervous system (CNS) involvement, termed neuropsychiatric SLE (NPSLE). The CNS manifestations of SLE are diverse and have a broad spectrum of severity and prognostic implications. Patients with NPSLE typically present with nonspecific symptoms, such as headache and cognitive impairment, but might also experience devastating features, such as memory loss, seizures and stroke. Some features of NPSLE, in particular those related to coagulopathy, have been characterized and an evidence-based treatment algorithm is available. The cognitive and affective manifestations of NPSLE, however, remain poorly understood. Various immune effectors have been evaluated as contributors to its pathogenesis, including brain-reactive autoantibodies, cytokines and cell-mediated inflammation. Additional brain-intrinsic elements (such as resident microglia, the blood-brain barrier and other neurovascular interfaces) are important facilitators of NPSLE. As yet, however, no unifying model has been found to underlie the pathogenesis of NPSLE, suggesting that this disease has multiple contributors and perhaps several distinct aetiologies. This heterogeneity presents a challenge for clinicians who have traditionally relied on empirical judgement in choosing treatment modalities for patients with NPSLE. Improved understanding of this manifestation of SLE might yield further options for managing this disease.

Proportions of Th17 cells and Th17-related cytokines in neuromyelitis optica spectrum disorders patients: A meta-analysis

BACKGROUND

T helper (Th17) cells play an important role in many autoimmune diseases. In this meta-analysis, we aimed to specify the proportion of Th17 cells and the levels of Th17-related cytokines in neuromyelitis optica spectrum disorders (NMOSD) patients, we did this meta-analysis.

METHODS

Using previously reported data from PubMed, EMBASE, and Web of Science and Cochrane, we explored the proportion of Th17 cells in CD4⁺ T cells in peripheral blood (PB) and the level of Th17-related cytokines, such as interleukin (IL)1β, IL6, IL17, IL21, IL22, IL23 and transforming growth factor -beta (TGFβ), in cerebrospinal fluid (CSF), plasma, and serum in NMOSD patients compared to control group and multiple sclerosis (MS) patients.

RESULTS

In total, 38 trials were included for our analysis. Results showed that the proportion of Th17 cells was higher in NMOSD patients than in the control and MS groups. The levels of IL1β, IL6, IL17 and IL21 in CSF and plasma, and IL6, IL21, IL22, and IL23 in the serum were higher in NMOSD patients than in the control group. The levels of IL6 in CSF and serum and IL17 in plasma and serum were higher in NMOSD patients than in MS patients.

CONCLUSION

The proportion of Th17 cells and the levels of Th17-related cytokines was increased in NMOSD patients compared with the control group and MS patients. The results of this meta-analysis indicated that Th17 cells and Th17-associated cytokines may play an essential role in the pathogenesis of NMOSD. PROSPERO registration: CRD42019128785.

Lupus: the new epidemic

Is systemic lupus erythematosus (SLE) is occurring more frequently now than in decades past? Despite improvements in the identification of patients with SLE, the development of new classification criteria, and the recognition of several biomarkers used alone or in combination, the diagnosis of SLE is still a challenge for clinicians, in particular early in the course of the disease, which makes the recognition of secular trends difficult to ascertain. Lacking a uniform definition of preclinical lupus or incomplete lupus, it is difficult to predict accurately which patients would go on to develop SLE. We will briefly review the classification criteria, early or preclinical SLE, the epidemiology of SLE, antinuclear antibodies-negative SLE, and biomarkers of the disease.

Brain Single Photon Emission Computed Tomography Scan (SPECT) and functional MRI in Systemic Lupus Erythematosus Patients with Cognitive Dysfunction: A Systematic Review

Objectives

Systemic lupus erythematosus (SLE) is an autoimmune disease with a wide range of clinical manifestations. Cognitive dysfunction is one of the manifestations that could present prior to the emergence of any other neuropsychiatric involvements in SLE. Cognitive dysfunction is a subtle condition occurring with a high frequency. However, there is no data on the correlation of cognitive dysfunction with central nervous system (CNS) imaging findings, in particular single-photon emission computed tomography scan (SPECT) and functional MRI. We decided to perform a systematic review of brain SPECT and fMRI in SLE patients with cognitive dysfunction.

Methods

PubMed, Scopus, and Google Scholar databases were searched until April 2017 with the following keywords: "SLE OR systemic lupus erythematous OR lupus" AND "functional MRI OR functional magnetic resonance imaging OR fMRI OR SPECT or SCAN". A total of 1,767articles were found. Two rheumatologists reviewed the articles and finally 14 articles were selected for the final systematic review.

Results

The fMRI and SPECT imaging techniques could provide valuable information regarding the SLE patients with cognitive dysfunction at the early stages of the disease.

Conclusion

Brain SPECT scan and fMRI are used as functional imaging tools in SLE. Both of these diagnostic modalities are sensitive in reflecting the subtle brain damages in SLE patients with cognitive dysfunction. Brain fMRI and SPECT scan could be significantly beneficial in the diagnosis and initial management of cognitive dysfunction in SLE. Nevertheless, prospective studies could be useful in confirming the application of these diagnostic modalities in the clinical setting.

Relation of intrathecal oligoclonal band production to inflammatory mediator and immunotherapy response in 208 children with OMS

In 208 children with opsoclonus-myoclonus syndrome (OMS), CSF IgG oligoclonal bands (OCB) and 22 immunomarkers in CSF and 21 in serum/blood were measured. In 36 untreated OMS, 58% were OCB(+), whereas 55% of treated OMS were OCB(-). OCB positivity or negativity did not alter concentrations or frequencies of immunomarkers. The phenotypes of OCB(+) and OCB(-) patients were not distinctive. CSF B cells were expanded in untreated OMS regardless of OCB positivity. These data reveal a much higher frequency of OCB positivity in untreated OMS than previously realized and a disconnect between intrathecal OCB and inflammatory mediator production.

Advances in Biomarker-Guided Therapy for Pediatric- and Adult-Onset Neuroinflammatory Disorders: Targeting Chemokines/Cytokines

The concept and recognized components of “neuroinflammation” are expanding at the intersection of neurobiology and immunobiology. Chemokines (CKs), no longer merely necessary for immune cell trafficking and positioning, have multiple physiologic, developmental, and modulatory functionalities in the central nervous system (CNS) through neuron–glia interactions and other mechanisms affecting neurotransmission. They issue the “help me” cry of neurons and astrocytes in response to CNS injury, engaging invading lymphoid cells (T cells and B cells) and myeloid cells (dendritic cells, monocytes, and neutrophils) (adaptive immunity), as well as microglia and macrophages (innate immunity), in a cascade of events, some beneficial (reparative), others destructive (excitotoxic). Human cerebrospinal fluid (CSF) studies have been instrumental in revealing soluble immunobiomarkers involved in immune dysregulation, their dichotomous effects, and the cells—often subtype specific—that produce them. CKs/cytokines continue to be attractive targets for the pharmaceutical industry with varying therapeutic success. This review summarizes the developing armamentarium, complexities of not compromising surveillance/physiologic functions, and insights on applicable strategies for neuroinflammatory disorders. The main approach has been using a designer monoclonal antibody to bind directly to the chemo/cytokine. Another approach is soluble receptors to bind the chemo/cytokine molecule (receptor ligand). Recombinant fusion proteins combine a key component of the receptor with IgG1. An additional approach is small molecule antagonists (protein therapeutics, binding proteins, and protein antagonists). CK neutralizing molecules (“neutraligands”) that are not receptor antagonists, high-affinity neuroligands (“decoy molecules”), as well as neutralizing “nanobodies” (single-domain camelid antibody fragment) are being developed. Simultaneous, more precise targeting of more than one cytokine is possible using bispecific agents (fusion antibodies). It is also possible to inhibit part of a signaling cascade to spare protective cytokine effects. “Fusokines” (fusion of two cytokines or a cytokine and CK) allow greater synergistic bioactivity than individual cytokines. Another promising approach is experimental targeting of the NLRP3 inflammasome, amply expressed in the CNS and a key contributor to neuroinflammation. Serendipitous discovery is not to be discounted. Filling in knowledge gaps between pediatric- and adult-onset neuroinflammation by systematic collection of CSF data on CKs/cytokines in temporal and clinical contexts and incorporating immunobiomarkers in clinical trials is a challenge hereby set forth for clinicians and researchers.

Defective Suppressor of Cytokine Signaling 1 Signaling Contributes to the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving injuries in multiple organs and systems. Exaggerated inflammatory responses are characterized as end-organ damage in patients with SLE. Although the explicit pathogenesis of SLE remains unclear, increasing evidence suggests that dysregulation of cytokine signals contributes to the progression of SLE through the Janus kinase/signal transducer and activator of transcription (STAT) signaling pathway. Activated STAT proteins translocate to the cell nucleus and induce transcription of target genes, which regulate downstream cytokine production and inflammatory cell infiltration. The suppressor of cytokine signaling 1 (SOCS1) is considered as a classical inhibitor of cytokine signaling. Recent studies have demonstrated that SOCS1 expression is decreased in patients with SLE and in murine lupus models, and this negatively correlates with the magnitude of inflammation. Dysregulation of SOCS1 signals participates in various pathological processes of SLE such as hematologic abnormalities and autoantibody generation. Lupus nephritis is one of the most serious complications of SLE, and it correlates with suppressed SOCS1 signals in renal tissues. Moreover, SOCS1 insufficiency affects the function of several other organs, including skin, central nervous system, liver, and lungs. Therefore, SOCS1 aberrancy contributes to the development of both systemic and local inflammation in SLE patients. In this review, we discuss recent studies regarding the roles of SOCS1 in the pathogenesis of SLE and its therapeutic implications.

Organ-specific biomarkers in lupus

Systemic lupus erythematosus (SLE) is a complex and highly heterogeneous disease, which affects multiple organs, including joints, skin, kidneys, heart, hematopoietic system, and nerve system. While the etiopathogenesis of SLE still remains unclear, genetic susceptibilities and aberrant epigenetic modifications are believed to be involved. For precision therapy, it is necessary to assess accurately and objectively organ involvements and disease activity, which is difficult by current clinical laboratory tests. Biomarkers, which are a biologic, genetic, epigenetic or a chemical characteristic and conveniently detectable, serve as measures of disease diagnosis, activity, prognosis, and manifestation prediction, thereby providing instruction for individualized therapy. In addition, biomarkers differ according to different manifestations, since the disease activity index and treatments vary significantly. For example, unlike other non-renal SLE, lupus nephritis requires significant immunosuppressive drugs. Over the past decades, the research on biomarkers in lupus has been strengthened and numerous promising biomarkers have been identified at levels of genomics, transcriptomics and proteomics. In this review, we summarize the conventional and novel biomarkers in the tissue-specific manner, and discuss their roles in specific organ diagnosis, future manifestation prediction, disease activity assessment and their correlation with histology results. By doing so, it aims to shed a light on individualized treatment.

Interleukin 2 Activates Brain Microvascular Endothelial Cells Resulting in Destabilization of Adherens Junctions

The pleiotropic cytokine interleukin 2 (IL2) disrupts the blood-brain barrier and alters brain microcirculation, underlying vascular leak syndrome that complicates cancer immunotherapy with IL2. The microvascular effects of IL2 also play a role in the development of multiple sclerosis and other chronic neurological disorders. The mechanism of IL2-induced disruption of brain microcirculation has not been determined previously. We found that both human and murine brain microvascular endothelial cells express constituents of the IL2 receptor complex. Then we established that signaling through this receptor complex leads to activation of the transcription factor, nuclear factor κB, resulting in expression of proinflammatory interleukin 6 and monocyte chemoattractant protein 1. We also discovered that IL2 induces disruption of adherens junctions, concomitant with cytoskeletal reorganization, ultimately leading to increased endothelial cell permeability. IL2-induced phosphorylation of vascular endothelial cadherin (VE-cadherin), a constituent of adherens junctions, leads to dissociation of its stabilizing adaptor partners, p120-catenin and β-catenin. Increased phosphorylation of VE-cadherin was also accompanied by a reduction of Src homology 2 domain-containing protein-tyrosine phosphatase 2, known to maintain vascular barrier function. These results unravel the mechanism of deleterious effects induced by IL2 on brain microvascular endothelial cells and may inform the development of new measures to improve IL2 cancer immunotherapy, as well as treatments for autoimmune diseases affecting the central nervous system.

Drug repositioning in SLE: crowd-sourcing, literature-mining and Big Data analysis

Lupus patients are in need of modern drugs to treat specific manifestations of their disease effectively and safely. In the past half century, only one new treatment has been approved by the US Food and Drug Administration (FDA) for systemic lupus erythematosus (SLE). In 2014–2015, the FDA approved 71 new drugs, only one of which targeted a rheumatic disease and none of which was approved for use in SLE. Repositioning/repurposing drugs approved for other diseases using multiple approaches is one possible means to find new treatment options for lupus patients. “Big Data” analysis approaches this challenge from an unbiased standpoint whereas literature mining and crowd sourcing for candidates assessed by the CoLTs (Combined Lupus Treatment Scoring) system provide a hypothesis-based approach to rank potential therapeutic candidates for possible clinical application. Both approaches mitigate risk since the candidates assessed have largely been extensively tested in clinical trials for other indications. The usefulness of a multi-pronged approach to drug repositioning in lupus is highlighted by orthogonal confirmation of hypothesis-based drug repositioning predictions by “Big Data” analysis of differentially expressed genes from lupus patient samples. The goal is to identify novel therapies that have the potential to affect disease processes specifically. Involvement of SLE patients and the scientists that study this disease in thinking about new drugs that may be effective in lupus though crowd-sourcing sites such as LRxL-STAT ( www.linkedin.com/in/lrxlstat ) is important in stimulating the momentum needed to test these novel drug targets for efficacy in lupus rapidly in small, proof-of-concept trials conducted by LuCIN, the Lupus Clinical Investigators Network ( www.linkedin.com/in/lucinstat ).

Dysregulated fibroblast growth factor (FGF) signaling in neurological and psychiatric disorders

The role of the fibroblast growth factor (FGF) system in brain-related disorders has received considerable attention in recent years. To understand the role of this system in neurological and psychiatric disorders, it is important to identify the specific members of the FGF family that are implicated, their location and the various mechanisms they can be modulated. Each disorder appears to impact specific molecular players in unique anatomical locations, and all of these could conceivably become targets for treatment. In the last several years, the issue of how to target this system directly has become an area of increasing interest. To date, the most promising therapeutics are small molecule inhibitors and antibodies that modulate FGF receptor (FGFR) function. Beyond attempting to modify the primary players affected by a given brain disorder, it may prove useful to target molecules, such as membrane-bound or extracellular proteins that interact with FGF ligands or FGFRs to modulate signaling.

Antibodies to microtubule-associated protein-2 in the cerebrospinal fluid are a useful diagnostic biomarker for neuropsychiatric systemic lupus erythematosus

OBJECTIVE

Previous reports indicate that serum anti-microtubule-associated protein 2 (MAP-2) antibodies are common in sera from patients with neuropsychiatric systemic lupus erythematosus (NPSLE). Differential diagnosis of NPSLE is occasionally difficult because of differential diagnosis which can mimic NPSLE. Therefore, specific biomarkers for NPSLE are needed. We conducted this study to clarify whether cerebrospinal fluid (CSF) anti-MAP-2 antibodies are a useful diagnostic biomarker for NPSLE.

METHODS

Enzyme-linked immunosorbent assay was conducted to measure CSF concentrations of anti-MAP-2 and anti-ribosomal P antibodies and of IL-6 in NPSLE patients (n = 24) and non-NPSLE controls (n = 17). The non-NPSLE controls consisted of systemic lupus erythematosus patients with neuropsychiatric symptoms caused by non-NPSLE conditions (n = 10) and patients with other connective tissue diseases (n = 7).

RESULTS

Significantly higher anti-MAP-2 antibody titers were found in the CSF of patients with NPSLE versus non-NPSLE controls. The prevalence of anti-MAP-2 antibodies was 33.3% (8/24) in NPSLE patients when a positive cutoff value was 3 standard deviations above the mean optical density of non-NPSLE controls. None of the controls had anti-MAP-2 antibodies in their CSF. Both anti-ribosomal P antibody titers and concentration of IL-6 in the CSF were significantly higher in patients with NPSLE having anti-MAP-2 antibodies than in patients with non-NPSLE controls.

CONCLUSION

Anti-MAP-2 antibodies could be detected in the CSF of 33.3% of patients with NPSLE, and its presence was highly specific for NPSLE. We propose that CSF anti-MAP-2 antibodies are a novel and useful diagnostic biomarker for NPSLE.

The role of icaritin in regulating Foxp3/IL17a balance in systemic lupus erythematosus and its effects on the treatment of MRL/lpr mice

Systemic lupus erythematosus (SLE) is a female predominant autoimmune disease characterized by multi-organ dysfunctions. However, current available therapies control the disease at the cost of many potential adverse effects. The development of safer and more effective therapies for SLE is a critical unmet need. Icaritin (ICT) is an active monomer extracted from Chinese herbals named the Epimedium genus. In this study, we found that ICT exhibited the capacity of regulating Foxp3/IL17a balance, enhancing Treg cell suppressive activities, and inhibiting over-activation of CD4(+)T cells from SLE. We also observed that ICT regulated Foxp3/IL17a balance by increasing STAT5b expression and histone methylation modification. Subsequent experiments further confirmed that ICT-treated mice exhibited amelioration of renal damages and suggested that ICT may be a potential new drug for the treatment of SLE.