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.

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.

The conundrum of neuropsychiatric systemic lupus erythematosus: Current and novel approaches to diagnosis

Recognising neuropsychiatric involvement by systemic lupus erythematosus (SLE) is of growing importance, however many barriers to this exist at multiple levels of our currently available diagnostic algorithms that may ultimately delay its diagnosis and subsequent treatment. The heterogeneous and non-specific clinical syndromes, serological and cerebrospinal fluid (CSF) markers and neuroimaging findings that often do not mirror disease activity, highlight important research gaps in the diagnosis of neuropsychiatric SLE (NPSLE). Formal neuropsychological assessments or the more accessible screening metrics may also help improve objective recognition of cognitive or mood disorders. Novel serum and CSF markers, including autoantibodies, cytokines and chemokines have also shown increasing utility as part of diagnosis and monitoring, as well as in distinguishing NPSLE from SLE patients without SLE-related neuropsychiatric manifestations. Novel neuroimaging studies also expand upon our existing strategy by quantifying parameters that indicate microarchitectural integrity or provide an assessment of neuronal function. Some of these novel markers have shown associations with specific neuropsychiatric syndromes, suggesting that future research move away from considering NPSLE as a single entity but rather into its individually recognized neuropsychiatric manifestations. Nevertheless, it is likely that a composite panel of these investigations will be needed to better address the gaps impeding recognition of neuropsychiatric involvement by SLE.

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.

Neuropsychiatric manifestations in childhood-onset systemic lupus erythematosus

Neuropsychiatric manifestations occur frequently and are challenging to diagnose in childhood-onset systemic lupus erythematosus (SLE). Most patients with childhood-onset SLE have neuropsychiatric events in the first 2 years of disease. 30-70% of patients present with more than one neuropsychiatric event during their disease course, with an average of 2-3 events per person. These symptoms are associated with disability and mortality. Serum, cerebrospinal fluid, and neuroimaging findings have been described in childhood-onset SLE; however, only a few have been validated as biomarkers for diagnosis, monitoring response to treatment, or prognosis. The aim of this Review is to describe the genetic risk, clinical and neuroimaging characteristics, and current treatment strategies of neuropsychiatric manifestations in childhood-onset SLE.

Neuropsychiatric Systemic Lupus Erythematosus: A 2021 Update on Diagnosis, Management, and Current Challenges

Patients with systemic lupus erythematosus (SLE) experience neuropsychiatric symptoms. The term neuropsychiatric SLE (NPSLE) is a generic term that refers to a series of neurological and psychiatric symptoms directly related to SLE. In approximately 30% of patients with neuropsychiatric symptoms, SLE is the primary cause (NPSLE), and symptoms manifest more frequently around SLE onset. Neurovascular and psychotic conditions can also lead to NPSLE. Pathogenesis of NPSLE is implicated in both neuroinflammatory and ischemic mechanisms, and it is associated with high morbidity and mortality. After diagnosing and assigning causality, NPSLE treatment is individualized according to the type of neuropsychiatric manifestations, type of the predominant pathway, activity of SLE, and severity of the clinical manifestations. There are many problems to be addressed with regards to the diagnosis and management of NPSLE. Controlled clinical trials provide limited guidance for management, and observational cohort studies support symptomatic, antithrombotic, and immunosuppressive agents. The purpose of this review was to provide a detailed and critical review of the literature on the pathophysiology, diagnosis, and treatment of NPSLE. This study aimed to identify the shortcoming in diagnostic biomarkers, novel therapies against NPSLE, and additional research needs.

Hippocampal microglia CD40 mediates NPSLE cognitive dysfunction in mice

Neuropsychiatric systemic lupus erythematosus (NPSLE) is the most serious and complicated clinical manifestation of lupus erythematosus. Cognitive dysfunction is the most common symptom of NPSLE. A variety of potential mechanisms or mediators related to the pathogenesis of NPSLE cognitive dysfunction have been proposed. However, the involvement of microglia CD40 has not been reported yet. This study aimed to investigate whether hippocampal microglia CD40 of MRL/MpJ-Fas^lpr (MRL/lpr) mice was involved in NPSLE cognitive dysfunction. This study found, using quantitative polymerase chain reaction, western blotting and immunohistochemistry, that hippocampal CD40 was aberrantly overexpressed in the MRL/lpr lupus mice. It also determined using flow cytometry and immunofluorescence that the aberrantly overexpressed CD40 was mainly derived from hippocampal microglia. The adeno-associated virus was used to inhibit microglia CD40 expression, and the brain damage and cognitive dysfunction of MRL/lpr mice improved. Also, imiquimod (IMQ)-induced lupus mice had the same NPSLE cognitive dysfunction, brain damage, and overexpressed hippocampal microglia CD40 as MRL/lpr mice. Therefore, IMQ-induced lupus mouse was proposed as one of the mouse models for studying NPSLE cognitive dysfunction for the first time in this study. The findings indicated that hippocampal microglia CD40 was involved in the development of NPSLE cognitive dysfunction, thus providing a novel research direction for the study of the pathogenesis of NPSLE.

The management of neuropsychiatric lupus in the 21st century: still so many unmet needs?

Neuropsychiatric (NP) events occur in the majority of patients with SLE and predominantly affect the CNS in addition to the peripheral and autonomic systems. Approximately 30% of all NP events are attributable to SLE (NPSLE) and present most frequently around the time of SLE onset. NPSLE is associated with increased morbidity and mortality and the proposed pathogenesis includes both ischaemic and neuroinflammatory mechanisms. Following diagnosis and causal attribution, the treatment of NPSLE is tailored to the type of NP event, the predominant putative pathogenic pathway and the activity and severity of the clinical event. There is a dearth of controlled clinical trials to guide management, but therapeutic options include symptomatic, antithrombotic and immunosuppressive agents that are supported by observational cohort studies. Our objective was to review what is currently known about NPSLE and to identify deficiencies in diagnostic biomarkers, novel therapies and clinical trials for this manifestation of SLE.

Correlation of Serum BACE1 With Emergence Delirium in Postoperative Patients: A Preliminary Study

Background: The mechanism underlying delirium, a common acute fluctuating mental state, may be related to the activation of a neuroinflammatory response. In this study, we attempted to investigate whether plasma inflammatory response markers, vascular and cerebrovascular injury-related markers, and neurodegeneration-associated markers were associated with emergence delirium (ED).

Methods: Patients aged 50 years or above who underwent elective laparoscopic surgery under general anesthesia were included in this study. Delirium was assessed postoperatively with the Richmond Agitation Sedation Scale (RASS) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) scale. Plasma samples were collected from ED patients and non-ED patients to test concentrations of inflammation markers, including interleukin 6 (IL-6), chitinase 3-like 1 (CHI3L1), S100 calcium-binding protein B (S100B), lipoprotein-associated phospholipase-A2 (Lp-PLA2), and macrophage migration inhibitory factor (MIF); vascular and cerebrovascular injury-related markers, including intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1); and neurodegeneration-associated markers, including alpha-synuclein (α-Syn) and β-secretase 1 (BACE1). Binary logistic regression analysis was performed to analyze the relationship between biomarkers and ED, and receiver operating characteristic (ROC) curves were used to analyze the diagnostic value of biomarkers.

Results: A total of 104 patients were included in this study, with an average age of 63.69 ± 7.21. IL-6 (OR = 2.73, 95% CI: 1.66–6.44, P = 0.022), S100B (OR = 4.74, 95% CI: 1.88–11.95, P = 0.001), and BACE1 (OR = 6.54, 95% CI: 2.57–16.65, P < 0.000) were independent biological indicators for the occurrence of ED.CHI3L1, Lp-PLA2, MIF, ICAM-1, VCAM-1, and α-Syn were unrelated to ED. Plasma BACE1 level had a possible diagnostic value for ED [area under curve (AUC) = 0.75, 95% CI: 0.66–0.85], whereas plasma IL-6 (AUC = 0.62, 95% CI: 0.51–0.73) and S100B (AUC = 0.65, 95% CI: 0.54–0.76) levels had little diagnostic value for distinguishing ED vs. non-ED.

Conclusion: Higher levels of systemic inflammation marker IL-6, cerebral inflammation marker S100B, and neurodegeneration-associated marker BACE1 are related to ED. Plasma BACE1 may be a potential diagnostic biomarker for ED.

Prevalence, involved domains, and predictor of cognitive dysfunction in systemic lupus erythematosus

BACKGROUND

Cognitive Dysfunction (CD) can occur in Systemic Lupus Erythematosus (SLE) before the occurrence of Neuropsychiatric Lupus Erythematosus (NPSLE). Given the reversibility and fluctuation of SLE-related CD, the research for possible predictors is of great significance for early detection and intervention.

OBJECTIVE

We sought to determine the prevalence, involved domains, and possible predictors of CD in SLE patients.

METHODS

We conducted a retrospective cross-sectional study at Nanfang Hospital from 2018 to 2019. A total of 78 SLE patients were recruited. The Montreal Cognitive Assessment (MoCA) scale was used to screen cognitive function. Demographic, clinical, and laboratory characteristics were collected. The serum anti-methyl-d-aspartate receptor (anti-NMDAR) antibody and S100β were measured by enzyme-linked immunosorbent assay (ELISA). Multivariate logistic regression analysis and ROC curve were used to assess the predictor of SLE-related CD.

RESULTS

Of 78 recruited patients,53 (67.9%) had CD. It mainly involved delayed recall, abstract generalization, verbal repetition, and fluency. The disease activity index (SLEDAI) was not associated with SLE-related CD (p > 0.05). Multivariate logistic regression showed that an increase in each year of education there was a decrease in the likelihood of CD (OR 0.261, CI 0.080-0.857, p = 0.027) whereas with each unit increase in serum anti-NMDAR antibody there was an increased likelihood of SLE-related CD (OR 1.568, CI 1.073-2.292, p = 0.020).

CONCLUSION

The prevalence of SLE-related CD was 67.9% in our study and SLE-related CD was not associated with disease activity. Serum anti-NMDAR antibody can be used as a predictor for SLE-related CD.

Association of S100B polymorphisms and serum S100B with risk of systemic lupus erythematous in a Chinese population

The aim of this study was to investigate whether the S100B polymorphisms are associated with systemic lupus erythematous (SLE) in a Chinese population. A total of 313 SLE patients and 396 control subjects were enrolled in the present study. The genotypes of three SNPs (rs9722, rs881827 and rs1051169) in S100B gene were detected by single base extension polymerase chain reaction (SBE-PCR). Serum S100B levels were determined by enzyme-linked immunosorbent assay (ELISA). Rs1051169 was associated with an increased risk of SLE (C vs. G: adjusted OR=1.46, 95% CI, 1.18-1.80, p=0.001; CC vs. GG: adjusted OR=1.99, 95% CI, 1.32-3.02, p=0.001; CC+GC vs. GG: adjusted OR=1.54, 95% CI, 1.13-2.11, p=0.007; CC vs. GC+GG: adjusted OR=1.67, 95% CI, 1.16-2.42, p=0.006). Haplotype analysis showed that the G-G-C haplotype was associated with an increased risk of SLE (OR=1.50, 95% CI, 1.14-1.98, p=0.004). Stratified analyses showed that the rs1051169 polymorphism was associated with an increased risk of neurologic disorder in SLE patients (C vs. G: OR=1.78, 95% CI, 1.22-2.59, p=0.003; GC vs. GG: OR=2.33, 95% CI, 1.14-4.77, P=0.019; CC vs. GG: OR=3.02, 95% CI, 1.39-6.53, p=0.004; CC+GC vs. GG: OR=2.57, 95% CI=1.31-5.04, p=0.005). In addition, SLE patients with neurologic disorder carrying the rs1051169 GC/CC genotypes present a higher serum S100B levels compared with that carrying the GG genotype (p < 0.05). Our results indicate that the rs1051169 polymorphism may be involved in the pathogenesis of SLE.

Review: Nervous System Disease in Systemic Lupus Erythematosus: Current Status and Future Directions

The American College of Rheumatology's case definitions for 19 neuropsychiatric syndromes in systemic lupus erythematosus (SLE) constitute a comprehensive classification of nervous system events in this disease. However, additional strategies are needed to determine whether a neuropsychiatric syndrome is attributable to SLE versus a competing comorbidity. Cognitive function is a clinical surrogate of overall brain health, with applications in both diagnosis and determination of clinical outcomes. Ischemic and inflammatory mechanisms are both key components of the immunopathogenesis of neuropsychiatric SLE (NPSLE), including abnormalities of the blood-brain barrier and autoantibody-mediated production of proinflammatory cytokines. Advances in neuroimaging provide a platform to assess novel disease mechanisms in a noninvasive way. The convergence of more rigorous clinical characterization, validation of biomarkers, and brain neuroimaging provides opportunities to determine the efficacy of novel targeted therapies in the treatment of NPSLE.

Peripheral levels of brain-derived neurotrophic factor and S100B in neuropsychiatric systemic lupus erythematous

BACKGROUND

The aim of this study was to investigate serum S100B and brain-derived neurotrophic factor (BDNF) in systemic lupus erythematous (SLE) patients, with and without neuropsychiatric (NP) manifestation activity.

METHODS

We assessed 47 SLE patients and 20 selected healthy individuals. Disease activity was assessed according to the SLE disease activity index (SLEDAI). Serum BDNF and S100B were measured by enzyme-linked immunosorbent assay.

RESULTS

Serum S100B protein was significantly higher in SLE patients. BDNF levels were significantly decreased in active SLE, when compared with inactive SLE, but not when compared with controls. S100B was clearly higher in the NPSLE group, when compared with the non-NPSLE or control groups. Receiver operating characteristic analysis of S100B revealed an area under the curve of 0.706 that discriminated NPSLE patients with peripheral polyneuropathy.

CONCLUSIONS

Our findings reinforce the use of serum S100B as a biomarker in SLE, particularly for NPSLE. Moreover, we found a strong association between serum S100B and peripheral neuropathy, indicating a specific utility for this biomarker in SLE that warrants clinical investigation.

Lipocalin-2 is a pathogenic determinant and biomarker of neuropsychiatric lupus

Neuropsychiatric manifestations in lupus (NPSLE) affect ∼20-40% of patients. In the central nervous system, lipocalin-2 (LCN2) can promote injury through mechanisms directly linked to NPSLE, including brain barrier disruption, neurotoxicity, and glial activation. Since LCN2 is elevated in lupus and has been implicated in neuroinflammation, we investigated whether LCN2 is required for the pathogenesis of NPSLE. Here, we investigated the effects of LCN2 deficiency on the development of neurobehavioral deficits in the B6.Sle1.Sle3 (Sle1,3) mouse lupus model. Sle1,3 mice exhibited depression-like behavior and impaired spatial and recognition memory, and these deficits were attenuated in Sle1,3-LCN2KO mice. Whole-brain flow cytometry showed a significant increase in brain infiltrating leukocytes in Sle1,3 mice that was not reduced by LCN2 deficiency. RNA sequencing on sorted microglia revealed that several genes differentially expressed between B6 and Sle1,3 mice were regulated by LCN2, and that these genes are key mediators of the neuroinflammatory cascade. Importantly, LCN2 is upregulated in the cerebrospinal fluid of NPSLE patients across 2 different ethnicities. Our findings establish the Sle1,3 strain as an NPSLE model, demonstrate that LCN2 is a major regulator of the detrimental neuroimmune response in NPSLE, and identify CSF LCN2 as a novel biomarker for NPSLE.