A Conscious Resting State fMRI Study in SLE Patients Without Major Neuropsychiatric Manifestations

Recent advances in the diagnosis and management of neuropsychiatric lupus

Neuropsychiatric manifestations of systemic lupus erythematosus (SLE) are common and frequently associated with a substantial negative impact on health outcomes. The pathogenesis of neuropsychiatric SLE (NPSLE) remains largely unknown, but a single pathogenic mechanism is unlikely to be responsible for the heterogeneous array of clinical manifestations, and a combination of inflammatory and ischaemic mechanistic pathways have been implicated. Currently, valid and reliable biomarkers for the diagnosis of NPSLE are lacking, and differentiating NPSLE from nervous system dysfunction not caused by SLE remains a major challenge for clinicians. However, correct attribution is essential to ensure timely institution of appropriate treatment. In the absence of randomized clinical trials on NPSLE, current treatment strategies are derived from clinical experience with different therapeutic modalities and their efficacy in the management of other manifestations of SLE or of neuropsychiatric disease in non-SLE populations. This Review describes recent advances in the understanding of NPSLE that can inform diagnosis and management, as well as unanswered questions that necessitate further research.

Correlation between the changes of brain amplitude of low-frequency fluctuation and cognitive impairment in patients with neuropsychiatric lupus

PURPOSE

To explore the relationship between brain function changes and clinical serological indicators and behavioral cognitive assessment in patients with neuropsychiatric systemic lupus erythematosus (NPSLE), and understand the pathogenesis of NPSLE from the perspective of imaging.

METHODS

The resting-state functional imaging data, clinical serological, and behavioral cognitive assessment scores of 28 patients with NPSLE and 22 healthy controls (HC) were prospectively collected. The resting-state amplitude of low-frequency fluctuation (ALFF) values obtained from the analysis and processing were correlated with the serological data and behavioral cognitive assessment scores to determine the relationship between these data.

RESULTS

The average age of the patients of the NPSLE group was older than that of the HC group; significant differences in education level, Auditory Verbal Learning Test Hua Shan Version (AVLT-H), and Trail Making Test scores were observed between the two groups. The NPSLE group demonstrated increased brain activity in the insula, precentral gyrus, and superior temporal gyrus, and decreased brain activity in the superior parietal gyrus. The ALFF value of the insula positively correlated with the Anti-β2gp1 antibody and negatively correlated with the anti-nucleosome antibody and the AVL-recall (RC) score. The ALFF of the precentral gyrus negatively correlated with the AVL-immediate recall (I). The ALFF value of the superior temporal gyrus negatively correlated with the AVL-RC score. The left superior parietal gyrus positively correlated with the c-reactive protein. The right superior parietal gyrus positively correlated with the System Lupus Erythematosus Disease Activity Index and negatively correlated with the AVL-I score.

CONCLUSION

Patients with NPSLE show different brain activity changes in different brain regions, and the abnormal brain regions are correlated with certain lupus antibodies, inflammatory factors, and cognitive assessment, thereby suggesting that the correlation between the three could provide novel insights into the pathogenesis of NPSLE.

Functional Brain Network Alterations in Patients With Systemic Lupus Erythematosus With Different Cognitive Function States: A Graph Theory Analysis Study

OBJECTIVE

The study aimed to investigate the characteristics of brain functional network disruption in patients with systemic lupus erythematosus (SLE) with different cognitive function states by using graph theory analysis and to explore their relationship with clinical data and neuropsychiatric scales.

METHODS

Resting-state functional magnetic resonance imaging data were collected from 38 female SLE patients and 44 healthy controls. Based on Montreal Cognitive Assessment (MoCA) scores, SLE patients were divided into a high MoCA group (MoCA-H; MoCA score, ≥26) and a low MoCA group (MoCA-L; MoCA score, <26). The matrix of resting-state functional brain networks of subjects in the 3 groups was constructed by using the graph theory approach. The topological properties of the functional brain networks, including global and local metrics, in the 3 groups were calculated. The differences in the topological properties of networks between the 3 groups were compared. In addition, Spearman correlation analysis was used to explore the correlation between altered topological properties of brain networks and clinical indicators, as well as neuropsychiatric scales in SLE patients in the MoCA-L group.

RESULTS

At the global level, in the sparsity threshold range of 0.10 to 0.34, the values of small-world properties were greater than 1 in all 3 groups, indicating that functional brain networks of both 3 groups had small-world properties. There were statistically significant differences in the characteristic path length, global, and local efficiency between 3 groups ( F = 3.825, P = 0.0260; F = 3.722, P = 0.0285; and F = 3.457, P = 0.0364, respectively). Systemic lupus erythematosus patients in the MoCA-L group showed increased characteristic path length ( t = 2.816, P = 0.00651), decreased global ( t = -2.729, P = 0.00826), and local efficiency ( t = -2.623, P = 0.0109) compared with healthy controls. No statistically significant differences in local metrics were found between the MoCA-H group and the healthy control, MoCA-L groups. At the local level, there was statistically significant difference in the node efficiency among the 3 groups ( P < 0.05 after Bonferroni correction). Compared with healthy controls, SLE patients in the MoCA-L group showed decreased node efficiency in left anterior cingulate paracingulate gyrus, bilateral putamen, bilateral pallidum, and left Heschl gyrus. No statistically significant differences in the local metrics were found between the MoCA-H, MoCA-L, and healthy control groups. Correlation analysis in SLE patients in the MoCA-L group showed that the characteristic path length was positively correlated with C4 levels ( r = 0.587, P = 0.007), the global and local efficiencies were negatively correlated with C4 levels ( r = -0.599, P = 0.005; r = -0.599, P = 0.005, respectively), and the node efficiency in the bilateral putamen was negatively correlated with C4 levels ( r = -0.611, P = 0.004; r = -0.570, P = 0.009). The node efficiency in the left pallidum was negatively correlated with disease duration ( r = -0.480, P = 0.032). The node efficiency in the left Heschl gyrus was negatively correlated with IgM levels ( r = -0.478, P = 0.033). No correlation was noted between other network metrics, clinical indicators, and neuropsychological scales.

CONCLUSIONS

The topological properties of functional brain networks were disrupted in SLE patients with low MoCA scores, suggesting that altered topological properties of the brain networks were associated with cognitive function in SLE patients. Correlation between altered topological properties of the brain networks and clinical indicators was noted in SLE patients with low MoCA scores, suggesting that altered topological properties of brain networks in SLE patients may have clinical significance as imaging markers for monitoring disease changes in patients with SLE.

Interaction of 5-HTTLPR and SLE disease status on resting-state brain function

BACKGROUND

Neuropsychiatric involvement in systemic lupus erythematosus (SLE) is a common clinical manifestation. In SLE patients, cerebral function is a more sensitive predictor of central nervous system damage, and abnormalities in cerebral function may be apparent before substantial neuropsychiatric symptoms occur. The 5-hydroxynyptamine(5-HT) system has the ability to interact with the majority of the neurochemical systems in the central nervous system (CNS), influencing brain function. Serotonin transporter gene-linked polymorphic region (5-HTTLPR) is an essential element of the 5-HT system gene polymorphism and is directly related to the control of 5-hydroxytryptamine transporter (5-HTT)gene expression. The relationship between 5-HTTLPR and functional brain measurements in SLE patients requires more investigation because it is one of the most attractive imaging genetics targets for shedding light on the pathophysiology of neuropsychiatric lupus.

METHODS

Resting-state functional magnetic resonance imaging (rs-fMRI) images were collected from 51 SLE patients without obvious neuropsychiatric manifestations and 44 healthy volunteers. Regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and fractional amplitude of low-frequency fluctuations (fALFF) were selected as indicators for evaluating brain function. In accordance with the Anatomical Automatic Labeling template, the gray matter was divided into 116 regions. The mean ReHo value, mean ALFF value, and mean fALFF value of each brain region were extracted. 5-HTTLPR genotypes of all research objects were tested by polymerase chain reaction and agarose gel electrophoresis. Two-way analysis of covariance was used to investigate whether there is an interaction effect between SLE disease status and 5-HTTLPR genotype on resting-state brain function.

RESULTS

In SLE patients with S/S homozygosity, there were notably lower mean ReHo, mean ALFF, and mean fALFF values observed in the right parietal, inferior angular gyrus, and the right paracentral lobule compared to healthy controls. However, this distinction was not evident among carriers of the L allele. Within the S/S genotype, SLE patients exhibited decreased mean ReHo in the left posterior cingulate gyrus, reduced mean fALFF in the left caudate nucleus, and diminished mean ALFF in the left temporal pole: superior temporal gyrus, in contrast to the HC group. Conversely, no such differences were discerned among carriers of the L allele. Notably, among L allele carriers, SLE patients displayed a higher mean ReHo value in the right hippocampus compared to the HC group, while demonstrating a lower mean ALFF value in the left medial and paracingulate gyrus in contrast to the HC group. Conversely, these differences were not apparent among S/S homozygotes.

CONCLUSIONS

Brain function in the right parietal and inferior angular gyrus and the right paracentral lobule is affected by the interaction effect of SLE disease status and 5-HTTLPR genotype.

Mouse models, antibodies, and neuroimaging: Current knowledge and future perspectives in neuropsychiatric systemic lupus erythematosus (NPSLE)

As a chronic autoimmune disease systemic lupus erythematosus (SLE) can also affect the central and the peripheral nervous system causing symptoms which are summed up as neuropsychiatric systemic lupus erythematosus (NPSLE). These symptoms are heterogenous including cognitive impairment, seizures, and fatigue, leading to morbidity or even mortality. At present, little is known about the pathophysiological processes involved in NPSLE. This review focuses on the current knowledge of the pathogenesis of NPSLE gained from the investigation of animal models, autoantibodies, and neuroimaging techniques. The antibodies investigated the most are anti-ribosomal P protein antibodies (Anti-rib P) and anti-N-Methyl-D-Aspartic Acid Receptor 2 antibodies (Anti-NR2), which represent a subpopulation of anti-dsDNA autoantibodies. Experimental data demonstrates that Anti-rib P and Anti-NR2 cause different neurological pathologies when applied intravenously (i.v.), intrathecally or intracerebrally in mice. Moreover, the investigation of lupus-prone mice, such as the MRL/MpJ-Faslpr/lpr strain (MRL/lpr) and the New Zealand black/New Zealand white mice (NZB × NZW F1) showed that circulating systemic antibodies cause different neuropsychiatric symptoms compared to intrathecally produced antibodies. Furthermore, neuroimaging techniques including magnetic resonance imaging (MRI) and positron emission tomography (PET) are commonly used tools to investigate structural and functional abnormalities in NPSLE patients. Current research suggests that the pathogenesis of NPSLE is heterogenous, complex and not yet fully understood. However, it demonstrates that further investigation is needed to develop individual therapy in NPSLE.

Resting state functional connectivity in SLE patients and association with cognitive impairment and blood-brain barrier permeability

OBJECTIVE

Extensive blood-brain barrier (BBB) leakage has been linked to cognitive impairment in SLE. This study aimed to examine the associations of brain functional connectivity (FC) with cognitive impairment and BBB dysfunction among patients with SLE.

METHODS

Cognitive function was assessed by neuropsychological testing (n = 77). Resting-state FC (rsFC) between brain regions, measured by functional MRI (n = 78), assessed coordinated neural activation in 131 regions across five canonical brain networks. BBB permeability was measured by dynamic contrast-enhanced MRI (n = 61). Differences in rsFC were compared between SLE patients with cognitive impairment (SLE-CI) and those with normal cognition (SLE-NC), between SLE patients with and without extensive BBB leakage, and with healthy controls.

RESULTS

A whole-brain rsFC comparison found significant differences in intra-network and inter-network FC in SLE-CI vs SLE-NC patients. The affected connections showed a reduced negative rsFC in SLE-CI compared with SLE-NC and healthy controls. Similarly, a reduced number of brain-wide connections was found in SLE-CI patients compared with SLE-NC (P = 0.030) and healthy controls (P = 0.006). Specific brain regions had a lower total number of brain-wide connections in association with extensive BBB leakage (P = 0.011). Causal mediation analysis revealed that 64% of the association between BBB leakage and cognitive impairment in SLE patients was mediated by alterations in FC.

CONCLUSION

SLE patients with cognitive impairment had abnormalities in brain rsFC which accounted for most of the association between extensive BBB leakage and cognitive impairment.

Serum miR-342-3p Acts as a Biomarker for Systemic Lupus Erythematosus and Participates in the Disease Progression

Purpose

The aim of this study was to investigate the diagnostic ability and prognostic value of miR-342-3p in SLE patients by detecting the expression level of serum miR-342-3p in SLE patients.

Patients and Methods

The expression level of serum miR-342-3p in all subjects was determined by qRT-PCR technology, and the correlation of miR-342-3p with SLEDAI scores was evaluated using Spearman correlation coefficient. The diagnostic value of miR-342-3p in SLE was assessed using ROC curve. The prognostic value of miR-342-3p in SLE patients was analyzed by Kaplan-Meier survival curve and multivariate COX regression.

Results

The qRT-PCR results showed that the expression level of serum miR-342-3p in SLE patients was significantly lower than that in healthy controls (P < 0.001). Serum miR-342-3p expression level was negatively correlated with SLEDAI scores (r = - 0.810, P < 0.001). The ROC curve suggested that serum miR-342-3p expression level was discriminative between SLE patients and healthy controls. Survival analysis results indicated that SLE patients with low serum miR-342-3p expression had a higher probability of poor prognosis of SLE (Log rank P = 0.003).

Conclusion

The expression level of serum miR-342-3p was valuable in the diagnosis of SLE. Meanwhile, the low expression level of serum miR-342-3p was associated with the poor prognosis of SLE.

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.

Dynamic changes of amplitude of low-frequency in systemic lupus erythematosus patients with cognitive impairment

Background

Cognitive dysfunction (CI) is frequently reported in patients with systemic lupus erythematosus (SLE), but the identification and assessment of SLE-related CI remain challenging. Previous studies have focused on changes in static brain activity, and no studies have investigated the characteristics of dynamic brain activity in SLE patients with CI.

Objects

We calculated the dynamic amplitude of low-frequency fluctuation (dALFF) by combining the ALFF with a sliding window method to assess the temporal variability of brain functional activity in SLE patients with and without CI.

Methods

Thirty-eight SLE with CI, thirty-eight SLE without CI, and thirty-eight healthy controls (HCs) were recruited. By comparing static ALFF (sALFF) and dALFF among the three groups, changes in brain activity intensity and its temporal variability were assessed in patients with SLE with or without CI. Spearman correlation coefficients were calculated between the brain function indicator and Mini-mental State Examination (MMSE) scores of SLE with CI.

Results

Subjects among the three groups exhibited significant sALFF differences in the right parahippocampal gyrus, left caudate nucleus, right putamen, and left cuneus. Compared to the SLE without CI, the right parahippocampal gyrus exhibited higher sALFF in the SLE with CI group. Compared to the HCs, the left caudate nucleus exhibited increased sALFF in the SLE with CI group. Participants in the three groups exhibited significant dALFF variability in the right parahippocampal gyrus, right lingual gyrus, and bilateral inferior occipital gyrus. Compared to the HCs, the right lingual gyrus exhibited reduced dALFF in the SLE without CI group. Compared to the HCs, the right parahippocampal gyrus exhibited increased dALFF, left calcarine fissure, and the surrounding cortex exhibited reduced dALFF in the SLE with CI group. There was no significant correlation between the MMSE score, sALFF, and dALFF in the SLE with CI group.

Conclusion

SLE patients with CI have abnormal brain activity intensity and stability. By analyzing the dynamics of intrinsic brain activity, it provides a new idea for evaluating SLE-related CI. However, more research and validation with multiple metrics are needed to determine the link between the severity of cognitive impairment (CI) and brain activity in patients with SLE.

Altered Intrinsic Regional Spontaneous Brain Activity in Patients With Severe Obesity and Meibomian Gland Dysfunction: A Resting-State Functional Magnetic Resonance Imaging Study

Purpose

To evaluate potential regional homogeneity (ReHo) cerebrum function lesions in people with severe obesity and meibomian gland dysfunction (SM) and probe the connection between aberrant cerebrum activity and clinical manifestations.

Patients and Methods

An aggregation of 12 patients with SM, and 12 healthy controls (HCs) closely matched in age and gender were enrolled. We applied corneal confocal microscopy and fundus angiography to compare imaging distinctions between the two groups. SMs were required to carefully fill out the Hospital Anxiety Depression Scale (HADS) forms, and a correlation analysis was performed. ReHo was also utilized to appraise partial differences in spontaneous cerebrum function. Receiver operating characteristic (ROC) curves were created to partition ReHo values between patients with SM and the HCs.

Results

ReHo values for the left cerebellum (LC), right fusiform gyrus (RFG), left inferior temporal gyrus (LITG), left rectus gyrus (LRG), right thalamus (RT), right caudate (RC), left insula (LI), and left thalamus (LT) of subjects with SM were notably higher than those of the HCs (P < 0.05). ReHo values of the right middle frontal gyrus (RMFG) in subjects with SM were decreased notably compared to the HCs (P < 0.05). ReHo values for the RMFG showed a negative correlation with the anxiety scores (ASs; r = −0.961, P < 0.001) and ReHo values for the RFG showed a positive correlation with the depression scores (DSs; r = 0.676, P = 0.016). The areas under the ROC curve were 1.000 (P < 0.001) for the RMFG, LC, LITG, LRG, RC, LI, and LT and 0.993 (P < 0.001) for the RFG and RT. The results from the ROC curve analysis indicated that changes in the ReHo values of some brain regions may help diagnose SM.

Conclusion

Our research emphasized that patients with SM had lesions in synchronized neural activity in many encephalic areas. Our discoveries may provide beneficial information for exploring the neuromechanics of SM.

Altered degree centrality in patients with non-neuropsychiatric systemic lupus erythematosus: a resting-state fMRI study

This study used a voxel-wise degree centrality (DC) method to evaluate differences in brain activity between patients with non-neuropsychiatric systemic lupus erythematosus (non-NP-SLE) and healthy controls (HCs) and to assess the relationship of DC values with clinical and neuropsychological data. Thirty-two female patients with non-NP-SLE and 28 well-matched HCs were recruited and underwent resting-state functional MRI. Differences in spontaneous brain activity between the two groups were evaluated using a DC method. Correlations between the altered DC values of specific brain regions and clinical and neuropsychological data were explored using Spearman correlation analysis. Receiver operating characteristics curve analysis was applied to differences in DC values in specific brain regions to determine their value in distinguishing patients with non-NP-SLE from HCs. Compared with HCs, DC values in patients with non-NP-SLE were significantly lower in the bilateral postcentral gyrus and the orbital part of the left superior frontal gyrus (LFMO). DC values in some specific brain regions such as the bilateral postcentral gyrus and the LFMO correlated with Mini-Mental State Examination scores in both subject groups. In patients with non-NP-SLE, DC values of the right postcentral gyrus were positively correlated with IgA levels, and DC values of the LFMO were positively correlated with Systemic Lupus Erythematosus Disease Activity Index 2000 scores, as well as IgA levels. Receiver operating characteristics curve analysis revealed that the DC values of specific brain regions can be used to differentiate patients with non-NP-SLE from HCs.

The effects of disease activity, inflammation, depression and cognitive fatigue on resting state fMRI in systemic lupus erythematosus

OBJECTIVES

Cognitive dysfunction (CD) and depression are interlinked comorbidities of SLE. They may be the result of altered brain mechanisms. This study aimed to examine SLE effects on functional connectivity (FC) within the default mode network (DMN) using resting state fMRI-and how depression may impact this.

METHODS

Demographic, clinical and psychiatric data were collected from 19 SLE-active, 23 SLE-stable and 30 healthy controls (HC) participants. A T2*-weighted rsfMR scan was acquired and analysed using independent component analysis (ICA). Group z-scores for nodes associated with the DMN were tested. Significant nodes were entered into a factor analysis. The combined factor was used in correlations with factors of interest. Significant variables were used in a mediation analysis.

RESULTS

14 DMN nodes were defined using ICA. In five nodes, the SLE groups had significantly reduced FC compared with the HC group (p < 0.01). Factor analysis generated one factor that only depression score correlated with for both the HC group (rs=-0.510) and SLE groups combined (rs=-0.390). Mediation analysis revealed depression score accounted for 22% of the altered FC in the DMN. Disease state accounted for the remaining 78%.

CONCLUSIONS

Altered FC was evident in DMN nodes for SLE groups irrespective of disease activity. Depression accounts for some of this effect but SLE directly accounted for more. Further studies are needed to assess if these changes may be a precursor to CD in SLE. If so, rs-fMRI could be an early marker for CD in SLE and help in future CD in SLE treatment trials.

Alterations of spontaneous brain activity in systematic lupus erythematosus patients without neuropsychiatric symptoms: A resting-functional MRI study

PURPOSE

To explore the alterations of spontaneous neuronal activity using amplitude of low-frequency fluctuation (ALFF), fractional amplitude of low-frequency fluctuation (fALFF), and regional homogeneity (ReHo) in non-NPSLE patients and their relationship with the anxiety and depression statuses.

METHODS

Twenty-three non-NPSLE patients and 28 healthy controls were enrolled in this study. Resting-state functional magnetic resonance imaging was firstly analyzed by ALFF, fALFF, and ReHo. The relationships between ALFF/fALFF/ReHo values of abnormal regions and anxiety/depression rating scales, including Self-Rating Anxiety (SAS) and Self-Rating Depression (SDS), were also analyzed.

RESULTS

Compared with HC, non-NPSLE had decreased ALFF values in the bilateral postcentral gyrus, while increased ALFF values in the bilateral inferior temporal gyrus, left putamen, and bilateral precuneus. Non-NPSLE showed reduced fALFF values in the left lingual gyrus, left middle occipital gyrus, right postcentral gyrus, and left superior parietal gyrus, while increased fALFF values were in the left inferior temporal gyrus, right hippocampus, bilateral precuneus, and bilateral superior frontal gyrus. Reduced ReHo values were in the bilateral postcentral gyrus and higher ReHo values were in the left inferior temporal gyrus, left putamen, and bilateral superior frontal gyrus. In the non-NPSLE group, the mean ALFF values of bilateral precuneus were positively correlated with the SAS rating scales (R = 0.5519, p = 0.0176); either were the mean ALFF values of right inferior temporal gyrus and SAS rating scales (R = 0.5380, p = 0.0213). The mean fALFF values of left inferior temporal gyrus were positively correlated with SAS rating scales (R = 0.5700, p = 0.0135). And the mean ReHo values of left putamen were positively correlated with SDS (R = 0.5477, p = 0.0186).

CONCLUSION

Non-NPSLE exhibited abnormal spontaneous neural activity and coherence in several brain regions mainly associated with cognitive and emotional functions. The ALFF values of bilateral PCUN, the right ITG, the fALFF values of left ITG, and the ReHo values of left PUT may be complementary biomarkers for assessing the psychiatric symptoms.

Disrupted resting-state interhemispheric functional connectivity in systemic lupus erythematosus patients with and without neuropsychiatric lupus

PURPOSE

The aim of the study is to explore interhemispheric homotopic functional connectivity alterations in systemic lupus erythematosus (SLE) patients with and without neuropsychiatric lupus (NPSLE and non-NPSLE, respectively) and their potential correlations with clinical characteristics and neuropsychological performance.

METHODS

Based on resting-state functional MRI (rs-fMRI) data collected from SLE patients and matched healthy controls (HCs), the voxel-mirrored homotopic connectivity (VMHC) analysis was conducted to measure functional homotopy. Subsequently, correlations between altered functional homotopy and clinical/neuropsychological data were analyzed.

RESULTS

Compared with the HC group, both NPSLE and non-NPSLE groups showed attenuated homotopic connectivity in middle temporal gyrus (MTG), cuneus (CUN), middle occipital gyrus (MOG), angular gyrus (ANG), and postcentral gyrus (PoCG). NPSLE patients also exhibited decreased homotopic connectivity in inferior parietal gyrus (IPG) and middle frontal gyrus (MFG). Compared with non-NPSLE patients, NPSLE patients showed weaker interhemispheric homotopic functional connectivity in MOG. Decreased homotopic functional connectivity in PoCG, IPG, and MOG were associated with the anxiety state of SLE patients.

CONCLUSIONS

Our findings revealed attenuated functional homotopy in both NPSLE and non-NPSLE groups compared to the HC group, which appeared to be more severe in patients with comorbid neuropsychiatric lupus. Interhemispheric homotopy dysconnectivity may participate in the neuropathology of anxiety symptoms in SLE.

Altered Temporal Dynamics of Brain Activity in Multiple-Frequency Bands in Non-Neuropsychiatric Systemic Lupus Erythematosus Patients with Inactive Disease

PURPOSE

In this study, we seek to investigate dynamic changes of brain activity in non-neuropsychiatric systemic lupus erythematosus (non-NPSLE) patients with inactive disease.

PATIENTS AND METHODS

Thirty-one non-NPSLE patients with inactive disease and 20 matched healthy controls underwent the blood oxygenation level-dependent fMRI examination. Dynamic regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuations (fALFF) were used to analyze the brain activity in typical band (0.01-0.08 Hz), slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz). Pearson's correlation analysis was performed to correlate dynamic regional homogeneity (dReHo) and dynamic fractional amplitude of low-frequency fluctuations (dfALFF) values for clusters of voxels where significant group differences were found with clinical variables in non-NPSLE patients with inactive disease.

RESULTS

In typical band, non-NPSLE patients showed increased dReHo in left middle occipital gyrus (MOG) compared to healthy controls. Meanwhile, patients showed decreased dfALFF in right superior frontal gyrus (SFG) and bilateral middle frontal gyrus (MFG) in typical band. In slow-4, increased dReHo in left MOG was found in non-NPSLE patients. In slow-5, non-NPSLE patients showed increased dReHo in left MOG, left calcarine fissure and surrounding cortex, right precentral gyrus (PreCG) and left postcentral gyrus (PoCG). Meanwhile, non-NPSLE patients showed decreased dfALFF in left SFG, right MFG, and right PreCG in slow-5. Moreover, the glucocorticoid dose showed significantly negative correlations with dReHo values in right PreCG in slow-5, left PoCG in slow-5, and left MOG in typical band.

CONCLUSION

dReHo and dfALFF abnormalities in different frequency bands may be the key characteristics in the pathogenesis mechanism of non-NPSLE.

Advanced neuroimaging in neuropsychiatric systemic lupus erythematosus

Neuropsychiatric lupus (NPSLE) comprises a disparate collection of syndromes affecting the central and peripheral nervous systems. Progress in the attribution of neuropsychiatric syndromes to SLE-related mechanisms and development of targeted treatment strategies has been impeded by a lack of objective imaging biomarkers that reflect specific neuropsychiatric syndromes and/or pathologic mechanisms. The present review addresses recent publications of neuroimaging techniques in NPSLE.

Using the Mouse to Model Human Diseases: Cognitive Impairment in Systemic Lupus Erythematosus

In this 2020 Dunlop-Dottridge Lecture, the authors discuss cognitive impairment (CI), one of the most prevalent neuropsychiatric syndromes in systemic lupus erythematosus (SLE). Patients often report CI as the most bothersome disease-related manifestation, with a great effect on their quality of life. Nevertheless, studies focusing on CI remain scarce and no effective targeted therapy has been identified. We herein present murine models of CI in SLE with insights into the pathogenesis of this condition as well as the role of the renin angiotensin system in microglial activation. We will discuss the role of neuroimaging as a useful objective assessment tool, describing our experience in previous and ongoing clinical trials of CI in patients with SLE.

Cognitive Dysfunction in Systemic Lupus Erythematosus: A Case for Initiating Trials

Cognitive dysfunction (CD) is an insidious and underdiagnosed manifestation of systemic lupus erythematosus (SLE) that has a considerable impact on quality of life, which can be devastating. Given the inconsistencies in the modes of assessment and the difficulties in attribution to SLE, the reported prevalence of CD ranges from 5% to 80%. Although clinical studies of SLE-related CD have been hampered by heterogeneous subject populations and a lack of sensitive and standardized cognitive tests or other validated objective biomarkers for CD, there are, nonetheless, strong data from mouse models and from the clinical arena that show CD is related to known disease mechanisms. Several cytokines, inflammatory molecules, and antibodies have been associated with CD. Proposed mechanisms for antibody- and cytokine-mediated neuronal injury include the abrogation of blood-brain barrier integrity with direct access of soluble molecules in the circulation to the brain and ensuing neurotoxicity and microglial activation. No treatments for SLE-mediated CD exist, but potential candidates include agents that inhibit microglial activation, such as angiotensin-converting enzyme inhibitors, or that protect blood-brain barrier integrity, such as C5a receptor blockers. Structural and functional neuroimaging data have shown a range of regional abnormalities in metabolism and white matter microstructural integrity in SLE patients that correlate with CD and could in the future become diagnostic tools and outcome measures in clinical trials aimed at preserving cognitive function in SLE.