Brain morphometric changes associated with childhood-onset systemic lupus erythematosus and neurocognitive deficit

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

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

Implications of Inflammatory Processes on a Developing Central Nervous System in Childhood-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is increasingly affecting pediatric and adult populations. Neuropsychiatric manifestations (ie, cognitive dysfunction and mood disorders) appear to occur with greater severity and poorer prognosis in childhood-onset SLE (cSLE) versus adult-onset SLE, negatively impacting school function, self-management, and psychosocial health, as well as lifelong health-related quality of life. In this review, we describe pathogenic mechanisms active in cSLE, such as maladaptive inflammatory processes and ischemia, which are hypothesized to underpin central phenotypes in patients with cSLE, and the role of alterations in protective central nervous system (CNS) barriers (ie, the blood-brain barrier) are also discussed. Recent findings derived from novel neuroimaging approaches are highlighted because the methods employed in these studies hold potential for identifying CNS abnormalities that would otherwise remain undetected with conventional multiple resonance imaging studies (eg, T2-weighted or fluid-attenuated inversion recovery sequences). Furthermore, we propose that a more robust presentation of neuropsychiatric symptoms in cSLE is in part due to the harmful impact of a chronic inflammatory insult on a developing CNS. Although the immature status of the CNS may leave patients with cSLE more vulnerable to harboring neuropsychiatric manifestations, the same property may represent a greater urgency to reverse the maladaptive effects associated with a proneuroinflammatory state, provided that effective diagnostic tools and treatment strategies are available. Finally, considering the crosstalk among the CNS and other organ systems affected in cSLE, we postulate that a finer understanding of this interconnectivity and its role in the clinical presentation in cSLE is warranted.

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.

Neuroimaging and biomarker evidence of neurodegeneration in asthma

BACKGROUND

Epidemiologic studies have shown that Alzheimer's disease (AD) and related dementias (ADRD) are seen more frequently with asthma, especially with greater asthma severity or exacerbation frequency.

OBJECTIVE

To examine the changes in brain structure that may underlie this phenomenon, we examined diffusion-weighted magnetic resonance imaging (dMRI) and blood-based biomarkers of AD (phosphorylated tau 181, p-Tau181), neurodegeneration (neurofilament light chain, NfL), and glial activation (glial fibrillary acidic protein, GFAP).

METHODS

dMRI data were obtained in 111 individuals with asthma, ranging in disease severity from mild to severe, and 135 healthy controls. Regression analyses were used to test the relationships between asthma severity and neuroimaging measures, as well as AD pathology, neurodegeneration, and glial activation, indexed by plasma p-Tau181, NfL, and GFAP, respectively. Additional relationships were tested with cognitive function.

RESULTS

Asthma participants had widespread and large-magnitude differences in several dMRI metrics, which were indicative of neuroinflammation and neurodegeneration, and which were robustly associated with GFAP and, to a lesser extent, NfL. The AD biomarker p-Tau181 was only minimally associated with neuroimaging outcomes. Further, asthma severity was associated with deleterious changes in neuroimaging outcomes, which in turn were associated with slower processing speed, a test of cognitive performance.

CONCLUSIONS

Asthma, particularly when severe, is associated with characteristics of neuroinflammation and neurodegeneration, and may be a potential risk factor for neural injury and cognitive dysfunction. There is a need to determine how asthma may affect brain health and whether treatment directed toward characteristics of asthma associated with these risks can mitigate these effects.

Axonal dysfunction is associated with interferon-γ levels in childhood-onset systemic lupus erythematosus: a multivoxel magnetic resonance spectroscopy study

OBJECTIVE

Axonal/neuronal damage has been shown to be a pathological finding that precedes neuropsychiatric manifestations in systemic lupus erythematosus (SLE). Therefore, the objective of this study was to determine the presence of axonal dysfunction in childhood-onset SLE patients (cSLE) and to determine clinical, immunological, and treatment features associated with its occurrence.

METHODS

We included 86 consecutive cSLE patients [median age 17 years (range 5-28)] and 71 controls [median age 18 years (5-28)]. We performed Proton Magnetic Resonance Spectroscopic Imaging (1H-MRSI) using point resolved spectroscopy sequence (PRESS) over the superior-posterior region of the corpus callosum and signals from N-acetylaspartate compounds (NAA), choline-based compounds (CHO); creatine containing compounds (Cr), myo-inositol (mI), lactate (Lac), glutamate (Glu), glutamine (Gln) and lactate (Lac) were measured and metabolites/Cr ratios were determined. Complete clinical, laboratory and neurological evaluations were performed in all subjects. Sera IL-4, IL-5, IL-6, IL-10, IL-12, IL-17, TNF- α, INF- γ cytokines levels, antiribosomal P protein antibodies (anti-P) and S100β were measured by enzyme-linked immunosorbent assay (ELISA) using commercial kits. Data were compared by non-parametric tests.

RESULTS

NAA/Cr ratios (p= 0.035) and Lac/Cr ratios (p= 0.019) levels were significantly decreased in cSLE patients when compared with controls. In multivariate analysis, interferon (IFN) gamma (γ) levels (OR = 4.1; 95% 2.01-7.9) and depressive symptoms (OR = 1.9; 95%CI = 1.1-3.2) were associated with NAA/Cr ratio. Increased Cho/Cr was associated with the presence of cognitive impairment (OR = 3.4; p< 0.001; 95%CI = 2.034-5.078). mI/Cr ratio correlated with cumulative glucocorticoids dosage (r = 0.361; p= 0.014).

CONCLUSION

NAA and CHO ratios may be useful as biomarkers in neuropsychiatric cSLE. Longitudinal studies are necessary to determine whether they predict structural damage.

Cerebral microvascular and microstructural integrity is regionally altered in patients with systemic lupus erythematosus

Background

To measure regional brain microvascular and microstructural changes in childhood-onset SLE (cSLE) using diffusion-weighted imaging (DWI) at multiple b values and investigate relationships of those measures with neurocognitive function and disease activity.

Methods

In this cross-sectional, case-control study, vascular volume fraction, effective diffusion, parenchymal diffusion, and blood flow parameters were regionally compared in cSLE patients and matched healthy controls. These markers of microvascular and microstructural integrity were derived by diffusion-weighted brain MRI and intravoxel incoherent motion (IVIM) modeling. Formal neurocognitive testing was completed focused on the domains of attention, visuoconstructional ability, working memory, and psychomotor speed. Test scores and measures of disease severity were regressed against regional microvascular integrity parameters among cSLE patients.

Results

Formal cognitive testing confirmed normal cognitive ability among all cSLE patients included in the analysis (n = 11). Nevertheless, reduction in blood volume fraction coincided with increased effective diffusion and flow parameters in cSLE patients vs. controls in posterior brain regions including the cuneus and precuneus. Regional microvascular measures correlated (|r| = 0.54–0.66) with neuropsychiatric scores and disease activity among cSLE patients.

Conclusions

There is imaging evidence, using IVIM, of degraded microvascular integrity in cSLE patients with normal cognitive ability. The observed regional changes correspond with posterior vascular border zones. These outcomes appear consistent with regional gray matter volume loss previously observed in cSLE patients with overt neurocognitive deficits, supporting the notion that adverse vascular changes precede loss of cognitive ability in cSLE. Longitudinal studies are needed to confirm the findings of this initial study.

Reduction of Total Brain and Cerebellum Volumes Associated With Neuronal Autoantibodies in Patients With APECED

CONTEXT

In autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), autoantibodies (AutoAbs) labeling brain neurons were reported; conversely, brain MRI alterations associated with these AutoAbs were never reported.

OBJECTIVES

To describe brain alterations in APECED and to correlate them with AutoAbs against glutamic acid decarboxylase (GAD), tyrosine hydroxylase (TH), and 5-tryptophan hydroxylase (5-HT) neurons.

DESIGN AND PARTICIPANTS

Fourteen Sardinian patients with APECED and age-matched control subjects were recruited for MRI analysis and blood sampling to detect AutoAbs to GAD, TH, and 5-HT neurons by using rat brain sections. The majority of patients (n = 12) were investigated for AutoAbs a decade earlier, and 7 of 12 were positive for AutoAbs to GAD and TH neurons.

MAIN OUTCOMES

Patients with APECED had smaller cerebellum and gray matter volumes, with a ventricular enlargement and a total cerebrospinal fluid (CSF) increase, compared with controls (P < 0.01). In 11 of 14 patients, brain abnormalities were associated with AutoAbs to GAD or TH neurons (titer 1:100 to 15,000) that had persisted for 10 years in 7 of 11 patients. AutoAbs to 5-HT neurons were revealed in all patients with AutoAbs to TH neurons. A decrease in whole brain and cerebellum volumes (P = 0.028) was associated with AutoAbs to GAD neurons, and a CSF increase was associated with AutoAbs to GAD and TH/5-HT neurons (P < 0.05). HLA alleles did not appear to be involved in neuronal autoimmunity.

CONCLUSIONS

Brain alterations and neuronal AutoAbs were observed in 78.6% of Sardinian patients with APECED, suggesting a brain autoimmune reaction. Prolonged clinical follow-up must be conducted for the possible appearance of clinical neurologic consequences.

Brain gray matter volume differences in obese youth with type 2 diabetes: a pilot study

BACKGROUND

Adults with type 2 diabetes (T2D) have significantly lower gray matter volume (GMV) compared to healthy peers. Whether GMV differences exist in youth with T2D remains unclear. Thus, we compared global and regional GMV between obese youth with T2D with age, race and sex similar healthy controls.

METHODS

In a cross-sectional study, 20 obese youth with T2D underwent T1-weighted brain magnetic resonance imaging (MRI). Comparisons were made to 20 age, race and sex similar controls. Differences in global and regional GMV between groups were identified using voxel-based morphometry (VBM).

RESULTS

Youth with T2D had a significantly lower global GMV-to-intracranial volume ratio (0.51±0.02 in T2D vs. 0.53±0.02 in controls, p=0.02, Cohen's d=0.85). There were 14 regions where GMV was significantly lower in the T2D group, and nine of these were found in either the temporal or occipital lobes. There were six regions with increased GMV in T2D. All regional differences were significant at p<0.05 after adjusting for multiple comparisons.

CONCLUSIONS

Results from this pilot study show obese youth with T2D have significantly lower global GMV and regional GMV differences, when compared to their age, race and sex similar peers. Future work is needed to determine whether these brain findings are a direct result of adolescent-onset T2D.

Altered Blood-Brain Barrier Permeability in Patients With Systemic Lupus Erythematosus: A Novel Imaging Approach

OBJECTIVE

To evaluate a safe, noninvasive magnetic resonance imaging (MRI) method to measure regional blood-brain barrier integrity and investigate its relationship with neurocognitive function and regional gray matter volume in juvenile-onset systemic lupus erythematosus (SLE).

METHODS

In this cross-sectional, case-control study, capillary permeability was measured as a marker of blood-brain barrier integrity in juvenile SLE patients and matched healthy controls, using a combination of arterial spin labeling and diffusion-weighted brain MRI. Regional gray matter volume was measured by voxel-based morphometry. Correlation analysis was done to investigate the relationship between regional capillary permeability and regional gray matter volume. Formal neurocognitive testing was completed (measuring attention, visuoconstructional ability, working memory, and psychomotor speed), and scores were regressed against regional blood-brain barrier integrity among juvenile SLE patients.

RESULTS

Formal cognitive testing confirmed normal cognitive ability in all juvenile SLE subjects (n = 11) included in the analysis. Regional capillary permeability was negatively associated (P = 0.026) with neurocognitive performance concerning psychomotor speed in the juvenile SLE cohort. Compared with controls (n = 11), juvenile SLE patients had significantly greater capillary permeability involving Brodmann's areas 19, 28, 36, and 37 and caudate structures (P < 0.05 for all).

CONCLUSION

There is imaging evidence of increased regional capillary permeability in juvenile SLE patients with normal cognitive performance using a novel noninvasive MRI technique. These blood-brain barrier outcomes appear consistent with functional neuronal network alterations and gray matter volume loss previously observed in juvenile SLE patients with overt neurocognitive deficits, supporting the notion that blood-brain barrier integrity loss precedes the loss of cognitive ability in juvenile SLE. Longitudinal studies are needed to confirm the findings of this pilot study.

Reduction of Cerebral and Corpus Callosum Volumes in Childhood-Onset Systemic Lupus Erythematosus: A Volumetric Magnetic Resonance Imaging Analysis

OBJECTIVE

There have been few studies in which the prevalence of cerebral atrophy in childhood-onset systemic lupus erythematosus (SLE) was evaluated using magnetic resonance imaging (MRI) volumetric measurements. This study was undertaken to determine the prevalence of cerebral and corpus callosum atrophy in childhood-onset SLE and to determine the possible relationships between atrophy and clinical, laboratory, and treatment features of the disease.

METHODS

We included 76 patients with childhood-onset SLE (69 female and 7 male; median age 16 years) and 66 age- and sex-matched healthy controls. Neurologic manifestations were analyzed according to the American College of Rheumatology (ACR) criteria. These SLE patients were further assessed for clinical and laboratory manifestations of SLE, disease activity (using the SLE Disease Activity Index), damage (using the Systemic Lupus International Collaborating Clinics/ACR Damage Index), and current and cumulative drug exposures. Scans were performed with a Philips 3.0T MRI scanner using a standardized protocol.

RESULTS

Childhood-onset SLE patients had significantly smaller cerebral and corpus callosum volumes than controls (median cerebral volume 1,067.9 cm(3) versus 1,172.7 cm(3) and median corpus callosum volume 11.6 cm(3) versus 13.7 cm(3) ; P < 0.001). The presence of structural abnormalities was observed in 42 patients (55.3%) with childhood-onset SLE. The presence of cerebral atrophy was associated with anticardiolipin antibodies (aCL) (P = 0.02), anti-double-stranded DNA (P = 0.02), and cumulative corticosteroid dose (P = 0.04). The presence of corpus callosum atrophy was associated with low complement level (P = 0.006) and acute confusional state (P = 0.01). Serum levels of S100B or high molecular weight neurofilament and the presence of anti-ribosomal P were not associated with atrophy.

CONCLUSION

Structural brain abnormalities were observed in 55.3% of the patients and were associated with neuropsychiatric manifestations, aCL, and corticosteroid use. To determine permanent neurologic damage, longitudinal studies must be conducted in these patients.

S100β is associated with cognitive impairment in childhood-onset systemic lupus erythematosus patients

Objective

To investigate serologic S100β protein levels in childhood-onset SLE patients (cSLE) and to elucidate their association with disease activity and neuropsychiatric (NP) manifestations.

Methods

We included 71 cSLE patients (67 females; median age 18 years; range 9–37 and 53 (47 females; median age of 20 years; range 6–29) age and sex matched healthy controls. Neurological manifestations were analysed according to the American College of Rheumatology (ACR) criteria. Cognitive evaluation was performed in all participants using Wechsler Intelligence Scale for Children (WISC-III) and Wechsler Adult Intelligence Scale (WAIS), according to age, and validated in Portuguese. SLE patients were further assessed for clinical and laboratory SLE manifestations, disease activity (SLE Disease Activity Index (SLEDAI)), damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)) and current drug exposures. Sera S100β protein levels were measured by enzyme-linked immunosorbent assay using commercial kits.

Results

The median S100β protein level was 116.55 pg/mL (range 1.53–468.50) in cSLE and 54.98 pg/mL (range 0.69–181.00) in healthy controls ( p < 0.001). An association was observed between S100β protein and NP manifestations ( p = 0.03). The S100β protein levels was associated with cognitive impairment in cSLE patients ( p = 0.006).

Conclusions

S100β protein levels are increased in cSLE with cognitive impairment. S100β may be considered a potential biomarker that underlies central nervous system (CNS) dysfunction, especially cognitive impairment.

The Neurochemical and Microstructural Changes in the Brain of Systemic Lupus Erythematosus Patients: A Multimodal MRI Study

The diagnosis and pathology of neuropsychiatric systemic lupus erythematosus (NPSLE) remains challenging. Herein, we used multimodal imaging to assess anatomical and functional changes in brains of SLE patients instead of a single MRI approach generally used in previous studies. Twenty-two NPSLE patients, 21 non-NPSLE patients and 20 healthy controls (HCs) underwent 3.0 T MRI with multivoxel magnetic resonance spectroscopy, T1-weighted volumetric images for voxel based morphometry (VBM) and diffusional kurtosis imaging (DKI) scans. While there were findings in other basal ganglia regions, the most consistent findings were observed in the posterior cingulate gyrus (PCG). The reduction of multiple metabolite concentration was observed in the PCG in the two patient groups, and the NPSLE patients were more prominent. The two patient groups displayed lower diffusional kurtosis (MK) values in the bilateral PCG compared with HCs (p < 0.01) as assessed by DKI. Grey matter reduction in the PCG was observed in the NPSLE group using VBM. Positive correlations among cognitive function scores and imaging metrics in bilateral PCG were detected. Multimodal imaging is useful for evaluating SLE subjects and potentially determining disease pathology. Impairments of cognitive function in SLE patients may be interpreted by metabolic and microstructural changes in the PCG.

Proof of principle: Transformation approach alters caudate nucleus volume and structure-function associations

Brain magnetic resonance image (MRI) registration alters structure orientation, size, and/or shape. To determine whether linear registration methods (image transformation to 6, 9, and 12° of freedom) alter structural volume and cognitive associations, we examined transformation alterations to the caudate nucleus within individuals diagnosed with Parkinson's disease (PD) and demographically matched non-PD peers. Volumes from native and six were expected be significantly different from 9 and 12° of freedom methods. Caudate nucleus volumes were expected to be associated with measures of processing speed and mental flexibility, but the strength of the association based on transformation approach was unknown. MRI brain scans from individuals with Parkinson's disease (n = 40) and age-matched controls (n = 40) were transformed using 6, 9, and 12° of freedom to an average brain template. Correlations controlling for total intracranial volume assessed expected structural-behavioral associations. Volumetric: Raw 9 and 12° transformed volumes were significantly larger than native and 6° volumes. Only 9 and 12° volumes revealed group differences with PD less than controls. Intracranial volume considerations were essential for native and 6° between group comparisons. Structural-Behavioral: The 9 and 12° caudate nucleus volume transformations revealed the expected brain-behavioral associations. Linear registration techniques alter volumetric and cognitive-structure associations. The study highlights the need to communicate transformation approach and group intracranial volume considerations.

Cognitive dysfunction and functional magnetic resonance imaging in systemic lupus erythematosus

Cognitive dysfunction is a common aspect of systemic lupus erythematosus (SLE) and is increasingly reported as a problem by patients. In many cases the exact cause is unclear. Limited correlations between specific autoantibodies or structural brain abnormalities and cognitive dysfunction in SLE have been reported. It may be that the most appropriate biomarkers have yet to be found. Functional magnetic resonance imaging (fMRI) is a technique used in many other conditions and provides sensitive measures of brain functionality during cognitive tasks. It is now beginning to be employed in SLE studies. These studies have shown that patients with SLE often perform similarly to healthy controls in terms of behavioural measures on cognitive tasks. However, SLE patients appear to employ compensatory brain mechanisms, such as increased response in fronto-parietal regions, to maintain adequate cognitive performance. As there have been only a few studies using fMRI in SLE to investigate cognitive dysfunction, many questions remain unanswered. Further research could, however, help to identify biomarkers for cognitive dysfunction in SLE.

Childhood-onset lupus with clinical neurocognitive dysfunction shows lower streamline density and pairwise connectivity on diffusion tensor imaging

OBJECTIVES

The objective of this report is to use diffusion-tensor imaging (DTI) for investigating white-matter connectivity changes associated with neurocognitive dysfunction in childhood-onset lupus (cSLE-NCD) as measured by formal neuropsychological testing.

METHODS

DTI was performed in six individuals with (cSLE-NCD) and nine without neurocognitive dysfunction (cSLE-noNCD) as well as 14 healthy controls. Presence of neurocognitive deficits was identified by formal neuropsychological testing. The brain was divided into 116 regions, and pairwise connectivity (defined as the number of streamlines with an endpoint in each of those regions) and streamline density (defined as the number of streamlines passing through a region regardless of endpoints) were evaluated. Group comparisons were made for regional and global measures of streamline density and pairwise connectivity.

RESULTS

A significant decrease in global streamline density was observed in the cSLE-NCD vs. control group (1189 vs. 1305 p = 0.002) and vs. cSLE-noNCD (1189 vs 1320 p = 0.001). The cSLE-noNCD and control groups had similar streamline density. A similar pattern for pairwise connectivity was observed with a significant decrease in the cSLE-NCD group (217) versus the cSLE-noNCD (236; p = 0.013) and control group (238; p = 0.004). Regional measures of pairwise connectivity displayed mixed results.

CONCLUSIONS

The analysis of DTI in this pilot study shows cSLE-NCD is associated with global loss of streamline density and pairwise connectivity, suggesting breakdown of the structural network. These results complement previously reported functional and volumetric findings that suggest cSLE-NCD is associated with measurable changes in gray and white matter. If confirmed in larger cohorts, DTI abnormalities could be used as imaging biomarkers of cSLE-NCD.

Loss of cerebral white matter in primary Sjögren's syndrome: a controlled volumetric magnetic resonance imaging study

BACKGROUND AND PURPOSE

Although brain involvement is common in primary Sjögren's syndrome (pSS), results from cerebral imaging studies are inconsistent. This study aimed to perform both voxel-wise and global brain volume analyses in a nearly population-based pSS cohort to explore whether the patients displayed any focal or diffuse volume differences compared with healthy subjects.

METHODS

Global grey matter (GM) and white matter (WM) volumes were measured and compared in 60 patients with pSS and 60 age- and gender-matched healthy subjects. Regression models were constructed with potential explanatory variables for GM and WM volumes. In the same groups, voxel-wise morphometric analyses were performed.

RESULTS

In analyses of global GM and WM, the patients had lower WM volumes than healthy subjects (540 ± 63 cm(3) vs. 564 ± 56 cm(3), P = 0.02), but no differences in GM. Voxel-wise analyses displayed no localized areas of GM or WM volume differences between pSS patients and healthy subjects.

CONCLUSION

Individuals with pSS have a diffuse reduction of cerebral WM but no localized loss of WM or GM. This indicates a general deleterious effect on WM due to pSS itself.