Quantitative susceptibility mapping of the normal-appearing white matter as a potential new marker of disability progression in multiple sclerosis.

OBJECTIVES: To investigate the normal-appearing white matter (NAWM) susceptibility in a cohort of newly diagnosed multiple sclerosis (MS) patients and to evaluate possible correlations between NAWM susceptibility and disability progression. METHODS: Fifty-nine patients with a diagnosis of MS (n = 53) or clinically isolated syndrome (CIS) (n = 6) were recruited and followed up. All participants underwent neurological examination, blood sampling for serum neurofilament light chain (sNfL) level assessment, lumbar puncture for the quantification of cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels, and brain MRI. T2-weighted scans were used to quantify white matter (WM) lesion loads. For each scan, we derived the NAWM volume fraction and the WM lesion volume fraction. Quantitative susceptibility mapping (QSM) of the NAWM was calculated using the susceptibility tensor imaging (STI) suite. Susceptibility maps were computed with the STAR algorithm. RESULTS: Primary progressive patients (n = 9) showed a higher mean susceptibility value in the NAWM than relapsing-remitting (n = 44) and CIS (n = 6) (p = 0.01 and p = 0.02). Patients with a higher susceptibility in the NAWM showed increased sNfL concentration (ρ = 0.38, p = 0.004) and lower CSF Aß levels (ρ = -0.34, p = 0.009). Mean NAWM susceptibility turned out to be a predictor of the expanded disability status scale (EDSS) worsening at follow-up (ß = 0.41, t = 2.66, p = 0.01) and of the MS severity scale (MSSS) (ß = 0.38, t = 2.43, p = 0.019). CONCLUSIONS: QSM in the NAWM seems to predict the EDSS increment over time. This finding might provide evidence on the role of QSM in identifying patients with an increased risk of early disability progression. KEY POINTS: • NAWM-QSM is higher in PPMS patients than in RRMS. • NAWM-QSM seems to be a predictor of EDSS worsening over time. • Patients with higher NAWM-QSM show increased sNfL concentration and lower CSF Aß levels.

Evidence of retinal anterograde neurodegeneration in the very early stages of multiple sclerosis: a longitudinal OCT study.

BACKGROUND: Neurodegenerative processes are present since the early stages of multiple sclerosis (MS), constituting the primary substrate of disability. As part of the CNS, retinal damage could be considered a reliable prognostic biomarker of neurodegeneration in MS. OBJECTIVES: To characterize longitudinal changes in the retinal layers' thickness and to investigate correlations between retinal atrophy and other prognostic biomarkers, i.e., cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels. METHODS: Forty-two eyes without a history of optic neuritis of 23 MS patients were recruited. All patients underwent spectral-domain-OCT scans (SD-OCT), brain magnetic resonance imaging (MRI), and lumbar puncture at baseline. SD-OCT and brain MRI were repeated after 12 months. Ten controls underwent the same OCT procedure. RESULTS: At baseline, macular ganglion cell/inner plexiform layer (mGCIPL) thickness was reduced in patients compared to controls (p = 0.008), without retinal nerve fiber layer (RNFL) thinning, that was revealed only at follow-up (p = 0.005). Patients with lower CSF Aß levels displayed reduced RNFL thickness values, both at baseline and follow-up. CONCLUSIONS: At very early clinical stages, mGCIPL thickness values were reduced without a concomitant peripapillary RNFL thinning. The longitudinal assessment demonstrated a RNFL loss in patients compared to HC, together with a plateau of mGCIPL thinning. Aßlow subgroup of patients showed a reduction of retinal nerve fiber layer thickness.

Amyloid PET as a marker of normal-appearing white matter early damage in multiple sclerosis: correlation with CSF ß-amyloid levels and brain volumes.

PURPOSE: The disease course of multiple sclerosis (MS) is unpredictable, and reliable prognostic biomarkers are needed. Positron emission tomography (PET) with ß-amyloid tracers is a promising tool for evaluating white matter (WM) damage and repair. Our aim was to investigate amyloid uptake in damaged (DWM) and normal-appearing WM (NAWM) of MS patients, and to evaluate possible correlations between cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels, amyloid tracer uptake, and brain volumes. METHODS: Twelve MS patients were recruited and divided according to their disease activity into active and non-active groups. All participants underwent neurological examination, neuropsychological testing, lumbar puncture, brain magnetic resonance (MRI) imaging, and 18F-florbetapir PET. Aß levels were determined in CSF samples from all patients. MRI and PET images were co-registered, and mean standardized uptake values (SUV) were calculated for each patient in the NAWM and in the DWM. To calculate brain volumes, brain segmentation was performed using statistical parametric mapping software. Nonparametric statistical analyses for between-group comparisons and regression analyses were conducted. RESULTS: We found a lower SUV in DWM compared to NAWM (p < 0.001) in all patients. Decreased NAWM-SUV was observed in the active compared to non-active group (p < 0.05). Considering only active patients, NAWM volume correlated with NAWM-SUV (p = 0.01). Interestingly, CSF Aß concentration was a predictor of both NAWM-SUV (r = 0.79; p = 0.01) and NAWM volume (r = 0.81, p = 0.01). CONCLUSIONS: The correlation between CSF Aß levels and NAWM-SUV suggests that the predictive role of ß-amyloid may be linked to early myelin damage and may reflect disease activity and clinical progression.

The loss of macular ganglion cells begins from the early stages of disease and correlates with brain atrophy in multiple sclerosis patients.

BACKGROUND: The importance of neurodegeneration in multiple sclerosis (MS) is increasingly well recognized. OBJECTIVES: To evaluate retinal pathology using optical coherence tomography (OCT) and to investigate possible associations between retinal layers' thickness and specific patterns of gray matter volume in patients with a new diagnosis of MS. METHODS: A total of 31 patients underwent OCT scans and brain magnetic resonance imaging. In total, 30 controls underwent the same OCT procedure. The association between focal cortical volume and OCT measurements was investigated with voxel-based morphometry (VBM). RESULTS: Compared to controls, patients' macular retinal nerve fiber layer (mRNFL), macular ganglion cell layer (mGCL), macular inner plexiform layer (mIPL), and macular ganglion cell-inner plexiform layer (mGCIPL) thickness were significantly reduced ( p = 0.0009, p = 0.0003, p = 0.0049, and p = 0.0007, respectively). Peripapillary RNFL (pRNFL) and temporal sector pRNFL (T-pRNFL) did not show any significant changes, although there was a trend toward T-pRNFL thinning ( p = 0.0254). VBM analysis showed that mGCIPL and pRNFL were significantly correlated with the volume reduction of occipital-parietal cortex ( p < 0.005). CONCLUSION: mRNFL, mGCL, and mIPL are significantly reduced in MS patients without concomitant pRNFL thinning. These retinal changes show a significant association with cortical regions that are known to be important for visuospatial performance.

CSF ß-amyloid predicts prognosis in patients with multiple sclerosis.

BACKGROUND: The importance of predicting disease progression in multiple sclerosis (MS) has increasingly been recognized, and hence reliable biomarkers are needed. OBJECTIVES: To investigate the prognostic role of cerebrospinal fluid (CSF) amyloid beta1-42 (Aß) levels by the determination of a cut-off value to classify patients in slow and fast progressors. To evaluate possible association with white matter (WM) and grey matter (GM) damage at early disease stages. METHODS: Sixty patients were recruited and followed up for 3-5 years. Patients underwent clinical assessment, brain magnetic resonance imaging (MRI; at baseline and after 1 year), and CSF analysis to determine Aß levels. T1-weighted volumes were calculated. T2-weighted scans were used to quantify WM lesion loads. RESULTS: Lower CSF Aß levels were observed in patients with a worse follow-up Expanded Disability Status Scale (EDSS; r = -0.65, p < 0.001). The multiple regression analysis confirmed CSF Aß concentration as a predictor of patients' EDSS increase (r = -0.59, p < 0.0001). Generating a receiver operating characteristic curve, a cut-off value of 813 pg/mL was determined as the threshold able to identify patients with worse prognosis (95% confidence interval (CI): 0.690-0.933, p = 0.0001). No differences in CSF tau and neurofilament light chain (NfL) levels were observed (p > 0.05). CONCLUSION: Low CSF Aß levels may represent a predictive biomarker of disease progression in MS.

CSF ß-amyloid and white matter damage: a new perspective on Alzheimer's disease.

OBJECTIVE: To assess the connection between amyloid pathology and white matter (WM) macrostructural and microstructural damage in demented patients compared with controls. METHODS: Eighty-five participants were recruited: 65 with newly diagnosed Alzheimer's disease (AD), non-AD dementia or mild cognitive impairment and 20 age-matched and sex-matched healthy controls. ß-amyloid1-42 (Aß) levels were determined in cerebrospinal fluid (CSF) samples from all patients and five controls. Among patients, 42 had pathological CSF Aß levels (Aß(+)), while 23 had normal CSF Aß levels (Aß(-)). All participants underwent neurological examination, neuropsychological testing and brain MRI. We used T2-weighted scans to quantify WM lesion loads (LLs) and diffusion-weighted images to assess their microstructural substrate. Non-parametric statistical tests were used for between-group comparisons and multiple regression analyses. RESULTS: We found an increased WM-LL in Aß(+) compared with both, healthy controls (p=0.003) and Aß(-) patients (p=0.02). Interestingly, CSF Aß concentration was the best predictor of patients' WM-LL (r=-0.30, p<0.05) when using age as a covariate. Lesion apparent diffusion coefficient value was higher in all patients than in controls (p=0.0001) and correlated with WM-LL (r=0.41, p=0.001). In Aß(+), WM-LL correlated with WM microstructural damage in the left peritrigonal WM (p<0.0001). CONCLUSIONS: WM damage is crucial in AD pathogenesis. The correlation between CSF Aß levels and WM-LL suggests a direct link between amyloid pathology and WM macrostructural and microstructural damage.

Recognition of viral and self-antigens by TH1 and TH1/TH17 central memory cells in patients with multiple sclerosis reveals distinct roles in immune surveillance and relapses.

BACKGROUND: Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) that is caused by autoreactive T cells and associated with viral infections. However, the phenotype of pathogenic T cells in peripheral blood remains to be defined, and how viruses promote MS is debated. OBJECTIVE: We aimed to identify and characterize potentially pathogenic autoreactive T cells, as well as protective antiviral T cells, in patients with MS. METHODS: We analyzed CD4+ helper T-cell subsets from peripheral blood or cerebrospinal fluid for cytokine production, gene expression, plasticity, homing potentials, and their reactivity to self-antigens and viral antigens in healthy subjects and patients with MS. Moreover, we monitored their frequencies in untreated and fingolimod- or natalizumab-treated patients with MS. RESULTS: TH1/TH17 central memory (TH1/TH17CM) cells were selectively increased in peripheral blood of patients with relapsing-remitting MS with a high disease score. TH1/TH17CM cells were closely related to conventional TH17 cells but had more pathogenic features. In particular, they could shuttle between lymph nodes and the CNS and produced encephalitogenic cytokines. The cerebrospinal fluid of patients with active MS was enriched for CXCL10 and contained mainly CXCR3-expressing TH1 and TH1/TH17 subsets. However, while TH1 cells responded consistently to viruses, TH1/TH17CM cells reacted strongly with John Cunningham virus in healthy subjects but responded instead to myelin-derived self-antigens in patients with MS. Fingolimod and natalizumab therapies efficiently targeted autoreactive TH1/TH17CM cells but also blocked virus-specific TH1 cells. CONCLUSIONS: We propose that autoreactive TH1/TH17CM cells expand in patients with MS and promote relapses after bystander recruitment to the CNS, whereas TH1 cells perform immune surveillance. Thus the selective targeting of TH1/TH17 cells could inhibit relapses without causing John Cunningham virus-dependent progressive multifocal encephalomyelitis.

CSF ß-amyloid as a putative biomarker of disease progression in multiple sclerosis.

BACKGROUND: Neurodegeneration plays a major role in determining disability in multiple sclerosis (MS) patients. Hence, there is increasing need to identify reliable biomarkers, which could serve as prognostic measure of disease progression. OBJECTIVES: To assess whether cerebrospinal fluid (CSF) tau and ß-amyloid (Aß) levels were altered in newly diagnosed MS patients and correlated with disability. Moreover, we investigated whether these CSF biomarkers associate with macroscopic brain tissue damage measures. METHODS: CSF Aß and tau levels were determined by enzyme-linked immunosorbent assay in CSF samples from 48 newly diagnosed MS patients, followed-up clinically for 3 years by recording their Expanded Disability Status Scale score at 6-month intervals, and 45 controls. All patients underwent magnetic resonance imaging at baseline and at the end of follow-up to quantify their lesion load (LL). RESULTS: CSF Aß levels were significantly reduced in patients compared to controls ( p < 0.001). Lower CSF Aß levels at baseline were a disability predictor at 3-year follow-up ( p = 0.009). CSF tau levels correlated with T2- and T1-LL ( p < 0.001). CONCLUSION: CSF Aß reduction is a promising biomarker of neurodegeneration and may predict patients' clinical outcome. Therefore, CSF Aß should be considered as a potential biomarker of prognostic value.

Balò's concentric sclerosis: still to be considered as a variant of multiple sclerosis?

Balò's concentric sclerosis (BCS) is considered a rare demyelinating disease and regarded as an aggressive variant of multiple sclerosis (MS). We describe three cases (one male and two females) with neuroimaging features suggestive of BCS and heterogeneous symptoms, with benign long-term clinical course upon treatment with natalizumab and fingolimod. Neurological examination, blood and cerebrospinal fluid analyses, brain and spinal cord magnetic resonance imaging (MRI) and brain proton magnetic resonance spectroscopy were performed. At onset, patient #1 showed predominant cognitive impairment with consciousness disturbances; patient #2 presented with left hemiparesis; patient #3 demonstrated hesitance in speech and in written word production, along with right central facial palsy. All patients showed the typical MRI changes associated with BCS, such as concentric rings or a whorled appearance on T2-weighted and contrast-enhanced T1-weighted images. They were treated with high dosage i.v. steroid with clinical improvement and followed-up for 3 years with different clinical course. Two patients fulfilled the revised McDonald criteria for MS and received preventive therapy, natalizumab and fingolimod, respectively, whereas the third patient is still stable without clinical and radiological evolution. All of them did not have new exacerbations or MRI lesions over 2-4 year follow-up. Our descriptions demonstrate the heterogeneity of clinical presentation of BCS. Moreover, these case reports suggest that BCS may neither be rapidly progressive nor fatal and may be considered part of the MS spectrum. In line with this hypothesis, current treatments for MS were effective in our patients.

Amyloid PET imaging and dementias: potential applications in detecting and quantifying early white matter damage.

PURPOSE: Positron emission tomography (PET) with amyloid tracers (amy-PET) allows the quantification of pathological amyloid deposition in the brain tissues, including the white matter (WM). Here, we evaluate amy-PET uptake in WM lesions (WML) and in the normal-appearing WM (NAWM) of patients with Alzheimer's disease (AD) and non-AD type of dementia. METHODS: Thirty-three cognitively impaired subjects underwent brain magnetic resonance imaging (MRI), Aß1-42 (Aß) determination in the cerebrospinal fluid (CSF) and amy-PET. Twenty-three patients exhibiting concordant results in both CSF analysis and amy-PET for cortical amyloid deposition were recruited and divided into two groups, amyloid positive (A+) and negative (A-). WML quantification and brain volumes' segmentation were performed. Standardized uptake values ratios (SUVR) were calculated in the grey matter (GM), NAWM and WML on amy-PET coregistered to MRI images. RESULTS: A+ compared to A- showed a higher WML load (p = 0.049) alongside higher SUVR in all brain tissues (p < 0.01). No correlations between CSF Aß levels and WML and NAWM SUVR were found in A+, while, in A-, CSF Aß levels were directly correlated to NAWM SUVR (p = 0.04). CSF Aß concentration was the only predictor of NAWM SUVR (adj R2 = 0.91; p = 0.04) in A-. In A+ but not in A- direct correlations were identified between WM and GM SUVR (p < 0.01). CONCLUSIONS: Our data provide evidence on the role of amy-PET in the assessment of microstructural WM injury in non-AD dementia, whereas amy-PET seems less suitable to assess WM damage in AD patients due to a plausible amyloid accrual therein.

Detection of the SQSTM1 Mutation in a Patient with Early-Onset Hippocampal Amnestic Syndrome.

Genetics has a major role in early-onset dementia, but the correspondence between genotype and phenotype is largely tentative. We describe a 54-year-old with familial early-onset slowly-progressive episodic memory impairment with the P392L-variant in SQSTM1. The patient showed cortical atrophy and hypometabolism in the temporal lobes, but no amyloidosis biomarkers. As symptoms/neuroimaging were suggestive for Alzheimer's disease-but biomarkers were not-and considering the family-history, genetic analysis was performed, revealing the P392L-variant in SQSTM1, which encodes for sequestosome-1/p62. Increasing evidence suggests a p62 involvement in neurodegeneration and SQSTM1 mutations have been found to cause amyotrophic lateral sclerosis/frontotemporal dementia. Our report suggests that the clinical spectrum of SQSTM1 variants is wider.

CSF ß-amyloid predicts early cerebellar atrophy and is associated with a poor prognosis in multiple sclerosis.

BACKGROUND: Neurodegeneration is present from the earliest stages of multiple sclerosis (MS) and is critically involved in MS related clinical disability. Aim of the present study was to assess the connection between amyloid burden and early cerebellar grey matter (GM) atrophy compared to early brain GM atrophy in MS patients. METHODS: Forty newly diagnosed relapsing-remitting (RR-) MS patients were recruited. ß-amyloid1-42 (Aß) levels were determined in cerebrospinal fluid (CSF) samples from all subjects. All participants underwent neurological examination and brain magnetic resonance imaging (MRI) at baseline. Twenty-nine out of 40 patients repeated a brain MRI at 1-year follow-up. T1-weighted scans were segmented using the Voxel-Based Morphometry (VBM) protocol and the Spatially Unbiased Infratentorial Toolbox (SUIT) from Statistical Parametric Mapping (SPM12). RESULTS: Between-group comparison of cerebellar parenchymal fraction (GM+WM/total cerebellar volume%) showed significant differences between Aßhigh and Aßlow at baseline (p < 0.0001) and follow-up (p = 0.02). Similarly, a between-group comparison of cerebellar GM fraction (GMF) showed significant differences between Aßhigh and Aßlow at baseline (p = 0.002) and follow-up (p = 0.04). The multiple regression analysis showed CSF Aß concentration as the best predictor of GMF both at baseline and over time (ß = 0.505, ß=0.377; p < 0.05). No significant results were found regarding global brain atrophy and CSF Aß concentration. CONCLUSIONS: Early cerebellar atrophy seems to be crucial in predicting a poor prognosis in MS, more than early global brain atrophy.

Low CSF ß-amyloid levels predict early regional grey matter atrophy in multiple sclerosis.

BACKGROUND AND PURPOSE: Grey matter (GM) atrophy is present from the earliest stages of multiple sclerosis (MS) and occurs largely in a nonrandom manner. However, the biological mechanisms underlying the progression of regional atrophy are still unclear. Aim of this study is to investigate whether amyloid pathology might be involved in determining the pattern of GM atrophy over time. METHODS: Forty-six subjects were recruited: 31 newly diagnosed relapsing-remitting (RR-) MS patients and 15 age- and sex-matched healthy controls (HC). Aß levels were determined in CSF samples from all subjects. All participants underwent brain magnetic resonance imaging (MRI) at baseline, and 23 out of 31 patients at one year follow-up. T1-weighted scans were segmented using the Geodesic Information Flows software. Non-parametric statistical tests were used for between-group comparisons and multiple regression analyses. RESULTS: CSF Aß concentration was the best predictor of global GM loss over time after age (ß = 0.403; p = 0.024), in particular in the left precuneus (p = 0.045), in the left middle cingulate gyrus (p = 0.009), in the left precentral gyrus (p = 0.021) and in the right angular gyrus (p = 0.029). CONCLUSIONS: CSF Aß levels seem to be crucial in MS early brain volume loss as GM atrophy manifests in regions particularly vulnerable to early Aß deposition.

Testing the 2018 NIA-AA research framework in a retrospective large cohort of patients with cognitive impairment: from biological biomarkers to clinical syndromes.

BACKGROUND: According to the 2018 NIA-AA research framework, Alzheimer's disease (AD) is not defined by the clinical consequences of the disease, but by its underlying pathology, measured by biomarkers. Evidence of both amyloid-ß (Aß) and phosphorylated tau protein (p-tau) deposition-assessed interchangeably with amyloid-positron emission tomography (PET) and/or cerebrospinal fluid (CSF) analysis-is needed to diagnose AD in a living person. Our aim was to test the new NIA-AA research framework in a large cohort of cognitively impaired patients to evaluate correspondence between the clinical syndromes and the underlying pathologic process testified by biomarkers. METHODS: We retrospectively analysed 628 subjects referred to our centre in suspicion of dementia, who underwent CSF analysis, together with neuropsychological assessment and neuroimaging, and were diagnosed with different neurodegenerative dementias according to current criteria, or as cognitively unimpaired. Subjects were classified considering CSF biomarkers, and the prevalence of normal, AD-continuum and non-AD profiles in each clinical syndrome was calculated. The positivity threshold of each CSF biomarker was first assessed by receiver operating characteristic analysis, using Aß-positive/negative status as determined by amyloid-PET visual reads. The agreement between CSF and amyloid-PET data was also evaluated. RESULTS: Among patients with a clinical diagnosis of AD, 94.1% were in the AD-continuum, whereas 5.5% were classified as non-AD and 0.4% were normal. The AD-continuum profile was found also in 26.2% of frontotemporal dementia, 48.6% of Lewy body dementia, 25% of atypical parkinsonism and 44.7% of vascular dementia. Biomarkers' profile did not differ in amnestic and not amnestic mild cognitive impairment. CSF Aß levels and amyloid-PET tracer binding negatively correlated, and the concordance between the two Aß biomarkers was 89%. CONCLUSIONS: The examination of the 2018 NIA-AA research framework in our clinical setting revealed a good, but incomplete, correspondence between the clinical syndromes and the underlying pathologic process measured by CSF biomarkers. The AD-continuum profile resulted to be a sensitive, but non-specific biomarker with regard to the clinical AD diagnosis. CSF and PET Aß biomarkers were found to be not perfectly interchangeable to quantify the Aß burden, possibly because they measure different aspects of AD pathology.

LncRNAs expression profile in peripheral blood mononuclear cells from multiple sclerosis patients.

LncRNA PCR arrays containing 90 common LncRNAs were used to screen lncRNA expression levels in PBMC from a discovery population of patients with MS. Data from discovery and replications cohorts showed a generalized dysregulation of lncRNA levels in MS patients compared with controls. MALAT1, MEG9, NRON, ANRIL, TUG1, XIST, SOX2OT, GOMAFU, HULC, BACE-1AS were significantly downregulated in MS patients in comparison with controls. Therefore, we performed a validation analysis in an independent cohort of Belgian origin. In this study, NRON and TUG1 downregulations in MS patients compared with controls were confirmed (p ≤ .05 and p ≤ .0001 respectively), whereas considering the other lncRNAs, the statistical threshold was not reached. LncRNAs profiling could thus represent a new challenge in the research of easy detectable biomarkers of disease susceptibility and progression.