Cognitive Impairment Is Related to Glymphatic System Dysfunction in Pediatric Multiple Sclerosis.

OBJECTIVE: The aim of this study was to investigate whether, compared to pediatric healthy controls (HCs), the glymphatic system is impaired in pediatric multiple sclerosis (MS) patients according to their cognitive status, and to assess its association with clinical disability and MRI measures of brain structural damage. METHODS: Sixty-five pediatric MS patients (females = 62%; median age = 15.5 [interquartile range, IQR = 14.5;17.0] years) and 23 age- and sex-matched HCs (females = 44%; median age = 14.1 [IQR = 11.8;16.2] years) underwent neurological, neuropsychological and 3.0 Tesla MRI assessment, including conventional and diffusion tensor imaging (DTI). We calculated the diffusion along the perivascular space (DTI-ALPS) index, a proxy of glymphatic function. Cognitive impairment (Co-I) was defined as impairment in at least 2 cognitive domains. RESULTS: No significant differences in DTI-ALPS index were found between HCs and cognitively preserved (Co-P) pediatric MS patients (estimated mean difference [EMD] = -0.002 [95% confidence interval = -0.069; 0.065], FDR-p = 0.956). Compared to HCs and Co-P patients, Co-I pediatric MS patients (n = 20) showed significantly lower DTI-ALPS index (EMD = -0.136 [95% confidence interval = -0.214; -0.058], FDR-p ≤ 0.004). In HCs, no associations were observed between DTI-ALPS index and normalized brain, cortical and thalamic volumes, and normal-appearing white matter (NAWM) fractional anisotropy (FA) and mean diffusivity (MD) (FDR-p ≥ 0.348). In pediatric MS patients, higher brain WM lesion volume (LV), higher NAWM MD, lower normalized thalamic volume, and lower NAWM FA were associated with lower DTI-ALPS index (FDR-p ≤ 0.016). Random Forest selected lower DTI-ALPS index (relative importance [RI] = 100%), higher brain WM LV (RI = 59.5%) NAWM MD (RI = 57.1%) and intelligence quotient (RI = 51.3%) as informative predictors of cognitive impairment (out-of-bag area under the curve = 0.762). INTERPRETATION: Glymphatic system dysfunction occurs in pediatric MS, is associated with brain focal lesions, irreversible tissue loss accumulation and cognitive impairment. ANN NEUROL 2024.

Choroid plexus and perivascular space enlargement in neuropsychiatric systemic lupus erythematosus.

Choroid plexus (CP) enlargement is proposed as a marker of neuroinflammation in immune-mediated conditions. CP involvement has also been hypothesized in the immunopathology of systemic lupus erythematosus (SLE). We investigated whether CP enlargement occurs in SLE patients and its association with neuropsychiatric involvement. Additionally, we explored abnormalities along the glymphatic system in SLE patients through enlarged perivascular space (PVS) quantification. Clinical assessment and 3 Tesla brain dual-echo and T1-weighted MRI scans were obtained from 32 SLE patients and 32 sex and age-matched healthy controls (HC). CPs were manually segmented on 3D T1-weighted sequence and enlarged PVS (ePVS) were assessed through Potter's score. Compared to HC, SLE patients showed higher normalized CP volume (nCPV) (p = 0.023), with higher CP enlargement in neuropsychiatric SLE (NPSLE) (n = 12) vs. non-NPSLE (p = 0.027) patients. SLE patients with antiphospholipid antibodies (APA) positivity (n = 18) had higher nCPV compared to HC (p = 0.012), while APA negative ones did not. SLE patients also had higher Potter's score than HC (p < 0.001), with a tendency towards a higher number of basal ganglia ePVS in NPSLE vs. non-NPSLE patients. Using a random forest analysis, nCPV emerged as a significant predictor of NPSLE, together with T2-hyperintense white matter (WM) lesion volume (LV) and APA positivity (out-of-bag AUC 0.81). Our findings support the hypothesis of a role exerted by the CP in SLE physiopathology, especially in patients with neuropsychiatric involvement. The higher prevalence of ePVS in SLE patients, compared to HC, suggests the presence of glymphatic system impairment in this population.

Unraveling the heterogeneous pathological substrates of relapse-onset multiple sclerosis: a multiparametric voxel-wise 3 T MRI study.

BACKGROUND: In multiple sclerosis (MS), pathological processes affecting brain gray (GM) and white matter (WM) are heterogeneous. OBJECTIVE: To apply a multimodal MRI approach to investigate the regional distribution of the different pathological processes occurring in the brain WM and GM of relapse-onset MS patients. METHODS: Fifty-seven MS patients (forty-two relapsing remitting [RR], fifteen secondary progressive [SP]) and forty-seven age- and sex-matched healthy controls (HC) underwent a multimodal 3 T MRI acquisition. Between-group voxel-wise differences of brain WM and GM volumes, magnetization transfer ratio (MTR), T1-weighted(w)/T2w ratio, intracellular volume fraction (ICV_f), and quantitative susceptibility mapping (QSM) maps were investigated. RESULTS: Compared to HC, RRMS showed significant WM, deep GM and cortical atrophy, significantly lower MTR and T1w/T2w ratio of periventricular and infratentorial WM, deep GM and several cortical areas, lower ICV_f in supratentorial and cerebellar WM and in some cortical areas, and lower QSM values in bilateral periventricular WM (p < 0.001). Compared to RRMS, SPMS patients showed significant deep GM and widespread cortical atrophy, significantly lower MTR of periventricular WM, deep GM and cerebellum, lower T1w/T2w ratio of fronto-temporal WM regions, lower ICV_f of some fronto-tempo-occipital WM and cortical areas. They also had increased QSM and T1w/T2w ratio in the pallidum, bilaterally (p < 0.001). CONCLUSION: A periventricular pattern of demyelination and widespread GM and WM neuro-axonal loss are detectable in RRMS and are more severe in SPMS. Higher T1w/T2w ratio and QSM in the pallidum, possibly reflecting iron accumulation and neurodegeneration, may represent a relevant MRI marker to differentiate SPMS from RRMS.

Correspondence among gray matter atrophy and atlas-based neurotransmitter maps is clinically relevant in multiple sclerosis.

In multiple sclerosis (MS), gray matter (GM) atrophy progresses in a non-random manner, possibly in regions with a high distribution of specific neurotransmitters involved in several relevant central nervous system functions. We investigated the associations among regional GM atrophy, atlas-based neurotransmitter distributions and clinical manifestations in a large MS patients' group. Brain 3 T MRI scans, neurological examinations and neuropsychological evaluations were obtained from 286 MS patients and 172 healthy controls (HC). Spatial correlations among regional GM volume differences and atlas-based nuclear imaging-derived neurotransmitter maps, and their associations with MS clinical features were investigated using voxel-based morphometry and JuSpace toolbox. Compared to HC, MS patients showed widespread GM atrophy being spatially correlated with the majority of neurotransmitter maps (false discovery rate [FDR]-p ≤ 0.004). Patients with a disease duration ≥ 5 vs < 5 years had significant cortical, subcortical and cerebellar atrophy, being spatially correlated with a higher distribution of serotoninergic and dopaminergic receptors (FDR-p ≤ 0.03). Compared to mildly-disabled patients, those with Expanded Disability Status Scale ≥ 3.0 or ≥ 4.0 had significant cortical, subcortical and cerebellar atrophy being associated with serotonergic, dopaminergic, opioid and cholinergic maps (FDR-p ≤ 0.04). Cognitively impaired vs cognitively preserved patients had widespread GM atrophy being spatially associated with serotonergic, dopaminergic, noradrenergic, cholinergic and glutamatergic maps (FDR-p ≤ 0.04). Fatigued vs non-fatigued MS patients had significant cortical, subcortical and cerebellar atrophy, not associated with neurotransmitter maps. No significant association between GM atrophy and neurotransmitter maps was found for depression. Regional GM atrophy with specific neurotransmitter systems may explain part of MS clinical manifestations, including locomotor disability, cognitive impairment and fatigue.

In vivo quantification of brain soma and neurite density abnormalities in multiple sclerosis.

BACKGROUND: Soma and neurite density imaging (SANDI) is a new biophysical model that incorporates soma in addition to neurite density, thus possibly providing more specific information about the complex pathological processes of multiple sclerosis (MS). PURPOSE: To discriminate the pathological abnormalities of MS white matter (WM) lesions, normal-appearing (NA) WM and cortex and to evaluate the associations among SANDI-derived measures, clinical disability, and conventional MRI variables. METHODS: Twenty healthy controls (HC) and 23 MS underwent a 3 T brain MRI. Using SANDI on diffusion-weighted sequence, the fractions of neurite (fneurite) and soma (fsoma) were assessed in WM lesions, NAWM, and cortex. RESULTS: Compared to HC WM, MS NAWM showed lower fneurite (false discovery rate [FDR]-p = 0.011). In MS patients, WM lesions showed lower fneurite and fsoma compared to both HC and MS NAWM (FDR-p < 0.001 for all). In the cortex, MS patients had lower fneurite and fsoma compared to HC (FDR-p ≤ 0.009). Compared to both HC and RRMS, PMS patients had lower fneurite in NAWM (vs HC: FDR-p < 0.001; vs RRMS: FDR-p = 0.003) and cortex (vs HC: FDR-p < 0.001; vs RRMS: p = 0.031, not surviving FDR correction), and lower cortical fsoma (vs HC: FDR-p < 0.001; vs RRMS: FDR-p = 0.009). Compared to HC, PMS also showed a higher fsoma in NAWM (FDR-p = 0.015). Fneurite and fsoma in the different brain compartments were correlated with age, phenotype, disease duration, disability, WM lesion volumes, normalized brain, cortical, and WM volumes (r from - 0.761 to 0.821, FDR-p ≤ 0.4). CONCLUSIONS: SANDI may represent a clinically relevant model to discriminate different neurodegenerative phenomena that gradually accumulate through MS disease course.

Choroid plexus enlargement in paediatric multiple sclerosis: clinical relevance and effect of sex.

BACKGROUND: Choroid plexus (CP) enlargement has been suggested as a reliable marker of neuroinflammation in adult multiple sclerosis (MS). We investigated CP volume in patients with paediatric MS compared with matched healthy controls (HC), possible sex-related effect, and the associations with clinical and structural MRI variables. METHODS: Brain 3.0 T dual-echo and three-dimensional (3D) T1-weighted sequences were selected retrospectively from 69 patients with paediatric MS and 23 age-matched and sex-matched HC. CP volume was manually obtained from 3D T1-weighted scans by two expert raters. RESULTS: CP segmentation was highly reproducible (intraobserver agreement: rater I=0.963, rater II=0.958; interobserver agreement=0.968). Compared with HC, patients with paediatric MS showed higher normalised CP volume (p<0.001). Both female and male patients with paediatric MS showed higher normalised CP volume compared with sex-matched HC (women: p<0.001 and men: p=0.021), with a significant disease×sex interaction (p=0.040). In patients with MS, a higher normalised CP volume was significantly associated with higher brain lesional volume (ß=0.252, p=0.017), larger lateral ventricle volume (ß=0.470, false discovery rate (FDR)-p<0.001), lower normalised brain volume (ß=-0.413, FDR-p=0.002) and lower normalised thalamic volume (ß=0.291, FDR-p=0.046). No associations with disease duration, Expanded Disability Status Scale score, normalised cortical and white matter volumes were found (FDR-p≥0.172). A significant effect of the disease in the negative association between normalised volumes of CP and thalami was observed (FDR-p=0.046). CONCLUSIONS: CP enlargement occurs in paediatric MS, suggesting its early involvement in the pathophysiology of the disease. The higher CP volume, which is found especially in female patients, supports the hypothesis of sex-related differences occurring already in paediatric MS.

A Deep Learning Approach to Predicting Disease Progression in Multiple Sclerosis Using Magnetic Resonance Imaging.

OBJECTIVES: Magnetic resonance imaging (MRI) is an important tool for diagnosis and monitoring of disease course in multiple sclerosis (MS). However, its prognostic value for predicting disease worsening is still being debated. The aim of this study was to propose a deep learning algorithm to predict disease worsening at 2 years of follow-up on a multicenter cohort of MS patients collected from the Italian Neuroimaging Network Initiative using baseline MRI, and compare it with 2 expert physicians. MATERIALS AND METHODS: For 373 MS patients, baseline T2-weighted and T1-weighted brain MRI scans, as well as baseline and 2-year clinical and cognitive assessments, were collected from the Italian Neuroimaging Network Initiative repository. A deep learning architecture based on convolutional neural networks was implemented to predict: (1) clinical worsening (Expanded Disability Status Scale [EDSS]-based model), (2) cognitive deterioration (Symbol Digit Modalities Test [SDMT]-based model), or (3) both (EDSS + SDMT-based model). The method was tested on an independent data set and compared with the performance of 2 expert physicians. RESULTS: For the test set, the convolutional neural network model showed high predictive accuracy for clinical (83.3%) and cognitive (67.7%) worsening, although the highest accuracy was reached when training the algorithm using both EDSS and SDMT information (85.7%). Artificial intelligence classification performance exceeded that of 2 expert physicians (70% of accuracy for the human raters). CONCLUSIONS: We developed a robust and accurate model for predicting clinical and cognitive worsening of MS patients after 2 years, based on conventional T2-weighted and T1-weighted brain MRI scans obtained at baseline. This algorithm may be valuable for supporting physicians in their clinical practice for the earlier identification of MS patients at risk of disease worsening.

Defibrotide for Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease Prophylaxis in High-Risk Adult Patients: A Single-Center Experience Study.

Sinusoidal obstruction syndrome (SOS), also known as hepatic veno-occlusive disease (VOD), is a serious complication after hematopoietic stem cell transplantation (HSCT). SOS/VOD usually occurs within 3 weeks of HSCT, but the 2016 European Society for Blood and Marrow Transplantation diagnosis criteria have been revised to include late forms. Prophylactic use of defibrotide is recommended in the pediatric setting, but its value remains uncertain in the adult population. We report here a single-center series of 63 adult patients considered at high risk for SOS/VOD who received defibrotide prophylaxis in combination with ursodeoxycholic acid between May 2012 and August 2016. The median duration of defibrotide therapy was 23 days. Bleeding occurred in 14 patients (21.5%). Defibrotide prophylaxis was discontinued in 7 patients (10.8%): 4 cases (6.3%) due to bleeding and 3 cases (4.6%) because of the need for antithrombotic therapy. Overall, SOS/VOD occurred in 4 cases (6.3%) within 21 days after HSCT (days 13 and 14) in 2 cases and late-onset SOS/VOD (days 57 and 58) in the other 2 cases. SOS/VOD was moderate in 1 case, very severe in 3 cases, with 2 deaths related to SOS/VOD. Cumulative incidence of grades II to IV acute graft-versus-host disease and transplant-associated thrombotic microangiopathy were 22.2% and 3.2%, respectively. With a median follow-up of 31 months (range, 10.7 to 60.3), the rates of 2-year overall survival, progression-free survival, incidence of relapse, and nonrelapse mortality were 56.5%, 49%, 28.7%, and 22.3%, respectively. In our experience defibrotide prophylaxis is associated with a low incidence of SOS/VOD after allogeneic HSCT in a high-risk adult population with an acceptable safety profile.

Upfront autologous stem cell transplantation for newly diagnosed elderly multiple myeloma patients: a prospective multicenter study.

The feasibility and efficacy of high-dose melphalan followed by autologous hematopoietic stem cell transplantation in newly diagnosed elderly patients with multiple myeloma was analyzed prospectively. Fifty-six multiple myeloma patients, aged 65 years or over, from 6 French centers were studied. The induction therapy was bortezomib-based in combination with dexamethasone and either thalidomide, cyclophosphamide or lenalidomide, for 4-6 cycles. Peripheral blood stem cells were collected after high-dose cyclophosphamide plus G-CSF or G-CSF alone, with plerixafor if needed. The conditioning regimen consisted of melphalan at 140 mg/m2 in 18 patients (36%) and 200 mg/m2 in 32 (64%). Three months post autologous hematopoietic stem cell transplantation, a 2-month consolidation phase with either lenalidomide plus dexamethasone or bortezomib-based combination therapy was allowed, but maintenance treatment was not given. All but 6 patients underwent autologous hematopoietic stem cell transplantation and 3 had tandem transplantations. The treatment-related mortality was 0% at 100 days post transplantation. Sixty-eight percent received consolidation therapy following transplantation. The best response achieved was 40% complete response, 36% very good partial response, and 18% partial response. After a median follow up of 21 months (range 6-31), the estimated progression-free and overall survival rates at two years were 76% [95%CI: (61.6-94.1)] and 88% [95%CI: (76.7-100)], respectively. The higher dose of melphalan (200 mg/m2) afforded superior progression-free and overall survival rates. This prospective study provides evidence for the safety and efficacy of autologous hematopoietic stem cell transplantation as a first-line treatment approach in elderly multiple myeloma patients. (clinicaltrials.gov identifier: 01671826).

Calcium signals inhibition sensitizes ovarian carcinoma cells to anti-Bcl-xL strategies through Mcl-1 down-regulation.

Ovarian carcinoma is the leading cause of death from gynecologic cancer in the developed world and is characterized by acquired chemoresistance leading to an overall 5-year survival rate of about 30 %. We previously showed that Bcl-xL and Mcl-1 cooperatively protect platinum-resistant ovarian cancer cells from apoptosis. Despite BH3-mimetics represent promising drugs to target Bcl-xL, anti-Mcl-1 strategies are still in pre-clinical studies and required new investigations. Calcium is a universal second messenger and dysregulation of calcium signal is often observed during carcinogenesis. As change in cytosolic free calcium concentration [Ca(2+)]i is known to control the fate of the cell by regulating Bcl-2 family members, we wonder if calcium signal could impact on Mcl-1 expression and if its pharmacological inhibition could be useful to sensitize ovarian carcinoma cells to anti-Bcl-xL strategies. We therefore studied the effect of different calcium signals inhibitors in ovarian carcinoma cell lines SKOV3 and IGROV1-R10 and analysed their effects on proliferation and Mcl-1 expression. We also exposed these cells to these inhibitors in combination with anti-Bcl-xL strategies (siRNA or BH3-mimetic: ABT-737). We found that calcium signaling regulates Mcl-1 through translational events and a calmodulin-mediated pathway. BAPTA-AM and calmodulin inhibitor combination with ABT-737 leads to apoptosis, a process that is reversed by Mcl-1 enforced expression. As Mcl-1 represents a crucial hurdle to the success of chemotherapy, these results could open to new area of investigation using calcium modulators to directly or indirectly target Mcl-1 and thus efficiently sensitize ovarian carcinoma cells to anti-Bcl-xL strategies.

Reduced expression of nicotinic AChRs in myotubes from spinal muscular atrophy I patients.

Spinal muscular atrophy (SMA) is an autosomal recessive disorder characterized by degeneration of motoneurons and skeletal muscle atrophy. In its most severe form, it leads to death before the age of 2 years. While primary degeneration of motor neurons is well established in this disease, and this results in neurogenic atrophy of skeletal muscle, we have previously reported evidence for a primary muscle defect. In this study, we used primary cultures of embryonic human skeletal muscle cells from patients with SMA and from controls to examine the effects of muscle fiber differentiation in the absence of a nerve component. Cultured SMA skeletal muscle cells are unable to fuse correctly to form multinuclear myotubes, the precursors of the myofibers. We also show that agrin-induced aggregates of nicotinic acetylcholine receptors, one of the earliest steps of neuromuscular junction formation, cannot be visualized by confocal microscopy on cells from SMA patients. In binding experiments, we demonstrate that this lack of clustering is due to defective expression of the nicotinic acetylcholine receptors in the myotubes of SMA patients whereas the affinity of alpha-bungarotoxin for its receptor remains unchanged regardless of muscle cell type (SMA or control). These observations suggest that muscle cells from SMA patients have intrinsic abnormalities that may affect proper formation of the neuromuscular junction.

Construction of a plasmid containing human SMN, the SMA determining gene, coupled to EGFP.

We describe here the construction of plasmid pEGFP-C3/SMN, bearing the human SMN gene coupled to the green fluorescent protein (GFP) sequence. The mutation of the SMN gene is responsible for spinal muscular atrophy (SMA), a frequent human infantile genetic disease. We introduced the SMN cDNA into the multiple cloning site of pEGFP-C3. This plasmid bears the neomycin-resistance sequence and the enhanced green fluorescent protein (EGFP). It results in the expression of a fusion protein bearing SMN coupled to a carboxy-terminal GFP tag, used for fluorescence localization studies. Transfection of primary human myoblasts with pEGFP-C3 or pEGFP-C3/SMN revealed that EGFP is intracellularly localized within the cytosol as well as in the nucleus, while the fusion protein EGFP-SMN localized within the nucleus in prominent dot-like structures termed "gems." These data demonstrate that human primary muscle cells can be efficiently transfected and may have important implications for the development of therapeutic strategies in SMA.