Monica Margoni

The choroid plexus (ChP) regulates CSF production and CNS homeostasis. In multiple sclerosis (MS), ChP enlargement occurs early in the disease course, yet its normative lifespan trajectory and relationship with MS-specific features remain poorly defined. We aimed to define the normative ChP volume model, to characterize its trajectory across the healthy lifespan, and to assess ChP enlargement in MS using z-scores, evaluating associations with demographic, clinical, MRI, and genetic variables, including human leukocyte antigen (HLA) and non-HLA polygenic risk scores (PRSs). This monocentric retrospective cross-sectional study included 461 healthy controls (HCs) and 727 patients with MS (age 18–70 years) who underwent 3T brain MRI and neurologic assessment. ChP volumes were quantified using ASCHOPLEX, normalized for head size, and modeled in HCs. We derived age-related normalized ChP volume (NChPV) trajectory across adulthood. Z-scores for patients with MS were computed. PRSs were calculated from established MS susceptibility loci, encompassing both HLA and non-HLA regions. In HCs, normalized brain volume, lateral ventricle volume, and its squared term were independently associated with NChPV (R² = 0.54). Model-derived NChPV trajectory remained stable until age 35 and then increased nonlinearly (p-FDR−2, p = 0.957). In cross-sectional analyses, NChPV z-scores, already elevated 1 year after disease onset (EM z-scores = 0.252, p-FDR−2, p < 0.001) and HLA genetic burden (standardized β = 0.097, p = 0.038), but not non-HLA PRSs (p ≥ 0.177). We provided a normative ChP volume model, characterized its trajectory across the healthy lifespan, and showed early, consistently higher ChP volume in patients with MS across ages and disease durations in cross-sectional analyses, linked to inflammatory lesion burden and HLA-mediated genetic risk. The ChP may represent a noninvasive biomarker of neuroinflammation and HLA-related immunogenetic background in MS.

The therapeutic scenario for multiple sclerosis (MS) has expanded rapidly over the last few years. Among the available treatments, anti-CD20 monoclonal antibodies, including rituximab, ocrelizumab, ofatumumab, and ublituximab, have shown significant results in reducing disease activity and slowing progression, particularly in relapsing MS. The distinct mechanisms of action, including the pharmacokinetic and pharmacodynamic profiles as well as the immunogenicity of these drugs, require careful consideration to tailor treatment for individual patients. A comprehensive review of the literature was conducted by searching PubMed and evaluating key studies, trials, and congress abstracts related to the use of anti-CD20 monoclonal antibodies. The analysis focused on the pharmacokinetic and pharmacodynamic profiles, as well as the immunogenicity, of anti-CD20 therapies currently available, with particular emphasis on the recently approved ublituximab. Ocrelizumab is effective in both relapsing-remitting and primary-progressive MS, using antibodydependent cellular cytotoxicity (ADCC) as its primary mechanism of action, with intravenous and subcutaneous administration options ensuring flexible treatment delivery. Ofatumumab depletes B-cells through enhanced complement-dependent cytotoxicity, offering convenient monthly subcutaneous self-administration. Ublituximab’s unique glycoengineered fragment crystallizable region enhances ADCC, resulting in rapid B-cell depletion and potentially improving its safety profile. Ublituximab allows for a shorter infusion time without requiring post-infusion monitoring after the second dose, provided there have been no prior reactions. Understanding the characteristics of different anti-CD20 monoclonal antibodies is critical for optimizing treatment, enhancing patient outcomes, and minimizing treatment burden. Ublituximab represents a promising option, offering a shorter infusion time and higher ADCC activity, which complements existing treatments such as ocrelizumab and ofatumumab.

The choroid plexus (CP) regulates immune functions and produces most CSF that circulates in the brain parenchyma through perivascular spaces, part of the glymphatic system. In multiple sclerosis (MS), CP enlargement and glymphatic dysfunction are associated with inflammatory activity, clinical disability, and brain damage, but their interrelation is unclear. We investigated whether glymphatic system dysfunction mediates the association between CP enlargement and brain damage in patients with MS. Brain fluid-attenuated inversion recovery, 3-dimensional T1-weighted, diffusion-weighted, and susceptibility-weighted sequences were obtained from 146 patients with MS and 72 healthy controls (HC). Glymphatic function was assessed using the diffusion along the perivascular space (DTI-ALPS) index, and CP volume was measured automatically. Patients with MS showed significantly higher white matter (WM) lesion and CP volumes (p < 0.001), and lower DTI-ALPS index, brain, WM, thalamic, and cortical volumes than HC (p ≤ 0.048). In patients with MS, higher CP volume correlated with a lower DTI-ALPS index (r = -0.305, false discovery rate p value = 0.001). Both measures were associated with higher total, periventricular, and juxtacortical (JC) WM lesion volumes (CP volume: r from 0.285 to 0.340, p-FDR ≤ 0.001; DTI-ALPS index: r from -0.301 to -0.444, p ≤ 0.001), and lower brain, thalamic, cortical, and WM volumes (CP volume: r from -0.246 to -0.405, p-FDR ≤ 0.006; DTI-ALPS index: from 0.269 to 0.497, p-FDR ≤ 0.003). The DTI-ALPS index partially mediated the associations of normalized choroid plexus volume with total, periventricular, and JC T2-hyperintense WM lesion volumes (standardized-β ranging from 0.073 to 0.115, relative effect ranging from 25.2% to 33.6%) and normalized brain, thalamic, cortical, and WM volumes (standardized-β ranging from -0.086 to -0.125, relative effect ranging from 25.3% to 52.7%). In MS, enlarged normalized CP volume may contribute to brain damage accumulation possibly through the promotion of a chronic proinflammatory state and the mediation of glymphatic system dysfunction.

In multiple sclerosis (MS), brain reserve serves as a protective factor against cognitive impairment. Previous research has suggested a structural counterpart in the spine-spinal cord reserve-seemed to be associated with physical disability. This study aimed to investigate the potential of the cervical canal area (CCaA) as a proxy for spinal cord reserve in a multicentric cohort of people with MS (PwMS). This retrospective, multicentric, longitudinal study included PwMS and healthy controls (HCs) from 9 European MAGNIMS sites. Baseline cervical 3D T1-weighted images were acquired, excluding poor-quality images. CCaA was estimated independently at the C2/C3 and C3/C4 levels. The Expanded Disability Status Scale (EDSS) score was assessed at baseline and 5-year follow-up. We analyzed mean CCaA differences between groups and the association of CCaA with baseline EDSS scores and disability progression using multivariable regression models adjusted for age, sex, spinal cord parenchymal fraction, and cervical cord lesions. After quality check, the cohort included 177 HCs (mean age 39.8 years, 57.6% women) and 428 PwMS (mean age 46.5 years, 60.8% women), comprising 289 people with relapsing MS (PwRMS) and 139 people with progressive MS (PwPMS). No significant differences in CCaA were found between HCs and PwRMS at C2/C3 or C3/C4 levels. Conversely, PwPMS showed a smaller CCaA at the C2/C3 level (210.51 mm²) than HCs (214.62 mm², estimated mean difference [EMD] -4.11, 95% CI -6.28 to -1.00, p = 0.007) and PwRMS (213.68 mm², EMD -3.17, 95% CI -5.22 to -0.34, p = 0.026). PwPMS also had a smaller CCaA at C3/C4 (165.16 mm²) than HCs (169.67 mm², EMD -4.51, 95% CI -5.50 to -1.60, p < 0.001) and PwRMS (169.44 mm², EMD -3.81, 95% CI -5.22 to -0.34, p < 0.001). At the C3/C4 level, CCaA and baseline EDSS scores were significantly associated (β = -0.13, p < 0.001); in addition, PwMS with clinical worsening at 5-year follow-up displayed a smaller baseline CCaA (worsened vs stable: 167.03 mm² vs 169.13 mm², EMD -2.10, 95% CI -3.98 to -023, p = 0.028). CCaA was associated with baseline EDSS scores and clinical worsening in a multicentric MS cohort, suggesting the existence of spinal cord reserve. PwPMS had a smaller CCaA, indicating that reduced spinal cord reserve might be characteristic of progressive MS. Therefore, spinal cord reserve may represent a novel radiologic marker for better understanding physical disability in MS.

A CSF-in gradient in cortical and thalamic gray matter (GM) damage has been found in multiple sclerosis (MS). We concomitantly explored the patterns of cortical, thalamic, and caudate microstructural abnormalities at progressive distances from CSF using a multiparametric MRI approach. For this cross-sectional study, from 3T 3D T1-weighted scans, we sampled cortical layers at 25%-50%-75% depths from pial surface and thalamic and caudate bands at 2-3-4 voxels from the ventricular-GM interface. Using linear mixed models, we tested between-group comparisons of magnetization transfer ratio (MTR) and R2* layer-specific z-scores, CSF-in across-layer z-score changes, and their correlations with clinical (disease duration and disability) and structural (focal lesions, brain, and choroid plexus volume) MRI measures. We enrolled 52 patients with MS (33 relapsing-remitting [RRMS], 19 progressive [PMS], mean age: 46.4 years, median disease duration: 15.1 years, median: EDSS 2.0) and 70 controls (mean age 41.5 ± 12.8). Compared with controls, RRMS showed lower MTR values in the outer and middle cortical layers (false-discovery rate [FDR]-p ≤ 0.025) and lower R2* values in all 3 cortical layers (FDR-p ≤ 0.016). PMS had lower MTR values in the outer and middle cortical (FDR-p ≤ 0.016) and thalamic (FDR-p ≤ 0.048) layers, and in the outer caudate layer (FDR-p = 0.024). They showed lower R2* values in the outer cortical layer (FDR-p = 0.003) and in the outer thalamic layer (FDR-p = 0.046) and higher R2* values in all 3 caudate layers (FDR-p ≤ 0.031). Both RRMS and PMS had a gradient of damage, with lower values closer to the CSF, for cortical (FDR-p ≤ 0.002) and thalamic (FDR-p ≤ 0.042) MTR. PMS showed a gradient of damage for cortical R2* (FDR-p = 0.005), thalamic R2* (FDR-p = 0.004), and caudate MTR (FDR-p ≤ 0.013). Lower MTR and R2* of outer cortical, thalamic, and caudate layers and steeper gradient of damage toward the CSF were significantly associated with older age, higher T2-hyperintense white matter lesion volume, higher thalamic lesion volume, and lower brain volume (β ≥ 0.08, all FDR-p ≤ 0.040). Lower MTR of outer caudate layer was associated with more severe disability (β = -0.26, FDR-p = 0.040). No correlations with choroid plexus volume were found. CSF-in damage gradients are heterogeneous among different GM regions and through MS course, possibly reflecting different dynamics of demyelination and iron loss/accumulation.

Chronic inflammation may contribute to cognitive dysfunction and fatigue in patients with multiple sclerosis (MS). Paramagnetic rim lesions (PRLs) and choroid plexus (CP) enlargement have been proposed as markers of chronic inflammation in MS being associated with a more severe disease course. However, their relation with cognitive impairment and fatigue has not been fully explored yet. Here, we investigated the contribution of PRL number and volume and CP enlargement to cognitive impairment and fatigue in patients with MS. Brain 3T MRI, neurologic evaluation, and neuropsychological assessment, including the Brief Repeatable Battery of Neuropsychological Tests and Modified Fatigue Impact Scale, were obtained from 129 patients with MS and 73 age-matched and sex-matched healthy controls (HC). PRLs were identified on phase images of susceptibility-weighted imaging, whereas CP volume was quantified using a fully automatic method on brain three-dimensional T1-weighted and fluid-attenuated inversion recovery MRI sequences. Predictors of cognitive impairment and fatigue were identified using random forest. Thirty-six (27.9%) patients with MS were cognitively impaired, and 31/113 (27.4%) patients had fatigue. Fifty-nine (45.7%) patients with MS had ≥1 PRLs (median = 0, interquartile range = 0;2). Compared with HC, patients with MS showed significantly higher T2-hyperintense white matter lesion (WM) volume; lower normalized brain, thalamic, hippocampal, caudate, cortical, and WM volumes; and higher normalized CP volume (p from <0.001 to 0.040). The predictors of cognitive impairment (relative importance) (out-of-bag area under the curve [OOB-AUC] = 0.707) were normalized brain volume (100%), normalized caudate volume (89.1%), normalized CP volume (80.3%), normalized cortical volume (70.3%), number (67.3%) and volume (66.7%) of PRLs, and T2-hyperintense WM lesion volume (64.0%). Normalized CP volume was the only predictor of the presence of fatigue (OOB-AUC = 0.563). Chronic inflammation, with higher number and volume of PRLs and enlarged CP, may contribute to cognitive impairment in MS in addition to gray matter atrophy. The contribution of enlarged CP in explaining fatigue supports the relevance of immune-related processes in determining this manifestation independently of disease severity. PRLs and CP enlargement may contribute to the pathophysiology of cognitive impairment and fatigue in MS, and they may represent clinically relevant therapeutic targets to limit the impact of these clinical manifestations in MS.

MRI plays a central role in the diagnosis of multiple sclerosis (MS) and in the monitoring of disease course and treatment response. Advanced MRI techniques have shed light on MS biology and facilitated the search for neuroimaging markers that may be applicable in clinical practice. MRI has led to improvements in the accuracy of MS diagnosis and a deeper understanding of disease progression. This has also resulted in a plethora of potential MRI markers, the importance and validity of which remain to be proven. Here, five recent emerging perspectives arising from the use of MRI in MS, from pathophysiology to clinical application, will be discussed. These are the feasibility of noninvasive MRI-based approaches to measure glymphatic function and its impairment; T1-weighted to T2-weighted intensity ratio to quantify myelin content; classification of MS phenotypes based on their MRI features rather than on their clinical features; clinical relevance of gray matter atrophy versus white matter atrophy; and time-varying versus static resting-state functional connectivity in evaluating brain functional organization. These topics are critically discussed, which may guide future applications in the field.

Objective Assessing the risk of clinical and radiological reactivation during pregnancy and post partum in women with multiple sclerosis (MS) treated with natalizumab (NTZ) throughout pregnancy (LONG_EXP) compared with women interrupting treatment before (NO_EXP) and within >−30 days and ≤90 days from conception (SHORT_EXP), and describing newborns’ outcomes. Methods Maternal clinical and radiological outcomes and obstetric and fetal outcomes were retrospectively collected and compared among groups (NO_EXP, SHORT_EXP, LONG_EXP). Predictors of clinical and radiological reactivation were investigated through univariable and multivariable analysis. Results 170 eligible pregnancies from 163 women referring to 29 Italian MS centres were included. Annualised relapse rate (ARR) was significantly lower in LONG_EXP (n=66, 0.02 (0.001–0.09)) compared with NO_EXP (n=31, 0.43 (0.21–0.75), p=0.002) and SHORT_EXP (n=73, 0.46 (0.30–0.66), p=0.0004) during pregnancy, and in LONG_EXP (0.12 (0.05–0.24)) compared with SHORT_EXP (0.30 (0.17–0.50), p=0.008) during post partum. Gadolinium-enhancing (Gd+) lesions were less frequent in LONG_EXP (n=6/50, 2.00%) compared with NO_EXP (n=9/21, 42.86%) and SHORT_EXP after delivery (n=17/49, 34.69%, p=0.010). Delaying NTZ resumption after delivery significantly increased the risk of relapses (OR=1.29 (95% CI 1.07 to 1.57), p=0.009) and Gd+ lesions (OR=1.49 (95% CI 1.17 to 1.89, p=0.001). Newborns’ weight, length, head circumference and gestational age did not differ among groups after adjusting for confounders. Anaemia was tracked in 4/69 LONG_EXP newborns. Congenital anomaly rate was within the expected range for the untreated MS population. Conclusions Our findings indicate that in women with MS treated with NTZ before conception, continuation of NTZ throughout pregnancy and its early resumption after delivery mitigate the risk of clinical and radiological reactivation. This approach has no major impact on newborns’ outcomes.