Secondary Progressive Conversion Research Articles

The glymphatic system as a potential biomarker and therapeutic target in secondary progressive multiple sclerosis

BackgroundMultiple sclerosis (MS) is a refractory immune-mediated inflammatory disease of the central nervous system, and some cases of the major subtype, relapsing-remitting (RR), transition to secondary progressive (SP). However, the detailed pathogenesis, biomarkers, and effective treatment strategies for secondary progressive multiple sclerosis have not been established. The glymphatic system, which is responsible for waste clearance in the brain, is an intriguing avenue for investigation and is primarily studied through diffusion tensor image analysis along the perivascular space (DTI-ALPS). This study aimed to compare DTI-ALPS indices between patients with RRMS and SPMS to uncover potential differences in their pathologies and evaluate the utility of the glymphatic system as a possible biomarker. MethodsA cohort of 26 patients with MS (13 RRMS and 13 SPMS) who met specific criteria were enrolled in this prospective study. Magnetic resonance imaging (MRI), including diffusion MRI, 3D T1-weighted imaging, and relaxation time quantification, was conducted. The ALPS index, a measure of glymphatic function, was calculated using diffusion-weighted imaging data. Demographic variables, MRI metrics, and ALPS indices were compared between patients with RRMS and those with SPMS. ResultsThe ALPS index was significantly lower in the SPMS group. Patients with SPMS exhibited longer disease duration and higher Expanded Disability Status Scale (EDSS) scores than those with RRMS. Despite these differences, the correlations between the EDSS score, disease duration, and ALPS index were minimal, suggesting that the impact of these clinical variables on ALPS index variations was negligible. DiscussionOur study revealed the potential microstructural and functional differences between RRMS and SPMS related to glymphatic system impairment. Although disease severity and duration vary among subtypes, their influence on ALPS index differences appears to be limited. This highlights the stronger association between SP conversion and changes in the ALPS index. These findings align with those of previous research, indicating the involvement of the glymphatic system in the progression of MS. ConclusionAlthough the causality remains uncertain, our study suggests that a reduced ALPS index, reflecting glymphatic system dysfunction, may contribute to MS progression, particularly in SPMS. This suggests the potential of the ALPS index as a diagnostic biomarker for SPMS and underscores the potential of the glymphatic system as a therapeutic target to mitigate MS progression. Future studies with larger cohorts and pathological validation are necessary to confirm these findings. This study provides new insights into the pathogenesis of SPMS and the potential for innovative therapeutic strategies.

Slowly Expanding Lesions Predict 9-Year Multiple Sclerosis Disease Progression.

Background and ObjectivesChronic active lesions contribute to multiple sclerosis (MS) severity, but their association with long-term disease progression has not been evaluated yet. White matter (WM) lesions showing linear expansion over time on serial T1- and T2-weighted scans (i.e., slowly expanding lesions [SELs]) have been proposed as a marker of chronic inflammation. In this study, we assessed whether SEL burden and microstructural abnormalities were associated with Expanded Disability Status Scale (EDSS) score worsening and secondary progressive (SP) conversion at 9.1-year follow-up in patients with relapsing-remitting (RR) MS.MethodsIn 52 patients with RRMS, SELs were identified among WM lesions by linearly fitting the Jacobian of the nonlinear deformation field between time points obtained combining 3T brain T1- and T2-weighted scans acquired at baseline and months 6, 12, and 24. Logistic regression analysis was applied to investigate the associations of SEL number, volume, magnetization transfer ratio (MTR), and T1-weighted signal intensity with disability worsening (i.e., EDSS score increase) and SP conversion after a median follow-up of 9.1 years.ResultsAt follow-up, 20/52 (38%) patients with MS showed EDSS score worsening; 13/52 (25%) showed SP conversion. A higher baseline EDSS score (for each point higher: OR = 3.15 [95% CI = 1.61; 8.38], p = 0.003), a higher proportion of SELs among baseline lesions (for each % increase: OR = 1.22 [1.04; 1.58], p = 0.04), and lower baseline MTR values of SELs (for each % higher: OR = 0.66 [0.41; 0.92], p = 0.033) were significant independent predictors of EDSS score worsening at follow-up (C-index = 0.892). A higher baseline EDSS score (for each point higher: OR = 6.37 [1.98; 20.53], p = 0.002) and lower baseline MTR values of SELs (for each % higher: OR = 0.48 [0.25; 0.89], p = 0.02) independently predicted SPMS conversion (C-index = 0.947).DiscussionThe proportion of SELs is associated with MS progression after 9 years. More severe SEL microstructural abnormalities independently predict EDSS score worsening and SPMS conversion. The quantification of SEL burden and damage using T1-, T2-weighted, and MTR sequences may identify patients with RRMS at a higher risk of long-term disability progression and SPMS conversion.Classification of EvidenceThis study provides Class III evidence that in patients with RRMS starting treatment with natalizumab or fingolimod, the proportion of SELs on brain MRI was associated with EDSS score worsening and SPMS conversion at 9-year follow-up.

B Cells in the CNS at Postmortem Are Associated With Worse Outcome and Cell Types in Multiple Sclerosis.

Background and ObjectivesTo define the clinical and pathologic correlations of compartmentalized perivascular B cells in postmortem progressive multiple sclerosis (MS) brains.MethodsBrain slices were acquired from 11 people with secondary progressive (SP) MS, 5 people with primary progressive (PP) MS, and 4 controls. Brain slices were immunostained for B lymphocytes (CD20), T lymphocytes (CD3), cytotoxic T lymphocytes (CD8), neuronal neurofilaments (NF200), myelin (SMI94), macrophages/microglia (CD68 and IBA1), astrocytes (glial fibrillary acidic protein [GFAP]), and mitochondria (voltage-dependent anion channel and cytochrome c oxidase subunit 4). Differences in CD20 immunostaining intensity between disease groups and associations between CD20 immunostaining intensity and both clinical variables and other immunostaining intensities were explored with linear mixed regression models and Cox regression models, as appropriate.ResultsCD20 immunostaining intensity was higher in PPMS (Coeff = 0.410; 95% confidence interval [CI] = 0.046, 0.774; p = 0.027) and SPMS (Coeff = 0.302; 95% CI = 0.020, 0.585; p = 0.036) compared with controls. CD20 immunostaining intensity was higher in cerebellar, spinal cord, and pyramidal onset (Coeff = 0.274; 95% CI = 0.039, 0.510; p = 0.022) compared with optic neuritis and sensory onset. Higher CD20 immunostaining intensity was associated with younger age at onset (hazard ratio [HR] = 1.033; 95% CI = 1.013, 1.053; p = 0.001), SP conversion (HR = 1.056; 95% CI = 1.022, 1.091; p = 0.001), wheelchair dependence (HR = 1.472; 95% CI = 1.108, 1.954; p = 0.008), and death (HR = 1.684; 95% CI = 1.238, 2.291; p = 0.001). Higher immunostaining intensity for CD20 was associated with higher immunostaining intensity for CD3 (Coeff = 0.114; 95% CI = 0.005, 0.224; p = 0.040), CD8 (Coeff = 0.275; 95% CI = 0.200, 0.350; p < 0.001), CD68 (Coeff = 0.084; 95% CI = 0.023, 0.144; p = 0.006), GFAP (Coeff = 0.002; 95% CI = 0.001, 0.004; p = 0.030), and damaged mitochondria (Coeff = 3.902; 95% CI = 0.891, 6.914; p = 0.011).DiscussionPerivascular B cells were associated with worse clinical outcomes and CNS-compartmentalized inflammation. Our findings further support the concept of targeting compartmentalized B-cell inflammation in progressive MS.

Atrophied Brain T2 Lesion Volume at MRI Is Associated with Disability Progression and Conversion to Secondary Progressive Multiple Sclerosis.

Background Atrophied T2 lesion volume at MRI is an imaging measure that reflects the replacement of T2 lesions by cerebrospinal fluid spaces in patients with multiple sclerosis (MS). Purpose To investigate the association of atrophied T2 lesion volume and development of disability progression (DP) and conversion to secondary progressive MS (SPMS). Materials and Methods This retrospective study included 1612 participants recruited from 2006 to 2016 and followed up for 5 years with clinical and MRI examinations. Accumulation of T2 lesion volume, atrophied T2 lesion volume, percentage brain volume change (PBVC), and percentage ventricular volume change (PVVC) were measured. Disability progression and secondary progressive conversion were defined by using standardized guidelines. Analysis of covariance (ANCOVA) adjusted for age and Cox regression adjusted for age and sex were used to compare study groups and explore associations between MRI and clinical outcomes. Results A total of 1314 patients with MS (1006 women; mean age, 46 years ± 11 [standard deviation]) and 124 patients with clinically isolated syndrome (100 women; mean age, 39 years ± 11) along with 147 healthy control subjects (97 women; mean age, 42 years ± 13) were evaluated. A total of 336 of 1314 (23%) patients developed DP, and in 67 of 1213 (5.5%) the disease converted from clinically isolated syndrome (CIS) or relapsing-remitting MS (RRMS) to SPMS. Patients with conversion to DP had higher atrophied T2 lesion volume (+34.4 mm3; 95% confidence interval [CI]: 17.2 mm3, 51.5 mm3; d = 0.27; P < .001) and PBVC (-0.21%; 95% CI: -0.36%, -0.05%; d = 0.19; P = .042) but not PVVC (0.36%; 95% CI: -0.93%, 1.65%; d = 0.04; P = .89) or T2 lesion volume change (-64.5 mm3; 95% CI: -315.2 mm3, 186.3 mm3; d = 0.03; P = .67) when compared with DP nonconverters. ANCOVA showed that atrophied T2 lesion volume was associated with conversion from CIS or RRMS to SPMS (+26.4 mm3; 95% CI: 4.2 mm3, 56.9 mm3; d = 0.23; P = .002) but not PBVC (-0.14%; 95% CI: -0.46%, 0.18%; d = 0.11; P = .66), PVVC (+0.18%; 95% CI: -2.49%, 2.72%; d = 0.01; P = .75), or T2 lesion volume change (-46.4 mm3; 95% CI: -460.8 mm3, 367.9 mm3; d = 0.03; P = .93). At Cox regression analysis, only atrophied T2 lesion volume was associated with the DP (hazard ratio, 1.23; P < .001) and conversion to SPMS (hazard ratio, 1.16; P = .008). Conclusion Atrophied brain T2 lesion volume is a robust MRI marker of MS disability progression and conversion into a secondary progressive disease course. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Chiang in this issue.

A 8-year retrospective cohort study comparing Interferon-β formulations for relapsing‐remitting multiple sclerosis

BackgroundInterferon-β has been approved for the treatment of relapsing-remitting (RR) multiple sclerosis (MS), whereas its efficacy in preventing long-term disability and conversion to secondary progressive (SP) MS is still debated. We aim to compare long-term clinical evolution of newly-diagnosed RRMS patients treated with different Interferon-β formulations. Methods507 patients were included in the analysis and followed-up for 8.5 ± 3.9 years. 37.6% were treated with subcutaneous Interferon-β1a 44mcg, 33.4% with intramuscular Interferon-β1a 30mcg, and 29.0% with subcutaneous Interferon-β1b 250mcg. Relapse occurrence, 1-point EDSS progression, reaching of EDSS 4.0 and conversion to SP were recorded as outcome measures. To reduce the selection bias, we calculated the propensity score of receiving the specific treatment considering age (32.7 ± 8.3 years), gender (female 63.1%), disease duration (2.7 ± 2.8 years), and baseline EDSS (1.5, range 1.0–3.5). Propensity score and covariates (age, gender, disease duration and EDSS) were included in the statistical models. ResultsAt Cox regression models, the reaching of EDSS 4.0 was not-significantly higher for Interferon-β1b 250mcg (HR = 1.207; p = 0.063) and for Interferon-β1a 30mcg (HR = 1.363; p = 0.095), when compared with Interferon-β1a 44mcg. The rate of SP conversion was higher for Interferon-β1b 250mcg (HR = 2.054; p = 0.042), and not-significantly higher for Interferon-β1a 30mcg (HR = 1.884; p = 0.081), when compared with Interferon-β1a 44mcg. ConclusionsPatients treated with Interferon-β1a 44mcg presented with a marginally reduced risk of disability accrual in the long-term, when compared with Interferon-β1b 250mcg and, at least in part, with Interferon-β1a 30mcg. Formulation, frequency of administration and dose of Interferon-β might affect the long-term clinical evolution of RRMS.

Grey:white matter ratio at diagnosis and the risk of 10-year multiple sclerosis progression.

Grey matter (GM) and white matter (WM) are both affected in multiple sclerosis (MS). WM is predominantly involved in inflammatory demyelination of relapsing-remitting MS (RRMS), whereas GM is predominantly involved in neurodegenerative processes of secondary progressive MS. Thus, we investigated the ratio between GM and WM volumes in predicting MS evolution. The present 10-year retrospective cohort study included 149 patients with newly-diagnosed RRMS, undergoing magnetic resonance imaging for segmentation and brain volumetry. The ratio between GM and normal-appearing WM (NAWM) volumes was calculated for each subject. Outcome measures of interest were Expanded Disability Status Scale (EDSS) progression, reaching EDSS 4.0 and conversion to secondary progressive (SP) MS. During a period of 10.6 ± 2.4 years, a median 1.5 EDSS progression was observed (range 0-5.5), 54 subjects (36.2%) reached EDSS 4.0 and 30 subjects (20.1%) converted to SP. With ordinal logistic regression models, EDSS progression was associated with GM:NAWM ratio (coefficient, -2.918; 95% CI, -4.739-1.097). With Cox regression models, subjects with higher GM:NAWM ratio at diagnosis had a 90% lower rate of reaching EDSS 4.0 (hazard ratio, 0.111; 95% CI, 0.020-0.609) and of converting to secondary progressive MS (hazard ratio, 0.017; 95% CI, 0.001-0.203) compared with subjects with lower GM:NAWM ratio. The GM:NAWM ratio is a predictor of disability progression and of SP conversion in subjects with newly diagnosed RRMS, suggesting that GM and NAWM are variably affected in relation to disease evolution from the early phases of MS.

Cognitive impairment at diagnosis predicts 10-year multiple sclerosis progression

Background: Cognitive impairment occurs from the early phases of multiple sclerosis (MS), and more frequently affects secondary progressive (SP) subjects than relapsing–remitting (RR). Objective: To investigate relationships between cognitive dysfunctions in newly diagnosed RRMS, and long-term MS-related outcomes. Methods: The present 10-year retrospective longitudinal study included 155 RRMS subjects, tested with the Rao Brief Repeatable Battery at MS diagnosis. The reaching of Expanded Disability Status Scale (EDSS) 4.0, and the SP conversion were recorded. Results: 67 subjects (43.2%) reached EDSS 4.0, and 34 subjects (21.9%) converted to SP during a follow-up period of 10.0±1.8 years. Subjects with cognitive impairment at diagnosis had a rate of reaching EDSS 4.0 more than three times greater (p<0.001; HR=3.183), and a rate of SP conversion more than two times greater, as compared to cognitively preserved subjects (p=0.008; HR=2.535). In particular, better scores in the Selective Reminding Test-Delayed Recall and in the Symbol Digit Modalities Test at baseline were associated with lower SP conversion rates during the follow-up period (p=0.018; HR=0.835; and p=0.001; HR=0.941, respectively). Conclusion: Cognitive impairment, with particular involvement of processing speed and memory, predicts disability progression and SP conversion in newly diagnosed RRMS, highlighting the importance of cognitive assessment from the beginning of MS.