Gray matter atrophy in multiple sclerosis despite clinical and lesion stability during natalizumab treatment

Exploring the effects of extended interval dosing of natalizumab and drug concentrations on brain atrophy in multiple sclerosis

BACKGROUND

Extended interval dosing (EID) of natalizumab treatment is increasingly used in multiple sclerosis. Besides the clear anti-inflammatory effect, natalizumab is considered to have neuroprotective properties as well.

OBJECTIVES

This study aimed to study the longitudinal effects of EID compared to standard interval dosing (SID) and natalizumab drug concentrations on brain atrophy.

METHODS

Patients receiving EID or SID of natalizumab with a minimum radiological follow-up of 2 years were included. Changes in brain atrophy measures over time were derived from clinical routine 3D-Fluid Attenuated Inversion Recovery (FLAIR)-weighted magnetic resonance imaging (MRI) scans using SynthSeg.

RESULTS

We found no differences between EID (n = 32) and SID (n = 50) for whole brain (-0.21% vs -0.16%, p = 0.42), ventricular (1.84% vs 1.13%, p = 0.24), and thalamic (-0.32% vs -0.32%, p = 0.97) annualized volume change over a median follow-up of 3.2 years. No associations between natalizumab drug concentration and brain atrophy rate were found.

CONCLUSION

We found no clear evidence that EID compared to SID or lower natalizumab drug concentrations have a negative impact on the development of brain atrophy over time.

Vascular disease risk factors in multiple sclerosis: Effect on metabolism and brain volumes

BACKGROUND

Vascular disease risk factors (VDRF) such as hypertension, hyperlipidemia, obesity, diabetes and heart disease likely play a role in disease progression in people with multiple sclerosis (PwMS) (Marrie, Rudick et al. 2010). Studies exploring the mechanistic connection between vascular disease and MS disease progression are scant. We hypothesized that phosphate energy metabolism impairment in PwMS with VDRFs (VDRF+) will be greater compared to PwMS without VDRFs (VDRF-) and is related to increased brain atrophy in VDRF+. To test this hypothesis, we planned to study the differences in the high energy phosphate (HEP) metabolites in cerebral gray matter as assessed by 31P magnetic resonance spectroscopic imaging (MRSI) and MRI brain volumetric in the VDRF+ and VDRF- PwMS at four different timepoints over a 3 yearlong period using a 7T MR system. We present here the results from the cross-sectional evaluation of HEP metabolites and brain volumes. We also evaluated the differences in clinical impairment, blood metabolic biomarkers and quality of life in VDRF+ and VDRF- PwMS in this cohort.

METHODS

Group differences in high energy phosphate metabolites were assessed from a volume of interest in the occipital region using linear mixed models. Brain parenchymal and white matter lesion volumes were determined from MR anatomic images. We present here the cross-sectional analysis of the baseline data collected as part of a longitudinal 3 yearlong study where we obtained baseline and subsequent 6-monthly clinical and laboratory data and annual 7T MRI volumetric and 31P MR spectroscopic imaging (MRSI) data on 52 PwMS with and without VDRF. Key clinical and laboratory outcomes included: body mass index (BMI), waist and thigh circumferences and disability [Expanded Disability Status Scale (EDSS)], safety (complete blood count with differential, complete metabolic), lipid panel including total cholesterol and HbA1C. We analyzed clinical and laboratory data for the group differences using student's t or χ2 test. We investigated relationship between phosphate metabolites and VDRF using mixed effect linear regression.

RESULTS

Complete MRI data were available for 29 VDRF+, age 56.3 (6.8) years [mean (SD)] (83% female), and 23 VDRF-, age 52.5 (7.5) years (57% female) individuals with MS. The mean value of normalized adenosine triphosphate (ATP) (calculated as the ratio of ATP to total phosphate signal in a voxel) was decreased by 4.5% (p < .05) in VDRF+ compared to VDRF- MS group. White matter lesion (WML) volume fraction in VDRF+ individuals {0.007 (0.007)} was more than doubled compared to VDRF- participants {0.003 (0.006), p= .02}.

CONCLUSIONS

We found significantly lower brain ATP and higher inorganic phosphate (Pi) in those PwMS with VDRFs compared to those without. ATP depletion may reflect mitochondrial dysfunction. Ongoing longitudinal data analysis from this study, not presented here, will evaluate the relationship of phosphate metabolites, brain atrophy and disease progression in PwMS with and without vascular disease.

Neurofilament-light and contactin-1 association with long-term brain atrophy in natalizumab-treated relapsing-remitting multiple sclerosis

BACKGROUND

Despite highly effective treatment strategies for patients with relapsing-remitting multiple sclerosis (RRMS), long-term neurodegeneration and disease progression are often considerable. Accurate blood-based biomarkers that predict long-term neurodegeneration are lacking.

OBJECTIVE

To assess the predictive value of serum neurofilament-light (sNfL) and serum contactin-1 (sCNTN1) for long-term magnetic resonance imaging (MRI)-derived neurodegeneration in natalizumab-treated patients with RRMS.

METHODS

sNfL and sCNTN1 were measured in an observational cohort of natalizumab-treated patients with RRMS at baseline (first dose) and at 3 months, Year 1, Year 2, and last follow-up (median = 5.2 years) of treatment. Disability progression was quantified using "EDSS-plus" criteria. Neurodegeneration was measured by calculating annualized percentage brain, ventricular, and thalamic volume change (PBVC, VVC, and TVC, respectively). Linear regression analysis was performed to identify longitudinal predictors of neurodegeneration.

RESULTS

In total, 88 patients (age = 37 ± 9 years, 75% female) were included, of whom 48% progressed. Year 1 sNfL level (not baseline or 3 months) was associated with PBVC (standardized (std.) β = -0.26, p = 0.013), VVC (standardized β = 0.36, p < 0.001), and TVC (standardized β = -0.24, p = 0.02). For sCNTN1, only 3-month level was associated with VVC (standardized β = -0.31, p = 0.002).

CONCLUSION

Year 1 (but not baseline) sNfL level was predictive for long-term brain atrophy in patients treated with natalizumab. sCNTN1 level did not show a clear predictive value.

Grey matter atrophy in patients with benign multiple sclerosis

BACKGROUND

Brain atrophy appears during the progression of multiple sclerosis (MS) and is associated with the disability caused by the disease.

METHODS

We investigated global and regional grey matter (GM) and white matter (WM) volumes, WM lesion load, and corpus callosum index (CCI), in benign relapsing-remitting MS (BRRMS, n = 35) with and without any treatment and compared those to aggressive relapsing-remitting MS (ARRMS, n = 46). Structures were analyzed by using an automated MRI quantification tool (cNeuro®).

RESULTS

The total brain and cerebral WM volumes were larger in BRRMS than in ARRMS (p = .014, p = .017 respectively). In BRRMS, total brain volumes, regional GM volumes, and CCI were found similar whether or not disease-modifying treatment (DMT) was used. The total (p = .033), as well as subcortical (p = .046) and deep WM (p = .041) lesion load volumes were larger in BRRMS patients without DMT. Cortical GM volumes did not differ between BRRMS and ARRMS, but the volumes of total brain tissue (p = .014) and thalami (p = .003) were larger in patients with BRRMS compared to ARRMS. A positive correlation was found between CCI and whole-brain volume in both BRRMS (r = .73, p < .001) and ARRMS (r = .80, p < .01).

CONCLUSIONS

Thalamic volume is the most prominent measure to differentiate BRRMS and ARRMS. Validation of automated quantification of CCI provides an additional applicable MRI biomarker to detect brain atrophy in MS.

Predictive MRI Biomarkers in MS—A Critical Review

Background and Objectives: In this critical review, we explore the potential use of MRI measurements as prognostic biomarkers in multiple sclerosis (MS) patients, for both conventional measurements and more novel techniques such as magnetization transfer, diffusion tensor, and proton spectroscopy MRI. Materials and Methods: All authors individually and comprehensively reviewed each of the aspects listed below in PubMed, Medline, and Google Scholar. Results: There are numerous MRI metrics that have been proven by clinical studies to hold important prognostic value for MS patients, most of which can be readily obtained from standard 1.5T MRI scans. Conclusions: While some of these parameters have passed the test of time and seem to be associated with a reliable predictive power, some are still better interpreted with caution. We hope this will serve as a reminder of how vast a resource we have on our hands in this versatile tool—it is up to us to make use of it.

Differential Effects of Fingolimod and Natalizumab on Magnetic Resonance Imaging Measures in Relapsing-Remitting Multiple Sclerosis

Fingolimod and natalizumab are approved disease-modifying drugs in relapsing-remitting multiple sclerosis (RRMS). The two drugs have different modes of action and may therefore influence different aspects of MS-related tissue damage. In this retrospective cohort study, we longitudinally compared patients treated with fingolimod and patients treated with natalizumab by measures based on structural magnetic resonance imaging (MRI). We included patients with RRMS given that two standardized MRI scans under the same drug were available with an interval of at least 6 months both from therapy start to baseline scan and from baseline scan to follow-up scan. After matching for age, baseline and follow-up scans from 93 patients (fingolimod, 48; natalizumab, 45) were investigated. Mean follow-up time was 1.9 years. We determined the number of new white matter lesions as well as thalamic, cortical, and whole-brain atrophy. After scaling for time of the interscan interval, measures were analyzed by group comparisons and, to account for demographic and clinical characteristics, by multiple regression models and a binary logistic regression model. Compared to natalizumab, fingolimod treatment went along with more new white matter lesions (median [interquartile range, IQR] 0.0 [0.0; 0.7] vs. 0.0 [0.0; 0.0] /year; p < 0.01) whereas whole-brain atrophy was lower (median [IQR] 0.2 [0.0; 0.5] vs. 0.5 [0.2; 1.0] %/year; p = 0.01). These significant differences were confirmed by multiple regression models and the binary logistic regression model. In conclusion, our observation is compatible with stronger neuroprotective properties of fingolimod compared to natalizumab.

Thalamus Atrophy in the Peri-Pregnancy Period in Clinically Stable Multiple Sclerosis Patients: Preliminary Results

Radiological activity in the post-partum period in MS patients is a well-known phenomenon, but there is no data concerning the influence of pregnancy on regional brain atrophy. The aim of this article was to investigate local brain atrophy in the peri-pregnancy period (PPP) in patients with MS. Thalamic volume (TV); corpus callosum volume (CCV) and classical MRI activity (new gadolinium enhancing lesions (Gd+), new T2 lesions, T1 lesions volume (T1LV) and T2 lesions volume (T2LV)) were analyzed in 12 clinically stable women with relapsing–remitting MS and with MRI performed in the PPP. We showed that there was a significant decrease in TV (p = 0.021) in the PPP. We also observed a significant increase in the T1 lesion volume (p = 0.028), new gadolinium-enhanced and new T2 lesions (in 46% and 77% of the scans, respectively) in the post-partum period. Our results suggest that the PPP in MS may be associated not only with classical MRI activity but, also, with regional brain atrophy.

Localised Grey Matter Atrophy in Multiple Sclerosis and Clinically Isolated Syndrome-A Coordinate-Based Meta-Analysis, Meta-Analysis of Networks, and Meta-Regression of Voxel-Based Morphometry Studies

Background: Atrophy of grey matter (GM) is observed in the earliest stages of multiple sclerosis (MS) and is associated with cognitive decline and physical disability. Localised GM atrophy in MS can be explored and better understood using magnetic resonance imaging and voxel-based morphometry (VBM). However, results are difficult to interpret due to methodological differences between studies. Methods: Coordinate-based analysis is a way to find the reliably observable results across multiple independent VBM studies. This work uses coordinate-based meta-analysis, meta-analysis of networks, and meta-regression to summarise the evidence from voxel-based morphometry of regional GM hanges in patients with MS and clinically isolated syndrome (CIS), and whether these measured changes are relatable to clinical features. Results: Thirty-four published articles reporting forty-four independent experiments using VBM for the assessment of GM atrophy between MS or CIS patients and healthy controls were identified. Analysis identified eight clusters of consistent cross-study reporting of localised GM atrophy involving both cortical and subcortical regions. Meta-network analysis identified a network-like pattern indicating that GM loss occurs with some symmetry between hemispheres. Meta-regression analysis indicates a relationship between disease duration or age and the magnitude of reported statistical effect in some deep GM structures. Conclusions: These results suggest consistency in MRI-detectible regional GM loss across multiple MS studies, and the estimated effect sizes and symmetries can help design prospective studies to test specific hypotheses.

Corpus callosum index correlates with brain volumetry and disability in multiple sclerosis patients

OBJECTIVE

To analyze the correlation between corpus callosum index (CCI), brain volumetry, and disability in multiple sclerosis (MS) patients. The brain volumetry consists of the corpus callosum, cortical gray matter, subcortical gray matter, and white matter volumes.

METHODS

This was a retrospective cross-sectional study from October 2018 to February 2019 of 30 patients with MS aged 20 to 61 years old. Brain volumetry was performed using FreeSurfer software. The CCI were measured manually using conventional best mid-sagittal T1W brain MRI. The anterior, posterior, and medium segments were measured and divided to its greatest anteroposterior diameter. Higher CCI values indicated greater corpus callosum volumes. Clinical evaluation was comprised of MS subtype, age of onset, relapse frequency and Expanded Disability Status Scale (EDSS).

RESULTS

Thirty MS patients with median of age 22 years were included. Relapsing-remitting (RRMS) subtype were 73.3%. Very significant correlations were shown between the CCI and corpus callosum volume (CCV) (r=0.79; p<0.0001) and cerebral white matter volume (r=0.81; p<0.0001). Significant correlations were shown between the CCI and cortical gray matter volume (r=0.64; p<0.0001) and subcortical gray matter volume (r=0.69; p<0.0001). The CCI was positively correlated with age of onset and inversely with EDSS. The CCV and CCI were smaller in secondary progressive MS (SPMS).

CONCLUSION

The CCI is easy and fast to obtain in conventional MRI and significantly correlated with brain volumetry, age of onset and disability in MS patients.

Two-year regional grey and white matter volume changes with natalizumab and fingolimod

OBJECTIVE

To compare the efficacy of fingolimod and natalizumab in preventing regional grey matter (GM) and white matter (WM) atrophy in relapsing-remitting multiple sclerosis (RRMS) over 2 years.

METHODS

Patients with RRMS starting fingolimod (n=25) or natalizumab (n=30) underwent clinical examination and 3T MRI scans at baseline (month (M) 0), M6, M12 and M24. Seventeen healthy controls were also scanned at M0 and M24. Tensor-based morphometry and SPM12 were used to assess the longitudinal regional GM/WM volume changes.

RESULTS

At M0, no clinical or GM/WM volume differences were found between treatment groups. At M24, both drugs reduced relapse rate (p<0.001 for both) and stabilised disability. At M6 vs M0, both groups experienced significant atrophy of several areas in the cortex, deep GM nuclei and supratentorial WM. Significant bilateral cerebellar GM and WM atrophy occurred in fingolimod patients only. At M12 vs M6 and M24 vs M12, further supratentorial GM and WM atrophy occurred in both groups. Bilateral GM/WM cerebellar atrophy continued to progress in fingolimod patients only. Compared with natalizumab, fingolimod-treated patients showed a significant cerebellar GM/WM atrophy, mainly at M6 vs M0, but still occurring up to M24. Compared with fingolimod, natalizumab-treated patients had a small number of areas of GM atrophy in temporo-occipital regions at the different time-points.

CONCLUSIONS

Natalizumab and fingolimod are associated with heterogeneous temporal and regional patterns of GM and WM atrophy progression. Compared with natalizumab, fingolimod-treated patients experience accelerated GM and WM atrophy in the cerebellum, while both drugs show minimal regional volumetric differences in supratentorial regions.

Differential white and gray matter damage in highly active multiple sclerosis: A prospective cohort study

We analyze the differential brain volume changes in highly active multiple sclerosis (HAMS) vs. non-HAMS patients during the disease onset.

METHODS

HAMS was defined as: a) patients with 1 relapse in the previous year and at least 1 T1 gadolinium-enhancing lesion or 9 or more T2 lesions while on therapy with other disease modifying treatment (DMD); or b) patients with 2 or more relapses in the previous year, whether on DMD or not. High-resolution T1 weighted MRI scans were acquired at onset and every 12 months for 2 years. Lesion load and brain volume measurements were determined. At onset, gray matter volume (GMV) and white matter volume (WMV) tissue volumes were calculated using the SIENAX. Longitudinal changes were estimated by using SIENA to calculate the percentage of brain volume loss. Differences between volumes per group at onset and at the end of the follow up were established.

RESULTS

64 patients, mean age 38.4 years, 35 (57%) women were included. A total of 14 (21%) were classified as HAMS. At onset, HAMS patients showed lower GMV and WMV volume compared with non-HAMS patients (p = 0.003 and p = 0.01, respectively). During the follow up, HAMS patients showed a higher decrease in GM volume compared with non-HAMS patients (-0.61 vs. - 0.77, p < 0.001) independent from new lesion as well as relapse rate activity during follow up.

CONCLUSION

HAMS increased rates of GMV atrophy over 24 months compared to non-HAMS patients independent from relapse rate and new T2 lesions.

Evaluation of brain volume alterations in HCV-infected patients after interferon-free therapy: A pilot study

The study was performed to evaluate cerebral volume changes in HCV-infected subjects before and after interferon-free therapy with direct-acting antiviral agents (DAA). We aimed also to estimate the impact of successful DAA therapy on the neuropsychological state of patients. Eleven HCV genotype 1 (GT1) patients treated with ombitasvir/paritaprevir (boosted with ritonavir) and dasabuvir, with or without ribavirin underwent brain magnetic resonance (MR) before and 24 weeks after completion of therapy. All patients achieved sustained viral response. Precise automatic parcellation was made using the fully-available software FreeSurfer 6.0. Statistically significant volume deceleration six months after treatment was found in the subcallosal cingulate gyrus, transverse frontopolar gyri and sulci, anterior segment of the circular sulcus of the insula and horizontal ramus of the anterior segment of the lateral sulcus. After DAA therapy we found statistically significant improvement in the performance of all three tasks of the Rey Complex Figure Test that permits the evaluation of different functions (attention, planning, working,memory). Additionally, significant amelioration in Percentage Conceptual Level Responses in The Wisconsin Card Sorting Test (a neurocognitive test for assessing intellectual functioning) was also discovered. Successful interferon-free therapy may lead to transient cerebral atrophy, probably by reducing neuroinflammation and oedema. This is the first pilot study of the alterations in brain volume after successful interferon-free therapy in chronic HCV patients. Longitudinal follow-up study is needed to observe further effects of therapy on cerebral structures volume changes.