Relapse recovery in multiple sclerosis: Effect of treatment and contribution to long-term disability

Should we stay or should we go? Recent insights on drug discontinuation in multiple sclerosis

BACKGROUND

The decision to discontinue disease-modifying therapies (DMTs) in patients with multiple sclerosis (PwMS) is a critical clinical challenge. Historically, DMTs were discontinued due to side effects, treatment limitations, or progression to secondary progressive MS. However, advancements in MS therapies, particularly high-efficacy DMTs (HE-DMTs) and the increased knowledge on disease courses and phenotypes have resulted in more personalized treatment approaches and introduced discussion on scheduled DMT discontinuation. This review explores the current evidence on DMT discontinuation, focusing on its implications for aging populations and the interplay between cardiovascular diseases (CVD) and MS.

CURRENT EVIDENCE AND INTERPLAY WITH CVD

Randomized trials such as DISCOMS and DOT-MS have provided insights into discontinuing DMTs in stable patients. In summary, both randomized clinical trials highlight the risk of disease reactivation following treatment discontinuation. Due to the limited sample size, neither study was able to conduct subgroup analyses based on age groups. Additionally, DOT-MS was terminated prematurely, direct comparisons with other studies should be avoided. While older studies and observational data (e.g., OFSEP) have shown relapse risks associated with discontinuation, particularly for drugs like natalizumab and fingolimod, there is limited data on HE-DMT discontinuation outcomes. Comorbidities, particularly CVDs, further complicate decisions regarding the continuation of DMTs in older adults. MS patients bear a higher burden of CVD, which is also associated with unfavorable disease courses. While optimizing cardiovascular risk profiles appears advisable, it remains unclear whether DMTs themselves have a positive impact on CVDs.

CONCLUSION

Given the complexities associated with discontinuing DMTs in MS patients, it is essential to balance the avoidance of polypharmacy with the potential risks of disease reactivation and the impact of comorbidities, especially CVDs, on disease progression. The interplay between MS and CVD highlights the importance of a holistic risk assessment when considering DMT discontinuation.

Plasma Exchange vs. Immunoadsorption: Effects on Immunological Markers and Predictive Value in Steroid-Refractory MS Attacks

Background

Evidence on neurochemical mechanisms underlying response to apheresis in steroid-refractory Multiple Sclerosis (MS) attacks is limited.

Objective

To examine the effect of immunoadsorption (IA) versus plasma exchange (PLEX) on serum immunological parameters [IgG, IgA, IgM, kappa- and lambda-immunoglobulin free light chains (κ-FLC, λ-FLC), CXCL13, CXCL12] and the predictive value of these parameters on response to apheresis.

Methods

Pre- and postprocedural serum samples of 38 participants (IA: n = 19, PLEX: n = 19) from the IAPEMS trial (NCT02671682), conducted in our tertiary centre, were examined.

Results

Serum immunoglobulins were strongly reduced after both procedures (IgG: IA median -96.04%; PLEX median -85.98%). κ-FLC levels were reduced after PLEX (median -34.74%), not affected by IA. Both procedures caused a decrease in λ-FLC levels. CXCL13 slightly increased after PLEX (median +24.16%), conversely decreased after IA (median -21.92%). CXCL12 levels were reduced after IA (median -45.69%), but not significantly altered after PLEX. None of the serum parameters evaluated showed predictive value for apheresis response.

Conclusion

IA and PLEX have a differential effect on serum immunological parameters. IA appears to reduce B-cell derived inflammation more effectively. This finding requires further evaluation and comparative analysis with clinical outcomes, especially in the context of the efficacy of B-cell therapies in treating MS.

Serum neurofilament light chain and glial fibrillary acidic protein for predicting response to apheresis in steroid-refractory multiple sclerosis relapses

BACKGROUND AND PURPOSE

The predictive value of serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) for apheresis outcome in steroid-refractory multiple sclerosis (MS) relapse has not yet been evaluated.

METHODS

We used pre- and postapheresis serum samples from 38 participants of the IAPEMS trial (clinicaltrials.gov: NCT02671682), which investigated the use of immunoadsorption versus plasma exchange for the treatment of steroid-refractory MS attacks. Response to apheresis was classified based on improvement on (i) the Expanded Disability Status Scale (EDSS), (ii) the affected functional system scores (FSS) of the EDSS, or (iii) the visual acuity for patients with optic neuritis, 4 weeks postapheresis. sNFL and sGFAP were measured by single molecule arrays.

RESULTS

Preprocedural sGFAP levels could discriminate between responders and nonresponders, determined by FSS improvement (p = 0.017). In multivariate logistic regression analysis, younger age (odds ratio [OR] = 0.781, 95% confidence interval [CI] = 0.635-0.962, p = 0.020) and lower sGFAP levels (OR = 0.948, 95% CI = 0.903-0.995, p = 0.031) could predict response to apheresis in the overall cohort. We could observe a trend towards a favourable apheresis outcome with higher sNfL levels (OR = 1.413, 95% CI = 0.965-2.069, p = 0.076). Analysis of the sNfL-to-sGFAP ratio showed an OR of 1.924 (95% CI = 1.073-3.451, p = 0.028) for predicting apheresis response. The ratio showed a better predictive value than the individual parameters. Neither biomarker was affected by the number of steroid cycles preapheresis.

CONCLUSIONS

Lower sGFAP levels, a higher sNfL-to-sGFAP ratio, and younger age are associated with a favourable apheresis outcome.

Multiple sclerosis lesions that impair memory map to a connected memory circuit

BACKGROUND

Nearly 1 million Americans are living with multiple sclerosis (MS) and 30-50% will experience memory dysfunction. It remains unclear whether this memory dysfunction is due to overall white matter lesion burden or damage to specific neuroanatomical structures. Here we test if MS memory dysfunction is associated with white matter lesions to a specific brain circuit.

METHODS

We performed a cross-sectional analysis of standard structural images and verbal memory scores as assessed by immediate recall trials from 431 patients with MS (mean age 49.2 years, 71.9% female) enrolled at a large, academic referral center. White matter lesion locations from each patient were mapped using a validated algorithm. First, we tested for associations between memory dysfunction and total MS lesion volume. Second, we tested for associations between memory dysfunction and lesion intersection with an a priori memory circuit derived from stroke lesions. Third, we performed mediation analyses to determine which variable was most associated with memory dysfunction. Finally, we performed a data-driven analysis to derive de-novo brain circuits for MS memory dysfunction using both functional (n = 1000) and structural (n = 178) connectomes.

RESULTS

Both total lesion volume (r = 0.31, p < 0.001) and lesion damage to our a priori memory circuit (r = 0.34, p < 0.001) were associated with memory dysfunction. However, lesion damage to the memory circuit fully mediated the association of lesion volume with memory performance. Our data-driven analysis identified multiple connections associated with memory dysfunction, including peaks in the hippocampus (T = 6.05, family-wise error p = 0.000008), parahippocampus, fornix and cingulate. Finally, the overall topography of our data-driven MS memory circuit matched our a priori stroke-derived memory circuit.

CONCLUSIONS

Lesion locations associated with memory dysfunction in MS map onto a specific brain circuit centered on the hippocampus. Lesion damage to this circuit fully mediated associations between lesion volume and memory. A circuit-based approach to mapping MS symptoms based on lesions visible on standard structural imaging may prove useful for localization and prognosis of higher order deficits in MS.

Relapse-associated worsening in a real-life multiple sclerosis cohort: the role of age and pyramidal phenotype

BACKGROUND AND PURPOSE

The overall disability in patients with relapsing-remitting multiple sclerosis is likely to be partly rather than entirely attributed to relapse.

MATERIALS AND METHODS

The aim was to investigate the determinants of recovery from first relapse and relapse-associated worsening (RAW) in relapsing-remitting multiple sclerosis patients from the Italian MS Registry during a 5-year epoch from the beginning of first-line disease-modifying therapy. To determine recovery, the functional system (FS) score was used to calculate the difference between the score on the date of maximum improvement and the score before the onset of relapse. Incomplete recovery was defined as a combination of partial (1 point in one FS) and poor recovery (2 points in one FS or 1 point in two FSs or any other higher combination). RAW was indicated by a confirmed disability accumulation measured by the Expanded Disability Status Scale score confirmed 6 months after the first relapse.

RESULTS

A total of 767 patients had at least one relapse within 5 years of therapy. Of these patients, 57.8% experienced incomplete recovery. Age (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.04; p = 0.007) and pyramidal phenotype were associated with incomplete recovery (OR = 2.1, 95% CI 1.41-3.14; p < 0.001). RAW was recorded in 179 (23.3%) patients. Age (OR = 1.02, 95% CI 1.01-1.04; p = 0.029) and pyramidal phenotype (OR = 1.84, 95% CI 1.18-2.88; p = 0.007) were the strongest predictors in the multivariable model.

CONCLUSIONS

Age and pyramidal phenotype were the strongest determinants of RAW in early disease epochs.

Neurodegeneration in multiple sclerosis

Axonal loss in multiple sclerosis (MS) is a key component of disease progression and permanent neurologic disability. MS is a heterogeneous demyelinating and neurodegenerative disease of the central nervous system (CNS) with varying presentation, disease courses, and prognosis. Immunomodulatory therapies reduce the frequency and severity of inflammatory demyelinating events that are a hallmark of MS, but there is minimal therapy to treat progressive disease and there is no cure. Data from patients with MS, post-mortem histological analysis, and animal models of demyelinating disease have elucidated patterns of MS pathogenesis and underlying mechanisms of neurodegeneration. MRI and molecular biomarkers have been proposed to identify predictors of neurodegeneration and risk factors for disease progression. Early signs of axonal dysfunction have come to light including impaired mitochondrial trafficking, structural axonal changes, and synaptic alterations. With sustained inflammation as well as impaired remyelination, axons succumb to degeneration contributing to CNS atrophy and worsening of disease. These studies highlight the role of chronic demyelination in the CNS in perpetuating axonal loss, and the difficulty in promoting remyelination and repair amidst persistent inflammatory insult. Regenerative and neuroprotective strategies are essential to overcome this barrier, with early intervention being critical to rescue axonal integrity and function. The clinical and basic research studies discussed in this review have set the stage for identifying key propagators of neurodegeneration in MS, leading the way for neuroprotective therapeutic development. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology.

Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Inflammatory myelopathies can manifest with a combination of motor, sensory and autonomic dysfunction of variable severity. Depending on the underlying etiology, the episodes of myelitis can recur, often leading to irreversible spinal cord damage and major long-term disability. Three main demyelinating disorders of the central nervous system, namely multiple sclerosis (MS), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4+NMOSD) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD), can induce spinal cord inflammation through different pathogenic mechanisms, resulting in a more or less profound disruption of spinal cord integrity. This ultimately translates into distinctive clinical-MRI features, as well as distinct patterns of disability accrual, with a step-wise worsening of neurological function in MOGAD and AQP4+NMOSD, and progressive disability accrual in MS. Early recognition of the specific etiologies of demyelinating myelitis and initiation of the appropriate treatment is crucial to improve outcome. In this review article we summarize and compare the clinical and imaging features of spinal cord involvement in these three demyelinating disorders, both during the acute phase and over time, and outline the current knowledge on the expected patterns of disability accrual and outcomes. We also discuss the potential implications of these observations for patient management and counseling.

Optical Coherence Tomography in the Differential Diagnosis of Patients with Multiple Sclerosis and Patients with MRI Nonspecific White Matter Lesions

In the differential diagnosis of nonspecific white matter lesions (NSWMLs) detected on magnetic resonance imaging (MRI), multiple sclerosis (MS) should be taken into consideration. Optical coherence tomography (OCT) is a promising tool applied in the differential diagnostic process of MS. We tested whether OCT may be useful in distinguishing between MS and NSWMLs patients. In patients with MS (n = 41) and NSWMLs (n = 19), the following OCT parameters were measured: thickness of the peripapillary Retinal Nerve Fibre Layer (pRNFL) in superior, inferior, nasal, and temporal segments; thickness of the ganglion cell-inner plexiform layer (GCIPL); thickness of macular RNFL (mRNFL); and macular volume (MV). In MS patients, GCIPL was significantly lower than in NSWMLs patients (p = 0.024). Additionally, in MS patients, mRNFL was significantly lower than in NSWMLs patients (p = 0.030). The average segmental pRNFL and MV did not differ between MS and NSWMLs patients (p > 0.05). GCIPL and macular RNFL thinning significantly influenced the risk of MS (18.6% [95% CI 2.7%, 25.3%]; 27.4% [95% CI 4.5%, 62.3%]), and reduced GCIPL thickness appeared to be the best predictor of MS. We conclude that OCT may be helpful in the differential diagnosis of MS and NSWMLs patients in real-world settings.