Induction of apoptosis in CD4(+) T-cells is linked with optimal treatment response in patients with relapsing-remitting multiple sclerosis treated with Glatiramer acetate

Effect of Disease-Modifying Therapies on COVID-19 Vaccination Efficacy in Multiple Sclerosis Patients: A Comprehensive Review

According to current knowledge, the etiopathogenesis of multiple sclerosis (MS) is complex, involving genetic background as well as several environmental factors that result in dysimmunity in the central nervous system (CNS). MS is an immune-mediated, inflammatory neurological disease affecting the CNS. As part of its attack on the axons of the CNS, MS witnesses varying degrees of myelin and axonal loss. A total of about 20 disease-modifying therapies (DMTs) are available today that, both in clinical trials and in real-world studies, reduce disease activity, such as relapses, magnetic resonance imaging lesions, and disability accumulation. Currently, the world is facing an outbreak of the new coronavirus disease 2019 (COVID-19), which originated in Wuhan, Hubei Province, China, in December 2019 and spread rapidly around the globe. Viral infections play an important role in triggering and maintaining neuroinflammation through direct and indirect mechanisms. There is an old association between MS and viral infections. In the context of MS-related chronic inflammatory damage within the CNS, there has been concern regarding COVID-19 worsening neurological damage. A high rate of disability and increased susceptibility to infection have made MS patients particularly vulnerable. In addition, DMTs have been a concern during the pandemic since many DMTs have immunosuppressive properties. In this article, we discuss the impact of DMTs on COVID-19 risks and the effect of DMTs on COVID-19 vaccination efficacy and outcome in MS patients.

Fewer LAG-3+ T Cells in Relapsing-Remitting Multiple Sclerosis and Type 1 Diabetes

The coinhibitory receptor lymphocyte activation gene 3 (LAG-3) is an immune checkpoint molecule that negatively regulates T cell activation, proliferation, and homeostasis. Blockade or deletion of LAG-3 in autoimmune-prone backgrounds or induced-disease models has been shown to exacerbate disease. We observed significantly fewer LAG-3⁺ CD4 and CD8 T cells from subjects with relapsing-remitting multiple sclerosis (RRMS) and type 1 diabetes. Low LAG-3 protein expression was linked to alterations in mRNA expression and not cell surface cleavage. Functional studies inhibiting LAG-3 suggest that in subjects with RRMS, LAG-3 retains its ability to suppress T cell proliferation. However, LAG-3 expression was associated with the expression of markers of apoptosis, indicating a role for low LAG-3 in T cell resistance to cell death. In T cells from subjects with RRMS, we observed a global dysregulation of LAG-3 expression stemming from decreased transcription and persisting after T cell stimulation. These findings further support the potential clinical benefits of a LAG-3 agonist in the treatment of human autoimmunity.

Immunosuppression in Multiple Sclerosis and Other Neurologic Disorders

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by peripheral immune cell infiltration into the brain and spinal cord, demyelination, glial cell activation, and neuronal damage. Currently there is no cure for MS, however, available disease-modifying agents minimize inflammation in the CNS by various mechanisms. Approved drugs lessen severity of the disease and delay disease progression, however, they are still suboptimal as patients experience adverse effects and varying efficacies. Additionally, there is only one disease-modifying therapy available for the more debilitating, progressive form of MS. This chapter focuses on the presently-available therapeutics and, importantly, the future directions of MS therapy based on preclinical studies and early clinical trials. Immunosuppression in other neurological disorders including neuromyelitis optica spectrum disorders, myasthenia gravis, and Guillain-Barré syndrome is also discussed.

Reduced expression of L-selectin in T-cells correlates with relative lymphocyte increase in patients with RRMS treated with natalizumab - functional implication towards PML risk

Objectives: Natalizumab (NTZ), a treatment indicated for patients with highly active Relapsing - Remitting Multiple Sclerosis (RRMS), is known to induce increased relative frequency of lymphocytes. Progressive Multifocal Leukoencephalitis (PML) is a rare but serious adverse event related to NTZ. Moreover, reduced L-selectin (CD62L) expression in T-cells in cryopreserved samples of patients with RRMS under NTZ has been proposed as a biomarker of pre-PML state. We explore the association between L-selectin expression in T-cells and hematological parameters in freshly processed samples of patients with RRMS under NTZ.Methods: We studied L-selectin expression in patients with: RRMS under NTZ (n=34), fingolimod (FTY, n=14), interferon-beta (IFNβ, n=22), glatiramer acetate (GA, N=17); in 9 patients with secondary progressive (SP) MS and in 6 healthy controls. Twenty-two patients under NTZ and 6 patients under FTY were followed for 18 months. One NTZ-treated patient developed PML during the study.Results: Patients under NTZ exhibited increased relative frequency of lymphocytes (40.02±1.45) compared to patients under first-line treatment (30.57±1.68, p<0.001) and to patients with SPMS (29±1.56, p=0.02), and a lower mean L-selectin expression in (69.39±1.73) compared to patients under first-line treatment (79.1±1.17, p=0.003). A negative correlation between the relative frequency of CD4+CD62L+ T-cells and the absolute lymphocyte counts (Pearson's r=0.367, p=0.033) was observed.Discussion: We hereby provide mechanistic insight in a possible pathway implicated in NTZ-related PML risk. These results further underline the need for thorough validation of L-selectin expression in T-cells as a potential pre-PML biomarker.