Prospective trial of natalizumab personalised extended interval dosing by therapeutic drug monitoring in relapsing-remitting multiple sclerosis (NEXT-MS).

BACKGROUND: Extended interval dosing (EID) of natalizumab is a promising strategy to optimise treatment in multiple sclerosis (MS). Personalised EID by therapeutic drug monitoring can enable further extension of treatment intervals. METHODS: The NEXT-MS trial is an investigator-initiated prospective phase IV non-randomised study. Adults with a diagnosis of relapsing-remitting MS who received ≥6 natalizumab infusions were included in three groups: personalised EID with a target drug trough concentration of 10 µg/mL (EID10), an exploratory group of personalised EID with a target of 5 µg/mL (EID5) and standard interval dosing (SID) of 4 weeks. The primary outcome is radiological disease activity (new/newly enlarged T2 lesions) comparing the EID10 group to a historical cohort of SID (HSID). RESULTS: Results of the first phase of the NEXT-MS trial are reported here (n=376) as the study will continue with an amended protocol. In the EID10 group (n=251), incidence rate of radiological activity was 10.0 per 1000 person-years, which was non-inferior to the HSID cohort (24.7 per 1000 person-years (n=87), incidence rate difference 14.7, 90% CI -4.5 to 34.0). Incidence rate of radiological activity was 10.0 per 1000 person-years in the EID5 group (n=65), and 47.0 per 1000 person-years in the SID group (n=60). Serum neurofilament light levels did not increase over time within the EID groups. There were no cases of progressive multifocal leukoencephalopathy. CONCLUSIONS: MS disease activity is adequately controlled with personalised natalizumab EID. Interval extension to a drug trough concentration of 5 µg/mL is likely a safe target to extend natalizumab treatment intervals >6 weeks. TRIAL REGISTRATION NUMBER: NCT04225312.

Whole Exome Sequencing in Multi-Incident Families Identifies Novel Candidate Genes for Multiple Sclerosis.

Multiple sclerosis (MS) is a degenerative disease of the central nervous system in which auto-immunity-induced demyelination occurs. MS is thought to be caused by a complex interplay of environmental and genetic risk factors. While most genetic studies have focused on identifying common genetic variants for MS through genome-wide association studies, the objective of the present study was to identify rare genetic variants contributing to MS susceptibility. We used whole exome sequencing (WES) followed by co-segregation analyses in nine multi-incident families with two to four affected individuals. WES was performed in 31 family members with and without MS. After applying a suite of selection criteria, co-segregation analyses for a number of rare variants selected from the WES results were performed, adding 24 family members. This approach resulted in 12 exonic rare variants that showed acceptable co-segregation with MS within the nine families, implicating the genes MBP, PLK1, MECP2, MTMR7, TOX3, CPT1A, SORCS1, TRIM66, ITPR3, TTC28, CACNA1F, and PRAM1. Of these, three genes (MBP, MECP2, and CPT1A) have been previously reported as carrying MS-related rare variants. Six additional genes (MTMR7, TOX3, SORCS1, ITPR3, TTC28, and PRAM1) have also been implicated in MS through common genetic variants. The proteins encoded by all twelve genes containing rare variants interact in a molecular framework that points to biological processes involved in (de-/re-)myelination and auto-immunity. Our approach provides clues to possible molecular mechanisms underlying MS that should be studied further in cellular and/or animal models.

A Delphi panel on treatment of high disease activity relapsing remitting multiple sclerosis in the Netherlands.

Aim: To gain insight into current treatment and barriers to optimal treatment for high disease activity relapsing remitting multiple sclerosis (MS) in the Netherlands. Materials & methods: A two-round Delphi panel using an online questionnaire was conducted. Seven MS neurologists from diverse locations in the Netherlands were invited to participate. Result: Out of the seven MS neurologists, five completed both questionnaire rounds. Conclusion: Effectiveness and side effects along with patient's lesion load were the most important factors for choosing a disease modifying therapy (DMTs). Respondents felt restricted to optimally treat their patients due to reimbursement restrictions for certain disease modifying therapies, although agreed that satisfactory treatment options are currently available. The answers show consensus between the participating MS neurologists with high certainty of answers.

The Interactive Web-Based Program MSmonitor for Self-Management and Multidisciplinary Care in Persons With Multiple Sclerosis: Quasi-Experimental Study of Short-Term Effects on Patient Empowerment.

BACKGROUND: Empowerment helps persons with a chronic disease to self-manage their condition and increase their autonomy and participation. MSmonitor (Curavista bv) is an interactive Web-based program for self-management and multidisciplinary care in multiple sclerosis (MS). It includes, among others, short questionnaires on fatigue (Modified Fatigue Impact Scale-5 [MFIS-5]) and health-related quality of life (HRQoL, Leeds Multiple Sclerosis Quality of Life [LMSQoL]); long questionnaires on disabilities, perception of disabilities (Multiple Sclerosis Impact Profile), and HRQoL (Multiple Sclerosis Quality of Life-54); a Medication and Adherence Inventory and an Activity Diary. The combination MFIS-5, LMSQoL, and Medication and Adherence Inventory constitutes the Quick Scan. OBJECTIVE: This study aimed to investigate the short-term effects of MSmonitor on empowerment in patients with MS. METHODS: We conducted a quasi-experimental study in a general hospital. Of the 180 patients with MS, 125 were eligible, 30 used MSmonitor, and 21 participated in the study (mean age 45.4 years, SD 10.2 years). A total of 24 eligible patients who did not use MSmonitor constituted the control group (mean age 49.3 years, SD 11.4 years). At baseline and at 4 months, we assessed self-efficacy (Multiple Sclerosis Self-Efficacy Scale [MSSES]), participation and autonomy (Impact on Participation and Autonomy [IPA] questionnaire), and self-management (Partners In Health [PIH] questionnaire). Differences between time points and groups were tested with paired t tests and χ² tests. RESULTS: In the MSmonitor group, follow-up values remained unchanged for MSSES control (P=.19), MSSES function (P=.62), IPA limitations (P=.26), IPA problems (P=.40), PIH recognition and management of symptoms (P=.52), PIH adherence to treatment (P=.80), and PIH coping (P=.73), whereas the PIH knowledge score had improved (mean 27.8, SD 1.7 vs mean 28.7, SD 2.0; P=.02). The overall utilization rate of the program components was 83% and that of the Quick Scan was 95%. In the control group, all outcomes had remained unchanged. CONCLUSIONS: The results suggest that for first-time users of the MSmonitor program and their health care providers, it may not be justified to expect a short-term improvement in empowerment in terms of self-efficacy, self-management, autonomy, or participation. Furthermore, a lack of effect on empowerment is not because of nonusage of the program components.

5HT4 agonists inhibit interferon-gamma-induced MHC class II and B7 costimulatory molecules expression on cultured astrocytes.

A failure of tight control of MHC class II expression on astrocytes may play a role in the development of autoimmune responses in multiple sclerosis. The 5-HT(4) serotonin receptor agonists cisapride and prucalopride, at concentrations between 10(-10) M and 10(-8) M, reduced interferon-gamma-induced MHC class II immunostaining in cultured astrocytes derived from newborn Wistar rats by approximately 50-60%. The magnitude of MHC class II inhibition by 5-HT(4) agonists was comparable to that of interferon-beta. The alpha(1)-adrenergic receptor agonist phenylephrine was without effect. Cisapride (10(-9) M) also prevented interferon-gamma-induced B7-1 and B7-2 immunostaining. Our results suggest that 5-HT(4) agonists may have therapeutic potential in multiple sclerosis by inhibiting the up-regulation of immune responsiveness of astrocytes in the central nervous system.

Simvastatin inhibits interferon-gamma-induced MHC class II up-regulation in cultured astrocytes.

Based on their potent anti-inflammatory properties and a preliminary clinical trial, statins (HMG-CoA reductase inhibitors) are being studied as possible candidates for multiple sclerosis (MS) therapy. The pathogenesis of MS is unclear. One theory suggests that the development of autoimmune lesions in the central nervous system may be due to a failure of endogenous inhibitory control of MHC class II expression on astrocytes, allowing these cells to adapt an interferon (IFN)-gamma-induced antigen presenting phenotype. By using immunocytochemistry in cultured astrocytes derived from newborn Wistar rats we found that simvastatin at nanomolar concentrations inhibited, in a dose-response fashion, up to 70% of IFN-gamma-induced MHC class II expression. This effect was reversed by the HMG-CoA reductase product mevalonate. Suppression of the antigen presenting function of astrocytes might contribute to the beneficial effects of statins in MS.

Beta 2-adrenoceptor involvement in inflammatory demyelination and axonal degeneration in multiple sclerosis.

Relapses of multiple sclerosis (MS) are considered to be the clinical expression of acute T-cell-mediated inflammatory demyelinating lesions disseminated in the CNS, whereas disease progression seems to result from widespread axonal degeneration. The pathophysiology of both disease components is incompletely understood. Astrocytes in MS lack beta(2)-adrenoceptors, which via cAMP-mediated processes inhibit the expression of major histocompatibility (MHC) class II molecules and stimulate glycogenolysis in normal conditions. In a pro-inflammatory CNS environment this beta(2)-adrenoceptor defect might allow astrocytes to transform into facultative antigen-presenting cells that can initiate the inflammatory cascade. The same receptor defect might impair astrocytic glycogenolysis, which normally generates lactate that is transported to axons as an energy source. Failure of axonal energy metabolism might result in axonal degeneration through mechanisms that involve intra-axonal accumulation of Ca(2+) ions and mitochondrial dysfunction. If this hypothesis is correct, therapies designed to elevate cAMP levels in astrocytes should reduce or prevent both relapses and progression of MS.

Astrocytic beta2-adrenergic receptors and multiple sclerosis.

Despite intensive research, the cause and a cure of multiple sclerosis (MS) have remained elusive and many aspects of the pathogenesis are not understood. Immunohistochemical experiments have shown that astrocytic beta(2)-adrenergic receptors are lost in MS. Because norepinephrine mediates important supportive and protective actions of astrocytes via activation of these beta(2)-adrenergic receptors, we postulate that this abnormality may play a prominent role in the pathogenesis of MS. First, it may allow astrocytes to act as facultative antigen-presenting cells, thereby initiating T-cell mediated inflammatory responses that lead to the characteristic demyelinated lesions. Second, it may contribute to inflammatory injury by stimulating the production of nitric oxide and proinflammatory cytokines, and reducing glutamate uptake. Third, it may lead to apoptosis of oligodendrocytes by reducing the astrocytic production of trophic factors, including neuregulin, nerve growth factor and brain-derived neurotrophic factor. Fourth, it may impair astrocytic glycogenolysis, which supplies energy to axons, and this may represent a mechanism underlying axonal degeneration that is hold responsible for the progressive chronic disability.

Reactive astrocytes in chronic active lesions of multiple sclerosis express co-stimulatory molecules B7-1 and B7-2.

Astrocytes in active lesions of multiple sclerosis (MS) express major histocompatibility (MHC) class II molecules, and may play an important role in the presentation of antigen to myelin-specific T cells.However, it has been postulated that astrocytes are unable to act as antigen-presenting cells (APCs) because they would lack the B7 co-stimulatory molecules to activate these T cells. By using double labeling immunofluorescence staining, we demonstrate that reactive astrocytes in chronic active plaques of multiple sclerosis express the co-stimulatory molecules B7-1 and B7-2, and hence have the necessary attributes to act as antigen-presenting cells.

Are astrocytes central players in the pathophysiology of multiple sclerosis?

An interaction between antimyelin T cells and antigen-presenting glial cells is a crucial step in the cascade of immune events that lead to the inflammatory lesions in multiple sclerosis (MS). One of the most debated and controversial issues is whether microglial cells or astrocytes are the key players in initiating the (auto)immune reactions in the central nervous system in MS. Many investigators consider microglia to be the responsible intrinsic immunoeffector cells. In this review, we speculate that in MS astrocytes may serve as primary (facultative) antigen-presenting cells due to a failure of noradrenergic suppression of class II major histocompatibility complex molecules, which is caused by a loss of beta(2)-adrenergic receptors. If this hypothesis is correct, pharmacologic suppression of the antigen-presenting capacities of astrocytes may be a potential therapy for MS.

Aminergic receptors in astrogliotic plaques from patients with multiple sclerosis.

Cultured astrocytes express a spectrum of neurotransmitter receptors. However, little is known about these receptors in situ. We previously reported the absence of beta(2) adrenergic receptors on astrocytes in multiple sclerosis (MS). Here we used [(3)H]-radioligands and receptor autoradiography to screen for a variety of other aminergic receptors in six silent chronic astrogliotic plaques in brain tissue obtained from five patients with MS. Dopamine D(1) and histamine H(1) receptors were absent. We detected specific binding for cholinergic muscarinic receptors > dopamine D(2), alpha(1-) and alpha(2)-adrenergic receptors > 5-HT(1A), 5-HT(1B/D), 5-HT(2A), 5-HT(2c), 5-HT(4), and dopamine D(3) receptors. Radiotracers for these aminergic receptors might be useful for studying astrogliosis in patients with MS, and compounds acting at some of these receptors may have potential to modulate astroglial function in MS.