MxA mRNA quantification and disability progression in interferon beta-treated multiple sclerosis patients

Even though anti-interferon beta (IFNβ) antibodies are the main determinants of IFNβ bioactivity loss and Myxovirus-resistance protein A (MxA) is the most established marker of IFNβ biological activity in IFNβ-treated multiple sclerosis patients, their usefulness in the routine clinical practice is still debated. Therefore, 118 multiple sclerosis patients naïve for treatment were enrolled for a 3-year longitudinal observational study mimicking the conditions of a real-world setting. In order to evaluate the kinetics of bioactivity loss in blood samples obtained every 6 months after therapy initiation, MxA and interferon receptor isoform/subunit mRNA were quantified by real-time PCR, anti-IFNβ binding antibodies were detected by radioimmunoprecipitation, and neutralizing antibodies by cytopathic effect inhibition assay. Clinical measures of disease activity and disability progression were also obtained at all time points. We found that, at the individual-patient level, the response to IFNβ therapy was extremely heterogeneous, including patients with stable or transitory, early or late loss of IFNβ bioactivity, and patients with samples lacking MxA mRNA induction in spite of absence of antibodies. No interferon receptor isoform alterations that could explain these findings were found. At the group level, none of these biological features correlated with the measures of clinical disease activity or progression. However, when MxA mRNA was evaluated not at the single time point as a dichotomic marker (induced vs. non-induced), but as the mean of its values measured over the 6-to-24 month period, the increasing average MxA predicted a decreasing risk of short-term disability progression, independently from the presence of relapses. Therefore, a more bioactive treatment, even if unable to suppress relapses, reduces their severity by an amount that is proportional to MxA levels. Together with its feasibility in the routine laboratory setting, these data warrant the quantification of MxA mRNA as a primary tool for a routine monitoring of IFNβ therapy.

Understanding the pharmacology of stroke and multiple sclerosis through imaging

Stroke and multiple sclerosis (MS) illustrate how clinical imaging can facilitate early phase drug development and most effective medicine use in the clinic. Imaging has enhanced understanding of the dynamics of evolution of disease pathophysiology, better defining treatment targets. Imaging measures can enable stratification of patients for clinical trials and for most cost-effective use in the clinic. In MS, imaging has allowed smaller Phase II clinical trials and contributed to medicine differentiation. It also has led to consideration of suppression of inflammation and neurodegeneration as meaningfully distinct pharmacodynamic concepts. Similar imaging measures can be used in preclinical and clinical studies. Testing translational pharmacological hypotheses using clinical imaging more explicitly could improve the success of the next generation of stroke therapeutics.

Electromagnetic field stimulation potentiates endogenous myelin repair by recruiting subventricular neural stem cells in an experimental model of white matter demyelination

Electromagnetic fields (EMFs) may affect the endogenous neural stem cells within the brain. The aim of this study was to assess the effects of EMFs on the process of toxin-induced demyelination and subsequent remyelination. Demyelination was induced using local injection of lysophosphatidylcholine within the corpus callosum of adult female Sprague-Dawley rats. EMFs (60 Hz; 0.7 mT) were applied for 2 h twice a day for 7, 14, or 28 days postlesion. BrdU labeling and immunostaining against nestin, myelin basic protein (MBP), and BrdU were used for assessing the amount of neural stem cells within the tissue, remyelination patterns, and tracing of proliferating cells, respectively. EMFs significantly reduced the extent of demyelinated area and increased the level of MBP staining within the lesion area on days 14 and 28 postlesion. EMFs also increased the number of BrdU- and nestin-positive cells within the area between SVZ and lesion as observed on days 7 and 14 postlesion. It seems that EMF potentiates proliferation and migration of neural stem cells and enhances the repair of myelin in the context of demyelinating conditions.

Therapies for multiple sclerosis: considerations in the pediatric patient

Current and emerging therapies for multiple sclerosis (MS) offer promise for improved disease control and long-term clinical outcome. To date, these therapies have been evaluated solely in the context of adult MS. However, onset of MS in children is being increasingly recognized, and recent studies have identified a significant impact of MS onset during childhood on cognitive and physical functioning. Optimization of pediatric MS care requires that promising new therapies be made available to children and adolescents, but also that safety and tolerability and potential influence of therapies on the developing immune and neural networks of pediatric patients be closely considered. We propose care algorithms illustrating models for therapy that detail careful monitoring of pediatric patients with MS, provide definitions for inadequate treatment response and treatment escalation, and foster multinational collaboration in future therapeutic trials.

Health care situation of patients with relapsing-remitting multiple sclerosis receiving immunomodulatory therapy: a retrospective survey of more than 9000 German patients with MS

BACKGROUND AND PURPOSE

First-line immunomodulatory treatment with interferon-beta or glatiramer acetate is accepted as effective basic therapy in patients with relapsing-remitting multiple sclerosis (RRMS). However, a considerable portion of patients does not benefit from treatment.

METHOD

To test basic immunomodulatory treatment under real-life conditions, we retrospectively analyzed clinical and subclinical disease activity within the last 12 months in a cohort of 9916 patients with RRMS, of which 7896 patients were receiving immunomodulatory treatment. In addition, factors associated with treating physicians' consideration of a switch of current treatment were assessed.

RESULTS

The majority of treated patients (approximately 66%) experienced no relapse during the last 12 months. However, in line with common clinical study findings, about one-third (approximately 34%) of patients had relapses. When MRI data were taken into account, approximately one-quarter (24%) of patients would qualify for therapy escalation to monoclonal antibody natalizumab. Relapse rate in the preceding year (the year directly prior to the start of retrospective data collection) was strongly associated with considering a switch of current treatment. In addition, therapy switch was more often considered in younger patients. The relationship between MRI findings in the absence of clinical symptoms and consideration of a treatment switch was not as clear.

CONCLUSIONS

This analysis confirms that disease progression occurs in a considerable proportion of patients with RRMS. These patients should be considered for therapy escalation.

Current approaches to the identification and management of breakthrough disease in patients with multiple sclerosis

Disease-modifying drugs (DMDs) for relapsing-remitting multiple sclerosis (RRMS) are only partly effective -- breakthrough disease commonly occurs despite treatment. Breakthrough disease is predictive of continued disease activity and a poor prognosis. Availability of several DMDs offers the possibility of tailoring treatment to individual patients with RRMS and altering treatment in patients with breakthrough disease. However, no biological or imaging markers have been validated to guide initial treatment, markers of individual responsiveness to DMDs are scarce, and there is no class 1 evidence to guide alternative therapy in patients with breakthrough disease. In this Review, we discuss proposed strategies to monitor patients with RRMS being treated with DMDs, outline approaches to identifying therapeutic response in individual patients, review MRI and biological markers of treatment response, and summarise the role of antibodies in biological therapies. We also outline possible strategies for the management of patients with breakthrough disease and highlight areas in which research is needed.