Current therapeutic options in pediatric multiple sclerosis

Inhibition of Human Neutrophil Functions In Vitro by Multiple Sclerosis Disease-Modifying Therapies

There is a growing optimism about the potential of new disease-modifying therapies (DMTs) in the management of relapsing-remitting multiple sclerosis (RRMS) patients. However, this initial enthusiasm has been tempered by evidence indicating that multiple sclerosis (MS) patients undergoing DMT may be at higher risk of developing infections through incompletely understood mechanisms. As neutrophils provide the first line of defense against pathogens, here we have compared the effects of some of the commonly used MS DMTs (i.e., moderate-efficacy injective, first-line: interferonβ-1b (IFNβ-1b), glatiramer acetate (GA); and high-efficacy, second-line: fingolimod (FTY) and natalizumab (NAT)) on the in vitro viability and functions of neutrophils isolated from healthy subjects. All the DMTs tested impaired the ability of neutrophils to kill Klebsiella pneumoniae, whereas none of them affected the rate of neutrophil apoptosis or CD11b and CD62L cell surface expression. Intriguingly, only FTY exposure negatively affected K. pneumoniae-induced production of reactive oxygen species (ROS) in polymorphonuclear leukocytes (PMNs). Furthermore, neutrophils exposed to K. pneumoniae secreted enhanced amounts of CXCL8, IL-1β and TNF-α, which were differentially regulated following DMT pretreatment. Altogether, these findings suggest that DMTs may increase the susceptibility of MS patients to microbial infections, in part, through inhibition of neutrophil functions. In light of these data, we recommend that the design of personalized therapies for RRMS patients should take into account not just the mechanism of action of the chosen DMT but also the potential risk of infection associated with the administration of such therapeutic compounds to this highly vulnerable population.

Multiple Sclerosis: Immunopathology and Treatment Update

The treatment of multiple sclerosis (MS) has changed over the last 20 years. All immunotherapeutic drugs target relapsing remitting MS (RRMS) and it still remains a medical challenge in MS to develop a treatment for progressive forms. The most common injectable disease-modifying therapies in RRMS include β-interferons 1a or 1b and glatiramer acetate. However, one of the major challenges of injectable disease-modifying therapies has been poor treatment adherence with approximately 50% of patients discontinuing the therapy within the first year. Herein, we go back to the basics to understand the immunopathophysiology of MS to gain insights in the development of new improved drug treatments. We present current disease-modifying therapies (interferons, glatiramer acetate, dimethyl fumarate, teriflunomide, fingolimod, mitoxantrone), humanized monoclonal antibodies (natalizumab, ofatumumb, ocrelizumab, alentuzumab, daclizumab) and emerging immune modulating approaches (stem cells, DNA vaccines, nanoparticles, altered peptide ligands) for the treatment of MS.

Reprint of: Nrf2/ARE-mediated antioxidant actions of pro-electrophilic drugs

Living cells maintain a balance between oxidation and reduction, and perturbations of this redox balance are thought to contribute to various diseases. Recent attempts to regulate redox state have focused on electrophiles (EPs), which activate potent cellular defense systems against oxidative stress. One example of this approach is exemplified by carnosic acid (CA) and carnosol (CS), compounds that are found in the herb rosemary (Rosmarinus officinalis). Importantly, CA and CS themselves are not electrophilic, but in response to oxidation, become electrophilic, and then activate the Keap1/Nrf2/ARE (antioxidant-response element) transcription pathway to synthesize endogenous antioxidant "phase 2"enzymes. As a result of our efforts to develop these compounds as therapeutics for brain health, we have formulated two innovative criteria for drug development: the first concept is the use of pro-electrophilic drugs (PEDs) that are innocuous in and of themselves; and the second concept involves the use of compounds that are pathologically activated therapeutics (PATs); i.e., these small molecules are chemically converted to their active form by the very oxidative stress that they are designed to then combat. The chemical basis for PED and PAT drugs is embodied in the ortho- and para-hydroquinone electrophilic cores of the molecules, which are oxidized by the Cu(2+)/Cu(+) cycling system (or potentially by other transition metals). Importantly, this cycling pathway is under stringent regulation by the cell redox state. We propose that redox-dependent quinone formation is the predominant mechanism for formation of PED and PAT drugs from their precursor compounds. In fact, redox-dependent generation of the active form of drug from the "pro-form" distinguishes this therapeutic approach from traditional EPs such as curcumin, and results in a decrease in clinical side effects at therapeutic concentrations, e.g., lack of reaction with other thiols such as glutathione (GSH), which can result in lowering GSH and inducing oxidative stress in normal cells. We consider this pro-drug quality of PED/PAT compounds to be a key factor for generating drugs to be used to combat neurodegenerative diseases that will be clinically tolerated. Given the contribution of oxidative stress to the pathology of multiple neurodegenerative diseases, the Keap1/Nrf2/ARE pathway represents a promising drug target for these PED/PAT agents.

Nrf2/ARE-mediated antioxidant actions of pro-electrophilic drugs

Living cells maintain a balance between oxidation and reduction, and perturbations of this redox balance are thought to contribute to various diseases. Recent attempts to regulate redox state have focused on electrophiles (EPs), which activate potent cellular defense systems against oxidative stress. One example of this approach is exemplified by carnosic acid (CA) and carnosol (CS), compounds that are found in the herb rosemary (Rosmarinus officinalis). Importantly, CA and CS themselves are not electrophilic, but in response to oxidation, become electrophilic, and then activate the Keap1/Nrf2/ARE (antioxidant-response element) transcription pathway to synthesize endogenous antioxidant "phase 2" enzymes. As a result of our efforts to develop these compounds as therapeutics for brain health, we have formulated two innovative criteria for drug development: the first concept is the use of pro-electrophilic drugs (PEDs) that are innocuous in and of themselves; and the second concept involves the use of compounds that are pathologically activated therapeutics (PATs);i.e., these small molecules are chemically converted to their active form by the very oxidative stress that they are designed to then combat. The chemical basis for PED and PAT drugs is embodied in the ortho- and para-hydroquinone electrophilic cores of the molecules, which are oxidized by the Cu(2+)/Cu(+) cycling system (or potentially by other transition metals). Importantly, this cycling pathway is under stringent regulation by the cell redox state. We propose that redox-dependent quinone formation is the predominant mechanism for formation of PED and PAT drugs from their precursor compounds. In fact, redox-dependent generation of the active form of drug from the "pro-form" distinguishes this therapeutic approach from traditional EPs such as curcumin, and results in a decrease in clinical side effects at therapeutic concentrations, e.g., lack of reaction with other thiols such as glutathione (GSH), which can result in lowering GSH and inducing oxidative stress in normal cells. We consider this pro-drug quality of PED/PAT compoundsto be a key factor for generating drugs to be used to combat neurodegenerative diseases that will be clinically tolerated. Given the contribution of oxidative stress to the pathology of multiple neurodegenerative diseases, the Keap1/Nrf2/ARE pathway represents a promising drug target for these PED/PAT agents.

Pediatric multiple sclerosis: current concepts and consensus definitions

Multiple sclerosis (MS), a chronic inflammatory autoimmune disease of the central nervous system (CNS) commonly diagnosed in adults, is being recognized increasingly in children. An estimated 1.7%-5.6% of all patients with MS have clinical symptoms before reaching the age of 18 years. In comparison with adults, the diagnosis of MS in children can be more difficult, being dismissed or misdiagnosed as other clinical disorders. Although adults and children share basic aspects of the disorder, children have distinctive clinical features, neuroimaging, laboratory, and courses of the disease. The 2010 McDonald criteria have simplified the requirements for establishing the diagnosis of MS and have been proposed to be applicable for the diagnosis of pediatric MS, mainly in children 12 years and older. This paper describes the distinctive features of common pediatric demyelinating disorders, including MS, and summarizes the most recent advances based on the available literature.

Depression in multiple sclerosis: a review of assessment and treatment approaches in adult and pediatric populations

Multiple sclerosis is a chronic demyelinating disease affecting one million people worldwide, with a significant burden of psychiatric comorbidity. Depression is the commonest psychiatric manifestation but still remains largely underdiagnosed and undertreated. The present work reviews current knowledge on diagnosis, assessment, and somatic and psychotherapeutic treatment interventions for depression in adult and pediatric populations of patients with multiple sclerosis.

Esclerosis múltiple en pacientes pediátricos: fisiopatología, diagnóstico y manejo

ResumenObjetivo: Revisar la literatura disponible sobre esclerosis múltiple en la población pediátrica.Métodos: Revisión sistemática de la literatura encontrada en las bases de datos Scopus y PubMed posterior al año 2000.Resultados y Conclusiones: La Esclerosis Múltiple es una enfermedad con una tasa de incidencia de 2 – 4 / 100.000 habitantes en Colombia, de la cual la población pediátrica representa entre 2,7 – 5% de los casos. Las causas que se han atribuido a la enfermedad son múltiples, incluyendo factores ambientales como infecciones virales o bacterianas, exposición a humo de cigarrillo o deficiencia de vitamina D, entre otras, genéticas e inmunológicas. Su diagnóstico se basa en los hallazgos clínicos e imagenológicos, previa exclusión de enfermedades más comunes. Su tratamiento se divide en tres ejes: el tratamiento de eventos agudos, el tratamiento modificador de la enfermedad y el tratamiento sintomático. Para el primero los medicamentos de primera elección son los corticoides, para el segundo los medicamentos inmunomoduladores como Acetato de Glatiramer y para el tercero se debe realizar un enfoque multidisciplinario. Su pronóstico a largo plazo es variable y depende en alguna medida de la respuesta al tratamiento.