Neuromyelitis optica (NMO) is a chronic inflammatory autoimmune disease of the central nervous system (CNS) characterized by acute optic neuritis (ON) and transverse myelitis (TM). NMO is caused by a pathogenic serum IgG antibody against the water channel aquoporin 4 (AQP4) in the majority of patients. AQP4-antibody (AQP4-ab) presence is highly specific, and differentiates NMO from multiple sclerosis. It binds to AQP4 channels on astrocytes, triggering activation of the classical complement cascade, causing granulocyte, eosinophil, and lymphocyte infiltration, culminating in injury first to astrocyte, then oligodendrocytes followed by demyelination and neuronal loss. NMO spectrum disorder (NMOSD) has recently been defined and stratified based on AQP4-ab serology status. Most NMOSD patients experience severe relapses leading to permanent neurologic disability, making suppression of relapse frequency and severity, the primary objective in disease management. The most common treatments used for relapses are steroids and plasma exchange.Currently, long-term NMOSD relapse prevention includes off-label use of immunosuppressants, particularly rituximab. In the last 2 years however, three pivotal clinical trials have expanded the spectrum of drugs available for NMOSD patients. Phase III studies have shown significant relapse reduction compared to placebo in AQP4-ab-positive patients treated with satralizumab, an interleukin-6 receptor (IL-6R) inhibitor, inebilizumab, an antibody against CD19⁺B cells; and eculizumab, an antibody blocking the C5 component of complement. In light of the new evidence on NMOSD pathophysiology and of preliminary results from ongoing trials with new drugs, we present this descriptive review, highlighting promising treatment modalities as well as auspicious preclinical and clinical studies.

Multiple sclerosis (MS), is an emergent disease in Latin America (LATAM), which raises substantial socioeconomic challenges to a region where most countries remain as economies in development. To assess barriers to access and utilization of MS care services in a regional cohort survey. We conducted a cross-sectional study based on a self-reported survey. Patients with MS (PwMS) completed this regional survey in 12 Latin American (LATAM) countries. PwMS were also divided into those with healthcare insurance (including certain local national social security programs) and those without healthcare insurance (treated at public institutions). We surveyed 1469 PwMS and identified significant regional differences in relation to access to complementary tests, rehabilitation services, and prescription of disease-modifying therapies (DMTs). Between 44.4% and 73.5% of PwMS were unemployed and nearly 50% had completed higher education. PwMS receiving care from the private sector reported greater access to imaging, DMTs, and fewer problems obtaining DMTs compared to those treated at public institutions. Multivariate analysis showed that lack of private insurance (OR = 2.21, p < 0.001), longer MS duration (OR = 1.02, p = 0.001), lower level of education (OR = 0.66, p = 0.009), and unemployment (OR = 0.73, p = 0.03) were independently associated with inappropriate delivery of DMTs. These findings suggest barriers to access and utilization of MS care services across LATAM are prevalent. We identified several factors predicting unmet healthcare needs in PwMS.

Bruton’s tyrosine kinase inhibitors: a promising emerging treatment option for multiple sclerosis. Expert Opinion on Emerging Drugs. Accepted 9 September 2020.