Genetic Basis of Inflammatory Demyelinating Diseases of the Central Nervous System: Multiple Sclerosis and Neuromyelitis Optica Spectrum.

Demyelinating diseases alter myelin or the coating surrounding most nerve fibers in the central and peripheral nervous systems. The grouping of human central nervous system demyelinating disorders today includes multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) as distinct disease categories. Each disease is caused by a complex combination of genetic and environmental variables, many involving an autoimmune response. Even though these conditions are fundamentally similar, research into genetic factors, their unique clinical manifestations, and lesion pathology has helped with differential diagnosis and disease pathogenesis knowledge. This review aims to synthesize the genetic approaches that explain the differential susceptibility between these diseases, explore the overlapping clinical features, and pathological findings, discuss existing and emerging hypotheses on the etiology of demyelination, and assess recent pathogenicity studies and their implications for human demyelination. This review presents critical information from previous studies on the disease, which asks several questions to understand the gaps in research in this field.

Neuromyelitis optica spectrum disorder: pathophysiological approach.

Aim: To review the main pathological findings of Neuromyelitis Optica Spectrum Disorder (NMOSD) associated with the presence of autoantibodies to aquaporin-4 (AQP4) as well as the mechanisms of astrocyte dysfunction and demyelination. Methods: An comprehensive search of the literature in the field was carried out using the database of The National Center for Biotechnology Information from . Systematic searches were performed until July 2022. Results: NMOSD is an inflammatory and demyelinating disease of the central nervous system mainly in the areas of the optic nerves and spinal cord, thus explaining mostly the clinical findings. Other areas affected in NMOSD are the brainstem, hypothalamus, and periventricular regions. Relapses in NMOSD are generally severe and patients only partially recover. NMOSD includes clinical conditions where autoantibodies to aquaporin-4 (AQP4-IgG) of astrocytes are detected as well as similar clinical conditions where such antibodies are not detected. AQP4 are channel-forming integral membrane proteins of which AQ4 isoforms are able to aggregate in supramolecular assemblies termed orthogonal arrays of particles (OAP) and are essential in the regulation of water homeostasis and the adequate modulation of neuronal activity and circuitry. AQP4 assembly in orthogonal arrays of particles is essential for AQP4-IgG pathogenicity since AQP4 autoantibodies bind to OAPs with higher affinity than for AQP4 tetramers. NMOSD has a complex background with prominent roles for genes encoding cytokines and cytokine receptors. AQP4 autoantibodies activate the complement-mediated inflammatory demyelination and the ensuing damage to AQP4 water channels, leading to water influx, necrosis and axonal loss. Conclusions: NMOSD as an astrocytopathy is a nosological entity different from multiple sclerosis with its own serological marker: immunoglobulin G-type autoantibodies against the AQP4 protein which elicits a complement-dependent cytotoxicity and neuroinflammation. Some patients with typical manifestations of NMSOD are AQP4 seronegative and myelin oligodendrocyte glycoprotein positive. Thus, the detection of autoantibodies against AQP4 or other autoantibodies is crucial for the correct treatment of the disease and immunosuppressant therapy is the first choice.

Association of serum MIP-1alpha, MIP-1beta, and RANTES with clinical manifestations, disease activity, and damage accrual in systemic lupus erythematosus.

The aim of this study was to determine if macrophage inflammatory protein (MIP) 1alpha, MIP-1beta, and RANTES (regulated upon activation normally T-cell expressed and secreted) serum concentrations are associated with clinical manifestations, disease activity, and damage accrual in patients with systemic lupus erythematosus (SLE). A cross-sectional study was performed in 62 SLE patients (per American College of Rheumatology criteria) participating in a longitudinal study and 20 healthy subjects. MIP-1alpha, MIP-1beta, and RANTES serum concentrations were determined by enzyme-linked immunosorbent assay. Demographic parameters, clinical manifestations, serologic features, pharmacologic treatments, disease activity, and damage accrual were determined at study visit. Disease activity was assessed with the Systemic Lupus Erythematosus Activity Measure (SLAM), and disease damage was assessed with Systemic Lupus International Collaborating Clinic Damage Index (SDI). The relation between the variables was studied with the Student t test and the Pearson r correlation test. SLE patients were more likely to have higher concentrations of MIP-1beta and RANTES than healthy individuals. In addition, they had a trend to have higher concentrations of MIP-1alpha. Patients with discoid lupus were more likely to have higher levels of MIP-1alpha. Elevation of MIP-1beta correlated with higher SDI score. No association was found between serum chemokines levels and disease activity. In conclusion, SLE patients have higher serum levels of MIP-1beta and RANTES than healthy individuals. MIP-1alpha is associated with discoid lupus, and MIP-1beta correlates with damage accrual in SLE. This study suggests that chemokines may have a role in the pathogenesis of SLE.