Unveiling autonomic failure in synucleinopathies: Significance in diagnosis and treatment.

Autonomic failure is frequently encountered in synucleinopathies such as multiple system atrophy (MSA), Parkinson's disease (PD), Lewy body disease, and pure autonomic failure (PAF). Cardiovascular autonomic failure affects quality of life and can be life threatening due to the risk of falls and the increased incidence of myocardial infarction, stroke, and heart failure. In PD and PAF, pathogenic involvement is mainly post-ganglionic, while in MSA, the involvement is mainly pre-ganglionic. Cardiovascular tests exploring the autonomic nervous system (ANS) are based on the analysis of continuous, non-invasive recordings of heart rate and digital blood pressure (BP). They assess facets of sympathetic and parasympathetic activities and provide indications on the integrity of the baroreflex arc. The tilt test is widely used in clinical practice. It can be combined with catecholamine level measurement and analysis of baroreflex activity and cardiac variability for a detailed analysis of cardiovascular damage. MIBG myocardial scintigraphy is the most sensitive test for early detection of autonomic dysfunction. It provides a useful measure of post-ganglionic sympathetic fiber integrity and function and is therefore an effective tool for distinguishing PD from other parkinsonian syndromes such as MSA. Autonomic cardiovascular investigations differentiate between certain parkinsonian syndromes that would otherwise be difficult to segregate, particularly in the early stages of the disease. Exploring autonomic failure by gathering information about residual sympathetic tone, low plasma norepinephrine levels, and supine hypertension can guide therapeutic management of orthostatic hypotension (OH).

Treatment of neuromyelitis optica with rituximab: a 2-year prospective multicenter study.

OBJECTIVE: Neuromyelitis optica (NMO) is a very severe autoimmune disorder of the central nervous system. It affects young subjects and has a poor prognosis both on a functional and vital level. Therefore, it is imperative to reduce the frequency of relapses. The purpose of this study was to evaluate the clinical and neuroradiological effectiveness of rituximab (RTX) on active forms of NMO. METHODS: We conducted a 2-year open prospective multicenter study that included 32 patients treated with RTX at a dose of 375 mg/m2/week for 1 month. When the number of circulating CD19+ B cells reached 1%, a maintenance therapy was started, consisting of two infusions of 1 g of RTX, administered at a 15-day interval. The primary objective was to reduce the annual relapse rate (ARR), in comparison to that observed in the 2 years before treatment onset. RESULTS: Rituximab administration reduced the ARR from 1.34 to 0.56 (p = 0.0005). The average Expanded Disability Status Scale (EDSS) score significantly improved by 1.1 point, from 5.9 (2-9) to 4.8 (0-9) after 2 years (p = 0.03). Anti-aquaporin-4 antibodies' level predicted treatment failure (p = 0.03). Frequency of Gad+ lesions in spinal cord decreased from 23.3 to 14.2%. RTX treatment did not prevent the death of three patients (treatment failure in two patients and acute myeloid leukemia in a patient previously treated with mitoxantrone). CONCLUSION: Rituximab is clinically effective in active forms of NMO, although few patients are resistant to the treatment.

Brain immunohistopathological study in a patient with anti-NMDAR encephalitis.

BACKGROUND AND PURPOSE: Anti-N-methyl-D-asparate (NMDA) receptor encephalitis is thought to be antibody-mediated. To perform an immunohistopathological study of the inflammatory reaction in a brain biopsy performed before immunomodulatory treatments in a patient with anti-NMDA receptor encephalitis. METHODS: An immunohistochemical study was performed using CD3, CD68, CD20, CD138 and CD1a antibodies. RESULTS: Prominent B-cell cuffing was present around brain vessels accompanied by some plasma cells, while macrophages and T cells were scattered throughout the brain parenchyma. CONCLUSION: These findings suggest that the B cells interact with the T cells and are involved in antibody secretion by the plasma cells.

Bone marrow CD34+/B220+ progenitors target the inflamed brain and display in vitro differentiation potential toward microglia.

Recent evidence indicates that microglial cells may not derive from blood circulating mature monocytes as they express features of myeloid progenitors. Here, we observed that a subpopulation of microglial cells expressed CD34 and B220 antigens during brain development. We thus hypothesized that microglia, or a subset of microglial cells, originate from blood circulating CD34+/B220+ myeloid progenitors, which could target the brain under developmental or neuroinflammatory conditions. Using experimental allergic encephalomyelitis (EAE) as a model of chronic neuroinflammation, we found that a discrete population of CD34+/B220+ cells expands in both blood and brain of diseased animals. In EAE mice, intravenous transfer experiments showed that macrophage-colony stimulating factor (M-CSF) -expanded CD34+ myeloid progenitors target the inflamed central nervous system (CNS) while keeping their immature phenotype. Based on these results, we then assessed whether CD34+/B220+ cells display in vitro differentiation potential toward microglia. For this purpose, CD34+/B220+ cells were sorted from M-CSF-stimulated bone marrow (BM) cultures and exposed to a glial cell conditioned medium. Under these experimental conditions, CD34+/B220+ cells were able to differentiate into microglial-like cells showing the morphological and phenotypic features of native microglia. Overall, our data suggest that under developmental or neuroinflammatory conditions, a subpopulation of microglial cells derive from CNS-invading CD34+/B220+ myeloid progenitors.