Antibody Content against Epstein-Barr Virus in Blood Extracellular Vesicles Correlates with Disease Activity and Brain Volume in Patients with Relapsing-Remitting Multiple Sclerosis.

We aimed to analyze whether EVs carry antibodies against EBV antigens and the possibility that they could serve as diagnostic and disease activity blood biomarkers in RRMS. This was a prospective and observational study including patients with RRMS with active and inactive disease and healthy controls. Blood EVs were isolated by precipitation. Titers of antibodies against nuclear (anti-EBNA1) and capsid (anti-VCA) EBV antigens in EVs and in plasma, as well as content of myelin antibodies in EVs were determined by ELISA. An exploratory analysis of correlations with clinical and radiological data was performed. Patients with RRMS had higher titers of anti-VCA inside EVs and free in plasma than healthy controls. Patients with active disease showed higher levels of anti-EBNA1 in EVs, but not in plasma, than patients with inactive disease. EV anti-VCA levels correlated with disease duration and with decreased brain volume structures-total brain, white matter, gray matter, cerebellum, hippocampus, -but not with T2/FLAIR lesion volume or EDSS, SDMT, or 9HPT. In addition, EV anti-VCA correlated with EV anti-MBP. The anti-VCA and anti-EBNA1 content in EVs could represent diagnostic and disease activity blood biomarkers, respectively, in RRMS.

Dual role of peripheral B cells in multiple sclerosis: emerging remote players in demyelination and novel diagnostic biomarkers.

Introduction: Multiple sclerosis is an inflammatory and demyelinating disease caused by a pathogenic immune response against the myelin sheath surfaces of oligodendrocytes. The demyelination has been classically associated with pathogenic B cells residing in the central nervous system that release autoreactive antibodies against myelin. The aim of the present study was to investigate whether extracellular vesicles (EVs) mediate delivery of myelin autoreactive antibodies from peripheral B cells against oligodendrocytes in multiple sclerosis (MS) and to analyze whether these EVs could mediate demyelination in vitro. We also studied the role of these EV-derived myelin antibodies as a diagnostic biomarker in MS. Methods: This is a prospective, observational, and single-center study that includes patients with MS and two control groups: patients with non-immune white matter lesions and healthy controls. We isolated B-cell-derived EVs from the blood and cerebrospinal fluid (CSF) and analyzed their myelin antibody content. We also studied whether antibody-loaded EVs reach oligodendrocytes in patients with MS and the effect on demyelination of B-cell-derived EVs containing antibodies in vitro. Results: This study enrolled 136 MS patients, 23 white matter lesions controls, and 39 healthy controls. We found autoreactive myelin antibodies in EVs that were released by peripheral B cells, but not by populations of B cells resident in CSF. We also identified a cut-off of 3.95 ng/mL of myelin basic protein autoantibodies in EVs from peripheral B cells, with 95.2% sensitivity and 88.2% specificity, which allows us to differentiate MS patients from healthy controls. EV-derived myelin antibodies were also detected in the oligodendrocytes of MS patients. Myelin antibody-loaded EVs from B cells induced myelin markers decrease of oligodendrocytes in vitro. Discussion: Peripheral reactive immune cells could contribute remotely to MS pathogenesis by delivering myelin antibodies to oligodendrocytes. EV-derived myelin antibodies could play a role as diagnostic biomarker in MS.

Brain and immune system-derived extracellular vesicles mediate regulation of complement system, extracellular matrix remodeling, brain repair and antigen tolerance in Multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is an immune-mediated central nervous system disease whose course is unpredictable. Finding biomarkers that help to better comprehend the disease's pathogenesis is crucial for supporting clinical decision-making. Blood extracellular vesicles (EVs) are membrane-bound particles secreted by all cell types that contain information on the disease's pathological processes. PURPOSE: To identify the immune and nervous system-derived EV profile from blood that could have a specific role as biomarker in MS and assess its possible correlation with disease state. RESULTS: Higher levels of T cell-derived EVs and smaller size of neuron-derived EVs were associated with clinical relapse. The smaller size of the oligodendrocyte-derived EVs was related with motor and cognitive impairment. The proteomic analysis identified mannose-binding lectin serine protease 1 and complement factor H from immune system cell-derived EVs as autoimmune disease-associated proteins. We observed hepatocyte growth factor-like protein in EVs from T cells and inter-alpha-trypsin inhibitor heavy chain 2 from neurons as white matter injury-related proteins. In patients with MS, a specific protein profile was found in the EVs, higher levels of alpha-1-microglobulin and fibrinogen ß chain, lower levels of C1S and gelsolin in the immune system-released vesicles, and Talin-1 overexpression in oligodendrocyte EVs. These specific MS-associated proteins, as well as myelin basic protein in oligodendrocyte EVs, correlated with disease activity in the patients with MS. CONCLUSION: Neural-derived and immune-derived EVs found in blood appear to be good specific biomarkers in MS for reflecting the disease state.

Therapeutic plasma exchange for myasthenia gravis, Guillain-Barre syndrome, and other immune-mediated neurological diseases, over a 40-year experience.

BACKGROUND: Therapeutic plasma exchange (TPE) was first used in neurology in the 1980s for myasthenia gravis (MG) and Guillain-Barré syndrome (GBS). Indications have since grown. Fear of complications with this treatment modality limit its use. RESEARCH DESIGN & METHODS: A study of patients undergoing TPE for neurological diseases (1981-2020) in a University Hospital in Madrid, Spain. Clinical indications, complications, procedure number, apheresis technique and replacement fluids were prospectively recorded and retrospectively analyzed. Historical trends were studied. RESULTS: 159 patients (48.69 ±18.15 years, 54.3% females) underwent TPE using central-venous catheter and replacement fluid albumin. We performed 1207 procedures over 189 cycles (6.4 ±3.8 procedures/cycle). Most patients underwent TPE for category I-II indications, mainly GBS and MG (77.7%). Complication rate was low (3.9% procedures), mostly hypotensive/vasovagal reactions (55.3%) and vascular access-related complications (38.3%). Most were mild-moderate (92.9%), permitting TPE completion, and somewhat more frequent during the first procedure (38.3%) and after periods of little TPE use. GBS patients were more prone to complications than MG patients (6.5% vs. 1.2%,p<0.001) mainly hypotensive/vasovagal reactions (3.7% vs. 1.0%,p=0.008). CONCLUSIONS: TPE is well-tolerated with low complication rate (<4% procedures), mainly hypotensive/vasovagal reactions. Patients with GBS seem more prone to them than MG patients. Acquaintance with this technique seems necessary.

Frequency and Characterization of Movement Disorders in Anti-IgLON5 Disease.

OBJECTIVE: Anti-IgLON5 disease is a recently described neurological disease that shares features of autoimmunity and neurodegeneration. Abnormal movements appear to be frequent and important but have not been characterized and are under-reported. Here we describe the frequency and types of movement disorders in a series of consecutive patients with this disease. METHODS: In this retrospective, observational study, the presence and phenomenology of movement disorders were assessed with a standardized clinical questionnaire. Available videos were centrally reviewed by three experts in movement disorders. RESULTS: Seventy two patients were included. In 41 (57%) the main reason for initial consultation was difficulty walking along with one or several concurrent movement disorders. At the time of anti-IgLON5 diagnosis, 63 (87%) patients had at least one movement disorder with a median of three per patient. The most frequent abnormal movements were gait and balance disturbances (52 patients, 72%), chorea (24, 33%), bradykinesia (20, 28%), dystonia (19, 26%), abnormal body postures or rigidity (18, 25%), and tremor (15, 21%). Other hyperkinetic movements (myoclonus, akathisia, myorhythmia, myokymia, or abdominal dyskinesias) occurred in 26 (36%) patients. The craniofacial region was one of the most frequently affected by multiple concurrent movement disorders (23 patients, 32%) including dystonia (13), myorhythmia (6), chorea (4) or myokymia (4). Considering any body region, the most frequent combination of multiple movement disorders consisted of gait instability or ataxia associated with craniofacial dyskinesias or generalized chorea observed in 31(43%) of patients. In addition to abnormal movements, 87% of patients had sleep alterations, 74% bulbar dysfunction, and 53% cognitive impairment. Fifty-five (76%) patients were treated with immunotherapy, resulting in important and sustained improvement of the movement disorders in only seven (13%) cases. CONCLUSIONS: Movement disorders are a frequent and leading cause of initial neurological consultation in patients with anti-IgLON5 disease. Although multiple types of abnormal movements can occur, the most prevalent are disorders of gait, generalized chorea, and dystonia and other dyskinesias that frequently affect craniofacial muscles. Overall, anti-IgLON5 disease should be considered in patients with multiple movement disorders, particularly if they occur in association with sleep alterations, bulbar dysfunction, or cognitive impairment.

Clinical manifestations of the anti-IgLON5 disease.

OBJECTIVE: To report the presentation, main syndromes, human leukocyte antigen (HLA) association, and immunoglobulin G (IgG) subclass in the anti-IgLON5 disease: a disorder with parasomnias, sleep apnea, and IgLON5 antibodies. METHODS: This was a retrospective clinical analysis of 22 patients. The IgG subclass was determined using reported techniques. RESULTS: Patients' median age was 64 years (range 46-83). Symptoms that led to initial consultation included sleep problems (8 patients; 36%), gait abnormalities (8; 36%), bulbar dysfunction (3; 14%), chorea (2; 9%), and cognitive decline (1; 5%). By the time of diagnosis of the disorder, 4 syndromes were identified: (1) a sleep disorder with parasomnia and sleep breathing difficulty in 8 (36%) patients; (2) a bulbar syndrome including dysphagia, sialorrhea, stridor, or acute respiratory insufficiency in 6 (27%); (3) a syndrome resembling progressive supranuclear palsy (PSP-like) in 5 (23%); and (4) cognitive decline with or without chorea in 3 (14%). All patients eventually developed parasomnia, sleep apnea, insomnia, or excessive daytime sleepiness. HLA-DRB1*10:01 and HLA-DQB1*05:01 were positive in 13/15 (87%) patients; the DRB1*10:01 allele was 36 times more prevalent than in the general population. Among 16 patients with paired serum and CSF samples, 14 had IgLON5 antibodies in both, and 2 only in serum (both had a PSP-like syndrome). Twenty of 21 patients had IgG1 and IgG4 antibodies; the latter predominated in 16. CONCLUSIONS: Patients with IgLON5 antibodies develop a characteristic sleep disorder preceded or accompanied by bulbar symptoms, gait abnormalities, oculomotor problems, and, less frequently, cognitive decline. IgG4 subclass antibodies predominate over IgG1; we confirm a strong association with the HLA-DRB1*10:01 allele.

Differential glatiramer acetate treatment persistence in treatment-naive patients compared to patients previously treated with interferon.

BACKGROUND: In the treatment of multiple sclerosis, a change of therapy is considered after treatment failure or adverse events. Although disease modifying drugs' (DMD) efficacy and side effects have been fully analysed in clinical trials, the effects of previous therapy use are less well studied. We aimed to study medication persistence with glatiramer acetate in treatment-naive patients and in patients previously treated with interferon. METHODS: A retrospective study of relapsing-remitting multiple sclerosis patients treated with glatiramer acetate in an MS Unit of a Spanish University Hospital (January 2004--September 2013). Treatment time on glatiramer acetate was studied. Reasons for treatment discontinuation were considered as follows: lack of efficacy, serious adverse event, injection-related side effect, pregnancy and lost to follow-up. Use of prior DMD was registered and analysed. Homogeneity of groups was analysed using Fisher's and Mann-Whitney's tests. The Kaplan Meier method and Cox regression model were used to estimate time to and risk of treatment discontinuation. RESULTS: In total, 155 relapsing-remitting multiple sclerosis patients were treated with glatiramer acetate: 100 treatment-naive patients and 55 treated previously with interferon. At the end of the study, 76 patients (49.0%) continued on glatiramer acetate (with an average treatment time (ATT) of 50.4 months, s.d.32.8) and 50 patients (32.3%) had switched therapy: 27 patients (17.4%) for inefficacy (ATT 29.2 months, s.d.17.5), 20 patients (12.9%) for injection site reactions (ATT 16.5 months, s.d.20.3) and 3 patients (1.9%) after serious adverse events (ATT 15.7 months, s.d.15.1). ATT in our cohort was 39 months (s.d.30.0), median follow-up 34 months. Six months after glatiramer acetate initiation, probability of persisting on GA was 91.4%, 82.5% after 12 months and 72.5% after 2 years. The risk of glatiramer acetate treatment discontinuation was 2.8 [1.7 - 4.8] times greater for treatment-naive patients than for patients treated previously with interferon and this was hardly modified after adjusting for sex and age. CONCLUSIONS: Glatiramer acetate was safe and useful with low rates of serious adverse events and low rates of break-through disease. Injection intolerance proved a major limitation to glatiramer acetate use. Patients who had been previously treated with interferons presented a lower probability of glatiramer acetate discontinuation than treatment-naive patients.

Gamma-aminobutyric acid GABRA4, GABRE, and GABRQ receptor polymorphisms and risk for essential tremor.

Some clinical and experimental data suggest a possible role of γ-aminobutyrate (GABA)-ergic mechanisms in the pathophysiology of essential tremor (ET). We studied the allelic and genotype frequencies of the single nucleotide polymorphisms, such as GABRA4-L26M (Leu26Met, rs2229940), GABRE-S102A (Ser26Ala, rs1139916), and GABRQ-I478F (Ile26Phe, rs3810651), in 200 patients with familial ET and 250 healthy controls using TaqMan genotyping. GABRA4-L26M, GABRE-S102A, and GABRQ-I478F genotype and allelic frequencies did not differ significantly between patients with ET and controls, and were unrelated to the age at onset of tremor or sex. The GABRQ-478F allele seemed to be related to improvement of tremor with ethanol use among men (odds ratio=2.32, 95% confidence interval=0.26-4.3, P=0.007, Pc=0.021). The results of this study suggest that the single nucleotide polymorphisms studied in the GABRA4, GABRE, and GABRQ genes are not related to the risk for familial ET.

Gamma-aminobutyric acid (GABA) receptor rho (GABRR) polymorphisms and risk for essential tremor.

Some clinical and experimental data suggest a possible role of gamma-aminobutyrate (GABA)-ergic mechanisms in the pathophysiology of essential tremor (ET), such as the improvement of ET with some GABAergic drugs and the development of an experimental model of ET in GABA A receptor alpha-1 knockout mice (postural and kinetic tremor and motor incoordination similar to human ET). To investigate the possible association between the GABA receptor subtype rho1, rho2, and rho3 (GABRR1, GABRR2, and GABRR3) genotypes and allelic variants of the single nucleotide polymorphisms GABRR1-M26V (Met26Val, rs12200969), GABRR1-H27R (His26Arg, rs1186902), GABRR2-T455M (Thr55Met, rs282129), and GABRR3-Y205X (Tyr205X, rs832032), and the risk for ET, we studied the frequency of the previously mentioned GABRR genotypes and allelic variants in 200 patients with ET and 250 healthy controls using TaqMan genotyping. The frequencies of the GABBR1 genotypes and allelic variants of the studied polymorphisms did not differ significantly between patients with ET and controls, and were unrelated with the age at onset of tremor, gender, localization of tremor, and response of tremor to ethanol. These data suggest that the single nucleotide polymorphisms studied in the GABBR genes are not related to the risk for ET.

Dopamine receptor D3 (DRD3) genotype and allelic variants and risk for essential tremor.

To investigate the possible association between dopamine receptor D3 genotype (DRD3) and allelic variants and the risk for developing essential tremor (ET). Leukocytary DNA from 201 patients with ET and 282 healthy controls was studied for the genotype DRD3 and the occurrence of DRD3 allelic variants by using allele-specific PCR amplification and MslI-RFLP's analyses. A meta-analysis of previous studies was performed. The frequencies of the DRD3Ser/Gly genotype and of the allelic variant DRDGly were significantly higher in patients with ET than in controls (P < 0.017 and <0.005, respectively), These findings were especially relevant in women (OR = 1.73, 95% CI: 1.15-2.59, P = 0.008), and in patients with earlier onset of the disease with (P = 0.014). The frequencies of the DRD3Ser/Gly and DRD3Gly/Gly genotypes and of the allelic variant DRD3Gly in patients were significantly higher in patients with voice tremor, but not with head, tongue, or chin tremor, than in controls. The meta-analysis indicated association of variant genotypes with ET risk (OR = 1.18, 95% CI 1.01-1.38). These results suggest that DRD3 genotype and the variant DRD3Gly allelic variant is associated with the risk for and age at onset of ET, and with the risk for voice tremor, in Caucasian Spanish people.

The nonsynonymous Thr105Ile polymorphism of the histamine N-methyltransferase is associated to the risk of developing essential tremor.

OBJECTIVE: We analyzed in patients with essential tremor (ET) the Thr105Ile polymorphism of the Histamine N-methyltransferase (HNMT) enzyme that is associated to Parkinson's disease (PD) risk. METHODS: Leukocytary DNA from 204 ET patients and a control group of 295 unrelated healthy individuals was studied for the nonsynonymous HNMT Thr105Ile polymorphism by using amplification-restriction analyses. RESULTS: Patients with ET showed a higher frequency of homozygous HNMT 105Thr genotypes leading to high metabolic activity (p < 0.015) with a statistically significant gene-dose effect, as compared to healthy subjects. These findings were independent of gender, and of tremor localization, but the association of the HNMT polymorphism is more prominent among patients with late-onset ET (p < 0.007). CONCLUSION: These results, combined with previous findings indicating alterations in the frequency for the HNMT Thr105Ile polymorphism in patients with PD, suggest that alterations of histamine homeostasis in the SNC are associated with the risk of movement disorders.

Alcohol dehydrogenase 2 genotype and allelic variants are not associated with the risk for essential tremor.

OBJECTIVE: To investigate the possible association between alcohol dehydrogenase 1B, beta-polypeptide (ADH2) genotype and allelic variants and the risk for developing essential tremor (ET). METHODS: Leukocytary DNA from 204 ET patients and 200 healthy controls was studied for the genotype ADH2 and the occurrence of ADH2 allelic variants using allele-specific polymerase chain reaction amplification and MslI-restriction fragment length polymorphism's analyses. RESULTS: The frequencies of the ADH2*1/ADH2*2 genotype and of the allelic variant ADH2*2 did not differ significantly in ET patients when compared with those of the controls. The mean age at onset of ET did not differ significantly between patients with genotypes ADH2*1/ADH2*2 and ADH2*1/ADH2*1. The frequencies of the genotype ADH2*1/ADH2*2 and of the allelic variant ADH2*2 in patients with voice, tongue, and chin tremors did not differ from those of the controls, whereas patients with voice tremor showed lower frequencies of mutated genotypes and ADH2*2 alleles. The frequencies of ADH2 genotypes and ADH2 alleles did not differ significantly between patients who did not drink ethanol and those who reported improvement, no improvement, or unknown response of tremor to ethanol. CONCLUSIONS: These results suggest that ADH2 genotype and allelic variants are not associated with the risk for ET in white Spanish people.

Changes at the CYP2C locus and disruption of CYP2C8/9 linkage disequilibrium in patients with essential tremor.

To identify low-penetrance genes related to sporadic essential tremor (ET) at the CYP2C locus, located in chromosome 10 q23.33. Leukocytary DNA from 200 ET patients and a control group of 300 unrelated healthy individuals with known CYP2C19 genotypes was studied for common CYP2C8 and CYP2C9 allelic variants by using amplification-restriction analyses. Patients with ET showed the following differences compared with healthy subjects: a 1.6-fold reduction in the frequency for CYP2C8*3 (p=0.006), a 1.35-fold reduction of CYP2C9*2 (p=0.05) and a 1.52-fold reduction in the frequency for CYP2C9*3 (p=0.07). The frequency for patients with ET carrying at least one defective allele was 1.33-fold reduced as compared with healthy subjects (p=0.002). In addition, a disruption of the CYP2C8*3/CYP2C9*2 linkage disequilibrium was observed in ET patients, with a 2.1-fold reduction in the percentage for carriers of the haplotype CYP2C8*3 plus CYP2C9*2 in ET patients (p=0.0001). These findings were independent of gender, age, age of onset, or clinical symptoms. These results suggest that alterations at the CYP2C gene locus are associated with the risk for ET.

Environmental risk factors for essential tremor.

We conducted a case-control study searching for a possible role of environment in the risk of essential tremor (ET). We interviewed 142 ET patients and 284 age- and sex-matched controls about a family history of ET, exposure to environmental products containing lead, mercury, manganese, solvents and beta-carbolines, and exposure to agricultural work, well water, pesticides, and cigarette smoking and alcohol drinking habits. In a univariate study, reported family history of ET and exposure to agricultural work, pesticides, smelting, frosted glass, paintings, wheat, corn, and barley were more frequent in the ET patient group. With a multivariate study, only reported family history of ET and exposure to agricultural work and frosted glass remained significant. Time of exposure to agricultural work, wheat and barley was significantly higher in ET patients. Age at onset of ET was significantly lower in patients with a family history of tremor and higher in patients exposed to iron-manganese alloys and alcohol. Time of exposure, but not total consumption of alcohol and cigarettes, was correlated with age at onset of ET. In conclusion, our study shows that the association between ET and reported family history of ET was robust, and that there were also associations between ET and exposure to some environmental factors (agricultural work and frosted glass).

CYP2C19 polymorphism and risk for essential tremor.

Many patients with essential tremor (ET) develop acute adverse effects to primidone. We investigated the association between CYP2C19 polymorphism (possibly related to primidone metabolism) and the risk for developing essential ET and acute adverse effects to primidone. Leukocytary DNA from 200 ET patients and 300 healthy controls was studied for the genotype CYP2C19 and the occurrence of CYP2C19 allelic variants by using allele-specific PCR amplification and Sma I and BamH I RFLP analyses. The frequencies of the genotype CYP2C19*1/CYP2C19*2 and of the allelic variant CYP2C19*2 were significantly higher in ET patients than in controls. The mean age at onset of ET did not differ significantly between patients with genotypes CYP2C19*1/CYP2C19*2andCYP2C19*1/CYP2C19*1. The frequencies of the genotype CYP2C19*1/CYP2C19*2 and the allelic variant CYP2C19*2 were similar in ET patients who developed acute adverse effects to primidone, in those who tolerated primidone and in controls; the frequencies were also similar in patients with head, voice, tongue and chin tremor compared with controls. These results suggest that heterozygosis CYP2C19*1/CYP2C19*2 is associated with the risk for ET, but not with the age at onset of ET, the presentation of acute side effects of primidone, or the existence of head, voice, tongue or chin tremor.

Drug-induced myoclonus: frequency, mechanisms and management.

Myoclonus is a sudden, abrupt, brief, 'shock-like' involuntary movement caused by muscular contractions ('positive myoclonus') or a sudden brief lapse of muscle contraction in active postural muscles ('negative myoclonus' or 'asterixis'). Various disorders can cause myoclonus including neurodegenerative and systemic metabolic disorders and CNS infections. In addition, myoclonus has been described as an adverse effect of some drugs. Level II evidence is available to indicate that levodopa, cyclic antidepressants and bismuth salts can cause myoclonus, while there is less robust evidence to associate numerous other drugs with the induction of myoclonus. The pharmacological mechanisms responsible for this adverse effect are not well established, although increased serotonergic transmission may be involved in the induction of myoclonus by several drugs. Drug-induced myoclonus usually resolves after withdrawal of the offending drug, but in some cases specific treatments are needed.