Repeated assessment of key clinical walking measures can induce confounding practice effects.

Accurate functional outcome measures are critical for both clinical trials and routine patient assessments. Many functional outcomes improve with test repetition, a phenomenon that can confound the findings of longitudinal assessments. In this viewpoint, we tackle the poorly considered issue of practice effects in prevailing clinical walking tests based on current literature, while also presenting the original data from our own work, in which we investigated practice effects in the timed 25-foot walk (T25FW), timed-up and go (TUG), and 2-minute walk test (2MWT). In these tests, performed on 3 consecutive days in 10 patients with multiple sclerosis and 40 healthy controls, we observed significant practice effects in several established walking outcomes, including a 9.0% improvement in patients' TUG performance (p = 0.0146). Pre-training in these walking tests prior to baseline measurement may mitigate practice effects, thereby improving the accuracy and value of their repeated use in research and clinical settings.

High EDSS can predict risk for upper urinary tract damage in patients with multiple sclerosis.

BACKGROUND: Neurogenic lower urinary tract dysfunction (NLUTD) is very common in patients with multiple sclerosis (MS), and it might jeopardize renal function and thereby increase mortality. Although there are well-known urodynamic risk factors for upper urinary tract damage, no clinical prediction parameters are available. OBJECTIVE: We aimed to assess clinical parameters potentially predicting urodynamic risk factors for upper urinary tract damage. METHODS: A consecutive series of 141 patients with MS referred from neurologists for primary neuro-urological work-up including urodynamics were prospectively evaluated. Clinical parameters taken into account were age, sex, duration, and clinical course of MS and Expanded Disability Status Scale (EDSS). RESULTS: Multivariate modeling revealed EDSS as a clinical parameter significantly associated with urodynamic risk factors for upper urinary tract damage (odds ratio = 1.34, 95% confidence interval (CI) = 1.06-1.71, p = 0.02). Using receiver operator characteristic (ROC) curves, an EDSS of 5.0 as cutoff showed a sensitivity of 86%-87% and a specificity of 52% for at least one urodynamic risk factor for upper urinary tract damage. CONCLUSION: High EDSS is significantly associated with urodynamic risk factors for upper urinary tract damage and allows a risk-dependent stratification in daily neurological clinical practice to identify MS patients requiring further neuro-urological assessment and treatment.

Sudan black: a fast, easy and non-toxic method to assess myelin repair in demyelinating diseases.

AIMS: The search for novel drugs that enhance myelin repair in entities such as multiple sclerosis has top priority in neurological research, not least because remyelination can hinder further neurodegeneration in neuro-inflammatory conditions. Recently, several new compounds with the potential to boost remyelination have been identified using high-throughput in vitro screening methods. However, assessing their potential to enhance remyelination in vivo using plastic embedded semi-thin sections or electron microscopy, even though being the gold standard for assessing remyelination, is toxic, extremely time-consuming and expensive. METHODS: We screened available myelin dyes for a staining candidate which offers a faster and easier alternative to visualize remyelination in cryo-sections. RESULTS: We identified sudan black as a candidate with excellent myelin resolution and we show that our adapted sudan black staining can demonstrate myelin repair in rodent spinal cord cryosections as reliable as in semithin sections, but much faster, easier, less toxic and less expensive. Besides that, it can resolve the small myelinated axons in the corpus callosum. The staining can yet readily be combined with immunostainings which can be challenging in semithin sections. We validated the method in human spinal cord tissue as well as in experimental demyelination of the rat spinal cord by a lysolecithin time course experiment. As proof-of-principle, we demonstrate that sudan black is able to reliably detect the remyelination enhancing properties of benztropine. CONCLUSION: Our adapted sudan black staining can be used to rapidly and non-toxically screen for remyelinating therapies in demyelinating diseases.

Nogo-A antibodies enhance axonal repair and remyelination in neuro-inflammatory and demyelinating pathology.

Two hallmarks of chronic multiple sclerosis lesions are the absence of significant spontaneous remyelination and primary as well as secondary neurodegeneration. Both characteristics may be influenced by the presence of inhibitory factors preventing myelin and neuronal repair. We investigated the potential of antibodies against Nogo-A, a well-known inhibitory protein for neuronal growth and plasticity, to enhance neuronal regeneration and remyelination in two animal models of multiple sclerosis. We induced a targeted experimental autoimmune encephalomyelitis (EAE) lesion in the dorsal funiculus of the cervical spinal cord of adult rats resulting in a large drop of skilled forelimb motor functions. We subsequently observed improved recovery of forelimb function after anti-Nogo-A treatment. Anterograde tracing of the corticospinal tract revealed enhanced axonal sprouting and arborisation within the spinal cord gray matter preferentially targeting pre-motor and motor spinal cord laminae on lesion level and above in the anti-Nogo-A-treated animals. An important additional effect of Nogo-A-neutralization was enhanced remyelination observed after lysolecithin-induced demyelination of spinal tracts. Whereas remyelinated fiber numbers in the lesion site were increased several fold, no effect of Nogo-A-inhibition was observed on oligodendrocyte precursor proliferation, migration, or differentiation. Enhancing remyelination and promoting axonal regeneration and plasticity represent important unmet medical needs in multiple sclerosis. Anti-Nogo-A antibodies hold promise as a potential new therapy for multiple sclerosis, in particular during the chronic phase of the disease when neurodegeneration and remyelination failure determine disability evolution.

Bottom-up Visual Integration in the Medial Parietal Lobe.

Largely based on findings from functional neuroimaging studies, the medial parietal lobe is known to contribute to internally directed cognitive processes such as visual imagery or episodic memory. Here, we present 2 patients with behavioral impairments that extend this view. Both had chronic unilateral lesions of nearly the entire medial parietal lobe, but in opposite hemispheres. Routine neuropsychological examination conducted >4 years after the onset of brain damage showed little deficits of minor severity. In contrast, both patients reported persistent unusual visual impairment. A comprehensive series of tachistoscopic experiments with lateralized stimulus presentation and comparison with healthy participants revealed partial visual hemiagnosia for stimuli presented to their contralesional hemifield, applying inferential single-case statistics to evaluate deficits and dissociations. Double dissociations were found in 4 experiments during which participants had to integrate more than one visual element, either through comparison or formation of a global gestalt. Against the background of recent neuroimaging findings, we conclude that of all medial parietal structures, the precuneus is the most likely candidate for a crucial involvement in such bottom-up visual integration.

Homocysteine metabolism is associated with cerebrospinal fluid levels of soluble amyloid precursor protein and amyloid beta.

Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. The objective of this study was to investigate the relationships between cerebral amyloid production and both blood and cerebrospinal fluid (CSF) markers of the homocysteine metabolism. We assessed CSF concentrations of soluble APPα, soluble APPß, and amyloid ß1-42 (Aß1-42), as well as plasma levels of homocysteine (Hcys), total vitamin B12, and folate, and CSF concentrations of homocysteine (Hcys-CSF), 5-methyltetrahydrofolate (5-MTHF), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) in 59 subjects with normal cognition. Linear regression analyses were performed to assess associations between homocysteine metabolism parameters and amyloid production. The study was approved by the Ethical Committee of the University of Bonn. After controlling for age, gender, APOEe4 status, and albumin ratio (Qalb), higher Aß1-42 CSF levels were associated with high Hcys and low vitamin B12 plasma levels as well as with high Hcys, high SAH, and low 5-MTHF CSF levels. Higher CSF concentrations of sAPPα and sAPPß were associated with high SAH levels. The results suggest that disturbed homocysteine metabolism is related to increased CSF levels of sAPP forms and Aß1-42, and may contribute to the accumulation of amyloid pathology in the brain. Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. We found associations between CSF levels of soluble APP forms and Aß1-42, and markers of the homocysteine metabolism in both plasma and CSF in adults with normal cognition. Disturbed homocysteine metabolism may represent a target for preventive and early disease-modifying interventions in Alzheimer's disease.

Prolonged-release fampridine in multiple sclerosis: Improved ambulation effected by changes in walking pattern.

BACKGROUND: Prolonged-release fampridine (PR-fampridine, 4-aminopyridine) increases walking speed in the timed 25-foot walk test (T25FW) in some patients (timed-walk responders) with multiple sclerosis (MS). OBJECTIVE: To explore the effects of PR-fampridine on different aspects of walking function and to identify associated gait modifications in subjects with MS. METHODS: In this prospective, randomized, placebo-controlled, double-blind, phase II study (FAMPKIN; clinicaltrials.gov, NCT01576354), subjects received a 6-week course of oral placebo or PR-fampridine treatment (10 mg, twice daily) before crossing over. Using 3D-motion-analysis, kinematic and kinetic parameters were assessed during treadmill walking (primary endpoint). Clinical outcome measures included T25FW, 6-minute walk test (6MWT), and balance scales. Physical activity in everyday life was measured with an accelerometer device. RESULTS: Data from 55 patients were suitable for analysis. Seventeen subjects were timed-walk responders under PR-fampridine. For the total study population and for responders, a significant increase in walking speed (T25FW) and distance (6MWT) was observed. Gait pattern changes were found at the single-subject level and correlated with improvements in the T25FW and 6MWT. Physical activity was increased in responders. CONCLUSION: PR-fampridine improves walking speed, endurance, and everyday physical activity in a subset of subjects with MS and leads to individual modifications of the gait pattern.

Cognitive Impairment in Multiple Sclerosis: Clinical Manifestation, Neuroimaging Correlates, and Treatment.

Cognitive impairment is found in up to 70% of patients with multiple sclerosis (MS). Once thought of as a variant of subcortical dementia with a characteristic set of deficits, we now know that MS-related cognitive impairment can have many faces. This conceptual change in neuropsychology is embedded in a paradigm shift in the neuroscientific understanding of MS over the past 25 years: Partly based on modern neuroimaging techniques, the classical view of MS as an inflammatory demyelinating disease affecting the white matter of the central nervous system has been extended. In particular, many studies have shown that the MS pathology also includes neurodegeneration, and that gray matter structures such as the cerebral cortex can also show focal lesions, atrophy, or both. The authors present an updated summary of the clinical manifestation and neuroimaging correlates of cognitive impairment in MS, and discuss the relatively few treatment options available to date.

The relevance of cortical lesions in patients with multiple sclerosis.

BACKGROUND: Recent studies suggest that cortical lesions in multiple sclerosis (MS) substantially contribute to clinical disease severity. The present study aimed at investigating clinical, neuroanatomical, and cognitive correlates of these cortical lesions with a novel approach, i.e. by comparing two samples of relapsing-remitting multiple sclerosis (RRMS) patients, one group with and the other without cortical lesions. METHODS: High-resolution structural MRI was acquired from 42 RRMS patients and 43 controls (HC). The patient group was dichotomized based on the presence versus absence of DIR-hyperintense cortex-involving lesions, resulting in a cortical lesion group (CL, n = 32) and a non-cortical lesion group (nCL, n =10). Cognitive functioning was assessed in all participants with a comprehensive neuropsychological battery, covering mnestic, executive, and attentional functions. RESULTS: Highest densities of cortical lesions in the CL group were observed in the bilateral parahippocampal gyrus. Relative to HC, patients with cortical lesions - but not those without - showed significant global cortical thinning and mnestic deficits. The two patient groups did not differ from each other regarding demographic and basic disease characteristics such as EDSS scores. CONCLUSION: The appearance of cortical lesions in MS patients is associated with cortical thinning as well as mnestic deficits, which might be key characteristics of a 'cortically dominant' MS subtype.

Clinically isolated neurosarcoidosis: a recommended diagnostic path.

The involvement of the central nervous system in sarcoidosis can manifest with a variety of neurological symptoms, most of them nonspecific. We identified 13 patients with neurosarcoidosis diagnosed at our clinic. Six of 13 patients presented with clinically isolated neurosarcoidosis (CINS) without signs or symptoms of systemic disease. CINS patients were not different with respect to age, as well as imaging and spinal fluid findings, or disease course. However, we found spinal cord involvement in neurosarcoidosis patients much more common than previously described (in 8 out of 13 patients). Spinal cord affection was associated with older age at diagnosis and a less favorable response to therapy. Based on our findings, we propose a diagnostic path for neurosarcoidosis, including spinal magnetic resonance imaging (MRI) as a mandatory and early step during diagnostic workup.

JC virus granule cell neuronopathy and GCN-IRIS under natalizumab treatment.

Progressive multifocal leukoencephalopathy is the most common clinical presentation of JC virus (JCV)-associated central nervous system (CNS) disease and has emerged as a major safety concern in multiple sclerosis patients treated with the monoclonal antibody natalizumab. Here we report clinical, radiological, and histological findings of a case of cerebellar granule cell neuronopathy (GCN), a JCV-associated CNS disease, so far unreported amongst patients treated with natalizumab. GCN should be considered as a JCV CNS manifestation in patients with newly developed, progressive cerebellar signs under natalizumab treatment, especially in cases where cerebellar atrophy can be visualized by magnetic resonance imaging.

Chronic homocysteine exposure causes changes in the intrinsic electrophysiological properties of cultured hippocampal neurons.

Homocystinuria is an inborn error of metabolism characterized by plasma homocysteine levels up to 500 µM, premature vascular events and mental retardation. Mild elevations of homocysteine plasma levels up to 25 µM, which are common in the general population, are associated with vascular disease, cognitive impairment and neurodegeneration. Several mechanisms of homocysteine neurotoxicity have been investigated. However, information on putative effects of hyperhomocysteinemia on the electrophysiology of neurons is limited. To screen for such effects, we examined primary cultures of mouse hippocampal neurons with the whole-cell patch-clamp technique. Homocysteine was applied intracellularly (100 µM), or cell cultures were incubated with 100 µM homocysteine for 24 h. Membrane voltage was measured in current-clamp mode, and action potential firing was induced with short and prolonged current injections. Single action potentials induced by short current injections (5 ms) were not altered by acute application or incubation of homocysteine. When we elicited trains of action potentials with prolonged current injections (200 ms), a broadening of action potentials during repetitive firing was observed in control neurons. This spike broadening was unaltered by acute application of homocysteine. However, it was significantly diminished when incubation with homocysteine was extended to 24 h prior to recording. Furthermore, the number of action potentials elicited by low current injections was reduced after long-term incubation with homocysteine, but not by the acute application. After 24 h of homocysteine incubation, the input resistance was reduced which might have contributed to the observed alterations in membrane excitability. We conclude that homocysteine exposure causes changes in the intrinsic electrophysiological properties of cultured hippocampal neurons as a mechanism of neurological symptoms of hyperhomocysteinemia.

Homocysteine plasma levels in patients treated with antiepileptic drugs depend on folate and vitamin B12 serum levels, but not on genetic variants of homocysteine metabolism.

BACKGROUND: Antiepileptic drugs (AEDs) are commonly used in the treatment of epilepsy, psychiatric diseases and pain disorders. Several of these drugs influence blood levels of folate and vitamin B12 and, consequently, homocysteine. This may be relevant for AED effects and side effects. However, not only folate and vitamin B12, but also genetic variants modify homocysteine metabolism. Here, we aimed to determine whether there is a pharmacogenetic interaction between folate, vitamin B12 and genetic variants and homocysteine plasma level in AED-treated patients. METHODS: In this mono-center study, we measured homocysteine, folate and vitamin B12 plasma levels in a population of 498 AED-treated adult patients with epilepsy. In addition, we analyzed the genotypes of seven common genetic variants of homocysteine metabolism: methylenetetrahydrofolate reductase (MTHFR) c.677C>T and c.1298A>C, methionine synthase (MTR) c.2756A>G, dihydrofolate reductase (DHFR) c.594+59del19bp, cystathionine ß-synthase (CBS) c.844_855ins68, transcobalamin 2 (TC2) c.776C>G and methionine synthase reductase (MTRR) c.66G>A. RESULTS: On multivariate logistic regression, folate and vitamin B12 levels, but none of the genetic variants, were predictive for homocysteine levels. CONCLUSIONS: These data suggest that, in AED-treated patients, folate and vitamin B12 play important roles in the development of hyperhomocysteinemia, whereas genetic variants of homocysteine metabolism do not and thus do not contribute to the risk of developing hyperhomocysteinemia during AED treatment.

Methylation metabolism in sepsis and systemic inflammatory response syndrome.

We have recently shown that sepsis leads to alterations of methylation metabolism in a rodent model. In this study we analyzed methylation metabolism and DNA methylation in human sepsis. Patients treated in one of the Intensive Care Units (ICU) at the University Hospital Bonn diagnosed with sepsis or systemic inflammatory response syndrome (n = 12) and patients who were treated due to traumatic brain injury, or stroke without clinical or laboratory signs of sepsis or major inflammation (n = 22) were included. Blood samples were taken two times a week, until ICU treatment was discontinued. Deproteinized plasma was used for simultaneous determination of the ubiquitous methyl-group donor S-adenosylmethionine (SAM) and its demethylated residue, S-adenosylhomocysteine (SAH), by using stable isotope dilution tandem mass spectrometry. Homocysteine (Hcys), hydrolyzation product of SAH, was determined by fully automated particle-enhanced immunonephelometry, and global DNA-methylation was measured by liquid chromatography tandem mass spectrometry. SAM (p < 0.001) and SAH (p < 0.001) plasma levels were higher in septic patients suggesting an increased cellular release of SAM and SAH in septic patients. The SAM/SAH ratio was decreased in septic patients (p = 0.002). There were no differences in homocysteine plasma levels (p = 0.32) or global leukocyte DNA methylation between septic and non-septic patients (p = 0.21) suggesting that sepsis-induced changes in methylation metabolism do not affect homocysteine plasma levels or the availability of SAM-derived methyl groups for DNA methylation. Sepsis and systemic inflammatory response syndrome induce considerable changes of methylation metabolism without apparent functional consequences on homocysteine plasma levels or DNA methylation. Further studies may explore the clinical relevance of the observed changes.

Swiss analysis of multiple sclerosis: a multicenter, non-interventional, retrospective cohort study of disease-modifying therapies.

BACKGROUND: There is a scarcity of reports comparing efficacy and tolerability of the multiple sclerosis (MS) disease-modifying therapies [DMTs; intramuscular interferon-ß1a (IM IFNß-1a), subcutaneous (SC) IFNß-1a, SC IFNß-1b, SC glatiramer acetate (GA)] in a real-world setting. METHODS: This multicenter, non-interventional, retrospective cohort study analyzed data from 546 patients with clinically isolated or relapsing-remitting MS constantly treated with one DMT for 2 years. Annualized relapse rate (ARR), Expanded Disability Status Scale (EDSS) scores, and DMT tolerability were assessed. RESULTS: Demographic data were comparable across DMTs. There were no significant differences between DMT groups in ARR during study year 1 (p = 0.277) or study year 2 (p = 0.670), or in EDSS change between years 1 and 2 (p = 0.624). Adverse events were frequent (39-56%) in all groups. Flu-like symptoms were less frequent with GA treatment (2.3% vs. IM IFNß-1a, 46.7%; SC IFNß-1a, 39.8%; SC IFNß-1b, 25.8%; p < 0.05). Injection site reactions were less often reported with IM IFNß-1a (10.5% vs. SC IFNß-1a, 33.9%; SC IFNß-1b, 38.3%; GA, 26.1%; p < 0.05). CONCLUSIONS: All DMTs showed comparable effects on MS relapse rate and EDSS change, with IM IFNß-1a and GA being more tolerable with respect to injection site reactions and flu-like symptoms, respectively.

Effect modification by population dietary folate on the association between MTHFR genotype, homocysteine, and stroke risk: a meta-analysis of genetic studies and randomised trials.

BACKGROUND: The MTHFR 677C→T polymorphism has been associated with raised homocysteine concentration and increased risk of stroke. A previous overview showed that the effects were greatest in regions with low dietary folate consumption, but differentiation between the effect of folate and small-study bias was difficult. A meta-analysis of randomised trials of homocysteine-lowering interventions showed no reduction in coronary heart disease events or stroke, but the trials were generally set in populations with high folate consumption. We aimed to reduce the effect of small-study bias and investigate whether folate status modifies the association between MTHFR 677C→T and stroke in a genetic analysis and meta-analysis of randomised controlled trials. METHODS: We established a collaboration of genetic studies consisting of 237 datasets including 59,995 individuals with data for homocysteine and 20,885 stroke events. We compared the genetic findings with a meta-analysis of 13 randomised trials of homocysteine-lowering treatments and stroke risk (45,549 individuals, 2314 stroke events, 269 transient ischaemic attacks). FINDINGS: The effect of the MTHFR 677C→T variant on homocysteine concentration was larger in low folate regions (Asia; difference between individuals with TT versus CC genotype, 3·12 µmol/L, 95% CI 2·23 to 4·01) than in areas with folate fortification (America, Australia, and New Zealand, high; 0·13 µmol/L, -0·85 to 1·11). The odds ratio (OR) for stroke was also higher in Asia (1·68, 95% CI 1·44 to 1·97) than in America, Australia, and New Zealand, high (1·03, 0·84 to 1·25). Most randomised trials took place in regions with high or increasing population folate concentrations. The summary relative risk (RR) of stroke in trials of homocysteine-lowering interventions (0·94, 95% CI 0·85 to 1·04) was similar to that predicted for the same extent of homocysteine reduction in large genetic studies in populations with similar folate status (predicted RR 1·00, 95% CI 0·90 to 1·11). Although the predicted effect of homocysteine reduction from large genetic studies in low folate regions (Asia) was larger (RR 0·78, 95% CI 0·68 to 0·90), no trial has evaluated the effect of lowering of homocysteine on stroke risk exclusively in a low folate region. INTERPRETATION: In regions with increasing levels or established policies of population folate supplementation, evidence from genetic studies and randomised trials is concordant in suggesting an absence of benefit from lowering of homocysteine for prevention of stroke. Further large-scale genetic studies of the association between MTHFR 677C→T and stroke in low folate settings are needed to distinguish effect modification by folate from small-study bias. If future randomised trials of homocysteine-lowering interventions for stroke prevention are undertaken, they should take place in regions with low folate consumption. FUNDING: Full funding sources listed at end of paper (see Acknowledgments).

Antiepileptic drugs interact with folate and vitamin B12 serum levels.

OBJECTIVE: Antiepileptic drugs (AEDs) are important for the treatment of epilepsy, psychiatric diseases, and pain syndromes. Small studies have suggested that AED treatment reduces serum levels of folate and vitamin B12. METHODS: This prospective monocenter study aimed at testing the hypothesis that AED treatment is associated with folate and vitamin B12 serum levels in a large population. A total of 2730 AED-treated and 170 untreated patients with epilepsy and 200 healthy individuals were enrolled. RESULTS: Treatment with carbamazepine, gabapentin, oxcarbazepine, phenytoin, primidone, or valproate was associated with lower mean serum folate levels or with a higher frequency of folate levels below the reference range in comparison with the entire group of patients, untreated patients, or controls. Treatment with phenobarbital, pregabalin, primidone, or topiramate was associated with lower vitamin B12 levels compared with the entire group of patients. Vitamin B12 serum levels were higher in patients treated with valproate compared with the entire group of patients, untreated patients, and healthy controls. Folate or vitamin B12 levels below the reference range were associated with higher mean corpuscular volume (MCV) and higher homocysteine plasma levels. Vitamin substitution for 3 months in 141 patients with folate or vitamin B12 levels below the reference range yielded normal vitamin levels in 95% of the supplemented patients and reduced MCV and homocysteine plasma levels. INTERPRETATION: Treatment with most of the commonly used AEDs is associated with reduced folate or vitamin B12 serum levels and is a risk factor for hyperhomocysteinemia. Oral substitution is effective to restore vitamin, MCV, and homocysteine levels.

Determinants of the essential one-carbon metabolism metabolites, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine and folate, in cerebrospinal fluid.

BACKGROUND: Disturbances in the levels of one-carbon (1C) metabolism metabolites have been associated with a wide variety of neuropsychiatric diseases. Cerebrospinal fluid (CSF) levels of homocysteine (Hcy) and the other 1C metabolites, nor their interrelatedness and putative determinants, have been studied extensively in a healthy population. METHODS: Plasma and CSF samples from 100 individuals free from neuropsychiatric diseases were analyzed (55 male, 45 female; age 50±17 years). In blood, we measured plasma Hcy, serum folate and serum vitamin B12. In CSF, we measured total Hcy, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH) and 5-methyltetrahydrofolate (5-methylTHF). Highly selective analytical methods like liquid chromatography combined with either mass spectrometry or fluorescence detection were used. RESULTS: CSF Hcy was inversely correlated with CSF 5-methylTHF and positively with plasma Hcy, independent of serum folate status. CSF SAH correlated with age, lower CSF 5-methylTHF and higher CSF Hcy. CSF 5-methylTHF showed independent negative correlations with age and positive correlations with serum folate. CSF SAM did not correlate with any of the 1C metabolites. CONCLUSIONS: Aging is characterized by a reduction in CSF 5-methylTHF levels and increased CSF levels of the potentially neurotoxic transmethylation inhibitor SAH. CSF 5-methylTHF, which is itself determined in part by systemic folate status, is a powerful independent determinant of CSF levels of Hcy and SAH.

Central role of JC virus-specific CD4+ lymphocytes in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome.

Progressive multi-focal leucoencephalopathy and progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome are caused by infection of the central nervous system with the JC polyoma virus. Both are complications of monoclonal antibody therapy in multiple sclerosis and other autoimmune diseases. Progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome can obscure the diagnosis of progressive multi-focal leucoencephalopathy and lead to severe clinical disability and possibly death. Different from progressive multi-focal leucoencephalopathy, in which demyelination results from oligodendrocyte lysis by JC virus in the absence of an immune response, tissue destruction in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome is caused by a vigorous immune response within the brain. The cells and mediators that are involved in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome are as yet poorly understood. We examined two patients with multiple sclerosis, who developed progressive multi-focal leucoencephalopathy and later progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome under natalizumab therapy. Due to initially negative JC viral deoxyribonucleic acid testing in the cerebrospinal fluid, a diagnostic brain biopsy was performed in one patient. Histopathology revealed brain inflammation characterized by a prominent T cell infiltrate (CD4(+)> CD8(+) T cells), but also B/plasma cells and monocytes. Despite very low JC viral load, both patients showed high intrathecal anti-JC virus antibodies. Brain-infiltrating CD4(+) T cells were studied regarding antigen specificity and function. CD4(+) T cells were highly specific for peptides from several JC virus proteins, particularly the major capsid protein VP1. T cell phenotyping revealed CD4(+) Th1 and bifunctional Th1-2 cells. The latter secrete large amounts of interferon-γ and interleukin-4 explaining the strong brain inflammation, presence of plasma cells and secretion of intrathecal anti-VP1 antibodies. The functional phenotype of brain-infiltrating JC virus-specific CD4(+) T cells was confirmed and extended by examining brain-derived JC virus-specific CD4(+) T cell clones. Our data provide novel insight into the pathogenesis of progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome and indicate that JC virus-specific CD4(+) T cells play an important role in both eliminating JC virus from the brain, but also in causing the massive inflammation with often fatal outcome.

Alterations of homocysteine serum levels during alcohol withdrawal are influenced by folate and riboflavin: results from the German Investigation on Neurobiology in Alcoholism (GINA).

AIMS: Various studies have shown that plasma homocysteine (HCY) serum levels are elevated in actively drinking alcohol-dependent patients a during alcohol withdrawal, while rapidly declining during abstinence. Hyperhomocysteinemia has been associated not only with blood alcohol concentration (BAC), but also with deficiency of different B-vitamins, particularly folate, pyridoxine and cobalamin. METHODS: Our study included 168 inpatients (110 men, 58 women) after admission for detoxification treatment. BAC, folate, cobalamin, pyridoxine, thiamine and riboflavin were obtained on admission (Day 1). HCY was assessed on Days 1, 7 and 11. RESULTS: HCY levels significantly declined during withdrawal. General linear models and linear regression analysis showed an influence of BAC, folate and riboflavin on the HCY levels on admission as well as on HCY changes occurring during alcohol withdrawal. No significant influence was found for thiamine, cobalamin and pyridoxine. CONCLUSIONS: These findings show that not only BAC and plasma folate levels, but also plasma levels of riboflavin influence HCY plasma levels in alcohol-dependent patients.