Influence of MMR, MGMT Promotor Methylation and Protein Expression on Overall and Progression-Free Survival in Primary Glioblastoma Patients Treated with Temozolomide.

Glioblastoma is the most common malignant brain tumor in adults. Standard treatment includes tumor resection, radio-chemotherapy and adjuvant chemotherapy with temozolomide (TMZ). TMZ methylates DNA, whereas O6-methylguanine DNA methyltransferase (MGMT) counteracts TMZ effects by removing the intended proteasomal degradation signal. Non-functional MGMT mediates the mismatch repair (MMR) system, leading to apoptosis after futile repair attempts. This study investigated the associations between MGMT promoter methylation, MGMT and MMR protein expression, and their effect on overall survival (OS) and progression-free survival (PFS) in patients with glioblastoma. MGMT promoter methylation was assessed in 42 treatment-naïve patients with glioblastoma WHO grade IV by pyrosequencing. MGMT and MMR protein expression was analyzed using immunohistochemistry. MGMT promoter methylation was present in 52%, whereas patients <70 years of age revealed a significantly longer OS using a log-rank test and a significance threshold of p ≤ 0.05. MGMT protein expression and methylation status showed no correlation. MMR protein expression was present in all patients independent of MGMT status and did not influence OS and PFS. Overall, MGMT promoter methylation implicates an improved OS in patients with glioblastoma aged <70 years. In the elderly, the extent of surgery has an impact on OS rather than the MGMT promoter methylation or protein expression.

Immunosenescence in Neurological Diseases-Is There Enough Evidence?

The aging of the immune system has recently attracted a lot of attention. Immune senescence describes changes that the immune system undergoes over time. The importance of immune senescence in neurological diseases is increasingly discussed. For this review, we considered studies that investigated cellular changes in the aging immune system and in neurological disease. Twenty-six studies were included in our analysis (for the following diseases: multiple sclerosis, stroke, Parkinson's disease, and dementia). The studies differed considerably in terms of the patient groups included and the cell types studied. Evidence for immunosenescence in neurological diseases is currently very limited. Prospective studies in well-defined patient groups with appropriate control groups, as well as comprehensive methodology and reporting, are essential prerequisites to generate clear insights into immunosenescence in neurological diseases.

Epileptic seizures of suspected autoimmune origin: a multicentre retrospective study.

OBJECTIVE: To analyse autoantibody status in a well-defined European multicentre cohort of patients with epilepsy of unknown aetiology and to validate the recently proposed Antibody Prevalence in Epilepsy (APE2) and Response to ImmunoTherapy in Epilepsy (RITE2) scores. METHODS: We retrospectively collected clinical and paraclinical data of 92 patients referred to the Neurology Units of Verona and Salzburg between January 2014 and July 2019 with new-onset epilepsy, status epilepticus or chronic epilepsy of unknown aetiology. Fixed and live cell-based assays, tissue-based assays, immunoblot, and live rat hippocampal cell cultures were performed in paired serum/cerebrospinal fluid (CSF) to detect antineuronal and antiglial antibodies. The APE2 and RITE2 scores were then calculated and compared with clinical and laboratory data. RESULTS: Autoantibodies were detected in 29/92 patients (31.5%), with multiple positivity observed in 6/29 cases. The APE2 score (median 5, range 1-15) significantly correlated with antibody positivity (p=0.014), especially for the presence of neuropsychiatric symptoms (p<0.01), movement disorders (p<0.01), dysautonomia (p=0.03), faciobrachial dyskinesias (p=0.03) and cancer history (p<0.01). Status epilepticus was significantly more frequent in antibody-negative patients (p<0.01). Among the items of the RITE2 score, early initiation of immunotherapy correlated with a good treatment response (p=0.001), whereas a cancer history was significantly more common among non-responders (p<0.01). Persistence of neuropsychiatric symptoms and seizures correlated with antiepileptic maintenance after at least 1 year. CONCLUSIONS: This is the first study that independently validates the APE2 and RITE2 scores and includes the largest cohort of patients whose paired serum and CSF samples have been tested for autoantibodies possibly associated with autoimmune epilepsy.

Increased serum neurofilament light chain concentration indicates poor outcome in Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome (GBS) is an autoimmune disease that results in demyelination and axonal damage. Five percent of patients die and 20% remain significantly disabled on recovery. Recovery is slow in most cases and eventual disability is difficult to predict, especially early in the disease. Blood or cerebrospinal fluid (CSF) biomarkers that could help identify patients at risk of poor outcome are required. We measured serum neurofilament light chain (sNfL) concentrations from blood taken upon admission and investigated a correlation between sNfL and clinical outcome. METHODS: Baseline sNfL levels in 27 GBS patients were compared with a control group of 22 patients with diagnoses not suggestive of any axonal damage. Clinical outcome parameters for GBS patients included (i) the Hughes Functional Score (HFS) at admission, nadir, and discharge; (ii) the number of days hospitalised; and (iii) whether intensive care was necessary. RESULTS: The median sNfL concentration in our GBS sample on admission was 85.5 pg/ml versus 9.1 pg/ml in controls. A twofold increase in sNfL concentration at baseline was associated with an HFS increase of 0.6 at nadir and reduced the likelihood of discharge with favourable outcome by a factor of almost three. Higher sNfL levels upon admission correlated well with hospitalisation time (rs = 0.69, p < 0.0001), during which transfer to intensive care occurred more frequently at an odds ratio of 2.4. Patients with baseline sNfL levels below 85.5 pg/ml had a 93% chance of being discharged with an unimpaired walking ability. CONCLUSIONS: sNfL levels measured at hospital admission correlated with clinical outcome in GBS patients. These results represent amounts of acute axonal damage and reflect mechanisms resulting in disability in GBS. Thus, sNfL may serve as a convenient blood-borne biomarker to personalise patient care by identifying those at higher risk of poor outcome.

Aggressive course in encephalitis with opsoclonus, ataxia, chorea, and seizures: the first pediatric case of γ-aminobutyric acid type B receptor autoimmunity.

IMPORTANCE: Autoantibodies to the γ-aminobutyric acid type B (GABAB) receptor have recently been identified as a cause of autoimmune encephalitis. Most patients with GABAB encephalitis have presented with limbic encephalitis. About half of the cases reported have been paraneoplastic in origin, with the majority of tumors representing small cell lung cancer. OBSERVATIONS: We describe a 3-year-old boy who presented with a mixed movement disorder (opsoclonus, ataxia, and chorea) as well as seizures refractory to treatment. His seizures required continuous pentobarbital sodium infusion to be controlled. Despite treatment with intravenous corticosteroids and immunoglobulins, the patient ultimately died of overwhelming sepsis. CONCLUSIONS AND RELEVANCE: To our knowledge, this report represents the first pediatric case of GABAB-associated encephalitis. Our patient presented with encephalopathy, refractory seizures, and a mixed movement disorder rather than limbic encephalitis. γ-Aminobutyric acid type B receptor autoimmunity deserves consideration in pediatric patients presenting with encephalitis. Immune-mediated encephalitis with autoantibodies directed against synaptic proteins has become an important component of the differential diagnosis of patients with encephalitis. Current estimates suggest that a substantial proportion of patients once suspected to have viral encephalitis in fact have an autoimmune etiology for their symptoms.1 Additional autoantigen targets continue to be identified, and the phenotypic spectrum associated with autoimmune encephalitis continues to expand. We describe a 3-year-old patient who presented with acute-onset confusion, opsoclonus, chorea, and intractable seizures. Neuroimaging disclosed involvement of the brainstem, basal ganglia, and hippocampi. γ-Aminobutyric acid type B (GABAB) receptor autoantibodies were identified in the serum and cerebrospinal fluid (CSF). Despite immunomodulating therapy, the patient died of overwhelming sepsis. To our knowledge, this is the first description of a pediatric patient with GABAB receptor autoantibodies. The presence of opsoclonus, ataxia, and chorea expands the clinical phenotype and indicates that GABAB receptor autoimmunity should be considered in cases of pediatric encephalitis

Prognostic value of Ki67 index in anaplastic oligodendroglial tumours--a translational study of the European Organization for Research and Treatment of Cancer Brain Tumor Group.

AIMS: To evaluate the prognostic value and clinical utility of Ki67 tumour cell proliferation index in anaplastic oligodendroglial tumours (AOT). METHODS AND RESULTS: We performed anti-Ki67 immunostaining (MIB-1 antibody) of formalin-fixed and paraffin-embedded tumour tissue specimens of 128 patients with newly diagnosed AOT that were treated in a randomized Phase III trial. Ki67 index was assessed by three independent observers and was correlated to clinical, histopathological and molecular features (including 1p/19q co-deletion, epithelial growth factor receptor gene (EGFR) amplification, isocitrate dehydrogenase (IDH1) mutations, O6-methylguanine-DNA methyltransferase gene (MGMT) promoter methylation, and patient survival times. Intra- and inter-observer agreement of Ki67 index assessment was excellent. Univariable analysis (n = 79) showed that patients with a low Ki67 index had significantly more favourable progression-free survival (PFS) (P-value = 0.004, log-rank test) and overall survival (OS) (P-value = 0.003, log-rank test) than patients with a high Ki67 index, respectively. On multivariable analysis (n = 43), Ki67 index showed no independent association with PFS or OS. CONCLUSIONS: In AOT the Ki67 index has a strong prognostic impact on univariable analysis, but no independent influence on multivariable analysis. However, further prospective studies including larger numbers of cases and standardized evaluation of Ki67 index in conjunction with other relevant prognostic parameters are needed to draw definitive conclusions.

Improved preoperative evaluation of cerebral cavernomas by high-field, high-resolution susceptibility-weighted magnetic resonance imaging at 3 Tesla: comparison with standard (1.5 T) magnetic resonance imaging and correlation with histopathological findings--preliminary results.

OBJECTIVES: To compare high-field, high-resolution, susceptibility-weighted magnetic resonance imaging (3 Tesla [T] HR-SW-MRI) and standard (1.5 Tesla [T]) MRI for the detection of cerebral cavernomas. To evaluate the ability of 3 T HR-SW-MRI to visualize intralesional structures compared with standard (1.5 T) MRI, in correlation with histopathologic findings. MATERIALS AND METHODS: Seventeen patients with cerebral cavernomas underwent both standard (1.5 T) MRI (T1-SE, T2-TSE, T2*-GRE) and 3 T HR-SW-MRI (TR/TE 43.3/9.1 millisecond; 512 x 384 x 48 matrix; FOV 250 mm; SI 72 mm) at our institution. All MR images were evaluated by 3 radiologists in consensus for detectability, size (1 cm), and conspicuity (good, acceptable, poor) of the lesions at both field strengths, and for the presence of hypointense intralesional tubular structures. In 7 patients, MR findings were correlated with histopathologic findings. RESULTS: Both 3 T HR-SW-MRI and standard (1.5 T) MRI detected 22 lesions in 17 patients; 3 T HR-SW-MRI detected an additional 7 lesions in 6 patients. On average, 3 T HR-SW-MRI detected 1.706 +/- 0.92 (median = 1) lesions per patient, whereas standard (1.5 T) MRI detected 1.235 +/- 0.664 lesions per patient (P = 0.016). Lesion conspicuity was good in all 3 T HR-SW-MR images and good in 68.2% and acceptable in 31.8% of standard (1.5 T) MR images (P = 0.016). In 22 lesions detected at both field strengths, 3 T HR-SW-MRI demonstrated intralesional tubular structures in 72.7% and standard (1.5 T) MRI demonstrated these structures in 31.8% (P = 0.001). Intralesional tubular structure correlated to conglomerates of cavernous vessel, as verified by histopathology. CONCLUSION: Compared with standard (1.5 T) MRI, 3 T HR-SW-MRI allows superior detection and characterization of cerebral cavernomas. Despite increased susceptibility effects, ie, signal loss at higher magnetic field strengths, the visualization of intralesional tubular structures is feasible. This may be helpful in the diagnosis, presurgical planning, and noninvasive follow-up after gamma-knife radiosurgery.

Epitope specificity of autoreactive T and B cells associated with experimental autoimmune encephalomyelitis and optic neuritis induced by oligodendrocyte-specific protein in SJL/J mice.

The encephalitogenic potential of oligodendrocyte-specific protein (OSP) in mice, its specific localization in the intralamellar tight junctions in CNS myelin, and the detection of autoreactivity against OSP in multiple sclerosis (MS) strongly suggest the relevance of autoreactivity against OSP in the pathogenesis of MS. In this study, we have characterized the autoimmune T and B cells that are associated with clinicopathological manifestations of OSP-induced MS-like disease in mice by using recombinant soluble mouse OSP (smOSP) and synthetic overlapping peptides spanning smOSP. SJL/J mice immunized with smOSP developed chronic relapsing clinical experimental autoimmune encephalomyelitis accompanied with intense perivascular and parenchymal inflammatory infiltrates, widespread demyelination, axonal loss, and remarkable optic neuritis. The smOSP-primed lymph node cells reacted predominantly against OSP55-80 and to a lesser extent also to OSP22-46 and OSP179-207. Unexpectedly, in vitro selection with smOSP resulted in pathogenic smOSP-specific CD4+ T cells that reacted equally well against OSP55-80, OSP22-46, OSP45-66, and OSP179-207. Fine analysis of the anti-OSP autoimmunity revealed that the disease is primarily associated with CD4+ T cells directed against the major (OSP55-80) and the minor (OSP179-207) encephalitogenic regions that were further delineated, both in vitro and in vivo, to OSP55-66 and OSP194-207, respectively. In contrast, the OSP-induced Abs were predominantly directed against OSP22-46; these Abs were mostly of IgG1 isotype, but high levels of IgG2a and IgG2b and significant levels of IgE were also observed. The reactivity of pathogenic T cells to two encephalitogenic regions, OSP55-80 and OSP179-207, and their diverse TCRVbeta gene repertoire may impose difficulties for epitope-directed or TCR-targeting approaches to immune-specific modulation of OSP-related pathogenesis.

The myelin-associated oligodendrocytic basic protein region MOBP15-36 encompasses the immunodominant major encephalitogenic epitope(s) for SJL/J mice and predicted epitope(s) for multiple sclerosis-associated HLA-DRB1*1501.

Autoimmune response to the myelin-associated oligodendrocytic basic protein (MOBP), a CNS-specific myelin constituent, was recently suggested to play a role in the pathogenesis of multiple sclerosis (MS). The pathogenic autoimmune response to MOBP and the associated pathology in the CNS have not yet been fully investigated. In this study, we have characterized the clinical manifestations, pathology, T cell epitope-specificity, and TCRs associated with experimental autoimmune encephalomyelitis (EAE) induced in SJL/J mice with recombinant mouse MOBP (long isoform, 170 aa). Analysis of encephalitogenic MOBP-reactive T cells for reactivity to overlapping MOBP peptides defined MOBP15-36 as their major immunodominant epitope. Accordingly, MOBP15-36 was demonstrated to be the major encephalitogenic MOBP epitope for SJL/J mice, inducing severe/chronic clinical EAE associated with intense perivascular and parenchymal infiltrations, widespread demyelination, axonal loss, and remarkable optic neuritis. Molecular modeling of the interaction of I-A(s) with MOBP15-36, together with analysis of the MOBP15-36-specific T cell response to truncated peptides, suggests MOBP20-28 as the core sequence for I-A(s)-restricted recognition of the encephalitogenic region MOBP15-36. Although highly focused in their epitope specificity, the encephalitogenic MOBP-reactive T cells displayed a widespread usage of TCR Vbeta genes. These results would therefore favor epitope-directed, rather than TCR-targeted, approaches to therapy of MOBP-associated pathogenic autoimmunity. Localization by molecular modeling of a potential HLA-DRB1*1501-associated MOBP epitope within the encephalitogenic MOBP15-36 sequence suggests the potential relevance of T cell reactivity against MOBP15-36 to MS. The reactivity to MOBP15-36 detected in MS shown here and in another study further emphasizes the potential significance of this epitope for MS.