[Show abstract][Hide abstract] ABSTRACT: Recent evidence has implicated perituberal, MRI-normal brain tissue as a possible source of seizures in tuberous sclerosis complex (TSC). Data on aberrant structural features in this area that may predispose to the initiation or progression of seizures are very limited. We used immunohistochemistry and confocal microscopy to compare epileptogenic, perituberal, MRI-normal tissue with cortical tubers.
In every sample of epileptogenic, perituberal tissue, we found many abnormal cell types, including giant cells and cytomegalic neurons. The majority of giant cells were surrounded by morphologically abnormal astrocytes with long processes typical of interlaminar astrocytes. Perituberal giant cells and astrocytes together formed characteristic "microtubers". A parallel analysis of tubers showed that many contained astrocytes with features of both protoplasmic and gliotic cells.
Microtubers represent a novel pathognomonic finding in TSC and may represent an elementary unit of cortical tubers. Microtubers and cytomegalic neurons in perituberal parenchyma may serve as the source of seizures in TSC and provide potential targets for therapeutic and surgical interventions in TSC.
[Show abstract][Hide abstract] ABSTRACT: Extracellular RNAs (exRNAs) have been identified in all tested biofluids and have been associated with a variety of extracellular vesicles, ribonucleoprotein complexes and lipoprotein complexes. Much of the interest in exRNAs lies in the fact that they may serve as signalling molecules between cells, their potential to serve as biomarkers for prediction and diagnosis of disease and the possibility that exRNAs or the extracellular particles that carry them might be used for therapeutic purposes. Among the most significant bottlenecks to progress in this field is the lack of robust and standardized methods for collection and processing of biofluids, separation of different types of exRNA-containing particles and isolation and analysis of exRNAs. The Sample and Assay Standards Working Group of the Extracellular RNA Communication Consortium is a group of laboratories funded by the U.S. National Institutes of Health to develop such methods. In our first joint endeavour, we held a series of conference calls and in-person meetings to survey the methods used among our members, placed them in the context of the current literature and used our findings to identify areas in which the identification of robust methodologies would promote rapid advancements in the exRNA field.
[Show abstract][Hide abstract] ABSTRACT: Ten ongoing studies designed to test the possibility that extracellular RNAs may serve as biomarkers in human disease are described. These studies, funded by the NIH Common Fund Extracellular RNA Communication Program, examine diverse extracellular body fluids, including plasma, serum, urine and cerebrospinal fluid. The disorders studied include hepatic and gastric cancer, cardiovascular disease, chronic kidney disease, neurodegenerative disease, brain tumours, intracranial haemorrhage, multiple sclerosis and placental disorders. Progress to date and the plans for future studies are outlined.
[Show abstract][Hide abstract] ABSTRACT: Rationale: Platelets are known to participate in vascular pathologies; however, their role in neuroinflammatory diseases such as multiples sclerosis (MS) is unknown. Autoimmune CD4 T cells have been the main focus of studies of MS, although the factors that regulate T cell differentiation towards pathogenic Th1/Th17 phenotypes are not completely understood.
Objectives: We investigated the role of platelets in the modulation of CD4 T cell functions in MS patients and in mice with experimental autoimmune encephalitis (EAE), an animal model for MS.
Methods and Results: We found that early in MS and EAE platelets degranulated and produced a number of soluble factors serotonin (5HT), PF4 and PAF, which specifically stimulated differentiation of T cells towards pathogenic Th1, Th17 and IFN-γ/IL-17-producing CD4 T cells. At the later stages of MS and EAE platelets became exhausted in their ability to produce proinflammatory factors and stimulate CD4 T cells, but substantially increased their ability to form aggregates with CD4 T cells. Formation of platelet- CD4 T cell aggregates involved interaction of CD62P on activated platelets with adhesion molecule CD166 on activated CD4 T cells, contributing to downmodulation of CD4 T cell activation, proliferation and production of IFN-γ. Blocking of formation of platelet-CD4 T cell aggregates during progression of EAE substantially enhanced proliferation of CD4 T cell in the CNS and the periphery leading to exacerbation of the disease.
Conclusion: Our study indicates differential roles for platelets in the regulation of functions of pathogenic CD4 T cells during initiation and progression of CNS autoimmune inflammation.
Circulation Research 08/2015; DOI:10.1161/CIRCRESAHA.115.306847 · 11.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Multiple sclerosis (MS) commonly affects occupational function. We investigated the link between brain MRI and employment status. Patients with MS (n = 100) completed a Work Productivity and Activity Impairment (WPAI) (general health version) survey measuring employment status, absenteeism, presenteeism, and overall work and daily activity impairment. Patients "working for pay" were considered employed; "temporarily not working but looking for work," "not working or looking for work due to age," and "not working or looking for work due to disability" were considered not employed. Brain MRI T1 hypointense (T1LV) and T2 hyperintense (T2LV) lesion volumes were quantified. To assess lesional destructive capability, we calculated each subject's ratio of T1LV to T2LV (T1/T2). Normalized brain parenchymal volume (BPV) assessed brain atrophy. The mean (SD) age was 45.5 (9.7) years; disease duration was 12.1 (8.1) years; 75 % were women, 76 % were relapsing-remitting, and 76 % were employed. T1LV, T1/T2, Expanded Disability Status Scale (EDSS) scores, and activity impairment were lower and BPV was higher in the employed vs. not employed group (Wilcoxon tests, p < 0.05). Age, disease duration, MS clinical subtype, and T2LV did not differ between groups (p > 0.05). In multivariable logistic regression modeling, adjusting for age, sex, and disease duration, higher T1LV predicted a lower chance of employment (p < 0.05). Pearson correlations showed that EDSS was associated with activity impairment (p < 0.05). Disease duration, age, and MRI measures were not correlated with activity impairment or other WPAI outcomes (p > 0.05). We report a link between brain atrophy and lesions, particularly lesions with destructive potential, to MS employment status.
Journal of Neurology 07/2015; DOI:10.1007/s00415-015-7853-x · 3.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Magnetic resonance imaging (MRI) of the brain provides important outcome measures in the longitudinal evaluation of disease activity and progression in MS subjects. Two common measures derived from brain MRI scans are the brain parenchymal fraction (BPF) and T2 hyperintense lesion volume (T2LV), and these measures are routinely assessed longitudinally in clinical trials and observational studies. When measuring each outcome longitudinally, observed changes may be potentially confounded by variability in MRI acquisition parameters between scans. In order to accurately model longitudinal change, the acquisition parameters should thus be considered in statistical models. In this paper, several models for including protocol as well as individual MRI acquisition parameters in linear mixed models were compared using a large dataset of 3453 longitudinal MRI scans from 1341 subjects enrolled in the CLIMB study, and model fit indices were compared across the models. The model that best explained the variance in BPF data was a random intercept and random slope with protocol specific residual variance along with the following fixed-effects: baseline age, baseline disease duration, protocol and study time. The model that best explained the variance in T2LV was a random intercept and random slope along with the following fixed-effects: baseline age, baseline disease duration, protocol and study time. In light of these findings, future studies pertaining to BPF and T2LV outcomes should carefully account for the protocol factors within longitudinal models to ensure that the disease trajectory of MS subjects can be assessed more accurately.
[Show abstract][Hide abstract] ABSTRACT: There are no established variables that predict the success of curative resective epilepsy surgery in children with tuberous sclerosis complex (TSC).
We performed a multicenter observational study to identify preoperative factors associated with seizure outcome in children with TSC undergoing resective epilepsy surgery.
A retrospective chart review was performed in eligible children at New York Medical Center, Miami Children's Hospital, Cleveland Clinic Foundation, BC Children's Hospital, Hospital for Sick Children, and Sainte-Justine Hospital between January 2005 and December 2013. A time-to-event analysis was performed. The "event" was defined as seizures after resective epilepsy surgery.
Seventy-four patients (41 male) were included. The median age of the patients at the time of surgery was 120 months (range, 3-216 months). The median time to seizure recurrence was 24.0 ± 12.7 months. Engel Class I outcome was achieved in 48 (65%) and 37 (50%) patients at 1- and 2-year follow-up, respectively. On univariate analyses, younger age at seizure onset (hazard ratio [HR]: 2.03, 95% confidence interval [CI]: 1.03-4.00, P = .04), larger size of predominant tuber (HR: 1.03, 95% CI: 0.99-1.06, P = .12), and resection larger than a tuberectomy (HR: 1.86, 95% CI: 0.92-3.74, P = .084) were associated with a longer duration of seizure freedom. In multivariate analyses, resection larger than a tuberectomy (HR: 2.90, 95% CI: 1.17-7.18, P = .022) was independently associated with a longer duration of seizure freedom.
In this large consecutive cohort of children with TSC and medically intractable epilepsy, a greater extent of resection (more than just the tuber) is associated with a greater probability of seizure freedom. This suggests that the epileptogenic zone may include the cortex surrounding the presumed offending tuber.
EEG, electroencephalographyEZ, epileptic zoneIPD, individual participant dataTSC, tuberous sclerosis complex.
[Show abstract][Hide abstract] ABSTRACT: T helper cells producing IL-17A and IL-17F cytokines (Th17 cells) are considered the source of autoimmunity in rheumatoid arthritis (RA). In this study we characterized specific pathogenic features of Th17 cells in RA.Using nano-string technology we analyzed transcription of 419 genes in the peripheral blood CCR6(+)CXCR3(-) CD4(+) cells of 14 RA patients and 6 healthy controls and identified 109 genes discriminating Th17 cells of RA patients from the controls. Th17 cells of RA patients had aggressive pathogenic profile and in addition to signature cytokines IL-17, IL-23, and IL-21, and transcriptional regulators RORγt and JAK2, they produced high levels of IL-23R, CCL20, GM-CSF and transcription factor Tbet required for synovial homing. We showed that Th17 cells are enriched with Helios producing, Foxp3 and IL2RA deficient cells indicating altered regulatory profile. The follicular T-helper (Tfh) cells presented functional profile of adaptor molecules, transcriptional regulator Bcl-6 and B-cell activating cytokines IL-21, IL-31 and LIF. We observed that anti-TNF treatment had limited effect on the transcription signature of Th17 cells. Patients in remission retained the machinery of receptors (IL-23R and IL-1R1), pro-inflammatory cytokines (IL-17F, IL-23, IL-21 and TNF) and adaptor molecules (CXCR5 and CTLA-4), essential for efficient trans-differentiation and accumulation of Th17 cells.This study convincingly shows that the peripheral blood CCR6(+)CXCR3(-) CD4(+) cells of RA patients harbor pathogenic subsets of Th17 and Tfh cells, which may trans-differentiate from Tregs and contribute to perpetuation of the disease.
Molecular Medicine 06/2015; DOI:10.2119/molmed.2015.00057 · 4.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 4-year-old girl with a history of thoracic meningocele repair at the age of 3 months presented with progressive myelopathy. An intramedullary thoracic epidermoid was identified on MRI. The patient underwent excision of the epidermoid and subsequently returned to neurological baseline. This case illustrates the potential for delayed development of intraspinal epidermoid after initial repair of a simple meningocele.
[Show abstract][Hide abstract] ABSTRACT: Accumulation of IL-17-producing Th17 cells is associated with the development of multiple autoimmune diseases; however, the contribution of microRNA (miRNA) pathways to the intrinsic control of Th17 development remains unclear. Here, we demonstrated that miR-21 expression is elevated in Th17 cells and that mice lacking miR-21 have a defect in Th17 differentiation and are resistant to experimental autoimmune encephalomyelitis (EAE). Furthermore, we determined that miR-21 promotes Th17 differentiation by targeting and depleting SMAD-7, a negative regulator of TGF-β signaling. Moreover, the decreases in Th17 differentiation in miR-21-deficient T cells were associated with defects in SMAD-2/3 activation and IL-2 suppression. Finally, we found that treatment of WT mice with an anti-miR-21 oligonucleotide reduced the clinical severity of EAE, which was associated with a decrease in Th17 cells. Thus, we have characterized a T cell-intrinsic miRNA pathway that enhances TGF-β signaling, limits the autocrine inhibitory effects of IL-2, and thereby promotes Th17 differentiation and autoimmunity.
[Show abstract][Hide abstract] ABSTRACT: Subependymal giant cell astrocytomas (SEGAs) are benign tumors (WHO grade I) that occur almost exclusively in the setting of tuberous sclerosis (TS), a well-defined, multi-system genetic syndrome. Most commonly originating from the region of the caudate nucleus, these tumors may cause obstruction of cerebrospinal fluid circulation leading to hydrocephalus. Less frequently, they may hemorrhage spontaneously, causing precipitous neurological impairment . Mutations of the TSC-1 and TSC-2 genes, both effectors of the mTOR pathway (originally mammalian Target of Rapamycin, now formally mechanistic Target of Rapamycin), lead to the variably expressed systemic manifestations of TS; cardiac rhabdomyoma, renal angiolipomas, facial adenoma sebaceum, cortical tubers of the brain, and SEGAs. The standard treatment of symptomatic or enlarging SEGAs is surgical excision. Pharmacological effectors of the mTOR pathway, rapamycin (aka sirolimus) and its analogs have recently been shown to induce rapid involution of SEGAs; however, the optimal timing, dosage, safety, and duration of treatment remain areas of active clinical research. SEGAs in the context of TS represent an example of an emerging paradigm: targeted molecular-oncologic therapy.
Molecular Pathology of Nervous System Tumors, 01/2015: pages 143-151;
[Show abstract][Hide abstract] ABSTRACT: With multiple and increasingly effective therapies for relapsing forms of multiple sclerosis (MS), disease-free status or no evidence of disease activity (NEDA) has become a treatment goal and a new outcome measure. However, the persistence of NEDA over time and its predictive power for long-term prognosis are unknown.
To investigate NEDA during 7 years as measured by relapses, disability progression, and yearly magnetic resonance imaging (MRI).
Patients were selected from the 2200-patient Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women's Hospital (CLIMB) cohort study. Patients were required to have an initial diagnosis of clinically isolated syndrome or relapsing-remitting MS and a minimum of 7 years of prospective follow-up that included yearly brain MRI and biannual clinical visits (n = 219). Patients were analyzed independent of disease-modifying therapy. Patients were classified as having early (recent-onset) MS if they were 5 years or less from their first MS symptom at enrollment or otherwise considered to have established MS (>5 years from onset).
NEDA was defined as a composite that consisted of absence of relapses, no sustained Expanded Disability Status Scale score progression, and no new or enlarging T2 or T1 gadolinium-enhancing lesions on annual MRI. Relapses, progression, and MRI changes were also investigated as individual outcomes.
A total of 99 of 215 patients (46.0%) had NEDA for clinical and MRI measures at 1 year, but only 17 of 216 (7.9%) maintained NEDA status after 7 years. No differences were found in NEDA status between patients with early vs established MS. A dissociation was found between clinical and MRI disease activity. Each year, 30.6% (64 of 209) to 42.9% (93 of 217) of the cohort had evidence of either clinical or MRI disease activity but not both. NEDA at 2 years had a positive predictive value of 78.3% for no progression (Expanded Disability Status Scale score change ≤0.5) at 7 years. Only minor improvement was found in the positive predictive values with additional follow-up of 1 to 3 years.
NEDA is difficult to sustain long term even with treatment. NEDA status at 2 years may be optimal in terms of prognostic value in the longer term. Our results provide a basis for investigating NEDA as an outcome measure and treatment goal and for evaluating the effect of new MS drugs on NEDA.