Suzanne Z. Powell

Regulatory T‐lymphocytes mediate amyotrophic lateral sclerosis progression and survival

In amyotrophic lateral sclerosis (ALS) mice, regulatory T‐lymphocytes (Tregs) are neuroprotective, slowing disease progression. To address whether Tregs and FoxP3, a transcription factor required for Treg function, similarly influence progression rates of ALS patients, T‐lymphocytes from patients were assessed by flow cytometry. Both numbers of Tregs and their FoxP3 protein expressions were reduced in rapidly progressing ALS patients and inversely correlated with progression rates. The mRNA levels of FoxP3, TGF‐β, IL4 and Gata3, a Th2 transcription factor, were reduced in rapidly progressing patients and inversely correlated with progression rates. Both FoxP3 and Gata3 were accurate indicators of progression rates. No differences in IL10, Tbx21, a Th1 transcription factor or IFN‐γ expression were found between slow and rapidly progressing patients. A 3.5‐year prospective study with a second larger cohort revealed that early reduced FoxP3 levels were indicative of progression rates at collection and predictive of future rapid progression and attenuated survival. Collectively, these data suggest that Tregs and Th2 lymphocytes influence disease progression rates. Importantly, early reduced FoxP3 levels could be used to identify rapidly progressing patients.

T Cells Redirected to EphA2 for the Immunotherapy of Glioblastoma

Outcomes for patients with glioblastoma (GBM) remain poor despite aggressive multimodal therapy. Immunotherapy with genetically modified T cells expressing chimeric antigen receptors (CARs) targeting interleukin (IL)-13Rα2, epidermal growth factor receptor variant III (EGFRvIII), or human epidermal growth factor receptor 2 (HER2) has shown promise for the treatment of gliomas in preclinical models and in a clinical study (IL-13Rα2). However, targeting IL-13Rα2 and EGFRvIII is associated with the development of antigen loss variants, and there are safety concerns with targeting HER2. Erythropoietin-producing hepatocellular carcinoma A2 (EphA2) has emerged as an attractive target for the immunotherapy of GBM as it is overexpressed in glioma and promotes its malignant phenotype. To generate EphA2-specific T cells, we constructed an EphA2-specific CAR with a CD28-ζ endodomain. EphA2-specific T cells recognized EphA2-positive glioma cells as judged by interferon-γ (IFN-γ) and IL-2 production and tumor cell killing. In addition, EphA2-specific T cells had potent activity against human glioma-initiating cells preventing neurosphere formation and destroying intact neurospheres in coculture assays. Adoptive transfer of EphA2-specific T cells resulted in the regression of glioma xenografts in severe combined immunodeficiency (SCID) mice and a significant survival advantage in comparison to untreated mice and mice treated with nontransduced T cells. Thus, EphA2-specific T-cell immunotherapy may be a promising approach for the treatment of EphA2-positive GBM.

Surgical Neuropathology Update: A Review of Changes Introduced by the WHO Classification of Tumours of the Central Nervous System, 4th Edition

CONTEXT The World Health Organization (WHO) recently published its 4th edition of the classification of tumors of the central nervous system, incorporating a substantial number of important changes to the previous version (WHO 2000). The new WHO classification introduces 7 changes in the grading of central nervous system neoplasms, ranging in significance from minor to major, in categories of anaplastic oligoastrocytomas, meningiomas, choroid plexus tumors, pineal parenchymal tumors, ganglioglioma, cerebellar liponeurocytoma, and hemangiopericytomas. The 4th edition also introduces 10 newly codified entities, variants, and patterns, as well as 1 new genetic syndrome. A number of established brain tumors are reorganized, including medulloblastomas and primitive neuroectodermal tumors, in an attempt to more closely align classification with current understanding of central nervous system neoplasia. OBJECTIVE To summarize and discuss the most significant updates in the 4th edition for the practicing surgical pathologist, including (1) changes in grading among established entities; (2) newly codified tumor entities, variants, patterns, and syndromes; and (3) changes in the classification of existing brain tumors. DATA SOURCES The primary source for this review is the WHO Classification of Tumours of the Central Nervous System, 4th edition. Other important sources include the 3rd edition of this book and the primary literature that supported changes in the 4th edition. CONCLUSIONS The new edition of the WHO blue book reflects advancements in the understanding of brain tumors in terms of classification, grading, and new entities. The changes introduced are substantial and will have an impact on the practice of general surgical pathologists and neuropathologists.

Divergent differentiation in pleomorphic xanthoastrocytoma. Evidence for a neuronal element and possible relationship to ganglion cell tumors.

We report the detection of cytoplasmic immunoreactivity for neuronal/neuroendocrine antigens in a subpopulation of tumor cells within seven pleomorphic xanthoastrocytomas (PXAs). The expression of glial and neuronal polypeptides was examined in routinely prepared surgical resections by immunohistochemistry using well-characterized antibodies that recognize glial fibrillary acidic protein (GFAP), synaptophysin (SYN), and neurofilament triplet polypeptides (NFPs) in microwave-enhanced single- and double-immunolabelling experiments. Each neoplasm contained cells that were immunoreactive for SYN and/or NFPs, GFAP, and occasionally for both GFAP and either NFP or SYN. We conclude that abortive neuronal/neuroendocrine differentiation may occur in PXAs, suggesting a relationship between PXA and other developmental neoplasms that reveal a more overt neuronal phenotype, such as ganglioglioma, dysembryoplastic neuroepithelial tumor, and desmoplastic ganglioglioma, and with tumors expressing ambiguous glial/neuronal lineage, such as the subependymal giant cell tumor of tuberous sclerosis. These findings suggest that aberrant expression and accumulation of neuronal intermediate filaments may account for the large, pleomorphic cell morphology observed in many of these tumors.

Isofurans, but not F2-isoprostanes, are increased in the substantia nigra of patients with Parkinson's disease and with dementia with Lewy body disease

F2‐isoprostanes (F2‐IsoPs) are well‐established sensitive and specific markers of oxidative stress in vivo. Isofurans (IsoFs) are also products of lipid peroxidation, but in contrast to F2‐IsoPs, their formation is favored when oxygen tension is increased in vitro or in vivo. Mitochondrial dysfunction in Parkinsons disease (PD) may not only lead to oxidative damage to brain tissue but also potentially result in increased intracellular oxygen tension, thereby influencing relative concentrations of F2‐IsoPs and IsoFs. In this study, we attempted to compare the levels of F2‐IsoPs and IsoFs esterified in phospholipids in the substantia nigra (SN) from patients with PD to those of age‐matched controls as well as patients with other neurodegenerative diseases, including dementia with Lewy body disease (DLB), multiple system atrophy (MSA), and Alzheimers disease (AD). The results demonstrated that IsoFs but not F2‐IsoPs in the SN of patients with PD and DLB were significantly higher than those of controls. Levels of IsoFs and F2‐IsoPs in the SN of patients with MSA and AD were indistinguishable from those of age‐matched controls. This preferential increase in IsoFs in the SN of patients with PD or DLB not only indicates a unique mode of oxidant injury in these two diseases but also suggests different underlying mechanisms of dopaminergic neurodegeneration in PD and DLB from those of MSA.

Autopsy-proven Huntington's disease with 29 trinucleotide repeats

Huntingtons disease (HD) is a neurodegenerative disorder associated with expansion of CAG trinucleotide repeats in the huntingtin gene. A minimum of 36 CAG repeats is usually reported in patients with clinical features of HD; 30 to 35 repeats represent an intermediate range. Here we report a 65‐year‐old male with autopsy‐proven HD and 29 CAG repeats.

HER2-Specific Chimeric Antigen Receptor–Modified Virus-Specific T Cells for Progressive Glioblastoma: A Phase 1 Dose-Escalation Trial

Importance Glioblastoma is an incurable tumor, and the therapeutic options for patients are limited. Objective To determine whether the systemic administration of HER2-specific chimeric antigen receptor (CAR)–modified virus-specific T cells (VSTs) is safe and whether these cells have antiglioblastoma activity. Design, Setting, and Participants In this open-label phase 1 dose-escalation study conducted at Baylor College of Medicine, Houston Methodist Hospital, and Texas Children’s Hospital, patients with progressive HER2-positive glioblastoma were enrolled between July 25, 2011, and April 21, 2014. The duration of follow-up was 10 weeks to 29 months (median, 8 months). Interventions Monotherapy with autologous VSTs specific for cytomegalovirus, Epstein-Barr virus, or adenovirus and genetically modified to express HER2-CARs with a CD28.&zgr;-signaling endodomain (HER2-CAR VSTs). Main Outcomes and Measures Primary end points were feasibility and safety. The key secondary end points were T-cell persistence and their antiglioblastoma activity. Results A total of 17 patients (8 females and 9 males; 10 patients ≥18 years [median age, 60 years; range, 30-69 years] and 7 patients <18 years [median age, 14 years; range, 10-17 years]) with progressive HER2-positive glioblastoma received 1 or more infusions of autologous HER2-CAR VSTs (1 × 106/m2 to 1 × 108/m2) without prior lymphodepletion. Infusions were well tolerated, with no dose-limiting toxic effects. HER2-CAR VSTs were detected in the peripheral blood for up to 12 months after the infusion by quantitative real-time polymerase chain reaction. Of 16 evaluable patients (9 adults and 7 children), 1 had a partial response for more than 9 months, 7 had stable disease for 8 weeks to 29 months, and 8 progressed after T-cell infusion. Three patients with stable disease are alive without any evidence of progression during 24 to 29 months of follow-up. For the entire study cohort, median overall survival was 11.1 months (95% CI, 4.1-27.2 months) from the first T-cell infusion and 24.5 months (95% CI, 17.2-34.6 months) from diagnosis. Conclusions and Relevance Infusion of autologous HER2-CAR VSTs is safe and can be associated with clinical benefit for patients with progressive glioblastoma. Further evaluation of HER2-CAR VSTs in a phase 2b study is warranted as a single agent or in combination with other immunomodulatory approaches for glioblastoma.

Interobserver and intraobserver reproducibility in focal cortical dysplasia (malformations of cortical development).

Purpose:  Malformations of cortical development (MCD) (cortical dysplasias) are well‐recognized causes of intractable epilepsy. Although a histologic classification system for MCD has been proposed by Palmini et al. (Neurology; 2004; 62:S2), studies to date have not assessed reproducibility. The purpose of this study was to analyze inter‐ and intraobserver agreement among eight experienced neuropathologists (NPs) with respect to this classification system.

Expanding the spectrum of neuronal pathology in multiple system atrophy

Multiple system atrophy is a sporadic alpha-synucleinopathy that typically affects patients in their sixth decade of life and beyond. The defining clinical features of the disease include progressive autonomic failure, parkinsonism, and cerebellar ataxia leading to significant disability. Pathologically, multiple system atrophy is characterized by glial cytoplasmic inclusions containing filamentous alpha-synuclein. Neuronal inclusions also have been reported but remain less well defined. This study aimed to further define the spectrum of neuronal pathology in 35 patients with multiple system atrophy (20 male, 15 female; mean age at death 64.7 years; median disease duration 6.5 years, range 2.2 to 15.6 years). The morphologic type, topography, and frequencies of neuronal inclusions, including globular cytoplasmic (Lewy body-like) neuronal inclusions, were determined across a wide spectrum of brain regions. A correlation matrix of pathologic severity also was calculated between distinct anatomic regions of involvement (striatum, substantia nigra, olivary and pontine nuclei, hippocampus, forebrain and thalamus, anterior cingulate and neocortex, and white matter of cerebrum, cerebellum, and corpus callosum). The major finding was the identification of widespread neuronal inclusions in the majority of patients, not only in typical disease-associated regions (striatum, substantia nigra), but also within anterior cingulate cortex, amygdala, entorhinal cortex, basal forebrain and hypothalamus. Neuronal inclusion pathology appeared to follow a hierarchy of region-specific susceptibility, independent of the clinical phenotype, and the severity of pathology was duration-dependent. Neuronal inclusions also were identified in regions not previously implicated in the disease, such as within cerebellar roof nuclei. Lewy body-like inclusions in multiple system atrophy followed the stepwise anatomic progression of Lewy body-spectrum disease inclusion pathology in 25.7% of patients with multiple system atrophy, including a patient with visual hallucinations. Further, the presence of Lewy body-like inclusions in neocortex, but not hippocampal alpha-synuclein pathology, was associated with cognitive impairment (P = 0.002). However, several cases had the presence of isolated Lewy body-like inclusions at atypical sites (e.g. thalamus, deep cerebellar nuclei) that are not typical for Lewy body-spectrum disease. Finally, interregional correlations (rho ≥ 0.6) in pathologic glial and neuronal lesion burden suggest shared mechanisms of disease progression between both discrete anatomic regions (e.g. basal forebrain and hippocampus) and cell types (neuronal and glial inclusions in frontal cortex and white matter, respectively). These findings suggest that in addition to glial inclusions, neuronal pathology plays an important role in the developmental and progression of multiple system atrophy.

Giant Cell Glioblastoma and Pleomorphic Xanthoastrocytoma Show Different Immunohistochemical Profiles for Neuronal Antigens and p53 but Share Reactivity for Class III β-Tubulin

CONTEXT Giant cell glioblastoma multiforme (GCGBM) and pleomorphic xanthoastrocytoma (PXA) are clinically, radiographically, and histologically distinct tumors of the central nervous system. However, they share features of gross circumscription, reticulin deposition, lymphocytic infiltrates, and prominent populations of tumor giant cells. Neuronal antigens have been detected in the neoplastic cells of PXAs, but to our knowledge have not been studied previously in GCGBMs. While TP53 is mutated in most GCGBMs, a feature usually paralleled by strong immunostaining of the protein, the expression pattern of PXAs has not been extensively studied. OBJECTIVES To compare the immunoprofiles of GCGBM and PXA with regard to neuronal antigens and p53 and to evaluate the potential diagnostic utility of such a panel. DESIGN Archival paraffin sections of 9 GCGBMs and 9 PXAs were immunostained for class III beta-tubulin, neuronal nuclear antigen, neurofilament protein, synaptophysin, glial fibrillary acidic protein, and p53. RESULTS Giant cell glioblastomas were strongly immunoreactive for class III beta-tubulin and glial fibrillary acidic protein, but showed only rare staining for the other neuronal polypeptides. In contrast, PXAs usually showed at least focal staining of individual tumor cells for most of the neuronal antigens tested. Tubulin was strongly positive in tumor giant cells and in smaller neoplastic cells of both tumor types. Double-immunolabeling revealed distinct populations of tumor cells that expressed either glial fibrillary acidic protein or tubulin and dual-labeling of individual cells in GCGBM and PXA. Strong p53 staining was observed in many tumor cells in 5 of 8 GCGBMs tested, while staining for this antigen was negative or focally positive in 6 of 8 PXAs examined. CONCLUSIONS Giant cell glioblastoma multiforme and PXA show distinct patterns of immunoreactivity for neuronal antigens and p53 that may be useful diagnostically in difficult cases or in limited samples. These results provide further evidence of neuronal antigen expression by PXA.