Mesenchymal Stromal Cell Implants for Chronic Motor Deficits After Traumatic Brain Injury: Post Hoc Analysis of a Randomized Trial.

BACKGROUND AND OBJECTIVES: Traumatic brain injury (TBI) is frequently characterized by chronic motor deficits. Therefore, this clinical trial assessed whether intracranial implantation of allogeneic modified mesenchymal stromal (SB623) cells can improve chronic motor deficits after TBI. METHODS: Post hoc analysis of the double-blind, randomized, prospective, surgical sham-controlled, phase 2, STEMTRA clinical trial (June 2016 and March 2019) with 48 weeks of follow-up was conducted. In this international, multicenter clinical trial, eligible participants had moderate-to-severe TBI, were ≥12 months postinjury, and had chronic motor deficits. Participants were randomized in a 1:1:1:1 ratio to stereotactic surgical intracranial implantation of SB623 cells (2.5 × 106, 5.0 × 106, 10 × 106) or surgical sham-controlled procedure. The prespecified primary efficacy end point was significantly greater change from baseline of the Fugl-Meyer Motor Scale (FMMS) score, a measure of motor status, for the SB623 pooled vs control arm at 24 weeks. RESULTS: A total of 211 participants were screened, 148 were excluded, and 63 underwent randomization, of which 61 (97%; mean age, 34 [SD, 12] years; 43 men [70.5%]) completed the trial. Single participants in the SB623 2.5 × 106 and 5.0 × 106 cell dose groups discontinued before surgery. Safety and efficacy (modified intent-to-treat) were assessed in participants who underwent surgery (N = 61; SB623 = 46, controls = 15). The primary efficacy end point (FMMS) was achieved (least squares mean [SE] SB623: +8.3 [1.4]; 95% CI 5.5-11.2 vs control: +2.3 [2.5]; 95% CI -2.7 to 7.3; p = 0.04), with faster improvement of the FMMS score in SB623-treated groups than in controls at 24 weeks and sustained improvement at 48 weeks. At 48 weeks, improvement of function and activities of daily living (ADL) was greater, but not significantly different in SB623-treated groups vs controls. The incidence of adverse events was equivalent in SB623-treated groups and controls. There were no deaths or withdrawals due to adverse events. DISCUSSION: Intraparenchymal implantation of SB623 cells was safe and significantly improved motor status at 24 weeks in participants with chronic motor deficits after TBI, with continued improvement of function and ADL at 48 weeks. Cell therapy can modify chronic neurologic deficits after TBI. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02416492. Submitted to registry: April 15, 2015. First participant enrolled: July 6, 2016. Available at: classic.clinicaltrials.gov/ct2/show/NCT02416492. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that intracranial implantation of allogeneic stem (SB623) cells in adults with motor deficits from chronic TBI improves motor function at 24 weeks.

Cell Therapy for Chronic TBI: Interim Analysis of the Randomized Controlled STEMTRA Trial.

OBJECTIVE: To determine if chronic motor deficits secondary to traumatic brain injury (TBI) can be improved by implantation of allogeneic modified bone marrow-derived mesenchymal stromal/stem cells (SB623). METHODS: This 6-month interim analysis of the 1-year double-blind, randomized, surgical sham-controlled, phase 2 STEMTRA trial (NCT02416492) evaluated safety and efficacy of the stereotactic intracranial implantation of SB623 in patients with stable chronic motor deficits secondary to TBI. Patients in this multi-center trial (N = 63) underwent randomization in a 1:1:1:1 ratio to 2.5 × 106, 5.0 × 106, 10 × 106 SB623 cells or control. Safety was assessed in patients who underwent surgery (N = 61), and efficacy in the modified intent-to-treat population of randomized patients who underwent surgery (N = 61; SB623 = 46, control = 15). RESULTS: The primary efficacy endpoint of significant improvement from baseline of Fugl-Meyer Motor Scale score at 6 months for SB623-treated patients was achieved. SB623-treated patients improved by (LS mean [SE]) +8.3 (1.4) vs +2.3 (2.5) for control at 6 months, the LS mean difference was 6.0 (95% CI: 0.3-11.8); p = 0.040. Secondary efficacy endpoints improved from baseline, but were not statistically significant vs control at 6 months. There were no dose-limiting toxicities or deaths, and 100% of SB623-treated patients experienced treatment-emergent adverse events vs 93.3% of control patients (p = 0.25). CONCLUSIONS: SB623 cell implantation appeared to be safe and well tolerated, and patients implanted with SB623 experienced significant improvement from baseline motor status at 6 months compared to controls. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that implantation of SB623 was well tolerated and associated with improvement in motor status.

Biological intratumoral therapy for the high-grade glioma part II: vector- and cell-based therapies and radioimmunotherapy.

Management of high-grade gliomas (HGGs) remains a complex challenge with an overall poor prognosis despite aggressive multimodal treatment. New translational research has focused on maximizing tumor cell eradication through improved tumor cell targeting while minimizing collateral systemic side effects. In particular, biological intratumoral therapies have been the focus of novel translational research efforts due to their inherent potential to be both dynamically adaptive and target specific. This two part review will provide an overview of biological intratumoral therapies that have been evaluated in human clinical trials in HGGs, and summarize key advances and remaining challenges in the development of these therapies as a potential new paradigm in the management of HGGs. Part II discusses vector-based therapies, cell-based therapies and radioimmunotherapy.

Biological intratumoral therapy for the high-grade glioma part I: intratumoral delivery and immunotoxins.

Management of high-grade gliomas remains a complex challenge. Standard of care consists of microsurgical resection, chemotherapy and radiation, but despite these aggressive multimodality therapies the overall prognosis remains poor. A major focus of ongoing translational research studies is to develop novel therapeutic strategies that can maximize tumor cell eradication while minimizing collateral side effects. Particularly, biological intratumoral therapies have been the focus of new translational research efforts due to their inherent potential to be both dynamically adaptive and target specific. This two-part review will provide an overview of biological intratumoral therapies and summarize key advances and remaining challenges in intratumoral biological therapies for high-grade glioma. Part I focuses on discussion of the concepts of intratumoral delivery and immunotoxin therapies.

Diabetes Insipidus following Endoscopic Transsphenoidal Surgery for Pituitary Adenoma.

Objectives Pituitary adenoma (PA), among the most commonly encountered sellar pathologies, accounts for 10% of primary intracranial tumors. The reported incidence of postoperative diabetes insipidus (DI) is highly variable. In this study, we report our experience with DI following endoscopic transsphenoidal surgery (TSS) for PAs, elucidating the risk factors of postoperative DI, the likelihood of long-term DI, and the impact of DI on the length of stay (LOS). Methods The study included 178 patients who underwent endoscopic resection of PAs. Early DI was defined as that occurring within the first postoperative week. The mean follow-up was 36 months. Long-term DI was considered as DI apparent in the last follow-up visit. Results Of the 178 patients included in the study, 77% of the tumors were macroadenomas. Forty-seven patients (26%) developed early DI. Long-term DI was observed in 18 (10.1%) of the full cohort. Age younger than 50 years was significantly associated with a higher incidence of long-term DI ( p = 0.02). Macroadenoma and gross total resection were significantly associated with higher incidence of early DI ( p = 0.05 and p = 0.04, respectively). The mean LOS was 4 days for patients with early postoperative DI and 3 days for those without it. Conclusion The reported incidence of postoperative DI is significantly variable. We identified age younger than 50 years a risk factor for developing long-term postoperative DI. Gross total surgical resection and tumor size (> 1 cm) were associated with development of early DI. Early DI increased the LOS on average by 1 day.

Cavernous Sinus Involvement by Pituitary Adenomas: Clinical Implications and Outcomes of Endoscopic Endonasal Resection.

Background Parasellar invasion of pituitary adenomas (PAs) into the cavernous sinus (CS) is common. The management of the CS component of PA remains controversial. Objective The objective of this study was to analyze CS involvement in PA treated with endoscopic endonasal approaches, including incidence, surgical risks, surgical strategies, long-term outcomes, and our treatment algorithm. Methods We reviewed a series of 176 surgically treated PA with particular attention to CS involvement and whether the CS tumor was approached medial or lateral to the internal carotid artery. Results The median duration of follow-up was 36 months. Macroadenomas and nonfunctional adenomas represented 77 and 60% of cases, respectively. CS invasion was documented in 23% of cases. CS involvement was associated with a significantly diminished odds of gross total resection (47 vs. 86%, odds ratio [OR]: 5.2) and increased the need for subsequent intervention (4 vs. 40%, OR: 14.4). Hormonal remission was achieved in 15% of hormonally active tumors. Rates of surgical complication were similar regardless of CS involvement. Conclusion Our tailored strategy beginning with a medial approach and adding lateral exposure as needed resulted in good outcomes with low morbidity in nonfunctional adenomas. Functional adenomas involving the CS were associated with low rates of hormonal remission necessitating higher rates of additional treatment.

Revealing cancer subtypes with higher-order correlations applied to imaging and omics data.

BACKGROUND: Patient stratification to identify subtypes with different disease manifestations, severity, and expected survival time is a critical task in cancer diagnosis and treatment. While stratification approaches using various biomarkers (including high-throughput gene expression measurements) for patient-to-patient comparisons have been successful in elucidating previously unseen subtypes, there remains an untapped potential of incorporating various genotypic and phenotypic data to discover novel or improved groupings. METHODS: Here, we present HOCUS, a unified analytical framework for patient stratification that uses a community detection technique to extract subtypes out of sparse patient measurements. HOCUS constructs a patient-to-patient network from similarities in the data and iteratively groups and reconstructs the network into higher order clusters. We investigate the merits of using higher-order correlations to cluster samples of cancer patients in terms of their associations with survival outcomes. RESULTS: In an initial test of the method, the approach identifies cancer subtypes in mutation data of glioblastoma, ovarian, breast, prostate, and bladder cancers. In several cases, HOCUS provides an improvement over using the molecular features directly to compare samples. Application of HOCUS to glioblastoma images reveals a size and location classification of tumors that improves over human expert-based stratification. CONCLUSIONS: Subtypes based on higher order features can reveal comparable or distinct groupings. The distinct solutions can provide biologically- and treatment-relevant solutions that are just as significant as solutions based on the original data.

Magnetic resonance perfusion image features uncover an angiogenic subgroup of glioblastoma patients with poor survival and better response to antiangiogenic treatment.

BACKGROUND: In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies. METHODS: Quantitative image features characterizing subregions of tumors and the whole tumor were extracted from preoperative and pretherapy perfusion magnetic resonance (MR) images of 117 GBM patients in 2 independent cohorts. Unsupervised consensus clustering was performed to identify robust clusters of GBM in each cohort. Cox survival and gene set enrichment analyses were conducted to characterize the clinical significance and molecular pathway activities of the clusters. The differential treatment efficacy of antiangiogenic therapy between the clusters was evaluated. RESULTS: A subgroup of patients with elevated perfusion features was identified and was significantly associated with poor patient survival after accounting for other clinical covariates (P values <.01; hazard ratios > 3) consistently found in both cohorts. Angiogenesis and hypoxia pathways were enriched in this subgroup of patients, suggesting the potential efficacy of antiangiogenic therapy. Patients of the angiogenic subgroups pooled from both cohorts, who had chemotherapy information available, had significantly longer survival when treated with antiangiogenic therapy (log-rank P=.022). CONCLUSIONS: Our findings suggest that an angiogenic subtype of GBM patients may benefit from antiangiogenic therapy with improved overall survival.

Anti-CD47 Treatment Stimulates Phagocytosis of Glioblastoma by M1 and M2 Polarized Macrophages and Promotes M1 Polarized Macrophages In Vivo.

Tumor-associated macrophages (TAMs) represent an important cellular subset within the glioblastoma (WHO grade IV) microenvironment and are a potential therapeutic target. TAMs display a continuum of different polarization states between antitumorigenic M1 and protumorigenic M2 phenotypes, with a lower M1/M2 ratio correlating with worse prognosis. Here, we investigated the effect of macrophage polarization on anti-CD47 antibody-mediated phagocytosis of human glioblastoma cells in vitro, as well as the effect of anti-CD47 on the distribution of M1 versus M2 macrophages within human glioblastoma cells grown in mouse xenografts. Bone marrow-derived mouse macrophages and peripheral blood-derived human macrophages were polarized in vitro toward M1 or M2 phenotypes and verified by flow cytometry. Primary human glioblastoma cell lines were offered as targets to mouse and human M1 or M2 polarized macrophages in vitro. The addition of an anti-CD47 monoclonal antibody led to enhanced tumor-cell phagocytosis by mouse and human M1 and M2 macrophages. In both cases, the anti-CD47-induced phagocytosis by M1 was more prominent than that for M2. Dissected tumors from human glioblastoma xenografted within NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ mice and treated with anti-CD47 showed a significant increase of M1 macrophages within the tumor. These data show that anti-CD47 treatment leads to enhanced tumor cell phagocytosis by both M1 and M2 macrophage subtypes with a higher phagocytosis rate by M1 macrophages. Furthermore, these data demonstrate that anti-CD47 treatment alone can shift the phenotype of macrophages toward the M1 subtype in vivo.

Multiple Subsets of Brain Tumor Initiating Cells Coexist in Glioblastoma.

Brain tumor-initiating cells (BTICs) are self-renewing multipotent cells critical for tumor maintenance and growth. Using single-cell microfluidic profiling, we identified multiple subpopulations of BTICs coexisting in human glioblastoma, characterized by distinct surface marker expression and single-cell molecular profiles relating to divergent bulk tissue molecular subtypes. These data suggest BTIC subpopulation heterogeneity as an underlying source of intra-tumoral bulk tissue molecular heterogeneity, and will support future studies into BTIC subpopulation-specific therapies. Stem Cells 2016;34:1702-1707.

Magnetic resonance image features identify glioblastoma phenotypic subtypes with distinct molecular pathway activities.

Glioblastoma (GBM) is the most common and highly lethal primary malignant brain tumor in adults. There is a dire need for easily accessible, noninvasive biomarkers that can delineate underlying molecular activities and predict response to therapy. To this end, we sought to identify subtypes of GBM, differentiated solely by quantitative magnetic resonance (MR) imaging features, that could be used for better management of GBM patients. Quantitative image features capturing the shape, texture, and edge sharpness of each lesion were extracted from MR images of 121 single-institution patients with de novo, solitary, unilateral GBM. Three distinct phenotypic "clusters" emerged in the development cohort using consensus clustering with 10,000 iterations on these image features. These three clusters--pre-multifocal, spherical, and rim-enhancing, names reflecting their image features--were validated in an independent cohort consisting of 144 multi-institution patients with similar tumor characteristics from The Cancer Genome Atlas (TCGA). Each cluster mapped to a unique set of molecular signaling pathways using pathway activity estimates derived from the analysis of TCGA tumor copy number and gene expression data with the PARADIGM (Pathway Recognition Algorithm Using Data Integration on Genomic Models) algorithm. Distinct pathways, such as c-Kit and FOXA, were enriched in each cluster, indicating differential molecular activities as determined by the image features. Each cluster also demonstrated differential probabilities of survival, indicating prognostic importance. Our imaging method offers a noninvasive approach to stratify GBM patients and also provides unique sets of molecular signatures to inform targeted therapy and personalized treatment of GBM.

Glioblastoma multiforme: exploratory radiogenomic analysis by using quantitative image features.

PURPOSE: To derive quantitative image features from magnetic resonance (MR) images that characterize the radiographic phenotype of glioblastoma multiforme (GBM) lesions and to create radiogenomic maps associating these features with various molecular data. MATERIALS AND METHODS: Clinical, molecular, and MR imaging data for GBMs in 55 patients were obtained from the Cancer Genome Atlas and the Cancer Imaging Archive after local ethics committee and institutional review board approval. Regions of interest (ROIs) corresponding to enhancing necrotic portions of tumor and peritumoral edema were drawn, and quantitative image features were derived from these ROIs. Robust quantitative image features were defined on the basis of an intraclass correlation coefficient of 0.6 for a digital algorithmic modification and a test-retest analysis. The robust features were visualized by using hierarchic clustering and were correlated with survival by using Cox proportional hazards modeling. Next, these robust image features were correlated with manual radiologist annotations from the Visually Accessible Rembrandt Images (VASARI) feature set and GBM molecular subgroups by using nonparametric statistical tests. A bioinformatic algorithm was used to create gene expression modules, defined as a set of coexpressed genes together with a multivariate model of cancer driver genes predictive of the module's expression pattern. Modules were correlated with robust image features by using the Spearman correlation test to create radiogenomic maps and to link robust image features with molecular pathways. RESULTS: Eighteen image features passed the robustness analysis and were further analyzed for the three types of ROIs, for a total of 54 image features. Three enhancement features were significantly correlated with survival, 77 significant correlations were found between robust quantitative features and the VASARI feature set, and seven image features were correlated with molecular subgroups (P < .05 for all). A radiogenomics map was created to link image features with gene expression modules and allowed linkage of 56% (30 of 54) of the image features with biologic processes. CONCLUSION: Radiogenomic approaches in GBM have the potential to predict clinical and molecular characteristics of tumors noninvasively. Online supplemental material is available for this article.

Multiplex meta-analysis of medulloblastoma expression studies with external controls.

We propose and discuss a method for doing gene expression meta-analysis (multiple datasets) across multiplex measurement modalities measuring the expression of many genes simultaneously (e.g. microarrays and RNAseq) using external control samples and a method of heterogeneity detection to identify and filter on comparable gene expression measurements. We demonstrate this approach on publicly available gene expression datasets from samples of medulloblastoma and normal cerebellar tissue and identify some potential new targets in the treatment of medulloblastoma.

Sex differences in clinical presentation and treatment outcomes in Moyamoya disease.

BACKGROUND: Moyamoya (MM) disease is an idiopathic steno-occlusive angiopathy occurring more frequently in females. OBJECTIVE: To evaluate sex differences in preoperative symptoms and treatment outcomes after revascularization surgery. METHODS: We analyzed 430 MM disease patients undergoing 717 revascularization procedures spanning 19 years (1991-2010) and compared gender differences in preoperative symptoms and long-term outcomes after surgical revascularization. RESULTS: A total of 307 female and 123 male patients (ratio, 2.5:1) with a mean age of 31.0 ± 16.7 years and adults-to-children ratio of 2.5:1 underwent 717 revascularization procedures. Female patients were more likely to experience preoperative transient ischemic attacks (odds ratio: 2.1, P = .001) and less likely to receive a diagnosis of unilateral MM disease (odds ratio: 0.6, P = .04). No association was observed between sex and risk of preoperative ischemic or hemorrhagic stroke. There was no difference in neurological outcome because both male and female patients experienced significant improvement in the modified Rankin Scale score after surgery (P < .0001). On Kaplan-Meier survival analysis, 5-year cumulative risk of adverse postoperative events despite successful revascularization was 11.4% in female vs 5.3% in male patients (P = .05). In multivariate Cox proportional hazards analysis, female sex trended toward an association with adverse postoperative events (hazard ratio: 1.9, P = .14). CONCLUSION: Female patients are more susceptible to the development of preoperative transient ischemic attack and may be at higher risk of adverse postoperative events despite successful revascularization. There is, however, no sex difference in neurological outcome because patients of both sexes experience significant improvement in neurological status with low risk of the development of future ischemic events after surgical revascularization.

Clinical neuroproteomics and biomarkers: from basic research to clinical decision making.

Clinical neuroproteomics aims to advance our understanding of disease and injury affecting the central and peripheral nervous systems through the study of protein expression and the discovery of protein biomarkers to facilitate diagnosis and treatment. The general premise of the biomarker field is that in vivo factors present in either tissue or circulating biofluids, reflect pathological changes, and can be identified and analyzed. This approach offers an opportunity to illuminate changes occurring at both the population and patient levels toward the realization of personalized medicine. This review is intended to provide research-driven clinicians with an overview of protein biomarkers of disease and injury for clinical use and to highlight methodology and potential pitfalls. We examine the neuroproteomic biomarker field and discuss the hallmarks and the challenges of clinically relevant biomarker discovery relating to central nervous system pathology. We discuss the issues in the maturation of potential biomarkers from discovery to Food and Drug Administration approval and review several platforms for protein biomarker discovery, including protein microarray and mass spectrometry-based proteomics. We describe the application of microfluidic technologies to the evolution of a robust clinical test. Finally, we highlight several biomarkers currently in use for cancer, ischemia, and injury in the central nervous system. Future efforts using these technologies will result in the maturation of existing and the identification of de novo biomarkers that could guide clinical decision making and advance diagnostic and therapeutic options for the treatment of neurological disease and injury.

Pathogenesis and radiobiology of brain arteriovenous malformations: implications for risk stratification in natural history and posttreatment course.

Brain arteriovenous malformations (BAVMs) are an important cause of intracerebral hemorrhage (ICH) in young adults. Biological predictors of future ICH risk are lacking, and controversy exists over previous studies of natural history risk among predominantly ruptured BAVM cohorts. Recent studies have suggested that the majority of BAVMs are now diagnosed as unruptured lesions, and that the risk according to natural history among these lesions may be less than previously assumed. In the first part of this review, the authors discuss available data on the natural history of BAVMs and highlight the need for future studies that aim to develop surrogate biomarkers of disease progression that accurately predict future risk of ICH in BAVMs. The etiology of BAVM remains unknown. Recent studies have suggested a role for genetic factors in the pathogenesis of sporadic BAVM, which is further supported by reports of familial occurrence of BAVM and association with known systemic genetic disorders (such as Osler-Weber-Rendu disease, Sturge-Weber disease, and Wyburn-Mason syndrome). Molecular characterization of BAVM tissue demonstrates a highly angiogenic milieu with evidence of increased endothelial cell turnover. Taken together with a number of reports of de novo BAVM formation, radiographic growth after initial BAVM diagnosis, and regrowth after successful treatment of BAVM, these findings challenge the long-held assumption that BAVMs are static lesions of congenital origin. In the second part of this review, the authors discuss available data on the origins of BAVM and offer insights into future investigations into genetics and endothelial progenitor cell involvement in the pathogenesis of BAVM. Current treatment options for BAVM focus on removal or obliteration of the lesion in an attempt to protect against future ICH risk, including microsurgical resection, endovascular embolization, and stereotactic radiosurgery (SRS). In the third part of this review, the authors discuss available data on SRS in BAVMs and highlight the need for future studies on the radiobiology of BAVMs, especially in regard to biomarker detection for tracking SRS response during the latency period. Insights from future investigations in BAVM may not only prove important for the development of novel therapies and relevant biomarkers for BAVM, but could also potentially benefit a variety of other disorders involving new vessel formation in the CNS, including stroke, tumors, moyamoya disease, and other cerebrovascular malformations.

Pathophysiology and genetic factors in moyamoya disease.

Moyamoya disease is an uncommon cerebrovascular condition characterized by progressive stenosis of the bilateral internal carotid arteries with compensatory formation of an abnormal network of perforating blood vessels providing collateral circulation. The etiology and pathogenesis of moyamoya disease remain unclear. Evidence from histological studies, proteomics, and endothelial progenitor cell analyses suggests new theories underlying the cause of vascular anomalies, including moyamoya disease. Familial moyamoya disease has been noted in as many as 15% of patients, indicating an autosomal dominant inheritance pattern with incomplete penetrance. Genetic analyses in familial moyamoya disease and genome-wide association studies represent promising strategies for elucidating the pathophysiology of this condition. In this review, the authors discuss recent studies that have investigated possible mechanisms underlying the etiology of moyamoya disease, including stem cell involvement and genetic factors. They also discuss future research directions that promise not only to offer new insights into the origin of moyamoya disease but to enhance our understanding of new vessel formation in the CNS as it relates to stroke, vascular anomalies, and tumor growth.

Association of tumor necrosis factor-alpha-238G>A and apolipoprotein E2 polymorphisms with intracranial hemorrhage after brain arteriovenous malformation treatment.

OBJECTIVE: We previously reported specific genotypes of polymorphisms in two genes, tumor necrosis factor-alpha (TNF-alpha-238G > A) and Apolipoprotein E (ApoE e2), as independent predictors of new intracranial hemorrhage (ICH) in the natural course of untreated brain arteriovenous malformations. We hypothesized that the risk of posttreatment ICH would also be greater in patients with brain arteriovenous malformations with these genotypes. METHODS: Two hundred fifteen patients undergoing brain arteriovenous malformation treatment (embolization, arteriovenous malformation resection, radiosurgery, or any combination of these) were genotyped and followed longitudinally. Association of genotype with new symptomatic ICH after initiation of treatment was assessed using Cox proportional hazards adjusted for treatment type, demographics, and established ICH risk factors censored at the time of the last follow-up evaluation or death. RESULTS: The cohort was 48% male and 55% Caucasian, and 52% had an ICH before the initiation of treatment; the mean age +/- standard deviation was 36.6 +/- 17.2 years. Posttreatment ICH occurred in 34 (16%) patients with a median follow-up period of 1.9 years (interquartile range, 1.6 yr). After adjustment, the risk of posttreatment ICH was greater for TNF-alpha-238 AG genotype (hazard ratio [HR], 3.5; 95% confidence interval [CI], 1.3-9.8; P = 0.016) and ApoE e2 (HR, 3.2; 95% CI, 1.0-9.7; P = 0.042). Similar trends for the TNF-alpha-238 AG genotype were seen in surgery (HR, 4.2; 95% CI, 0.6-28.8; P = 0.14) and radiosurgery subsets (HR, 3.8; 95% CI, 0.7-19.4; P = 0.11). An effect of ApoE e2 was seen in radiosurgery subsets (HR, 10.9; 95% CI, 1.3-93.7; P = 0.030), but not in surgery subsets (HR, 1.4; 95% CI, 0.3-7.4; P = 0.67). CONCLUSION: Despite a variety of different mechanisms for posttreatment hemorrhage, these data suggest that the TNF-alpha and ApoE genotypes may contribute common phenotypes of enhanced vascular instability that increase the risk of hemorrhagic outcome.

MMP-9 expression is associated with leukocytic but not endothelial markers in brain arteriovenous malformations.

Brain arteriovenous malformations (BAVM) have high matrix metalloproteinase-9 (MMP-9) expression, the source of which is unclear. We hypothesized MMP-9 production might be due to inflammation in BAVM. Compared to control brain tissues (n = 5), BAVM tissue (n = 139) had a higher expression (by ELISA) of myeloperoxidase (MPO) (193 +/- 189 vs. 6 +/- 3, ng/mg, P < .001), MMP-9 (28 +/- 32 vs. 0.7 +/- 0.6, ng/mg, P < .001), and IL-6 (102 +/- 218 vs. 0.1 +/- 0.1, pg/mg, P < .001), but not eNOS (114 +/- 87 vs. 65 +/- 9, pg/mg, P = .09). MMP-9 expression in BAVM highly correlated with myeloperoxidase (R2 = .76, P < .001), as well as with IL-6 (R2 = .32, P < .001). In contrast, MMP-9 in BAVM poorly correlated with the endothelial marker, eNOS (R2 = .03, P = .05), and CD31 (R2 = .004, P = .57). Compared to non-embolized patients (n = 46), patients with pre-operative embolization (n = 93) had higher levels of myeloperoxidase (236 +/- 205 vs. 106 +/- 108, ng/mg, P < .001) and MMP-9 (33 +/- 35 vs. 16 +/- 20, ng/mg, P < .001), however the correlation between MMP-9 and myeloperoxidase was equally strong for both groups (R2 = .69, n = 93, P < .001, for both). MMP-9 expression correlated with the lipocalin-MMP-9 complex, suggesting neutrophils as the MMP-9 source. MPO co-localized with majority of MMP-9 signal by immunohistochemistry. Our data suggest that inflammation is a prominent feature of BAVM lesional phenotype, and neutrophils appear to be a major source of MMP-9 in these lesions.