18F-FDG-PET Imaging Patterns in Autoimmune Encephalitis: Impact of Image Analysis on the Results

Brain positron emission tomography imaging with 18Fluorine-fluorodeoxyglucose (FDG-PET) has demonstrated utility in suspected autoimmune encephalitis. Visual and/or assisted image reading is not well established to evaluate hypometabolism/hypermetabolism. We retrospectively evaluated patients with autoimmune encephalitis between 2003 and 2018. Patients underwent EEG, brain magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) sampling and autoantibodies testing. Individual FDG-PET images were evaluated by standard visual reading and assisted by voxel-based analyses, compared to a normal database. For the latter, three different methods were performed: two based on statistical surface projections (Siemens syngo.via Database Comparison, and 3D-SSP Neurostat) and one based on statistical parametric mapping (SPM12). Hypometabolic and hypermetabolic findings were grouped to identify specific patterns. We found six cases with definite diagnosis of autoimmune encephalitis. Two cases had anti-LGI1, one had anti-NMDA-R and two anti-CASPR2 antibodies, and one was seronegative. 18F-FDG-PET metabolic abnormalities were present in all cases, regardless of the method of analysis. Medial–temporal and extra-limbic hypermetabolism were more clearly depicted by voxel-based analyses. We found autoantibody-specific patterns in line with the literature. Statistical surface projection (SSP) methods (Neurostat and syngo.via Database Comparison) were more sensitive and localized larger hypermetabolic areas. As it may lead to comparable and accurate results, visual analysis of FDG-PET studies for the diagnosis of autoimmune encephalitis benefits from voxel-based analysis, beyond the approach based on MRI, CSF sample and EEG

Elevated circulating metalloproteinase 7 predicts recurrent cardiovascular events in patients with carotid stenosis: a prospective cohort study

Background: Major adverse cardiovascular events are the main cause of morbidity and mortality over the long term in patients undergoing carotid endarterectomy. There are few reports assessing the prognostic value of markers of inflammation in relation to the risk of cardiovascular disease after carotid endarterectomy. Here, we aimed to determine whether matrix metalloproteinases (MMP-1, MMP-2, MMP-7, MMP-9 and MMP-10), tissue inhibitor of MMPs (TIMP-1) and in vivo inflammation studied by 18F-FDG-PET/CT predict recurrent cardiovascular events in patients with carotid stenosis who underwent endarterectomy. Methods: This prospective cohort study was carried out on 31 consecutive patients with symptomatic (23/31) or asymptomatic (8/31) severe (> 70%) carotid stenosis who were scheduled for carotid endarterectomy between July 2013 and March 2016. In addition, 26 healthy controls were included in the study. Plasma and serum samples were collected 2 days prior to surgery and tested for MMP-1, MMP-2, MMP-7, MMP-9, MMP-10, TIMP-1, high-density lipoprotein, low-density lipoprotein, high-sensitivity C-reactive protein and erythrocyte sedimentation rate. 18F-FDGPET/CT focusing on several territories’ vascular wall metabolism was performed on 29 of the patients because of no presurgical availability in 2 symptomatic patients. Histological and immunohistochemical studies were performed with antibodies targeting MMP-10, MMP-9, TIMP-1 and CD68. Results: The patients with carotid stenosis had significantly more circulating MMP-1, MMP-7 and MMP-10 than the healthy controls. Intraplaque TIMP-1 was correlated with its plasma level (r = 0.42 P = .02) and with 18F-FDG uptake (r = 0.38 P = .05). We did not find any correlation between circulating MMPs and in vivo carotid plaque metabolism assessed by 18F-FDG-PET. After a median follow-up of 1077 days, 4 cerebrovascular, 7 cardiovascular and 11 peripheral vascular events requiring hospitalization were registered. Circulating MMP-7 was capable of predicting events over and above the traditional risk factors (HR = 1.15 P = .006). When the model was associated with the variables of interest, the risk predicted by 18F-FDG-PET was not significant. Conclusions: Circulating MMP-7 may represent a novel marker for recurrent cardiovascular events in patients with moderate to severe carotid stenosis. MMP-7 may reflect the atherosclerotic burden but not plaque inflammation in this specific vascular territory

Estudio de la placa carotídea vulnerable: correlación entre los niveles de metaloproteasas y la presencia de actividad inflamatoria intraplaca

Introducción: La estenosis carotídea es responsable de un 20% de todos los ictus isquémicos. Teniendo en cuenta que la aterosclerosis es una enfermedad inflamatoria crónica, es posible que determinados marcadores de inflamación permitan predecir el riesgo de recurrencia de ictus, y otras complicaciones vasculares en pacientes con estenosis carotídea grave (>70%) sometidos a endarterectomía carotídea. El objetivo principal del presente estudio fue determinar si los niveles circulantes de metaloproteasas (MMPs) de matriz extracelular (MMP-1, MMP-2, MMP-7, MMP-9 y MMP-10), el inhibidor tisular de MMPs (TIMP-1) y la cuantificación de la inflamación in vivo de la placa carotídea estudiada de forma no invasiva mediante 18F-FDG-PET / CT son útiles para diferenciar entre pacientes con estenosis carótidea sintomáticas y asintomáticas, o en la predicción de eventos vasculares recurrentes en pacientes con estenosis carotídea sometidos a endarterectomía. Pacientes y métodos: Estudio de cohorte prospectivo, longitudinal multicéntrico. Se reclutaron pacientes atendidos en la Unidad de Ictus del Hospital de Navarra y la Clínica Universidad de Navarra con edades comprendidas entre 50-80 años con diagnóstico de infarto cerebral (con déficit menor) o AIT de origen aterotrombótico por estenosis carotídea grave, y pacientes con estenosis carotídea grave asintomática, que fueron sometidos a endarterectomía carotídea. Se obtuvieron muestras de plasma y suero 2 días antes de la cirugía y se analizaron los niveles de MMP-1, MMP-2, MMP-7, MMP9, MMP-10, TIMP-1, HDL, LDL, proteína C reactiva y velocidad de sedimentación globular. Se realizó un estudio 18F-FDG-PET / CT para cuantificar el metabolismo de la pared vascular de ambas carótidas y otros territorios vasculares, como reflejo de la presencia de inflamación intraplaca. Se realizaron estudios histológicos e inmunohistoquímicos con anticuerpos dirigidos frente a MMP-10, MMP-9, TIMP-1 y CD68 en la placa carotídea extraída quirúrgicamente mediante endarterectomía. Asimismo, se incluyeron en el estudio 26 controles sanos, trabajadores de la Universidad de Navarra, comparables en edad y sexo a la población de pacientes. Resultados: Se incluyeron 31 pacientes consecutivos con estenosis carotídea sintomática (n=23) o asintomática (n=8) grave a los que se les realizó endarterectomía carotídea entre julio de 2013 y marzo de 2016. Los pacientes con estenosis carotídea presentaron niveles circulantes de MMP-1, MMP-7 y MMP-10 significativamente más elevados que los controles sanos. No se encontró ninguna correlación entre las MMPs circulantes y el grado de inflamación en la placa carotídea in vivo evaluado mediante 18F-FDG-PET / CT. El TIMP-1 intraplaca se correlacionó moderadamente con su nivel plasmático (r = 0,42 p = 0,02) y con la captación de 18F-FDG-PET / CT (r = 0,38 p = 0,05). Después de una mediana de seguimiento de 1077 días, se registraron 4 eventos cerebrovasculares, 7 eventos cardiovasculares y 11 eventos vasculares periféricos que requirieron hospitalización. El nivel de MMP-7 circulante fue capaz de predecir eventos más allá de los factores de riesgo tradicionales (HR = 1,15 p = 0,006). Cuando el modelo de regresión se asoció con las variables de interés, la capacidad de la 18F-FDG-PET / CT para predecir eventos vasculares no fue significativa. Conclusiones: Los hallazgos del presente estudio no apoyan el uso de 18FFDG-PET / CT o los niveles de metaloproteasas o sus inhibidores para diferenciar estenosis carotídeas sintomáticas o asintomáticas y tampoco para establecer el riesgo de recurrencia de ictus. Nuestros hallazgos proporcionan evidencia de que la MMP-7 circulante podría representar un biomarcador de eventos cardiovasculares recurrentes en pacientes con estenosis carotídea grave

Estudio de la placa carotídea vulnerable: correlación entre los niveles de metaloproteasas y la presencia de actividad inflamatoria intraplaca

Introducción: La estenosis carotídea es responsable de un 20% de todos los ictus isquémicos. Teniendo en cuenta que la aterosclerosis es una enfermedad inflamatoria crónica, es posible que determinados marcadores de inflamación permitan predecir el riesgo de recurrencia de ictus, y otras complicaciones vasculares en pacientes con estenosis carotídea grave (>70%) sometidos a endarterectomía carotídea. El objetivo principal del presente estudio fue determinar si los niveles circulantes de metaloproteasas (MMPs) de matriz extracelular (MMP-1, MMP-2, MMP-7, MMP-9 y MMP-10), el inhibidor tisular de MMPs (TIMP-1) y la cuantificación de la inflamación in vivo de la placa carotídea estudiada de forma no invasiva mediante 18F-FDG-PET / CT son útiles para diferenciar entre pacientes con estenosis carótidea sintomáticas y asintomáticas, o en la predicción de eventos vasculares recurrentes en pacientes con estenosis carotídea sometidos a endarterectomía. Pacientes y métodos: Estudio de cohorte prospectivo, longitudinal multicéntrico. Se reclutaron pacientes atendidos en la Unidad de Ictus del Hospital de Navarra y la Clínica Universidad de Navarra con edades comprendidas entre 50-80 años con diagnóstico de infarto cerebral (con déficit menor) o AIT de origen aterotrombótico por estenosis carotídea grave, y pacientes con estenosis carotídea grave asintomática, que fueron sometidos a endarterectomía carotídea. Se obtuvieron muestras de plasma y suero 2 días antes de la cirugía y se analizaron los niveles de MMP-1, MMP-2, MMP-7, MMP9, MMP-10, TIMP-1, HDL, LDL, proteína C reactiva y velocidad de sedimentación globular. Se realizó un estudio 18F-FDG-PET / CT para cuantificar el metabolismo de la pared vascular de ambas carótidas y otros territorios vasculares, como reflejo de la presencia de inflamación intraplaca. Se realizaron estudios histológicos e inmunohistoquímicos con anticuerpos dirigidos frente a MMP-10, MMP-9, TIMP-1 y CD68 en la placa carotídea extraída quirúrgicamente mediante endarterectomía. Asimismo, se incluyeron en el estudio 26 controles sanos, trabajadores de la Universidad de Navarra, comparables en edad y sexo a la población de pacientes. Resultados: Se incluyeron 31 pacientes consecutivos con estenosis carotídea sintomática (n=23) o asintomática (n=8) grave a los que se les realizó endarterectomía carotídea entre julio de 2013 y marzo de 2016. Los pacientes con estenosis carotídea presentaron niveles circulantes de MMP-1, MMP-7 y MMP-10 significativamente más elevados que los controles sanos. No se encontró ninguna correlación entre las MMPs circulantes y el grado de inflamación en la placa carotídea in vivo evaluado mediante 18F-FDG-PET / CT. El TIMP-1 intraplaca se correlacionó moderadamente con su nivel plasmático (r = 0,42 p = 0,02) y con la captación de 18F-FDG-PET / CT (r = 0,38 p = 0,05). Después de una mediana de seguimiento de 1077 días, se registraron 4 eventos cerebrovasculares, 7 eventos cardiovasculares y 11 eventos vasculares periféricos que requirieron hospitalización. El nivel de MMP-7 circulante fue capaz de predecir eventos más allá de los factores de riesgo tradicionales (HR = 1,15 p = 0,006). Cuando el modelo de regresión se asoció con las variables de interés, la capacidad de la 18F-FDG-PET / CT para predecir eventos vasculares no fue significativa. Conclusiones: Los hallazgos del presente estudio no apoyan el uso de 18FFDG-PET / CT o los niveles de metaloproteasas o sus inhibidores para diferenciar estenosis carotídeas sintomáticas o asintomáticas y tampoco para establecer el riesgo de recurrencia de ictus. Nuestros hallazgos proporcionan evidencia de que la MMP-7 circulante podría representar un biomarcador de eventos cardiovasculares recurrentes en pacientes con estenosis carotídea grave

18F-FDG-PET Imaging Patterns in Autoimmune Encephalitis: Impact of Image Analysis on the Results

Brain positron emission tomography imaging with 18Fluorine-fluorodeoxyglucose (FDG-PET) has demonstrated utility in suspected autoimmune encephalitis. Visual and/or assisted image reading is not well established to evaluate hypometabolism/hypermetabolism. We retrospectively evaluated patients with autoimmune encephalitis between 2003 and 2018. Patients underwent EEG, brain magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) sampling and autoantibodies testing. Individual FDG-PET images were evaluated by standard visual reading and assisted by voxel-based analyses, compared to a normal database. For the latter, three different methods were performed: two based on statistical surface projections (Siemens syngo.via Database Comparison, and 3D-SSP Neurostat) and one based on statistical parametric mapping (SPM12). Hypometabolic and hypermetabolic findings were grouped to identify specific patterns. We found six cases with definite diagnosis of autoimmune encephalitis. Two cases had anti-LGI1, one had anti-NMDA-R and two anti-CASPR2 antibodies, and one was seronegative. 18F-FDG-PET metabolic abnormalities were present in all cases, regardless of the method of analysis. Medial–temporal and extra-limbic hypermetabolism were more clearly depicted by voxel-based analyses. We found autoantibody-specific patterns in line with the literature. Statistical surface projection (SSP) methods (Neurostat and syngo.via Database Comparison) were more sensitive and localized larger hypermetabolic areas. As it may lead to comparable and accurate results, visual analysis of FDG-PET studies for the diagnosis of autoimmune encephalitis benefits from voxel-based analysis, beyond the approach based on MRI, CSF sample and EEG

Elevated circulating metalloproteinase 7 predicts recurrent cardiovascular events in patients with carotid stenosis: a prospective cohort study

Background: Major adverse cardiovascular events are the main cause of morbidity and mortality over the long term in patients undergoing carotid endarterectomy. There are few reports assessing the prognostic value of markers of inflammation in relation to the risk of cardiovascular disease after carotid endarterectomy. Here, we aimed to determine whether matrix metalloproteinases (MMP-1, MMP-2, MMP-7, MMP-9 and MMP-10), tissue inhibitor of MMPs (TIMP-1) and in vivo inflammation studied by 18F-FDG-PET/CT predict recurrent cardiovascular events in patients with carotid stenosis who underwent endarterectomy. Methods: This prospective cohort study was carried out on 31 consecutive patients with symptomatic (23/31) or asymptomatic (8/31) severe (> 70%) carotid stenosis who were scheduled for carotid endarterectomy between July 2013 and March 2016. In addition, 26 healthy controls were included in the study. Plasma and serum samples were collected 2 days prior to surgery and tested for MMP-1, MMP-2, MMP-7, MMP-9, MMP-10, TIMP-1, high-density lipoprotein, low-density lipoprotein, high-sensitivity C-reactive protein and erythrocyte sedimentation rate. 18F-FDGPET/CT focusing on several territories’ vascular wall metabolism was performed on 29 of the patients because of no presurgical availability in 2 symptomatic patients. Histological and immunohistochemical studies were performed with antibodies targeting MMP-10, MMP-9, TIMP-1 and CD68. Results: The patients with carotid stenosis had significantly more circulating MMP-1, MMP-7 and MMP-10 than the healthy controls. Intraplaque TIMP-1 was correlated with its plasma level (r = 0.42 P = .02) and with 18F-FDG uptake (r = 0.38 P = .05). We did not find any correlation between circulating MMPs and in vivo carotid plaque metabolism assessed by 18F-FDG-PET. After a median follow-up of 1077 days, 4 cerebrovascular, 7 cardiovascular and 11 peripheral vascular events requiring hospitalization were registered. Circulating MMP-7 was capable of predicting events over and above the traditional risk factors (HR = 1.15 P = .006). When the model was associated with the variables of interest, the risk predicted by 18F-FDG-PET was not significant. Conclusions: Circulating MMP-7 may represent a novel marker for recurrent cardiovascular events in patients with moderate to severe carotid stenosis. MMP-7 may reflect the atherosclerotic burden but not plaque inflammation in this specific vascular territory

Id1 and PD-1 Combined Blockade Impairs Tumor Growth and Survival of KRAS-mutant Lung Cancer by Stimulating PD-L1 Expression and Tumor Infiltrating CD8+ T Cells

The use of PD-1/PD-L1 checkpoint inhibitors in advanced NSCLC is associated with longer survival. However, many patients do not benefit from PD-1/PD-L1 blockade, largely because of immunosuppression. New immunotherapy-based combinations are under investigation in an attempt to improve outcomes. Id1 (inhibitor of differentiation 1) is involved in immunosuppression. In this study, we explored the potential synergistic effect of the combination of Id1 inhibition and pharmacological PD-L1 blockade in three different syngeneic murine KRAS-mutant lung adenocarcinoma models. TCGA analysis demonstrated a negative and statistically significant correlation between PD-L1 and Id1 expression levels. This observation was confirmed in vitro in human and murine KRAS-driven lung cancer cell lines. In vivo experiments in KRAS-mutant syngeneic and metastatic murine lung adenocarcinoma models showed that the combined blockade targeting Id1 and PD-1 was more effective than each treatment alone in terms of tumor growth impairment and overall survival improvement. Mechanistically, multiplex quantification of CD3+/CD4+/CD8+ T cells and flow cytometry analysis showed that combined therapy favors tumor infiltration by CD8+ T cells, whilst in vivo CD8+ T cell depletion led to tumor growth restoration. Co-culture assays using CD8+ cells and tumor cells showed that T cells present a higher antitumor effect when tumor cells lack Id1 expression. These findings highlight that Id1 blockade may contribute to a significant immune enhancement of antitumor efficacy of PD-1 inhibitors by increasing PD-L1 expression and harnessing tumor infiltration of CD8+ T lymphocytes

Id1 and PD-1 Combined Blockade Impairs Tumor Growth and Survival of KRAS-mutant Lung Cancer by Stimulating PD-L1 Expression and Tumor Infiltrating CD8+ T Cells

The use of PD-1/PD-L1 checkpoint inhibitors in advanced NSCLC is associated with longer survival. However, many patients do not benefit from PD-1/PD-L1 blockade, largely because of immunosuppression. New immunotherapy-based combinations are under investigation in an attempt to improve outcomes. Id1 (inhibitor of differentiation 1) is involved in immunosuppression. In this study, we explored the potential synergistic effect of the combination of Id1 inhibition and pharmacological PD-L1 blockade in three different syngeneic murine KRAS-mutant lung adenocarcinoma models. TCGA analysis demonstrated a negative and statistically significant correlation between PD-L1 and Id1 expression levels. This observation was confirmed in vitro in human and murine KRAS-driven lung cancer cell lines. In vivo experiments in KRAS-mutant syngeneic and metastatic murine lung adenocarcinoma models showed that the combined blockade targeting Id1 and PD-1 was more effective than each treatment alone in terms of tumor growth impairment and overall survival improvement. Mechanistically, multiplex quantification of CD3+/CD4+/CD8+ T cells and flow cytometry analysis showed that combined therapy favors tumor infiltration by CD8+ T cells, whilst in vivo CD8+ T cell depletion led to tumor growth restoration. Co-culture assays using CD8+ cells and tumor cells showed that T cells present a higher antitumor effect when tumor cells lack Id1 expression. These findings highlight that Id1 blockade may contribute to a significant immune enhancement of antitumor efficacy of PD-1 inhibitors by increasing PD-L1 expression and harnessing tumor infiltration of CD8+ T lymphocytes