Percutaneous Gastrostomies: Associated Complications in PUSH vs. PULL Techniques over 12 Years in a Referral Centre.

Objectives: To compare complications associated with percutaneous gastrostomies performed using PUSH and PULL techniques, whether endoscopic (PEG) or radiological (PRG), in a tertiary-level hospital. Methods: This was a prospective observational study. Adult patients who underwent percutaneous PULL or PUSH gastrostomy using PEG or PRG techniques at the Virgen del Rocio University Hospital and subsequently followed up in the Nutrition Unit between 2009-2020 were included. X2 tests or Fisher's test were used for the comparison of proportions when necessary. Univariate analysis was conducted to study risk factors for PRG-associated complications. Results: n = 423 (PULL = 181; PUSH = 242). The PULL technique was associated with a higher percentage of total complications (37.6% vs. 23.8%; p = 0.005), exudate (18.2% vs. 11.2%; p = 0.039), and irritation (3.3% vs. 0%; p = 0.006). In the total sample, there were 5 (1.1%) cases of peritonitis, 3 (0.7%) gastrocolic fistulas, and 1 (0.2%) death due to complications associated with gastrostomy. Gender, age, and different indications were not risk factors for a higher number of complications. The most common indications were neurological diseases (35.9%), head and neck cancer (29%), and amyotrophic lateral sclerosis (17.2%). Conclusions: The PULL technique was associated with more total complications than the PUSH technique, but both were shown to be safe techniques, as the majority of complications were minor.

Gastrostomies: experience and complications with three modalities in a tertiary centre over a 26-year period.

Objectives: To describe the complications associated with the different gastrostomy techniques [endoscopic (PEG), radiologic (PRG), and surgical (SG)] performed in the last 26 years in a terciary hospital. Methods: Retrospective observational study. Patients who underwent gastrostomy at the Virgen del Rocío University Hospital between 1995 and 2021 were included. For PEG, the PULL technique was performed until 2018 and subsequently the PUSH technique predominantly. For PRG, a pigtail catheter was used until 2003, a balloon catheter between 2003 and 2009, and a balloon catheter with gastropexy between 2015 and 2021. For SG, the conventional technique (CSG) was performed until 2009 and since then the laparoscopic assisted percutaneous gastrostomy (PLAG) technique. Descriptive analysis was performed obtaining the median and quartiles of the quantitative variables [P50 (P25-P75)] and the frequency for the qualitative variables [n (%)].The comparison of complications between patients who underwent different techniques was performed with Fisher's test. Results: n = 1,070 (PEG = 608, PRG = 344, SG = 118). The three most frequent indications were head and neck tumors, neurological diseases and gastroesophageal tumors. The percentage of patients who had any complication was 48.9% (PEG-PULL), 23.7% (PEG-PUSH), 38.5% (pigtail PRG), 39.2% (balloon PRG), 29.7% (balloon with gastropexy PRG), 87.3% (CSG), and 41.26% (PLAG). 2 (0.18%) patients died from gastrostomy-related complications. 18(1.68%) presented with peritonitis and 5 (0.4%) presented with gastrocolic fistula. The rest of the complications were minor. Conclusion: Gastrostomy in any of its modalities is currently a safe procedure with a low rate of complications, most of which are minor.

Deliberative processes in health technology assessment of medicines: the case of Spain.

OBJECTIVES: Spain incorporated in 2020 changes in its health technology assessment (HTA), pricing, and reimbursement system for medicines including publishing reports, development of networks of experts, or consultation with stakeholders. Despite these changes, it is unclear how deliberative frameworks are applied and the process has been criticized for not being sufficiently transparent. This study analyses the level of implementation of deliberative processes in HTA for medicines in Spain. METHODS: We review the grey literature and summarize the Spanish HTA, pricing, and reimbursement process of medicines. We apply the deliberative processes for HTA checklist, developed to assess the overall context of the deliberative process, and identify the stakeholders involved and type of involvement following the framework for evidence-informed deliberative processes, a framework for benefit package design that aims to optimize the legitimacy of decision making. RESULTS: In the Spanish HTA, pricing, and reimbursement process deliberation takes place in order to exchange viewpoints and reach common ground, mainly during the prioritization, assessment, and appraisal steps. It is closed to the public, not clearly summarized in published documents and limited to the Ministry of Health, the regulatory agency, other Ministries, and experts with mostly clinical and/or pharmaceutical background. The views of stakeholders are only represented through consultation. Communication is the most commonly used form of stakeholder engagement. CONCLUSIONS: Despite improvements in transparency of the Spanish HTA process for evaluating medicines, aspects related to stakeholder involvement and implementation of deliberative frameworks need further attention in order to achieve further legitimacy of the process.

Percutaneous Radiology Gastrostomy (PRG)-Associated Complications at a Tertiary Hospital over the Last 25 Years.

OBJECTIVES: We aimed to describe and compare the complications associated with different percutaneous radiologic gastrostomy (PRG) techniques. METHODS: A retrospective and prospective observational study was conducted. Patients who underwent a PRG between 1995-2020 were included. TECHNIQUES: A pigtail catheter was used until 2003, a balloon catheter without pexy was used between 2003-2009 and a balloon catheter with gastropexy was used between 2015-2021. For the comparison of proportions, X2 tests or Fisher's test were used when necessary. Univariate analysis was performed to study the risk factors for PRG-associated complications. RESULTS: n = 330 (pigtail = 114, balloon-type without pexy = 28, balloon-type with pexy = 188). The most frequent indication was head and neck cancer. The number of patients with complications was 44 (38.5%), 11 (39.2%) and 54 (28,7%), respectively. There were seven (25%) cases of peritonitis in the balloon-type without-pexy group and 1 (0.5%) in the balloon-type with-pexy group, the latter being the only patient who died in the total number of patients (0.3%). Two (1%) patients of the balloon-type with-pexy group presented with gastrocolic fistula. The rest of the complications were minor. CONCLUSIONS: The most frequent complications associated with the administration of enteral nutrition through PRG were minor and the implementation of the balloon-type technique with pexy has led to a decrease in them.

Institutionalizing health technology assessment in Egypt: Situational analysis and roadmap.

Objective: To conduct a situational analysis with the aim to inform future health technology assessment efforts (HTA) in Egypt. Introduction: The Egyptian government has set universal health coverage as a 2030 target. Several agencies have been created in the context of the ongoing healthcare reform. The Egyptian Authority for Unified Procurement, Medical Supply and the Management of Medical Technology (UPA) is one of them and was established to support strategic procurement using HTA. Methods: Description of the development of HTA in Egypt supported by a literature search as part of a scoping exercise, and a stakeholder analysis and identification of HTA capacity survey, based on previous surveys, with relevant stakeholders conducted in 2022. This was followed by a stakeholder event where results were shared and further contextualized. Results: The UPA is expected to evaluate the cost-effectiveness of health technologies and public health programs. The HTA process is being developed, focusing on the assessment of the value of new pharmaceuticals being introduced to the Egyptian market. A total of 16 participants responded on behalf of their organizations to the stakeholder analysis and identification of HTA capacity survey. More than 80% of the respondents were familiar with current efforts conducted by UPA and strongly support the implementation of HTA in Egypt. Transparency was highlighted as an important criterion. Over 90% of the respondents mentioned economic analyses as an HTA product being developed in Egypt, and medicines were the type of technology that stakeholders ranked as first in the rank of health technologies that need the output from HTA urgently. Capability building and training were highlighted as areas in which further support is required. Conclusion: This study represents the first attempt to describe the current path for HTA in Egypt. There seems to be momentum in Egypt to proceed and advance with HTA institutionalization. It would be important that next steps are built on the skills and capabilities already in place in Egypt, ensure methods and processes are in place and up to date and involve the wider system in Egypt so stakeholders can appropriately contribute and participate in the HTA process.

Inhibition of pyrimidine biosynthesis targets protein translation in acute myeloid leukemia.

The mitochondrial enzyme dihydroorotate dehydrogenase (DHODH) catalyzes one of the rate-limiting steps in de novo pyrimidine biosynthesis, a pathway that provides essential metabolic precursors for nucleic acids, glycoproteins, and phospholipids. DHODH inhibitors (DHODHi) are clinically used for autoimmune diseases and are emerging as a novel class of anticancer agents, especially in acute myeloid leukemia (AML) where pyrimidine starvation was recently shown to reverse the characteristic differentiation block in AML cells. Herein, we show that DHODH blockade rapidly shuts down protein translation in leukemic stem cells (LSCs) and has potent and selective activity against multiple AML subtypes. Moreover, we find that ablation of CDK5, a gene that is recurrently deleted in AML and related disorders, increases the sensitivity of AML cells to DHODHi. Our studies provide important molecular insights and identify a potential biomarker for an emerging strategy to target AML.

Epigenetic Activation of Plasmacytoid DCs Drives IFNAR-Dependent Therapeutic Differentiation of AML.

Pharmacologic inhibition of epigenetic enzymes can have therapeutic benefit against hematologic malignancies. In addition to affecting tumor cell growth and proliferation, these epigenetic agents may induce antitumor immunity. Here, we discovered a novel immunoregulatory mechanism through inhibition of histone deacetylases (HDAC). In models of acute myeloid leukemia (AML), leukemia cell differentiation and therapeutic benefit mediated by the HDAC inhibitor (HDACi) panobinostat required activation of the type I interferon (IFN) pathway. Plasmacytoid dendritic cells (pDC) produced type I IFN after panobinostat treatment, through transcriptional activation of IFN genes concomitant with increased H3K27 acetylation at these loci. Depletion of pDCs abrogated panobinostat-mediated induction of type I IFN signaling in leukemia cells and impaired therapeutic efficacy, whereas combined treatment with panobinostat and IFNα improved outcomes in preclinical models. These discoveries offer a new therapeutic approach for AML and demonstrate that epigenetic rewiring of pDCs enhances antitumor immunity, opening the possibility of exploiting this approach for immunotherapies. SIGNIFICANCE: We demonstrate that HDACis induce terminal differentiation of AML through epigenetic remodeling of pDCs, resulting in production of type I IFN that is important for the therapeutic effects of HDACis. The study demonstrates the important functional interplay between the immune system and leukemias in response to HDAC inhibition. This article is highlighted in the In This Issue feature, p. 1397.

A Histone Deacetylase Inhibitor, Panobinostat, Enhances Chimeric Antigen Receptor T-cell Antitumor Effect Against Pancreatic Cancer.

PURPOSE: In this article, we describe a combination chimeric antigen receptor (CAR) T-cell therapy that eradicated the majority of tumors in two immunocompetent murine pancreatic cancer models and a human pancreatic cancer xenograft model. EXPERIMENTAL DESIGN: We used a dual-specific murine CAR T cell that expresses a CAR against the Her2 tumor antigen, and a T-cell receptor (TCR) specific for gp100. As gp100 is also known as pMEL, the dual-specific CAR T cells are thus denoted as CARaMEL cells. A vaccine containing live vaccinia virus coding a gp100 minigene (VV-gp100) was administered to the recipient mice to stimulate CARaMEL cells. The treatment also included the histone deacetylase inhibitor panobinostat (Pano). RESULTS: The combination treatment enabled significant suppression of Her2+ pancreatic cancers leading to the eradication of the majority of the tumors. Besides inducing cancer cell apoptosis, Pano enhanced CAR T-cell gene accessibility and promoted CAR T-cell differentiation into central memory cells. To test the translational potential of this approach, we established a method to transduce human T cells with an anti-Her2 CAR and a gp100-TCR. The exposure of the human T cells to Pano promoted a T-cell central memory phenotype and the combination treatment of human CARaMEL cells and Pano eradicated human pancreatic cancer xenografts in mice. CONCLUSIONS: We propose that patients with pancreatic cancer could be treated using a scheme that contains dual-specific CAR T cells, a vaccine that activates the dual-specific CAR T cells through their TCR, and the administration of Pano.

CDK4/6 Inhibition Promotes Antitumor Immunity through the Induction of T-cell Memory.

Pharmacologic inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6) are an approved treatment for hormone receptor-positive breast cancer and are currently under evaluation across hundreds of clinical trials for other cancer types. The clinical success of these inhibitors is largely attributed to well-defined tumor-intrinsic cytostatic mechanisms, whereas their emerging role as immunomodulatory agents is less understood. Using integrated epigenomic, transcriptomic, and proteomic analyses, we demonstrated a novel action of CDK4/6 inhibitors in promoting the phenotypic and functional acquisition of immunologic T-cell memory. Short-term priming with a CDK4/6 inhibitor promoted long-term endogenous antitumor T-cell immunity in mice, enhanced the persistence and therapeutic efficacy of chimeric antigen receptor T cells, and induced a retinoblastoma-dependent T-cell phenotype supportive of favorable responses to immune checkpoint blockade in patients with melanoma. Together, these mechanistic insights significantly broaden the prospective utility of CDK4/6 inhibitors as clinical tools to boost antitumor T-cell immunity. SIGNIFICANCE: Immunologic memory is critical for sustained antitumor immunity. Our discovery that CDK4/6 inhibitors drive T-cell memory fate commitment sheds new light on their clinical activity, which is essential for the design of clinical trial protocols incorporating these agents, particularly in combination with immunotherapy, for the treatment of cancer.This article is highlighted in the In This Issue feature, p. 2355.

Impact of Systemic Lupus Erythematosus on Pregnancy: Analysis of a Large 10-Year Longitudinal Mexican Cohort.

BACKGROUND: Pregnancy in patients with systemic lupus erythematosus is considered a high risk one since it is associated with a higher rate of maternal-fetal complications compared with the pregnancies in healthy women. OBJECTIVES: The aim of this study was to describe the maternal-fetal outcomes in a cohort of Mexican patients with systemic lupus erythematosus and to identify risk factors associated with adverse maternal and fetal outcomes. PATIENTS AND METHODS: A cohort of pregnant lupus patients was analyzed. Maternal-fetal complications were described, and clinical, biochemical, and immunological variables associated with obstetric adverse outcomes were studied. Descriptive statistics, comparison of variables using appropriate tests, and finally logistic regression analysis were performed to identify potential risk factors for adverse maternal and fetal outcomes. RESULTS: A total of 351 pregnancies were included in a 10-year period. The most frequently observed maternal adverse outcomes were lupus flare (35%) and preeclampsia (14.5%). Active lupus before pregnancy (hazards ratio [HR], 3.7; 95% confidence interval [CI], 1.1-12.5; p = 0.003) was a predictor for these complications, whereas the use of antimalarial drugs (HR, 0.4; 95% CI, 0.2-0.7; p = 0.007) was a protective factor. The most frequent fetal adverse outcomes were preterm birth (38.1%), miscarriages (10%), and low birth weight babies (28%), and very low birth weight newborns (11%). Proteinuria in early pregnancy (HR, 7.1; 95% CI, 1.01-50.3; p = 0.04) and preeclampsia (HR, 9.3; 95% CI, 1.7-49.7; p = 0.009) were risk factors associated with these complications. CONCLUSIONS: Variables related to systemic lupus erythematosus activity predict an adverse maternal outcome, whereas proteinuria in early pregnancy and preeclampsia are associated with an adverse fetal outcome.

NICE's evaluations of medicines authorized by EMA with conditional marketing authorization or under exceptional circumstances.

OBJECTIVES: To investigate the impact of the uncertainty stemming from products with European conditional marketing authorization (CMA) or authorization in exceptional circumstances (AEC) on the National Institute for Health and Care Excellence's (NICE) recommendations. METHODS: Products which received CMA/AEC by European Medicines Agency (EMA) up to 1 December 2016 were identified and matched with corresponding NICE decisions issued by August 2017, the status of which was then traced to August 2019. We assessed whether the conversion of CMA to full marketing authorization triggered a review of a NICE decision. The odds of a recommendation carrying a commercial arrangement for products with and without CMA/AEC were calculated. RESULTS: Fifty-four products were granted CMA/AEC by EMA. NICE conducted thirty evaluations of products with CMA/AEC. Twelve products were recommended by NICE by August 2017 and fourteen by August 2019. All recommendations had an associated commercial arrangement. The odds of carrying a commercial arrangement were higher for products with CMA/AEC compared to those with full authorization. Conversions from conditional to full authorization among products not recommended by NICE did not trigger an appraisal review. CONCLUSIONS: Uncertainty, stemming from the lack of robust clinical data of products authorized with CMA/AEC, has a substantial impact on HTA recommendations, frequently requiring risk mitigation mechanisms such as commercial and data collection arrangements. Further analyses should be conducted to assess whether the benefits of early access strategies outweigh the risks for patients and the healthcare system.

TET2 deficiency reprograms the germinal center B cell epigenome and silences genes linked to lymphomagenesis.

The TET2 DNA hydroxymethyltransferase is frequently disrupted by somatic mutations in diffuse large B cell lymphomas (DLBCLs), a tumor that originates from germinal center (GC) B cells. Here, we show that TET2 deficiency leads to DNA hypermethylation of regulatory elements in GC B cells, associated with silencing of the respective genes. This hypermethylation affects the binding of transcription factors including those involved in exit from the GC reaction and involves pathways such as B cell receptor, antigen presentation, CD40, and others. Normal GC B cells manifest a typical hypomethylation signature, which is caused by AID, the enzyme that mediates somatic hypermutation. However, AID-induced demethylation is markedly impaired in TET2-deficient GC B cells, suggesting that AID epigenetic effects are partially dependent on TET2. Last, we find that TET2 mutant DLBCLs also manifest the aberrant TET2-deficient GC DNA methylation signature, suggesting that this epigenetic pattern is maintained during and contributes to lymphomagenesis.

Use of antimalarial drugs is associated with a lower risk of preeclampsia in lupus pregnancy: A prospective cohort study.

INTRODUCTION: Several factors have been associated with the development of preeclampsia in women with systemic lupus erythematosus (SLE). OBJECTIVE: To identify risk factors associated with preeclampsia in patients with SLE and its impact on fetal outcomes. PATIENTS AND METHODS: We studied a prospective cohort of pregnancies in women with SLE from January 2009 to December 2018. Demographic, clinical, serological and drug use characteristics were compared between patients who developed preeclampsia and those who did not, as well as the main neonatal outcomes. An adjusted logistic regression analysis was performed to identify factors potentially associated with preeclampsia. RESULTS: We studied 316 pregnancies of 20 or more weeks of gestation. A total of 46 pregnancies (14.5%) were complicated by preeclampsia. A higher frequency of active disease before pregnancy (24.4% vs 11.3%, P = .01) and history of lupus nephritis (56.5% vs 30.1%, P < .001) were found in those patients who developed preeclampsia compared to those who did not. Preeclampsia was associated with a higher rate of prematurity, births of very low birth weight, stillbirth, and neonatal death. The multivariate analysis showed that the activity of the disease before (relative risk [RR] 2.7, 95% CI 1.04-7.4, P = .04) and during pregnancy (RR 3.0, 95% CI 1.0-9.1, P = .04) was associated with the development of preeclampsia. The use of antimalarial drugs during pregnancy was associated with a lower risk of preeclampsia (RR 0.21, 95% CI 0.08-0.53, P < .001). CONCLUSIONS: Our study suggests that the use of antimalarial drugs during pregnancy reduces the risk of preeclampsia in lupus pregnancies.

[Analysis of the situation, evaluation and improvement proposals of the Preventive Activities and Health Promotion Program (PAPPS)]. / Análisis de la situación, evaluación y propuestas de mejora del Programa de Actividades Preventivas y de Promoción de la Salud (PAPPS).

OBJECTIVE: To analyze the situation, evaluation and proposals for improvement of the Preventive Activities and Health Promotion Program (PAPPS). MATERIAL AND METHODS: A qualitative study of situation analysis was carried out for the evaluation of the PAPPS in 2 phases: 1) Generation of ideas and collection of information through a DAFO matrix, using 2 types of criteria: internal (strengths and weaknesses), and external (threats and opportunities); 2) Prioritization of the improvement proposals collected. Selection of participants: Key informants were identified taking into account their relationship and knowledge of the PAPPS program. All members of the PAPPS, expert groups and members with past participation were included, as well as the coordinators, including the autonomous leaders of the PAPPS. Two invitations to participate in the study were sent: the first from December 29, 2017 to February 11, 2018, and the second from January 10 to 23, 2019. The information was obtained from a questionnaire designed to be self-completed. RESULTS AND CONCLUSIONS: A total of 73 subjects answered the questionnaire. 35% of the participants were members of the PAPPS working groups, followed by family doctors from other areas, with 20.5%. The order of prioritization of the improvement proposals was as follows: 1) Unify recommendations with other semFYC working groups; 2) Prepare lists with "Recommendations not to do" from the point of view of prevention; 3) Incorporate PAPPS in the political agenda; 4) Greater coordination and interaction between groups with common competences; 5) Teaching in undergraduate and teaching units; 6) Review, update and dissemination of the program in Primary Care.

Probiotics' effectiveness on symptoms, histological features and feeding tolerance in ulcerative colitis / Efectividad de probióticos sobre síntomas, histología y tolerancia alimentaria en colitis ulcerativa

Background: Probiotics have been used in the adjuvant treatment of Ulcerative Colitis (UC). Objective: To evaluate the role of a combination of probiotics on the clinical, histological changes and feeding tolerance in patients with UC. Methods: An open UC patients with mild to moderate activity and clinical trial was conducted. Patients were randomized to receive or a combination of 6 strains of probiotics for 3 months while continuing their drug treatment established. UC activity was assessed by Truelove and Witts scale and histological findings by Gupta index. Descriptive statistics, Chi square test and Student t test for comparison of the two groups was performed. Results: In each group 17 patients were included. An improvement was found in the disease activity (52.9% vs. 23.5%, p = 0.07) and in histologic index (82.3% vs. 41.1%, p = 0.03) in patients treated with probiotics compared to the control group. Improved food tolerance was also observed in patients treated with probiotics. Conclusion: The study shows a beneficial short-term effect on symptoms, histological findings and feeding tolerance with the administration of a combination of 6 strains of probiotics in patients with UC.

Introducción: los probióticos han sido utilizados en el tratamiento adyuvante de la colitis ulcerativa (CU). Objetivo: evaluar el papel de una combinación de probióticos sobre las manifestaciones clínicas, cambios histológicos y tolerancia alimentaria en pacientes con CU. Métodos: se realizó un ensayo clínico abierto de pacientes con CU y actividad leve a moderada. Los pacientes se aleatorizaron para recibir, o no, una combinación de 6 cepas de probióticos durante 3 meses, mientras continuaban con el tratamiento farmacológico establecido. Se evaluó la actividad de la CU mediante la escala de Truelove and Witts, y los hallazgos histológicos mediante el índice de Gupta. Se realizó estadística descriptiva, prueba de Chi cuadrada y t de Student para la comparación de ambos grupos. Resultados: se incluyeron 17 pacientes por grupo. Se encontró una mejoría en la actividad de la enfermedad (52.9% frente a 23.5%, p = 0.07) y en el índice histológico (82.3% frente a 41.1%, p = 0.03) en los pacientes tratados con probióticos en comparación con el grupo control. También se observó una mejor tolerancia alimentaria en los pacientes tratados con probióticos. Conclusión: el estudio muestra un efecto benéfico a corto plazo sobre los síntomas, hallazgos histológicos y tolerancia alimentaria con la administración de una combinación de 6 cepas de probióticos en pacientes con CU.

Portal Angiogenesis in Chronic Liver Disease Patients Correlates with Portal Pressure and Collateral Formation.

BACKGROUND/AIMS: One hallmark of chronic liver disease in patients with portal hypertension is the formation of portal-systemic collaterals in which angiogenesis has a fundamental role. We studied patients with chronic liver disease undergoing liver transplantation to correlate levels of circulating angiogenic factors in portal and peripheral circulation with portal pressure and portal-systemic collaterals. METHODS: Sixteen patients who underwent liver transplantation were enrolled. During transplant surgery, we determined portal venous pressure and portal-systemic collateral formation. We determined angiogenics mediator levels in systemic and portal plasma. Peripheral plasma from healthy donors was measured as controls. RESULTS: Vascular endothelial growth factor (VEGF)-R1 and 2, Ang-1 and 2, Tie2, FGF- 1 and 2, CD163, PDGFR-ß, PDGFsRα, PDGF-AB and BB, CD163, TGF-ß VASH-1 levels were significantly different in the controls in comparison to cases. Significantly decreased portal venous levels of Ang-1, FGF-1, PDGF-AB/BB, and CC were observed in patients with higher portal pressure. Peripheral VEGF, Ang-1, pPDGF-AB, BB, and CC were significantly decreased in patients with more severe collateral formation. While peripheral VEGF-R1 was higher in patients with severe collateral formation. For portal circulation, VEGF, Ang-1, -pPDGF-AB, BB, and CC were significantly decreased in patients with more severe collateral formation Conclusions: Angiogenesis factors correlated with portal pressure and collateral formation and different patterns of circulating angiogenesis mediators were found in peripheral and portal blood of patients with chronic liver disease. These results support the importance of angiogenic pathways in cirrhosis and portal hypertension and highlight areas for further study to identify clinically useful noninvasive markers of portal pressure and collateral formation.

TET2 Deficiency Causes Germinal Center Hyperplasia, Impairs Plasma Cell Differentiation, and Promotes B-cell Lymphomagenesis.

TET2 somatic mutations occur in ∼10% of diffuse large B-cell lymphomas (DLBCL) but are of unknown significance. Herein, we show that TET2 is required for the humoral immune response and is a DLBCL tumor suppressor. TET2 loss of function disrupts transit of B cells through germinal centers (GC), causing GC hyperplasia, impaired class switch recombination, blockade of plasma cell differentiation, and a preneoplastic phenotype. TET2 loss was linked to focal loss of enhancer hydroxymethylation and transcriptional repression of genes that mediate GC exit, such as PRDM1. Notably, these enhancers and genes are also repressed in CREBBP-mutant DLBCLs. Accordingly, TET2 mutation in patients yields a CREBBP-mutant gene-expression signature, CREBBP and TET2 mutations are generally mutually exclusive, and hydroxymethylation loss caused by TET2 deficiency impairs enhancer H3K27 acetylation. Hence, TET2 plays a critical role in the GC reaction, and its loss of function results in lymphomagenesis through failure to activate genes linked to GC exit signals. SIGNIFICANCE: We show that TET2 is required for exit of the GC, B-cell differentiation, and is a tumor suppressor for mature B cells. Loss of TET2 phenocopies CREBBP somatic mutation. These results advocate for sequencing TET2 in patients with lymphoma and for the testing of epigenetic therapies to treat these tumors.See related commentary by Shingleton and Dave, p. 1515.This article is highlighted in the In This Issue feature, p. 1494.

Extracellular vesicles in DLBCL provide abundant clues to aberrant transcriptional programming and genomic alterations.

The biological role of extracellular vesicles (EVs) in diffuse large B-cell lymphoma (DLBCL) initiation and progression remains largely unknown. We characterized EVs secreted by 5 DLBCL cell lines, a primary DLBCL tumor, and a normal control B-cell sample, optimized their purification, and analyzed their content. We found that DLBCLs secreted large quantities of CD63, Alix, TSG101, and CD81 EVs, which can be extracted using an ultracentrifugation-based method and traced by their cell of origin surface markers. We also showed that tumor-derived EVs can be exchanged between lymphoma cells, normal tonsillar cells, and HK stromal cells. We then examined the content of EVs, focusing on isolation of high-quality total RNA. We sequenced the total RNA and analyzed the nature of RNA species, including coding and noncoding RNAs. We compared whole-cell and EV-derived RNA composition in benign and malignant B cells and discovered that transcripts from EVs were involved in many critical cellular functions. Finally, we performed mutational analysis and found that mutations detected in EVs exquisitely represented mutations in the cell of origin. These results enhance our understanding and enable future studies of the role that EVs may play in the pathogenesis of DLBCL, particularly with regards to the exchange of genomic information. Current findings open a new strategy for liquid biopsy approaches in disease monitoring.

Liver X Receptor Nuclear Receptors Are Transcriptional Regulators of Dendritic Cell Chemotaxis.

The liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DCs), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migration in vitro and in vivo Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished the LXR-dependent induction of DC chemotaxis. Using the low-density lipoprotein receptor-deficient (LDLR-/-) LDLR-/- mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for the efficient emigration of DCs in response to chemotactic signals during inflammation.

AICDA drives epigenetic heterogeneity and accelerates germinal center-derived lymphomagenesis.

Epigenetic heterogeneity is emerging as a feature of tumors. In diffuse large B-cell lymphoma (DLBCL), increased cytosine methylation heterogeneity is associated with poor clinical outcome, yet the underlying mechanisms remain unclear. Activation-induced cytidine deaminase (AICDA), an enzyme that mediates affinity maturation and facilitates DNA demethylation in germinal center (GC) B cells, is required for DLBCL pathogenesis and linked to inferior outcome. Here we show that AICDA overexpression causes more aggressive disease in BCL2-driven murine lymphomas. This phenotype is associated with increased cytosine methylation heterogeneity, but not with increased AICDA-mediated somatic mutation burden. Reciprocally, the cytosine methylation heterogeneity characteristic of normal GC B cells is lost upon AICDA depletion. These observations are relevant to human patients, since DLBCLs with high AICDA expression manifest increased methylation heterogeneity vs. AICDA-low DLBCLs. Our results identify AICDA as a driver of epigenetic heterogeneity in B-cell lymphomas with potential significance for other tumors with aberrant expression of cytidine deaminases.