Comparison of Oncological and Surgical Outcomes Between Formal Pancreatic Resections and Parenchyma-Sparing Resections for Small PanNETs (<2 cm): Pancreas2000 Research and Educational Program (Course 9) Study Protocol.

Pancreatic neuroendocrine tumors (PanNETs) are rare tumors but incidence is increasing. An increasing number of these tumors are diagnosed incidentally when they are small (<2 cm) and when patients are asymptomatic. The European Neuroendocrine Tumor Society (ENETS) recommends conservative watch and wait policy for these patients. However, best surgical approach (parenchyma-sparing or formal oncological resection) for these small tumors when surgery is indicated is currently unknown. Parenchyma-sparing resections such as enucleation is associated with higher risk of post-operative morbidity compared to formal oncological resections. They are also be associated with potentially inadequate surgical margin clearance and with lack of lymphadenectomy for full pathological staging. Method: This study is a retrospective study and the aim is to analyze pre-operative clinical predictors of nodal metastases for small PanNETs to identify which patients are at a lower risk of lymph node metastases and are therefore suitable for parenchyma-sparing resection. Conclusion: The primary endpoint of this study is to determine if pre-operative clinical predictors such as tumor size are associated with lymph node involvement in small PanNETs.

Role of Pre-operative Inflammatory Markers as Predictors of Lymph Node Positivity and Disease Recurrence in Well-Differentiated Pancreatic Neuroendocrine Tumours: Pancreas2000 Research and Educational Program (Course 9).

Pancreatic neuroendocrine tumours (PNET) is a rare disease and in the absence of metastases, surgical resection is recommended. Key factors affecting survival in PNETs are the stage and grade of the disease, but there is increasing evidence suggesting lymph node involvement is associated with shorter disease-free and overall survival. Ability to predict the likelihood of lymph node involvement at the time of diagnosis would affect surgical decision making in these patients. A systemic inflammatory index such as neutrophil to lymphocyte ratio or platelet to lymphocyte ratio has been associated with poor prognosis in several cancers. Method: This study is a retrospective multi-centre study. The data including pre-operative inflammatory markers such as haemoglobin, neutrophil, lymphocyte counts and pathological data including number of positive lymph nodes, tumour grade and size, are collected to assess the association between inflammatory index and lymph node involvement. Conclusion: This study aims to assess the value of routinely available pre-operative haematological markers in predicting lymph node involvement in non-functioning PNETs.

The regulation of T-cell recruitment to the human liver during acute liver failure.

BACKGROUND & AIMS: Acute liver failure (ALF) is a rare clinical syndrome with high mortality resulting from hepatocellular necrosis and loss of function. In seronegative hepatitis (SNH), a T-cell-rich infiltrate leads to immune-mediated hepatocyte destruction, whereas in paracetamol poisoning, toxic metabolites induce hepatocyte necrosis, followed by a macrophage-rich, lymphocytic infiltrate that is an important factor in driving repair and regeneration. The nature of the hepatic inflammatory infiltrate, key to ALF pathogenesis and outcome, is determined by the recruitment of effector cells from blood, but the molecular basis of recruitment is poorly understood. To determine the phenotype of circulating and hepatic lymphocytes in patients with ALF secondary to paracetamol overdose (POD) or SNH and investigate the molecular basis of lymphocyte recruitment. METHODS: We used FACS, immunohistochemistry and flow-based adhesion assays to determine the regulation of lymphocyte adhesion. RESULTS: SNH and POD intrahepatic lymphocytes were αLß2(hi), CD69(hi) and CD38(hi) with a distinct homing phenotype being L-selectin(lo), CXCR3(hi) and CCR5(+). Expression of chemokine ligands for the receptors CCR5, CXCR3 and CXCR6 and the adhesion molecules ICAM-1, VCAM-1 and VAP-1 was markedly increased in the liver in ALF. Lymphocytes isolated from the livers of patients with SNH showed enhanced chemokine-dependent adhesion and transmigration across the human hepatic endothelium in vitro under flow and used a combination of ß1 and ß2 integrins to adhere to endothelium and ß2 integrins, CD31 and VAP-1 to transmigrate. CONCLUSION: Aetiology-dependent combinations of adhesion molecules and chemokines expressed within tissue during ALF recruit lymphocytes with a distinct homing phenotype.

CD8 lineage-specific regulation of interleukin-7 receptor expression by the transcriptional repressor Gfi1.

Interleukin-7 receptor α (IL-7Rα) is essential for T cell survival and differentiation. Glucocorticoids are potent enhancers of IL-7Rα expression with diverse roles in T cell biology. Here we identify the transcriptional repressor, growth factor independent-1 (Gfi1), as a novel intermediary in glucocorticoid-induced IL-7Rα up-regulation. We found Gfi1 to be a major inhibitory target of dexamethasone by microarray expression profiling of 3B4.15 T-hybridoma cells. Concordantly, retroviral transduction of Gfi1 significantly blunted IL-7Rα up-regulation by dexamethasone. To further assess the role of Gfi1 in vivo, we generated bacterial artificial chromosome (BAC) transgenic mice, in which a modified Il7r locus expresses GFP to report Il7r gene transcription. By introducing this BAC reporter transgene into either Gfi1-deficient or Gfi1-transgenic mice, we document in vivo that IL-7Rα transcription is up-regulated in the absence of Gfi1 and down-regulated when Gfi1 is overexpressed. Strikingly, the in vivo regulatory role of Gfi1 was specific for CD8(+), and not CD4(+) T cells or immature thymocytes. These results identify Gfi1 as a specific transcriptional repressor of the Il7r gene in CD8 T lymphocytes in vivo.

Functional consequences of human lymphocyte cryopreservation: implications for subsequent interactions of cells with endothelium.

In order to understand human inflammatory diseases and to develop and assess new therapeutic strategies targeting leukocyte recruitment to tissue, it is necessary to study human lymphocyte interactions with endothelium. It is often not practical to carry out assays on fresh human samples and therefore cells may be cryopreserved and batched for later study. Furthermore, many forms of adoptive cell therapy use cryopreserved cells that are required to migrate to tissue after infusion in vivo. The consequences of cryopreservation on the adhesion and migration of leukocytes is not known leading us to study the effects of cryopreservation on lymphocyte phenotype, migration, and adhesion. Cryopreservation and subsequent thawing did not alter the proportion of retrieved T cell subsets. Overall levels of expression of ß1 or ß2 integrins were unaffected but marked changes were observed in other relevant receptors. Expression of CD69, a transmembrane protein that plays a critical role in lymphocyte egress from tissues and the chemokine receptor CXCR4, increased on thawed populations and levels of CD62L and CXCR3 were reduced on thawed cells but restored if cells were allowed to recover after thawing. These changes were associated with modulation of the ability of lymphocytes to migrate across cytokine-stimulated monolayers of endothelium toward recombinant CXCL11 and CXCL12. Thus cryopreservation and thawing of lymphocytes induces changes in their adhesive phenotype and modulates their ability to migrate across endothelial monolayers. These findings have implications for in vitro experimentation and for cell therapy in which cryopreserved cells are expected to migrate when reinfused into patients.

Vascular adhesion protein-1 as a potential therapeutic target in liver disease.

Vascular adhesion protein-1 (VAP-1) is a homodimeric, transmembrane sialoglycoprotein, and amine-oxidase enzyme constitutively expressed by hepatic endothelial cells, and as a soluble protein in serum (sVAP-1). VAP-1 mediates leukocyte adhesion and migration in an enzyme activity-dependent manner. We wished to determine whether VAP-1 blockade reduces leukocyte recruitment in inflammatory liver disease, and the mechanism by which this occurs. Our results show that VAP-1 is upregulated in the liver and serum of patients with inflammatory liver disease. Expression is maintained on hepatic sinusoidal endothelial cells (HSECs) isolated from explanted livers. Blockade of VAP-1 activity modestly decreases migration of normal lymphocytes across HSECs but has significant effects on the migration of peripheral blood lymphocytes (PBLs) and liver-derived lymphocytes across HSECs. Engagement of VAP-1 results in PI3-kinase-dependent NF-kappaB activation and increased chemokine and adhesion molecule expression. Thus complex mechanisms regulate VAP-1-mediated recruitment of leukocytes. Direct binding to endothelial VAP-1 protein, indirect enzyme-dependent activation of other endothelial adhesive pathways, and activation of leukocyte by VAP-1 ligand occupancy all contribute to adhesion. The restricted expression of VAP-1 and increased production of sVAP-1 in inflammatory liver disease confirm the validity of this molecule as a therapeutic target.