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Pancreatic ductal adenocarcinoma (PDAC) is a common type of pancreatic cancer with one of the worst survival rate of all malignancies. Recent studies have identified that immunosuppressive B cells could employ the PD‐1/PD‐L1 pathway to suppress antitumour T cell responses; hence, we examined the expression and function of PD‐L1 in B cells. We found that the PD‐L1 expression was significantly enriched in tumour‐infiltrating (TI) B cells than in peripheral blood (PB) B cells from the same patients. Additionally, the PB B cells from stage III and stage IV PDAC patients presented significantly higher PD‐L1 than the PB B cells from healthy controls. High PD‐L1 expression in PB B cells could be achieved by stimulation via CpG and less effectively via anti‐BCR plus CD40L, but not by coculture with pancreatic cancer cell lines in vitro. Also, STAT1 and STAT3 inhibition significantly suppressed PD‐L1 upregulation in stimulated B cells. CpG‐stimulated PB B cells could inhibit the IFN‐γ expression and proliferation of CD8 T cells in a PD‐L1‐dependent manner. Also, TI CD8 T cells incubated with whole TI B cells presented significantly lower IFN‐γ expression and lower proliferation, than TI CD8 T cells incubated with PD‐L1+ cell‐depleted TI B cells, suggesting that PD‐L1+ B cells could also suppress CD8 T cells in the tumour. Overall, this study identified that B cells could suppress CD8 T cells via PD‐L1 expression, indicating a novel pathway of immuno‐regulation in pancreatic cancer. [ABSTRACT FROM AUTHOR]

Background Treatment options for patients with portal vein ( PV) stenosis or occlusion after surgery are limited. The purpose of this study was to investigate the efficacy and safety of PV stent placement in patients with portal vein occlusion or stenosis after radical operation for hepatobiliary pancreatic malignant tumour. Methods We retrospectively reviewed the records of 59 patients who underwent portal venous stent placement at the Asan Medical Center, Seoul, Korea, for PV stenosis or occlusion between February 2008 and February 2012. Results Stents were placed in the portal venous system across stenotic ( n = 47) and occlusive ( n = 12) lesions after percutaneous transhepatic portography. Reasons for stent placement were tumour recurrence ( n = 30), portal vein resection and anastomosis ( n = 18) and post-operative inflammatory changes ( n = 11). Pressure gradients (superior mesenteric vein, main PV) decreased immediately after stent placement, from 10.5 mm Hg ± 4.4 (standard deviation) to 2.5 mm Hg ± 2.6 ( P < 0.0001). Liver function was improved post-stenting ( P < 0.05). The median time between the original surgery and stent placement was 16 (1-137) days in the vascular-orientated group and 306 (13-3703) days in the tumour recurrence group ( P < 0.0001). Transient fever developed in 11 patients, but resolved in 2-5 days. Stents were occluded in 15 of the 59 patients (25.4%). Conclusion PV stent placement is a safe choice, has an acceptable success rate and provides marked relief from portal hypertension due to portal vein occlusion or stenosis after hepatobiliary pancreatic surgery. Liver function data are also improved after portal venous stent placement. [ABSTRACT FROM AUTHOR]