Features of and Mechanisms Underlying Insulitis In aly/aly Male Mice as an Animal Model of Autoimmune Pancreatitis: Activation of CD11c+, CD4+, and Th2 Cells and Predominant Destruction of β-cells

Diabetes mellitus (DM) is observed in patients with autoimmune pancreatitis (AIP). The development of DM in AIP is believed to be due to blood flow obstruction of the endocrine gland that accompanies pancreatitis, as well as injury to the islets caused by inflammation. The latter is called insulitis and the detailed mechanisms underlying its development are not yet clear. The aim of the present study was to elucidate the mechanisms involved in the development of insulitis in AIP using aly mice as an animal model of AIP: results in aly/aly male mice, as the AIP group, were compared with those inaly/+ male mice as a control group. Mice in both groups were killed between 16 and 48 weeks of age, and pancreatitis and insulitis were evaluated histologically. Inflammatory and endocrine cells were evaluated by immunofluorescence staining with anti-CD4, anti-CD8, anti-CD11b, and anti-CD11c antibodies, as well as immunohistochemical analyses using insulin and glucagon antibodies. Plasma levels and the pancreatic content of interferon (IFN)-γ (as a Th1-secreted cytokine) and interleukin (IL)-4 (as a Th2-secreted cytokine) were determined. Pancreatitis was seen in aly/aly mice from 16 weeks of age and it developed gradually thereafter. Insulitis also developed gradually and was seen in mice after 24 weeks of age in association with a decrease in the number of islets. CD11c+ cells and CD4+ T cells were seen to infiltrate into the islets. Although the number of β-cells decreased with time, the number of α-cells was maintained until mice were 48 weeks of age. IFN-γ content peaked in mice at 16 weeks of age and declined rapidly from 20 weeks. There were two peaks in IL-4 content, one at 16 weeks and the other at 32 weeks, suggesting an association between IL-4 content and advanced insulitis after 32 weeks. In conclusion, the results suggest that insulitis in AIP is induced predominantly by the infiltration of CD11c+ cells and CD4+ T cells into the islets, and progression is facilitated by the imbalance of the activation of Th2 rather than Th1. Furthermore, insulitis in AIP predominantly involves β-cells rather than α-cells

Total pancreatectomy with remnant stomach preservation in a patient with a history of proximal gastrectomy and interposed jejunal reconstruction with right gastroepiploic conduit preservation: a case report

Abstract Background Pancreatic head resection following proximal gastrectomy jeopardizes the blood flow of the remnant stomach owing to right gastroepiploic conduit sacrifice, thereby necessitating total gastrectomy. However, owing to its high invasiveness, concomitant remnant total gastrectomy with pancreatectomy should be avoided as much as possible. Herein, we describe our experience of total pancreatectomy with right gastroepiploic conduit preservation in a patient with a history of proximal gastrectomy and reconstruction by jejunum interposition. Case presentation A 78-year-old woman with a history of gastric cancer was followed up at our institute for multiple intraductal papillary mucinous neoplasm, and main pancreatic duct stricture in the pancreatic head was newly detected. The cystic lesion was extended to the pancreatic body. Proximal gastrectomy and reconstruction by jejunal interposition were previously performed, and the mesenteric stalk of the interposed jejunum was approached through the retrocolic route. We planned total pancreatectomy with right gastroepiploic conduit preservation. Following adhesiolysis, the interposed jejunum and its mesentery lying in front of the pancreas were isolated. The arterial arcade from the common hepatic artery to the right gastroepiploic artery was detached from the pancreas. Furthermore, the right gastroepiploic vein was isolated from the pancreas. The pancreatic body and tail were pulled up in front of the remnant stomach, and the splenic artery and vein were resected. The pancreatic body and tail were pulled out to the right side, and the pancreatic head was divided from the pancreatic nerve plexus to the portal vein. The jejunal limb for entero-biliary anastomosis was passed through the hole behind the superior mesenteric artery and vein, and gastrointestinal anastomosis using the antecolic route and Braun anastomosis were performed. Conclusions To avoid remnant total gastrectomy, right gastroepiploic conduit preservation is an optional procedure for pancreatic head resection in patients who have undergone proximal gastrectomy with reconstruction by jejunal interposition