Hirofumi Yamanishi

Clinical significance of B cell-activating factor in autoimmune pancreatitis.

Objectives: Overexpression of B Cell-activating factor (BAFF) is involved in autoimmunity, but little is known about its role in autoimmune pancreatitis (AIP). The aim of this study was to investigate the role of BAFF in the diagnosis and pathogenesis of AIP. Methods: Patients with AIP (n = 19) were compared with 2 disease control groups (chronic pancreatitis [n = 17] and pancreatic cancer [n = 15]) and a healthy subject group (n = 19). Serum BAFF levels were assessed using an enzyme-linked immunosorbent assay. The expressions of BAFF and BAFF receptor in the pancreatic tissue of patients with AIP were estimated using immunohistochemistry. Results: Mean serum BAFF levels were higher in the patients with AIP than in the patients with chronic pancreatitis, the patients with pancreatic cancer, and the healthy subjects (P < 0.0001 for all groups). Using the cutoff value of 1389 pg/mL, the sensitivity and specificity to differentiate AIP from disease and healthy controls were 89.5% and 92.2%, respectively. Glucocorticoid therapy decreased serum BAFF levels below 1389 pg/mL in all patients with AIP (P < 0.0001). B Cell-activating factor and BAFF receptor were expressed on cells infiltrating the pancreas of patients with AIP. Conclusions: B Cell-activating factor could be a novel marker for diagnosis and treatment response in AIP and may contribute to its pathogenesis.

Regulatory Dendritic Cells Pulsed with Carbonic Anhydrase I Protect Mice from Colitis Induced by CD4+CD25− T Cells

Inflammatory bowel disease (IBD), which is characterized by a dysregulated intestinal immune response, is postulated to be controlled by intestinal self-antigens and bacterial Ags. Fecal extracts called cecal bacterial Ag (CBA) have been implicated in the pathogenesis of IBD. In this study, we identified a major protein of CBA related to the pathogenesis of IBD and established a therapeutic approach using Ag-pulsed regulatory dendritic cells (Reg-DCs). Using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry, carbonic anhydrase I (CA I) was identified as a major protein of CBA. Next, we induced colitis by transfer of CD4+CD25− T cells obtained from BALB/c mice into SCID mice. Mice were treated with CBA- or CA I-pulsed Reg-DCs (Reg-DCsCBA or Reg-DCsCA1), which expressed CD200 receptor 3 and produced high levels of IL-10. Treatment with Reg-DCsCBA and Reg-DCsCA1 ameliorated colitis. This effect was shown to be Ag-specific based on no clinical response of irrelevant Ag (keyhole limpet hemocyanin)-pulsed Reg-DCs. Foxp3 mRNA expression was higher but RORγt mRNA expression was lower in the mesenteric lymph nodes (MLNs) of the Reg-DCsCA1–treated mice compared with those in the MLNs of control mice. In the MLNs, Reg-DCsCA1–treated mice had higher mRNA expression of IL-10 and TGF-β1 and lower IL-17 mRNA expression and protein production compared with those of control mice. In addition, Reg-DCsCBA–treated mice had higher Foxp3+CD4+CD25+ and IL-10–producing regulatory T cell frequencies in MLNs. In conclusion, Reg-DCsCA1 protected progression of colitis induced by CD4+CD25− T cell transfer in an Ag-specific manner by inducing the differentiation of regulatory T cells.

Increased B Cell-Activating Factor Promotes Tumor Invasion and Metastasis in Human Pancreatic Cancer

B cell-activating factor (BAFF) is a cytokine belonging to the tumor necrosis factor (TNF) superfamily. It has been reported that BAFF is elevated in patients with autoimmune pancreatitis and contributes to the malignant potential of blood cancers and solid tumors. In this study, clinical evidence of increased BAFF levels in patients with pancreatic ductal adenocarcinoma (PDAC) was obtained, and the roles and mechanisms of BAFF in PDAC were clarified in human tissues of PDAC and from in vitro data of PDAC cell lines. Serum levels of BAFF in patients with PDAC were significantly higher than in healthy subjects (p = 0.0121). Patients with UICC stage IV PDAC (T1-4, N0-1, M1) had significantly higher levels of serum BAFF compared to patients with PDAC (p = 0.0182). BAFF was remarkably expressed in infiltrating B lymphocytes surrounding pancreatic cancer in human pancreatic tissues, suggesting that BAFF may play a role in progression of pancreatic cancer. PDAC cell lines were cultured with human recombinant BAFF, and morphology and gene expression were analyzed; pancreatic cancer cells changed to a fibroblast-like morphology, and showed altered gene expression of E-cadherin, vimentin and Snail. These BAFF-induced changes reflect enhanced cell motility and invasion. BAFF-R-overexpressing cell clones confirmed the association between these BAFF-induced changes and epithelial-mesenchymal transition (EMT)-related genes. BAFF was elevated in patients with metastatic advanced PDAC and induced alterations in PDAC cells via regulation of EMT-related genes. Elucidation of the precise role and mechanism of control of BAFF may lead to new therapeutic approaches with the aim of improving pancreatic cancer survival.

Oral administration of carbonic anhydrase I ameliorates murine experimental colitis induced by Foxp3−CD4+CD25− T cells

IBDs are thought to involve uncontrolled innate and adaptive immunity against intestinal self‐antigens and bacterial antigens. Mouse CA I is a major cecal bacterial antigen in fecal extracts and is implicated in the pathogenesis of IBD. We show here that oral tolerization to CA I induced antigen‐specific protection from intestinal inflammation in a murine model. Oral administration of CA I but not irrelevant antigen (KLH) ameliorated CD4+CD25− T cell transfer murine colitis and DSS‐induced murine colitis. Next, we investigated the mechanisms involved in the therapeutic effects of oral administration, such as induction of ALDH1a2, transcription factors, cytokines, CD103+CD11c+ DCs, and generation of Tregs. Oral administration of CA I induced ALDH1a2 mRNA expression in the MLN and colon. When compared with PBS‐treated mice, CA I‐treated mice had higher Foxp3+CD4+CD25+ Treg and CD103+CD11c+ DC numbers in the MLN and colon; had higher TGF‐β production in the MLN and colon; had lower RORγt mRNA expression in the MLN and colon; and had lower IL‐17 mRNA expression and production in the MLN. These results demonstrate that oral administration of CA I induced antigen‐specific immune tolerance by generating Foxp3+CD4+CD25+ Tregs and inhibiting Th17 cells in a murine colitis model, thus suggesting that oral tolerization with CA I is an effective therapeutic strategy for IBD regulation.

Utility of Contrast-Enhanced Transabdominal Ultrasonography to Diagnose Early Chronic Pancreatitis.

Purpose. The purpose of this study was to establish the relationship between the grade of chronic pancreatitis (CP) and pancreatic blood flow as measured by contrast-enhanced transabdominal ultrasonography (CEUS) and to diagnose early CP easily. Methods. This pilot study was conducted in 8 patients with CP, 7 patients with early CP, and 6 control participants. After injecting 0.015 mL/kg of perflubutane by manual bolus, values in one region of interest (ROI) in pancreatic parenchyma and one ROI including the superior mesenteric artery (SMA) were measured. Results. The ratio of blood flow in the SMA and pancreatic parenchyma increased with grade of CP and was significantly higher in patients with CP (5.41; 2.10–11.02) than in patients with early CP (2.46; 1.41–5.05) and control participants (2.32; 1.25–3.04) (P = 0.0279, P = 0.0142, resp.). The ratio of blood flow in the SMA and pancreatic parenchyma correlated with grade of CP (rs = 0.5904, P = 0.0048). Conclusion. The ratio of blood flow correlates with grade of CP on CEUS. This safe and convenient method may be useful to diagnose early CP.

An unusual case of subclinical diffuse glucagonoma coexisting with two nodules in the pancreas: characteristic features on computed tomography.

A lesion was discovered in the tail of the pancreas by ultrasonography performed during a health checkup for a 59-year-old Japanese man. Abdominal contrast-enhanced computed tomography (CE-CT) revealed strong enhancement in a 4-cm tumor in the pancreatic tail and in a 1-cm tumor in the pancreatic body. Serum glucagon levels were elevated to 54,405 pg/mL and a preoperative diagnosis of glucagonoma was made. The pancreatic tail and spleen were resected en bloc, along with a protruding tumor in the pancreatic body. However, histopathological evaluation revealed diffuse glucagonoma throughout the pancreas. When we retrospectively reviewed abdominal CE-CT after the operation, the entire pancreas was seen to be enlarged and diffusely enhanced by strong spots. Immunohistochemical examination using anti-CD31 demonstrated rich microvessels in two solid glucagonomas as well as microglucagonoma throughout the entire pancreas, indicating hypervascularity. Enlarged pancreas and diffuse enhancement of the pancreas by strong spots may be characteristic features of diffuse glucagonoma on abdominal CE-CT.

Rapid alternative absorption of dietary long-chain fatty acids with upregulation of intestinal glycosylated CD36 in liver cirrhosis

BACKGROUND Dietary long-chain fatty acid (LCFA) intake is an important risk factor for hepatic inflammation and hepatocarcinogenesis. An alternate route of dietary LCFA absorption has been suggested in patients with liver cirrhosis (LC). OBJECTIVE We aimed to determine this alternate route and to identify its mechanism. DESIGN Twenty healthy control subjects and 47 patients with LC-n = 23 with portal hypertension [PH(+)LC] and 24 without portal hypertension [PH(-)LC)]-were enrolled. [¹³C]Palmitate (an LCFA) and octanoate (a medium-chain fatty acid [MCFA]) were administered by using gastrointestinal endoscopy. Breath ¹³CO₂ was measured to quantify metabolized fatty acids. We also examined intestinal specimens of patients in these groups. RESULTS A more rapid increase in metabolized palmitate, which showed a pattern similar to that of octanoate metabolism, was observed in patients with LC than in healthy control subjects. The increase in the PH(-)LC group was higher than that in the PH(+)LC group. However, the concentration of metabolized palmitate increased with treatment of the PH(+)LC group with a portal-systemic shunt. Morphologic changes such as expanded lymph and blood vessels were present, and glycosylated CD36 increased in the jejunum of the PH(+)LC group. This group had high serum concentrations of glucagon-like peptide-2. These data suggest that dietary LCFAs, similar to MCFAs, are absorbed via blood vessels in patients with LC. CONCLUSIONS Rapid absorption of LCFAs by an alternative method occurred in patients with LC. This altered LCFA processing is likely related to upregulation of intestinal glycosylated CD36 and could contribute to pathogenesis in patients with LC.

Carbonic Anhydrate I Epitope Peptide Improves Inflammation in a Murine Model of Inflammatory Bowel Disease.

Background:Carbonic anhydrase I (CA I), a major cecal bacterial antigen, improves inflammatory bowel disease (IBD) symptoms in a murine model. The aim of this study was to identify the responsible epitope region within the CA I protein and evaluate its effect on inflammation using a murine IBD model. Methods:Candidate peptides within the CA I protein sequence that interact with major histocompatibility complex class II were chosen and their immune responses were evaluated using mesentery lymph nodes (MLNs) from a CD4+CD25− T-cell transfer murine colitis model. Mice were treated with regulatory dendritic cells (Reg-DCs)–pulsed CA I peptide. We assessed their clinical signs, histopathology, induction of cytokines and transcription factors, and generation of CD103+CD11c+ dendritic cells and regulatory T cells (Tregs). Results:We identified 4 candidate epitope peptides of CA I. Among these, Reg-DCs pulsed with CA I 58-73 peptide (Reg-DCsCA I 58-73) alone ameliorated colitis. Reg-DCsCA I 58-73-treated mice showed higher mRNA expression levels of forkhead box protein 3, aldehyde dehydrogenase family 1a2, transforming growth factor-&bgr;, and interleukin (Il)10, when compared with lower mRNA expression of retinoic acid–related orphan receptor gamma and Il17a in MLNs. Compared with control mice, these mice also showed higher numbers of Foxp3+CD4+CD25+ Tregs and CD103+CD11c+ dendritic cells in MLNs and colon. Administration of Reg-DCsCA I 58-73 induced antigen-specific Tregs in MLNs of colitic mice. Conclusions:CA I 58-73 peptide induces antigen-specific therapeutic effect in a murine IBD model using Reg-DCs, indicating that CA I 58-73 is a candidate epitope for IBD immunotherapy.

Diagnostic Challenge in Pancreatic Sarcoidosis using Endoscopic Ultrasonography.

We herein report a 55-year-old woman who presented with erythema and bilateral hilar lymphadenopathy 4 months prior to the detection of pancreatic lesions on an ultrasound. A skin biopsy showed evidence of sarcoidosis. The largest lesion in the tail of the pancreas was hypoechoic on endoscopic ultrasonography (EUS). The lesion was initially iso-enhanced on contrast enhanced-EUS (CE-EUS) but subsequently became hypoenhanced. The lesion revealed heterogeneous components of both soft and hard tissue on EUS elastography. She was ultimately diagnosed with pancreatic sarcoidosis based on the presence of noncaseating granulomas seen on pancreatic tissue retrieved through an EUS-guided fine needle aspiration biopsy.

Difficulty in management of intraductal papillary mucinous neoplasm-associated pancreatobiliary fistulas and the role of “pig-nose” appearance and intraductal ultrasonography in diagnosis

Pancreatobiliary fistulas associated with intraductal papillary mucinous neoplasms (IPMN) often develop obstructive jaundice and cholangitis; thus, early diagnosis is important. However, computed tomography and cholangiography, the current methods for detecting pancreatobiliary fistulas, are not always effective. We previously reported a case of IPMN-associated pancreatobiliary fistula and proposed a potential new diagnostic marker: the “pig-nose” appearance of the duodenal papilla, which results from dilated pancreatic and bile ducts and can be visualized via endoscopy. In this study, we report another three cases of IPMN-associated pancreatobiliary fistulas detected by a different technology, intraductal ultrasonography (IDUS). As with our previously reported case, we confirmed the utility of the “pig-nose” appearance and IDUS in the diagnosis of IPMN-associated pancreatobiliary fistulas. In addition, we found it difficult to manage biliary obstruction that resulted from the flow of mucinous material through pancreatobiliary fistulas. The obstruction was treated with endoscopic nasal biliary drainage (ENBD), but this was not always successful. In two of our cases, additional treatment with a large diameter fully covered metal stent failed to improve jaundice. Therefore, we conclude that standard endoscopic stenting may not be effective, and that alternative endoscopic methods or surgery may be necessary.