Masahiro Shiokawa

Risk of Cancer in Patients With Autoimmune Pancreatitis

OBJECTIVES:Although simultaneous occurrences of autoimmune pancreatitis (AIP) and cancer are occasionally observed, it remains largely unknown whether cancer and AIP occur independently or these disorders are interrelated. The aim of this study was to examine the relationship between AIP and cancer.METHODS:We conducted a multicenter, retrospective cohort study. One hundred and eight patients who met the Asian diagnostic criteria for AIP were included in the study. We calculated the proportion, standardized incidence ratio (SIR), relative risk, and time course of cancer development in patients with AIP. We also analyzed the clinicopathological characteristics of AIP patients with cancer in comparison with those without cancer.RESULTS:Of the 108 AIP patients, 18 cancers were found in 15 patients (13.9%) during the median follow-up period of 3.3 years. The SIR of cancer was 2.7 (95% confidence interval (CI) 1.4–3.9), which was stratified into the first year (6.1 (95% CI 2.3–9.9)) and subsequent years (1.5 (95% CI 0.3–2.8)) after AIP diagnosis. Relative risk of cancer among AIP patients at the time of AIP diagnosis was 4.9 (95% CI 1.7–14.9). In six of eight patients whose cancer lesions could be assessed before corticosteroid therapy for AIP, abundant IgG4-positive plasma cell infiltration was observed in the cancer stroma. These six patients experienced no AIP relapse after successful cancer treatment.CONCLUSIONS:Patients with AIP are at high risk of having various cancers. The highest risk for cancer in the first year after AIP diagnosis and absence of AIP relapse after successful treatment of the coexisting cancers suggest that AIP may develop as a paraneoplastic syndrome in some patients.

Involvement of activation of toll-like receptors and nucleotide-binding oligomerization domain-like receptors in enhanced IgG4 responses in autoimmune pancreatitis.

OBJECTIVE IgG4-related disease is a recently recognized entity affecting multiple organs, including the pancreas, biliary tracts, and salivary glands. Although IgG4-related disease is characterized by systemic IgG4 antibody responses and by infiltration of IgG4-expressing plasma cells, the innate immune responses leading to adaptive IgG4 antibody responses are poorly understood. The aim of this study was to clarify the innate immune responses leading to IgG4 antibody production. METHODS IgG4 and cytokine responses to various nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) and Toll-like receptor (TLR) ligands were examined using peripheral blood mononuclear cells (PBMCs) from healthy control subjects and patients with IgG4-related autoimmune pancreatitis. RESULTS Activation of NOD-2 in monocytes from healthy control subjects induced IgG4 production by B cells in a BAFF-dependent and T cell-independent manner. In addition, PBMCs from patients with IgG4-related disease produced a large amount of IgG4 upon stimulation with NLR and TLR ligands; this enhanced IgG4 production was associated with the induction of BAFF by NLR and TLR ligands. Monocytes from patients with IgG4-related disease induced IgG4 production by B cells from healthy control subjects upon stimulation with NLR and TLR ligands. CONCLUSION The results of these studies suggest that abnormal innate immune responses against microbial antigens may underlie the immunopathogenesis of IgG4-related disease.

Toll-like receptor activation in basophils contributes to the development of IgG4-related disease

BackgroundIgG4-related disease (IRD) is characterized by systemic IgG4 antibody responses and by infiltration of IgG4-expressing plasma cells into the affected organs. Although T helper type 2 (Th2) cytokines are implicated in enhanced IgG4 responses, molecular mechanisms accounting for the development of IgG4 antibody responses are poorly defined. Since basophils function as antigen-presenting cells for Th2 responses, we tried to clarify the role of basophils in the development of IgG4 responses in this study.MethodsIgG4 and cytokine responses to various nucleotide-binding oligomerization domain-like receptor and Toll-like receptor (TLR) ligands were examined by using basophils isolated from healthy controls and from patients with IgG4-related disease.ResultsActivation of TLRs in basophils from healthy controls induced IgG4 production by B cells, which effect was associated with enhanced production of B cell activating factor (BAFF) and IL-13. In addition, activation of TLRs in basophils from patients with IRD induced a large amount of IgG4 by B cells from healthy controls. This enhancement of IgG4 production was again associated with BAFF and IL-13.ConclusionsThese data suggest that innate immune responses mediated through TLRs may play a role in the development of IgG4-related disease, in part by production of BAFF from basophils.

Pathogenicity of IgG in patients with IgG4-related disease

Objective IgG4-related disease (IgG4-RD) is a systemic disease characterised by elevated serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in the affected tissues. The pathogenic role of IgGs, including IgG4, in patients with IgG4-RD, however, is unknown. Design We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal male Balb/c mice. Binding of patient IgGs to pancreatic tissue was also analysed in an ex vivo mouse organ culture model and in tissue samples from patients with autoimmune pancreatitis (AIP). Results Subcutaneous injection of patient IgG, but not control IgG, resulted in pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patient IgG1 or IgG4, with more destructive changes induced by IgG1 than by IgG4. The potent pathogenic activity of patient IgG1 was significantly inhibited by simultaneous injection of patient IgG4. Binding of patient IgG, especially IgG1 and IgG4, to pancreatic tissue was confirmed in both the mouse model and AIP tissue samples. Conclusions IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding affected tissues in neonatal mice.

Plasmacytoid Dendritic Cell Activation and IFN-α Production Are Prominent Features of Murine Autoimmune Pancreatitis and Human IgG4-Related Autoimmune Pancreatitis

The abnormal immune response accompanying IgG4-related autoimmune pancreatitis (AIP) is presently unclear. In this study, we examined the role of plasmacytoid dendritic cell (pDC) activation and IFN-α production in this disease as well as in a murine model of AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid). We found that the development of AIP in treated MRL/Mp mice occurred in parallel with pancreatic accumulation of pDCs producing IFN-α, and with pDC depletion and IFN-α-blocking studies, we showed that such accumulation was necessary for AIP induction. In addition, we found that the pancreas of treated MRL/Mp mice contained neutrophil extracellular traps (NETs) shown previously to stimulate pDCs to produce IFN-α. Consistent with these findings, we found that patients with IgG4-related AIP also exhibited pancreatic tissue localization of IFN-α–expressing pDCs and had significantly higher serum IFN-α levels than healthy controls. In addition, the inflamed pancreas of these patients but not controls also contained NETs that were shown to be capable of pDC activation. More importantly, patient pDCs cultured in the presence of NETs produced greatly increased levels of IFN-α and induced control B cells to produce IgG4 (but not IgG1) as compared with control pDCs. These data suggest that pDC activation and production of IFN-α is a major cause of murine AIP; in addition, the increased pDC production of IFN-α and its relation to IgG4 production observed in IgG4-related AIP suggest that this mechanism also plays a role in the human disease.

Activation-Induced Cytidine Deaminase Contributes to Pancreatic Tumorigenesis by Inducing Tumor-Related Gene Mutations

Pancreatic ductal adenocarcinoma (PDAC) develops via an accumulation of various gene mutations. The mechanism underlying the mutations in PDAC development, however, is not fully understood. Recent insight into the close association between the mutation pattern of various cancers and specific mutagens led us to investigate the possible involvement of activation-induced cytidine deaminase (AID), a DNA editing enzyme, in pancreatic tumorigenesis. Our immunohistochemical findings revealed AID protein expression in human acinar ductal metaplasia, pancreatic intraepithelial neoplasia, and PDAC. Both the amount and intensity of the AID protein expression increased with the progression from precancerous to cancerous lesions in human PDAC tissues. To further assess the significance of ectopic epithelial AID expression in pancreatic tumorigenesis, we analyzed the phenotype of AID transgenic (AID Tg) mice. Consistent with our hypothesis that AID is involved in the mechanism of the mutations underlying pancreatic tumorigenesis, we found precancerous lesions developing in the pancreas of AID Tg mice. Using deep sequencing, we also detected Kras and c-Myc mutations in our analysis of the whole pancreas of AID Tg mice. In addition, Sanger sequencing confirmed the presence of Kras, c-Myc, and Smad4 mutations, with the typical mutational footprint of AID in precancerous lesions in AID Tg mice separated by laser capture microdissection. Taken together, our findings suggest that AID contributes to the development of pancreatic precancerous lesions by inducing tumor-related gene mutations. Our new mouse model without intentional manipulation of specific tumor-related genes provides a powerful system for analyzing the mutations involved in PDAC.

Involvement of interleukin-17A-induced expression of heat shock protein 47 in intestinal fibrosis in Crohn's disease

Objective Intestinal fibrosis is a clinically important issue in Crohns disease (CD). Heat shock protein (HSP) 47 is a collagen-specific molecular chaperone involved in fibrotic diseases. The molecular mechanisms of HSP47 induction in intestinal fibrosis related to CD, however, remain unclear. Here we investigated the role of interleukin (IL)-17A-induced HSP47 expression in intestinal fibrosis in CD. Design Expressions of HSP47 and IL-17A in the intestinal tissues of patients with IBD were determined. HSP47 and collagen I expressions were assessed in intestinal subepithelial myofibroblasts (ISEMFs) isolated from patients with IBD and CCD-18Co cells treated with IL-17A. We examined the role of HSP47 in IL-17A-induced collagen I expression by administration of short hairpin RNA (shRNA) to HSP47 and investigated signalling pathways of IL-17A-induced HSP47 expression using specific inhibitors in CCD-18Co cells. Results Gene expressions of HSP47 and IL-17A were significantly elevated in the intestinal tissues of patients with active CD. Immunohistochemistry revealed HSP47 was expressed in α-smooth muscle actin (α-SMA)-positive cells and the number of HSP47-positive cells was significantly increased in the intestinal tissues of patients with active CD. IL-17A enhanced HSP47 and collagen I expressions in ISEMFs and CCD-18Co cells. Knockdown of HSP47 in these cells resulted in the inhibition of IL-17A-induced collagen I expression, and analysis of IL-17A signalling pathways revealed the involvement of c-Jun N-terminal kinase in IL-17A-induced HSP47 expression. Conclusions IL-17A-induced HSP47 expression is involved in collagen I expression in ISEMFs, which might contribute to intestinal fibrosis in CD.

Loss of RUNX3 expression by histone deacetylation is associated with biliary tract carcinogenesis

RUNX3 is a candidate tumor suppressor gene localized in 1p36, a region frequently inactivated through hypermethylation, histone modulation, and other processes in various human tumors. In this study, to elucidate a causal link between RUNX3 expression and biliary tract cancer, we investigated 17 human biliary cancer specimens. In addition, to examine roles of RUNX3 in biliary tract cancer, we restored silenced RUNX3 in the human biliary cancer cell line Mz‐ChA‐2 using a histone deacetylase inhibitor. Thirteen of 17 human cancer specimens exhibited suppressed RUNX3 expression compared with normal biliary ducts. Moreover, the decreased RUNX3 expression was related to a lower accumulation of acetylated histone H3 associated with RUNX3. In in vitro experiments, vorinostat, a member of a new class of highly potent histone deacetylase inhibitors, restored RUNX3 expression in Mz‐ChA‐2 cells. Furthermore, vorinostat‐induced RUNX3 significantly enhanced p21 expression and growth inhibition of Mz‐ChA‐2 cells through restoration of TGF‐β signaling. These data suggest the significance of histone deacetylation‐associated suppression of RUNX3 expression in biliary tract carcinogenesis. Furthermore, vorinostat might hold promise for treating biliary tract cancer through enhancement of TGF‐β signaling by restoration of RUNX3. (Cancer Sci 2011; 102: 776–783)

Autoimmune Pancreatitis Exhibiting Multiple Mass Lesions

Our case is a first report of autoimmune pancreatitis with multiple masses within the pancreas which was pathologically diagnosed by endoscopic ultrasound-guided fine needle aspiration and treated by steroid. The masses disappeared by steroid therapy. Our case is informative to know that autoimmune pancreatitis sometimes exhibits multiple masses within the pancreas and to diagnose it without unnecessary surgery.

Erratum to: Early diagnosis of pancreatic necrosis based on perfusion CT to predict the severity of acute pancreatitis

Yoshihisa Tsuji • Naoki Takahashi • Hiroyoshi Isoda • Koji Koizumi • Sho Koyasu • Miho Sekimoto • Yuichi Imanaka • Shujiro Yazumi • Masanori Asada • Yoshihiro Nishikawa • Hiroshi Yamamoto • Osamu Kikuchi • Tsukasa Yoshida • Tetsuro Inokuma • Shinji Katsushima • Naoki Esaka • Akihiro Okano • Chiharu Kawanami • Nobuyuki Kakiuchi • Masahiro Shiokawa • Yuzo Kodama • Ichiro Moriyama • Takafumi Kajitani • Yoshikazu Kinoshita • Tsutomu Chiba Published online: 26 April 2017 Japanese Society of Gastroenterology 2017