Hideyuki Shiomi

Multicentric Castleman's disease with abundant IgG4-positive cells: a clinical and pathological analysis of six cases

Background Differentiation between multicentric Castlemans disease and systemic immunoglobulin (Ig) G4-related lymphadenopathy is sometimes difficult. It has been suggested that measurement of the IgG4-/IgG-positive cell ratio is useful for the differential diagnosis of the two diseases. However, the authors present a detailed report of six patients with multicentric Castlemans disease with abundant IgG4-positive cells (IgG4-/IgG-positive cell ratio, >40%). Results In the present series, the patients showed systemic lymphadenopathy, polyclonal hypergammaglobulinaemia and elevated serum interleukin-6 (IL-6) and C-reactive protein levels. Further, anaemia, hypoalbuminaemia, hypocholesterolaemia and thrombocytosis were observed. These findings were consistent with those of multicentric Castlemans disease. Although five patients showed elevated serum IgG4 levels, only two patients showed an increased serum IgG4/IgG ratio. However, the two patients showed highly elevated serum IgG4 levels, but the serum IgG4/IgG ratios were, although increased, not very high. Also, a patient with increased serum IgG4/IgG ratio showed a good response to antihuman IL-6 receptor monoclonal antibody (tocilizumab). Histologically, the germinal centres were mostly small and regressive, and frequently penetrated by hyalinised blood vessels, and there was no eosinophil infiltration. These findings were different from those of IgG4-related lymphadenopathy. Conclusions The authors conclude that multicentric Castlemans disease sometimes occurs with abundant IgG4-positive cells and elevated serum IgG4 levels. Therefore, the two diseases cannot be differentially diagnosed by immunohistochemical staining alone. Laboratory findings, especially IL-6 level, C-reactive protein level and platelet count, are important for the differential diagnosis of the two diseases.

GCMS‐based metabolomic study in mice with colitis induced by dextran sulfate sodium

Background: Metabolomics provides data about all the metabolic processes of a cell or organism. So far, the changes that occur in the levels of metabolites during the development of colitis have not been fully elucidated. Here we examined the changes of metabolite levels in the serum and colon tissue of colitis mice using gas chromatography mass spectrometry (GC/MS) with the aim of achieving a detailed understanding of the pathogenesis of inflammatory bowel disease (IBD). Methods: To induce colitis, C57BL/6J mice were administered 3.0% dextran sulfate sodium (DSS) in their drinking water for 5 days and were subsequently given drinking water alone. Results: A total of 77 and 92 metabolites were detected in serum and colon tissue, respectively, and among the metabolites the compositions of TCA cycle intermediates and amino acids changed depending on the degree of colitis. Then, partial least square discriminant analysis (PLS‐DA), a multiple classification analysis, showed distinct clustering and clear separation of the groups according to the degree of colitis. Furthermore, PLS‐DA loadings plots revealed that succinic acid, indole‐3‐acetic acid, glutamic acid, and glutamine were the main contributors to the separation of each stage of colitis. In addition, it was revealed that supplementation with glutamine, the level of which was significantly decreased in the acute phase of colonic inflammation, attenuated colitis induced by DSS. Conclusions: Our results suggest that metabolomics is capable of representing the various degrees of colitis, and our findings will aid in the discovery of therapeutic agents for IBD and other inflammatory disorders by metabolomic approaches. (Inflamm Bowel Dis 2011;)

Predictors of malignant intraductal papillary mucinous neoplasm of the pancreas.

Goals The predictors of malignant intraductal papillary mucinous neoplasm (IPMN) and invasive IPMN were investigated in this study to determine the optimal indicators of surgical resection for IPMN. Background Recently, international consensus guidelines have described the standard indicators of resection for IPMN. However, the indicators of surgical resection for IPMN, especially for branch duct IPMN, still remain controversial. Study Eighty-two patients with IPMN who underwent surgical resection during April 1998 to January 2009, were retrospectively reviewed and examined with regard to their preoperative factors and pathologic diagnosis. Results Multivariate analysis showed that main duct IPMN (P<0.01) and earlier diabetes (P=0.03) were independent predictors of malignant IPMN. In branch duct IPMN, the diameter of the main pancreatic duct (MPD) was found to be significantly associated with malignancy by univariate analysis (P=0.034). An elevated serum CA19-9 level (P<0.01) was an independent predictor of invasive IPMN. Conclusions Our observations suggest that main duct IPMN, branch duct IPMN with MPD dilatation, and IPMN with an elevated serum CA19-9 level should be considered as indications for surgical resection.

Gamma interferon produced by antigen-specific CD4+ T cells regulates the mucosal immune responses to Citrobacter rodentium infection

ABSTRACT Citrobacter rodentium, a murine model pathogen for enteropathogenic Escherichia coli, colonizes the surface of intestinal epithelial cells and causes mucosal inflammation. This bacterium is an ideal model for investigating pathogen-host immune interactions in the gut. It is well known that gene transcripts for Th1 cytokines are highly induced in colonic tissue from mice infected with C. rodentium. However, it remains to be seen whether the Th1 or Th2 cytokines produced by antigen-specific CD4+ T cells provide effective regulation of the host immune defense against C. rodentium infection. To investigate the antigen-specific immune responses, C. rodentium expressing ovalbumin (OVA-C. rodentium), a model antigen, was generated and used to define antigen-specific responses under gamma interferon (IFN-γ)-deficient or interleukin-4 (IL-4)-deficient conditions in vivo. The activation of antigen-specific CD4+ T cells and macrophage phagocytosis were evaluated in the presence of IFN-γ or IL-4 in vitro. IFN-γ-deficient mice exhibited a loss of body weight and a higher bacterial concentration in feces during OVA-C. rodentium infection than C57BL/6 (wild type) or IL-4-deficient mice. This occurred through the decreased efficiency of macrophage phagocytosis and the activation of antigen-specific CD4+ T cells. Furthermore, a deficiency in antigen-specific CD4+ T-cell-expressed IFN-γ led to a higher susceptibility to mucosal and gut-derived systemic OVA-C. rodentium infection. These results show that the IFN-γ produced by antigen-specific CD4+ T cells plays an important role in the defense against C. rodentium.

Autophagy in the intestinal epithelium regulates Citrobacter rodentium infection

Autophagy, a ubiquitous degradation pathway, is important for the survival and homeostasis of cells. Previous studies have demonstrated the role of autophagy in host defense against bacterial infection, but the importance of autophagy in the intestinal epithelium for the regulation of bacterial infection has not been fully elucidated. In this study, we showed that the essential autophagy protein Atg7 is required for resistance to Citrobacter rodentium infection in the intestinal epithelium. Infected mice in which Atg7 had been conditionally deleted from the intestinal epithelium exhibited greater clinical evidence of disease and higher expression levels of pro-inflammatory cytokine mRNA in the large intestine. Moreover, C. rodentium clearance was reduced in the Atg7 conditional knockout mice. These results demonstrate that autophagy in intestinal epithelial cells plays an important role in host defense against C. rodentium infection and the regulation of C. rodentium infectious colitis.

Oral Treatment with Extract of Agaricus blazei Murill Enhanced Th1 Response through Intestinal Epithelial Cells and Suppressed OVA-Sensitized Allergy in Mice

To clarify the mechanism of the antiallergic activity of Agaricus blazei Murill extract (ABME), the present paper used an in vivo allergy model and an in vitro intestinal gut model. During OVA sensitization, the serum IgE levels decreased significantly in ABME group. Interleukin (IL)-4 and -5 produced from OVA-restimulated splenocytes was significantly decreased, and anti-CD3ε/CD28 antibody treatment also reduced IL-10, -4, and -5 production and increased IFN-γ production in ABME group. These results suggest that oral administration of ABME improves Th1/Th2 balance. Moreover, a coculture system constructed of Caco-2 cells and splenocytes from OT-II mice or RAW 264.7 cells indicated that the significant increases in IFN-γ production by ABME treatment. Therefore, it was concluded that the antiallergic activity of ABME was due to the activation of macrophages by epithelial cells and the promotion of the differentiation of naïve T cells into Th1 cells in the immune.

Role of Fc Receptors as a therapeutic target.

It has been forty years since the discovery of Fc Receptors and their function. Fc Receptors include the IgG receptors (FcgammaR), high-affinity IgE receptor (FcepsilonRI), IgA and IgA/IgM receptors, and neonatal Fc receptor for IgG (FcRn). In particular, the FcgammaRs have been well known to play an important role in many biologic processes including those associated with the response to infection and cancer as well as in the pathogenesis of immune-mediated diseases. Both positive and negative regulatory function has ascribed to Fc receptors and FcgammaRs in particular which serve to establish a threshold for immune cell activation. In other cases, Fc receptors such as FcRn possess a novel structure and function by playing a major role in the transport of IgG across polarized epithelial barriers at mucosal surfaces and in the regulation of IgG half-life. These diverse functions highlight the potential effectiveness of targeting Fc receptors for therapeutic purposes. This review summarizes new information available in the therapeutic applications of this biology.

Fcγ Receptor Regulation of Citrobacter rodentium Infection

ABSTRACT Citrobacter rodentium, a murine model pathogen for enteropathogenic Escherichia coli, colonizes the colon utilizing attaching and effacing lesions to adhere specifically to the surfaces of intestinal epithelial cells and cause mucosal inflammation. CD4+ T cells, B cells, and immunoglobulin G (IgG), but not secretory IgA or IgM, play a critical role in eradicating this pathogen. Consistent with the importance of IgG in C. rodentium eradication, IgG transport by the neonatal Fc receptor for IgG within the intestinal epithelium also has a critical role in the regulation of C. rodentium infection. It remains to be determined, however, whether Fcγ receptors (FcγRs), the receptors for the Fc portion of IgG, regulate this bacterial infection within mucosal tissues. Therefore, we investigated the roles of FcγRs during C. rodentium infection. Fc receptor common gamma chain (FcRγ)-deficient mice were more susceptible to C. rodentium-induced colitis. This occurred through decreased efficiency of FcR-mediated endocytosis and maturation of dendritic cells and consequently T-cell activation of antigen-specific T cells. Moreover, in the absence of FcγRs, phagocytosis by macrophages was significantly diminished. Therefore, activating FcγRs play an important role in defending against C. rodentium infection, indicating that the critical role played by IgG in this infection is not mediated by IgG alone but is dependent upon this class of receptors.

Asia-Pacific consensus guidelines for endoscopic management of benign biliary strictures

Abstract Benign biliary strictures (BBSs) are commonly caused by surgical injury, chronic pancreatitis, and inflammatory cholangiopathies. Although advanced imaging tests and tissue acquisition methods have been developed for evaluation of indeterminate biliary strictures, differentiation of BBSs from biliary malignancies remains a challenge to clinicians. The majority of BBSs have good response to nonsurgical treatment and surgical intervention mainly serves as a rescue when nonsurgical approaches fail. Endoscopic management is a safe, effective, and less-invasive treatment for BBSs compared with other approaches. Endoscopic biliary stricture dilation followed by placement of multiple plastic stents has been the first-line choice with good long-term ductal patency. Recently, covered self-expanding metal stents (CSEMSs) has been increasingly used in the management of BBSs with similar effectiveness but easier deployment, fewer endoscopic sessions compared with plastic stents. Moreover, other technologies are emerging in the diagnosis and management of BBSs. To assist clinicians in managing BBSs, the Asia-Pacific ERCP Club (APEC) has developed this statement through a systematic review of the literature.

IL-8 Expression in Granulocytic Epithelial Lesions of Idiopathic Duct-centric Pancreatitis (Type 2 Autoimmune Pancreatitis)

Type 2 autoimmune pancreatitis (type 2 AIP) develops in isolation or sometimes in association with ulcerative colitis. Its diagnosis requires the histologic confirmation of granulocytic epithelial lesions (GELs) with no diagnostic biomarker currently available. This study aimed to elucidate the tissue expression of cytokines and their diagnostic value in this condition. In quantitative polymerase chain reaction for multiple cytokines using tissue-derived mRNA, the expression level of interleukin (IL)-8 was markedly higher in type 2 AIP than in type 1 AIP (P<0.001). In immunostaining, IL-8 expression was detected in the ductal/ductular epithelium (11/13; 85%) and infiltrating neutrophils or lymphocytes (12/12; 100%) in type 2 AIP, but was almost entirely negative in type 1 AIP (n=13; both, P<0.001). Although obstructive pancreatitis adjacent to pancreatic cancers (peritumoral pancreatitis) exhibited IL-8 expression in the epithelium (3/12; 25%) and inflammatory cells (10/12; 83%), expression levels were significantly lower than those in type 2 AIP (P<0.001 and 0.020, respectively). The presence of either GELs or IL-8-positive epithelium discriminated type 2 AIP from type 1 AIP or obstructive pancreatitis with 92% sensitivity and 92% to 100% specificity. Furthermore, CD3/IL-8-coexpressing lymphocytes were almost restricted to type 2 AIP. Interestingly, a similar pattern of IL-8 expression was also observed in colonic biopsies of ulcerative colitis. In conclusion, the overexpression of IL-8 may underlie the development of GELs in type 2 AIP, and IL-8 immunostaining or IL-8/CD3 double staining may become an ancillary method for its diagnosis. The similar expression pattern of IL-8 in ulcerative colitis also suggests a pathogenetic link between the 2 conditions.