Satoko Inoue

Usefulness of quantitative real-time PCR assay for early detection of cytomegalovirus infection in patients with ulcerative colitis refractory to immunosuppressive therapies

Background: Studies suggest that cytomegalovirus (CMV) infection exacerbates ulcerative colitis (UC) refractory to immunosuppressive therapies. Early and accurate diagnosis of CMV infection is important for the treatment of UC. We evaluated the usefulness of quantitative real‐time polymerase chain reaction (PCR) for detecting CMV infection in inflamed colonic mucosa of patients with UC refractory to immunosuppressive therapies. Methods: From 2003 to 2006, 30 patients (mean age: 41 ± 18 years; 14 men, 16 women) with UC refractory to immunosuppressive therapies were enrolled in the study. We evaluated CMV infection by CMV antigenemia, histologic examination, and quantitative real‐time PCR for CMV using colonic mucosa and investigated the clinical outcomes of antiviral therapy. Results: CMV‐DNA was detected only in the inflamed colonic mucosa in 17 (56.7%) of 30 patients. Of the 17 CMV‐DNA‐positive patients, 4 were positive for CMV antigenemia or inclusion bodies on histologic examination; of the 13 CMV‐DNA‐negative patients none was positive for CMV antigenemia or inclusion bodies. Of the 17 CMV‐DNA‐positive patients, 12 (70.6%) were treated with ganciclovir for 2 weeks and 10 patients went into remission. Two other patients required colectomy after antiviral therapy. In contrast, of the 13 CMV‐DNA‐negative patients 12 (92.3%) achieved remission after intensifying their immunosuppressive therapies. Conclusions: Quantitative real‐time PCR assay for detecting CMV‐DNA is useful for early, accurate diagnosis of CMV infection in patients with UC refractory to immunosuppressive therapies, enabling prompt and appropriate treatment. (Inflamm Bowel Dis 2007)

Long-term effect of tacrolimus therapy in patients with refractory ulcerative colitis

Background  Little is known about long‐term outcome of tacrolimus therapy for ulcerative colitis.

The effect of proteasome inhibitor MG132 on experimental inflammatory bowel disease

Immunoproteasome up‐regulation enhances the processing of nuclear factor‐κB (NF‐κB) and degradation of IκBα, which correlates with increased amounts of NF‐κB in the various cells. Aberrant activation of NF‐κB is involved in the pathogenesis of inflammatory bowel disease (IBD). The aim of this study was to elucidate the effect of proteasome inhibitor MG132 on experimental IBD. We investigated the effects of MG132 on intestinal inflammation and epithelial regeneration in both interleukin‐10‐deficient (IL‐10−/−) mice and mice with dextran sulphate sodium (DSS)‐induced colitis. Body weight, histological findings and tumour necrosis factor (TNF)‐α mRNA expression, epithelial cell proliferation and NF‐κB p65 activity in colonic tissues were examined. The effects of MG132 on cell proliferation, migration and multiple drug resistance 1 (MDR1) gene expression were determined in vitro. MG132 ameliorated intestinal inflammation of IL‐10−/− mice by decreasing TNF‐α mRNA expression in the colonic tissues, which was associated with suppression of NF‐κB activation, and reduced significantly the number of Ki‐67‐positive intestinal epithelial cells. On the other hand, MG132 did not reduce intestinal inflammation in mice with DSS‐induced colitis, and delayed significantly the recovery of body weight and epithelial regeneration. MG132 also suppressed significantly epithelial cell proliferation, cell migration and MDR1 gene expression in vitro. Proteasome inhibition reduces T cell‐mediated intestinal inflammation, but may interrupt both epithelial regeneration and barrier function of colonic mucosa. Optimal use of proteasome inhibitor should be kept in mind when we consider its clinical application for patients with IBD.

The effect of tacrolimus (FK-506) on Japanese patients with refractory Crohn’s disease

BackgroundRecent evidence indicates that intravenous or oral therapy with tacrolimus (FK-506) is effective in treating patients with Crohn’s disease. We evaluated the usefulness of tacrolimus therapy for Japanese patients with refractory Crohn’s disease.MethodsFourteen adult Japanese patients with Crohn’s disease that was refractory to conventional therapies, including prednisolone (n = 5), azathioprine (n = 6), and infliximab (n = 5), were enrolled. Treatment with tacrolimus was started orally or intravenously and aimed for serum trough levels of 10–15 ng/ml. After the patients achieved clinical improvement, tacrolimus maintenance therapy was administered to maintain the trough level at 5–10 ng/ml.ResultsAll patients achieved remission or significant improvement 40 days after starting tacrolimus treatment. By 120 days after the start of therapy, 9 (64%) patients achieved remission, 2 patients (14%) achieved significant improvement, and only 3 patients (21%) relapsed. The relapsed patients were treated with infliximab therapy and achieved remission. Steroids were discontinued by the 5 patients who had taken steroids before the study began. Adverse effects of tacrolimus included a temporary increase in serum creatinine concentration (n = 1, 7%), hyperkalemia (n = 1, 7%), and tremor (n = 1, 7%).ConclusionsTacrolimus therapy is effective and well tolerated in patients with Crohn’s disease that is refractory to conventional therapies.

Efficacy of probiotic treatment with Bifidobacterium longum 536 for induction of remission in active ulcerative colitis: A randomized, double‐blinded, placebo‐controlled multicenter trial

We conducted a randomized, double‐blinded, placebo‐controlled trial to investigate the efficacy of Bifidobacterium longum 536 (BB536) supplementation for induction of remission in Japanese patients with active ulcerative colitis (UC).

SR-PSOX/CXCL16 plays a critical role in the progression of colonic inflammation

Background and aims Inflammatory bowel disease (IBD) is initiated and perpetuated by a dysregulated immune response to unknown environmental antigens such as luminal bacteria in genetically susceptible hosts. SR-PSOX/CXCL16, a scavenger receptor that binds phosphatidylserine and oxidised lipoprotein, has both phagocytic activity and chemotactic properties. The aim of this study was to investigate the role of SR-PSOX/CXCL16 in patients with IBD and experimental murine colitis. Methods The serum levels of SR-PSOX/CXCL16 were measured in patients with IBD. The roles of SR-PSOX/CXCL16 in phagocytosis of bacterial components and cytokine production by macrophages from wild-type (WT) and SR-PSOX/CXCL16 knockout (KO) mice were assessed. Colitis was induced by administering dextran sulfate sodium (DSS) to WT and SR-PSOX/CXCL16 KO mice. Colonic inflammation was analysed by clinical, histological and immunological parameters. Finally, the effect of a monoclonal antibody (mAb) to SR-PSOX/CXCL16 on DSS-induced colitis and trinitrobenzene sulfonic acid-induced colitis models was evaluated. Results Serum levels of SR-PSOX/CXCL16 correlated significantly with the disease activity of patients with IBD. Ex vivo experiments showed that SR-PSOX/CXCL16 was involved in both phagocytosis of bacterial antigens and the T helper 1 immune response through the production of interleukin 12 and interferon γ. In vivo murine experiments demonstrated the upregulated gene expression of SR-PSOX/CXCL16 in inflamed colonic tissues and the predominant expression of SR-PSOX/CXCL16 on macrophages. SR-PSOX/CXCL16 KO mice were less susceptible to colonic inflammation than were their WT littermates. Administration of SR-PSOX/CXCL16 mAb ameliorated the condition in the two different experimental colitis models. Conclusions SR-PSOX/CXCL16 plays a critical role in colonic inflammation and could be a potential therapeutic target for patients with IBD.

Upregulation of T-bet and tight junction molecules by Bifidobactrium longum improves colonic inflammation of ulcerative colitis

To the Editor: Manipulation of the mucosal microbiota to reduce the inflammatory potential of colonizing bacteria is an attractive therapy for patients with ulcerative colitis (UC). Therefore, probiotics treatments have been focused on the point of improving its intestinal microbial balance. We read with a great interest the review by Isaacs and Herfarth entitled “Role of probiotic therapy in IBD.”1 In that review, the authors described the effect of 4 weeks of symbiotic treatment (Bifidobactrium longum with Synergy 1) on patients with active UC reported by Furrie et al.2 Bifidobactrium longum (hereinafter BB536) was isolated from feces of a healthy baby in 1969.3 Thereafter, many physiological effects of BB536 have been reported and it has been used commercially for various food applications in several countries. The size of this study with BB536 was small, but there was a significant reduction of proinflammatory cytokines in mucosal biopsies in patients treated with the active therapy as compared to placebo. This finding was very promising for treatment with UC, but the exact mechanism of BB536 on patients with UC was not elucidated. Here we report data on an openlabel trial of BB536 for Japanese patients with UC and demonstrate its mechanism of reducing intestinal inflammation in patients with UC. Human study: From 2005 to 2007, 14 patients with UC (5 male, 9 female; mean age 43 5 years) who were refractory to more than 2250 mg of 5-aminosalicylate (5-ASA) were enrolled in this open-label study. The median disease duration prior to BB536 was 10 3.3 years. Six patients of these patients (42.8%) were afflicted with pancolitis and 3 (21.4%) had left-sided colitis; 5 (35.7%) had proctitis. Clinical activity was assessed with the Clinical Activity Index (CAI). The mean CAI score was 7 1.5 before BB536 administration. Patients who scored higher than 5 points in CAI were regarded as active phase and were treated with 2–3 1011 freeze-dried viable BB536 for 24 weeks. The clinical response was assessed at 24 weeks after administration of BB536. Clinical remission was defined as a decrease in the CAI to 4 or less. CAI was reduced in 12 of 14 patients at 24 weeks after starting BB536 therapy. Of note, 10 (67%) of 14 patients achieved clinical remission (2 had pancolitis; 3 had left-sided, and 5 had proctitis). The mean CAI significantly decreased at 8, 12, and 24 weeks compared to that before administration of BB536 (Fig. 1). Next we investigated the molecular mechanism of BB536 on cytokine production and expression of molecules related to mucosal barrier function. 1) Splenocytes of T cell receptorknockout (KO) mice resembling cytokine phenotype of UC (Th2 dominant) were stimulated with CD3/CD28 after pretreatment of heat-inactivated BB536. The production of IL-12, IFN, IL-4, and IL-13 in supernatants was measured by enzyme-linked immunosorbent assay (ELISA). T-bet and GATA-3 mRNA expression was evaluated by reversetranscriptase polymerase chain reaction (RT-PCR). 2) After inoculation of BB536 (1.5 1010CFU/mouse) to wildtype and Toll like receptor 2 KO mice, the gene expression of tight junction molecule (Claudin-1 and ZO-1) in colonic mucosa were analyzed by RTPCR. Stimulation with BB536 induced the production of both IL-12 and IFNfrom splenocytes and inhibited the production of IL-4 and IL-13. Stimulation with BB536 resulted in induction of Tbet mRNA expression in splenocytes, while it reduced GATA-3 mRNA expression. Moreover, gene expressions of claudin-1 and ZO-1 was upregulated in colonic tissue of wildtype mice after stimulation with BB536, while these upregulations were not observed in that of TLR-2 KO mice (Fig. 2).

Clinical features of Japanese patients with colonic angiodysplasia

Background and Aim:  With improvements in endoscopic resolution, angiodysplasia (AGD) has become an increasingly recognized disorder. The aim of this study was to describe the clinical features of Japanese patients with colonic AGD and compare them to the clinical features of Western patients.

Gastric mucosal hyperplasia via upregulation of gastrin induced by persistent activation of gastric innate immunity in major histocompatibility complex class II deficient mice

Background and aim: Major histocompatibility complex class II deficient (Aα0/0) mice have decreased CD4+ T cells, making them immunologically similar to patients with acquired immunodeficiency syndrome (AIDS). Both patients with AIDS and Aα0/0 mice have hypertrophic gastric folds. To clarify the mechanism of gastric mucosal hyperplasia, we investigated the pathophysiology and the role of the innate immunity in the stomach of Aα0/0 mice. Methods: Stomachs from 1–6 month old Aα0/0 mice, kept under specific pathogen free conditions, were examined at 1 month intervals histologically and immunohistochemically. Gene expression of proinflammatory cytokines, Toll-like receptors (TLRs), cyclooxygenase (COX)-2, and myeloperoxidase (MPO) activity in the gastric mucosa was investigated. Serum gastrin levels and gastric acidity were measured. Bacterial culture of the stomach was performed. To clarify the roles of hypergastrinaemia in the gastric mucosa, a gastrin receptor antagonist (AG041R) was administered. Results: Aα0/0 mice had a diffusely thick corpus mucosa with infiltration of CD11b+ granulocytes and macrophages. Anti-Ki67 staining demonstrated expansion of the proliferating neck zone. Gene expression of interleukin 1β, interferon γ, TLR-2, TLR-4, and COX-2 were upregulated, and MPO activity was increased. Only a small amount of non-pathogenic bacteria was detected in the stomach. Serum gastrin levels and Reg-Iα positive cells in the gastric mucosa increased, despite normal gastric acidity. After treatment with AG041R, gastric mucosal thickness was significantly reduced. Conclusion: Persistent activation of innate immunity in the stomach induced gastric mucosal hyperplasia through upregulation of gastrin synthesis in Aα0/0 mice, suggesting a pathophysiology similar to the gastric changes in patients with AIDS.

Gastrointestinal: Epidermal metaplasia of the esophagus

1627