Risk Factors for Delayed Hemorrhage after Colonic Endoscopic Mucosal Resection in Patients Not on Antithrombotic Therapy: Retrospective Analysis of 3,844 Polyps of 1,660 Patients.

BACKGROUND/AIMS: Colonic endoscopic mucosal resection (EMR) is safe for patients without antithrombotic therapy; however, EMR is associated with several risks. This study was performed to evaluate the risk of delayed hemorrhage in patients undergoing EMR without antithrombotic therapy. METHODS: In the present retrospective single-center study, 1,792 patients without antithrombotic therapy underwent colonic EMR from March 2012 to December 2016 at the Saga Medical Centre Koseikan. Risk factors were evaluated with respect to patient and lesion characteristics, the endoscopist's experience, and preventive hemoclips. Delayed hemorrhage was defined as bleeding for which emergency endoscopic hemostasis was applied >24 h after EMR. RESULTS: Among the 1,792 patients, 1,660 with 3,844 tumors were evaluated. Delayed hemorrhage occurred in 43 patients (2.6%) and 46 polyps (1.2%). Preventive hemoclips were applied in 996 patients (60.0%). Univariate analysis indicated that delayed hemorrhage occurred more frequently in young patients (3-39 years, p < 0.001, 40-59 years, p = 0.005) compared to > 60 years and in association with large polyps (> 10 mm, p = 0.003), hemoclip (p = 0.019), and pedunculated polyps (p = 0.024). Multivariate analysis indicated that risk factors for hemorrhage were young age (age of 3-39 years p < 0.001, 40-59 years, p = 0.005) and large polyps (> 10 mm, p < 0.001). The risk of delayed hemorrhage was increased by an estimated 8% with a 1-mm increase in polyp size. CONCLUSION: The present study suggests that young age (under 60 years old) and large polyp size are risk factors for causing delayed hemorrhage after colonic EMR in patients without antithrombotic therapy.

Lower Rebleeding Rate after Endoscopic Band Ligation than Endoscopic Clipping of the Same Colonic Diverticular Hemorrhagic Lesion: A Historical Multicenter Trial in Saga, Japan.

Objective This historical control study was performed to evaluate i) the rebleeding rate of bleeding colon diverticula treated with endoscopic band ligation (EBL) versus endoscopic clipping (EC) and ii) risk factors for rebleeding of diverticula initially treated by endoscopic hemostasis. Methods From January 2010 to December 2012, 68 patients were treated with EC, and from January 2013 to August 2016, 67 patients were treated with EBL. All patients in each group were followed up for one year to check for rebleeding. Results The rebleeding rate was lower in the EBL group (7 of 67, 10%) than in the EC group (21 of 68, 31%; p<0.01). This difference was mainly due to the lower rebleeding rate from the same hemorrhagic diverticulum initially treated by hemostasis (EBL: 4 of 67, 6%; EC: 15 of 68, 22%; p<0.01). The time span until rebleeding in the EBL group was ≤1 week. A multivariate analysis indicated that bleeding from the diverticula on the right side of the colon was a high-risk factor for rebleeding from the diverticula (odds ratio, 4.48; 95% confidence interval, 1.22-16.46; p=0.02). Conclusion The low rebleeding rate in the EBL group was attributed to the low degree of rebleeding from the same diverticulum, indicating that EBL was superior to EC in preventing rebleeding of an initially treated diverticulum.

[Recalcitrant pouchitis treated by budesonide foam:a case report].

This report presents the case of a 54-year-old man who had undergone restorative proctocolectomy with ileal pouch-anal anastomosis 15 years previously because of acute severe ulcerative colitis. After the operation, he experienced recalcitrant pouchitis and recurrent ulcer bleeding. There was a marked improvement in his symptoms following the administration of twice-daily budesonide 2mg foam injection for two months. Budesonide foam is suggested as a new therapy for pouchitis.

Aryl hydrocarbon receptor plays protective roles in ConA-induced hepatic injury by both suppressing IFN-γ expression and inducing IL-22.

The aryl hydrocarbon receptor (AhR), a ligand-activated nuclear transcription factor, is known to mediate the toxic and carcinogenic effects of various environmental pollutants, while AhR has been shown to protect animals from various types of tissue injury. ConA-induced hepatitis is known as a mouse model of acute liver injury. Here, we found a protective role of AhR in ConA-induced hepatitis. AhR is induced in the liver during ConA-induced hepatitis, and Ahr (-/-) mice were highly sensitive to this model. Bone marrow chimera experiments indicate that Ahr (-/-) hematopoietic cells are responsible for hypersensitivity to ConA-induced hepatitis. We found that IFN-γ from invariant NKT cells was up-regulated and IL-22 from innate lymphoid cells (ILCs) was abolished in Ahr (-/-) mice. In addition, IL-22 production was still observed in Rag2 (-/-) mice but it was severely reduced in Ahr (-/-) Rag2 (-/-) mice. ConA-induced IL-22 production was also dependent on retinoic acid-related orphan receptor γt. These results show that AhR has crucial protective roles in ConA-induced liver injury via promoting IL-22 production from ILCs and suppressing IFN-γ expression from NKT cells.

Aryl hydrocarbon receptor protects against bacterial infection by promoting macrophage survival and reactive oxygen species production.

Aryl hydrocarbon receptor (AhR) is crucial for various immune responses. The relationship between AhR and infection with the intracellular bacteria Listeria monocytogenes (LM) is poorly understood. Here, we show that in response to LM infection, AhR is required for bacterial clearance by promoting macrophage survival and reactive oxygen species (ROS) production. AhR-deficient mice were more susceptible to listeriosis, and AhR deficiency enhances bacterial growth in vivo and in vitro. On the other hand, pro-inflammatory cytokines were increased in AhR-deficient macrophages infected with LM despite enhanced susceptibility to LM infection in AhR-deficient mice. Subsequent studies demonstrate that AhR protects against macrophage cell death induced by LM infection through the induction of the antiapoptotic factor, the apoptosis inhibitor of macrophages, which promotes macrophage survival in the setting of LM infection. Furthermore, AhR promotes ROS production for bacterial clearance. Our results demonstrate that AhR is essential to the resistance against LM infection as it promotes macrophage survival and ROS production. This suggests that the activation of AhR by its ligands may be an effective strategy against listeriosis.

TRAF6 is essential for maintenance of regulatory T cells that suppress Th2 type autoimmunity.

Regulatory T cells (Tregs) maintain immune homeostasis by limiting inflammatory responses. TRAF6 plays a key role in the regulation of innate and adaptive immunity by mediating signals from various receptors including the T-cell receptor (TCR). T cell-specific deletion of TRAF6 has been shown to induce multiorgan inflammatory disease, but the role of TRAF6 in Tregs remains to be investigated. Here, we generated Treg-specific TRAF6-deficient mice using Foxp3-Cre and TRAF6-flox mice. Treg-specific TRAF6-deficient (cKO) mice developed allergic skin diseases, arthritis, lymphadenopathy and hyper IgE phenotypes. Although TRAF6-deficient Tregs possess similar in vitro suppression activity compared to wild-type Tregs, TRAF6-deficient Tregs did not suppress colitis in lymphopenic mice very efficiently due to reduced number of Foxp3-positive cells. In addition, the fraction of TRAF6-deficient Tregs was reduced compared with wild-type Tregs in female cKO mice without inflammation. Moreover, adoptive transfer of Foxp3 (+) Tregs into Rag2(-/-) mice revealed that TRAF6-deficient Tregs converted into Foxp3(-) cells more rapidly than WT Tregs under lymphopenic conditions. Fate-mapping analysis also revealed that conversion of Tregs from Foxp3(+) to Foxp3(-) (exFoxp3 cells) was accelerated in TRAF6-deficient Tregs. These data indicate that TRAF6 in Tregs plays important roles in the maintenance of Foxp3 in Tregs and in the suppression of pathogenic Th2 type conversion of Tregs.

Th17 cells carrying TCR recognizing epidermal autoantigen induce psoriasis-like skin inflammation.

Psoriasis is considered a Th17-type autoimmune skin inflammatory disease; however, involvement of an autoantigen-specific TCR has not been established. In this study, we show that psoriasis-like skin inflammation can be induced by autoreactive Th17 cells. We previously developed the desmoglein 3-specific TCR-transgenic (Dsg3H1) mouse, in which CD4⁺ T cells recognize physiological epidermal autoantigen. T cells from Dsg3H1 mice were polarized into Th17 cells in vitro and then adoptively transferred into Rag2⁻/⁻ mice. Dsg3H1-Th17 cells induced severe psoriasis-like skin inflammation within 2 wk after transfer in the tissues in which desmoglein 3 is expressed. Such pathology was not observed when wild-type Th17 cells or Th1-skewed Dsg3H1 T cells were transferred, and it was strongly suppressed by anti-IL-12/23 and anti-IL-17 Abs. Although IFN-γ⁺/IL-17⁺ T cells accumulated in the skin lesions of mice that received Dsg3H1-Th17 cells, IFN-γ-deficient Dsg3H1-Th17 cells were fully pathogenic. These results demonstrate that cutaneous psoriasis-like immunopathology can be developed by epidermis-specific recognition of Th17 cells, which is strictly dependent on IL-17 but not IFN-γ.

CDK inhibitors suppress Th17 and promote iTreg differentiation, and ameliorate experimental autoimmune encephalomyelitis in mice.

Th17 cells, which have been implicated in autoimmune diseases, require IL-6 and TGF-ß for early differentiation. Several Smad-independent pathways including the JNK and the RhoA-ROCK pathways have been implicated in the induction of RORγt, the master regulator of Th17, however, molecular mechanisms underlying Smad-independent pathway remain largely unknown. To identify novel pathways involved in Th17 differentiation, we screened 285 chemical inhibitors for known signaling pathways. Among them, we found that Kenpaullone, a GSK3-ß and CDK inhibitor, efficiently suppressed TGF-ß-mediated RORγt induction and enhanced Foxp3 induction in primary T cells. Another CDK inhibitor, Roscovitine, but not other GSK3-ß inhibitors, suppressed Th17 differentiation and enhanced iTreg development. Kenpaullone and Roscovitine suppressed experimental autoimmune encephalomyelitis (EAE), a typical Th17-mediated autoimmune disease model. These two compounds enhanced STAT5 phosphorylation and restored IL-2 production in the presence of TGF-ß. These data suggest that CDK inhibitors modulate TGF-ß-signaling pathways, which restore TGF-ß-mediated suppression of IL-2 production, thereby modifying the Th17/iTreg balance.