The gastrointestinal tract is the largest immune interface with the environment. Exposure to large numbers of dietary and microbial antigens requires complex and highly regulated immune responses by ...different mucosal cell types, which result in the induction and maintenance of intestinal homeostasis. Defects in this equilibrium can disrupt the homeostatic mechanisms and lead to chronic intestinal inflammation. We review the cell populations and mechanisms involved in the control of intestinal homeostasis and inflammation, focusing on inflammatory bowel diseases. We describe some aspects of gut immunity that could alter the delicate balance between inflammatory and tolerogenic responses and result in chronic gastrointestinal tract inflammation in patients.
Oxidative stress is defined as an imbalance between the production of free radicals and reactive oxygen species (ROS) and the ability of the body to neutralize them by anti-oxidant defense systems. ...Cells can produce ROS during physiological processes, but excessive ROS can lead to non-specific and irreversible damage to biological molecules, such as DNA, lipids, and proteins. Mitochondria mainly produce endogenous ROS during both physiological and pathological conditions. Enzymes like nicotinamide adenine dinucleotide phosphate oxidase (NOX), xanthine oxidase (XO), lipoxygenase (LOX), myeloperoxidase (MPO), and monoamine oxidase (MAO) contribute to this process. The body has enzymatic and non-enzymatic defense systems to neutralize ROS. The intake of bioactive phenols, like quercetin (Que), can protect against pro-oxidative damage by quenching ROS through a non-enzymatic system. In this study, we evaluate the ability of Que to target endogenous oxidant enzymes involved in ROS production and explore the mechanisms of action underlying its anti-oxidant properties. Que can act as a free radical scavenger by donating electrons through the negative charges in its phenolic and ketone groups. Additionally, it can effectively inhibit the activity of several endogenous oxidative enzymes by binding them with high affinity and specificity. Que had the best molecular docking results with XO, followed by MAO-A, 5-LOX, NOX, and MPO. Que’s binding to these enzymes was confirmed by subsequent molecular dynamics, revealing different stability phases depending on the enzyme bound. The 500 ns simulation showed a net evolution of binding for NOX and MPO. These findings suggest that Que has potential as a natural therapy for diseases related to oxidative stress.
The risk of colorectal cancer (CRC) is higher in patients with inflammatory bowel disease (IBD). Population-based data from patients with ulcerative colitis (UC) estimate that the risk of CRC is ...approximately 2- to 3-fold that of the general population; patients with Crohn's disease appear to have a similar increased risk. However, the true extent of colitis-associated cancer (CAC) in undertreated IBD is unclear. Data suggest that the size (i.e., severity and extent) and persistence of the inflammatory process is largely responsible for the development of CRC in IBD. As patients with IBD and CRC have a worse prognosis than those without a history of IBD, the impact of current therapies for IBD on CAC is of importance. Chronic inflammation of the gut has been shown to increase the risk of developing CAC in both UC and CD. Therefore, control of inflammation is pivotal to the prevention of CAC. This review presents an overview of the current knowledge of CAC in IBD patients, focusing on the role of inflammation in the pathogenesis of CAC and the potential for IBD drugs to interfere with the process of carcinogenesis by reducing the inflammatory process or by modulating pathways directly involved in carcinogenesis.
Chronic inflammation is thought to be the leading cause of many human cancers including colorectal cancer （CRC）. Accordingly, epidemiologic and clinical studies indicate that patients affected by ...ulcerative colitis and Crohn＇s disease, the two major forms of inflammatory bowel disease, have an increased risk of developing CRC. In recent years, the role of immune cells and their products have been shown to be pivotal in initiation and progression of colitis-associated CRC. On the other hand, activation of the immune system has been shown to cause dysplastic cell elimination and cancer suppression in other settings. Clinical and experimental data herein reviewed, while confirming chronic inflammation as a risk factor for colon carcinogenesis, do not completely rule out the possibility that under certain conditions the chronic activation of the mucosal immune system might protect from colonic dysplasia,
The nutritional status in inflammatory bowel disease (IBD) is often impaired, and adherence to the Mediterranean diet (MedDiet) remains under-investigated. The aim of this study was to assess diet ...quality (DQ) and adherence to MedDiet in a cohort of Sardinian IBD patients. We conducted a case-control study in which 50 Crohn’s disease (CD) and 50 ulcerative colitis (UC) patients were matched with 100 healthy controls each. The Diet Quality Index (DQI-I) and Medi-Lite were used to assess DQ and adherence to MedDiet, respectively. Subgroup analysis by disease characteristics and use of advanced therapies were also carried out. DQI-I scored significantly lower in IBD, independently of disease localization and behavior (CD) and disease extent (UC): DQI-I: CD 34.5 (IQR 33–37) vs. CTRL 40 (IQR 38.5–43) p < 0.0001; UC 34.5 (IQR 33–37) vs. CTRL 42 (IQR 40–44) p < 0.0001. Medi-Lite scores were significantly lower in stricturing and ileo-colonic CD and in extensive UC: Medi-Lite CD 7.5 (IQR 7–9) vs. CTRL 9 (IQR 7–10) p = 0.0379; UC 8 (IQR7–10) vs. CTRL 9 (IQR 8–10.5) p = 0.0046. IBD patients had a low DQ independently of disease type and phenotype. Patients with ileo-colonic stenosing CD or extensive UC had lower MedDiet adherence, suggesting that its benefits may be mitigated by low acceptance in specific subgroups.
Helicobacter pylori (Hp) infection is associated with a marked infiltration of the gastric mucosa by inflammatory cells. The molecular pathways that control Hp‐associated inflammatory reaction are ...complex, but locally induced cytokines seem to contribute to maintaining the ongoing inflammation. We have previously shown that IL‐17 is over‐produced in Hp‐infected gastric mucosa, and that IL‐17 stimulates the synthesis of IL‐8, the major neutrophil chemoattractant. Factors/mechanisms that regulate IL‐17 expression remain, however, unknown. In this study, we initially expanded our previous data, showing that CD4+ and CD8+ T cells are a source of IL‐17 in Hp‐infected samples. Since IL‐23 enhances T cell‐derived IL‐17 during bacterial infections, we then assessed the role of IL‐23 in controlling IL‐17 expression in Hp‐colonized stomach. Using real‐time PCR and ELISA, IL‐23 was detected in all gastric biopsies, but its expression was more pronounced in Hp‐infected samples in comparison to controls. Treatment of normal gastric lamina propria mononuclear cells (LPMC) with IL‐23 enhanced Stat3 activation and IL‐17 secretion, and pharmacological inhibition of Stat3 prevented IL‐23‐driven IL‐17 synthesis. Consistently, blockade of IL‐23 in cultures of LPMC from Hp‐infected patients reduced Stat3 activation and IL‐17 production. Data show that IL‐23 is overexpressed in Hp‐infected gastric mucosa where it could contribute to sustaining IL‐17 production.
Chronic inflammation is a major driving force in the development of cancer in many tissues, but the array of factors involved in this neoplastic transformation are not well understood. We have ...investigated the role of interleukin (IL)-21 in colitis-associated colon cancer (CAC), as this cytokine is overexpressed in the gut mucosa of patients with ulcerative colitis (UC), a chronic inflammatory disease associated with colon cancer. IL-21 was increased in the gut of patients with UC-associated colon cancer, and in mice with CAC induced by azoxymethane (AOM) and dextran sulfate sodium (DSS). After AOM+DSS treatment, IL-21 KO mice showed reduced mucosal damage, reduced infiltration of T cells, and diminished production of IL-6 and IL-17A. IL-21-deficient mice also developed fewer and smaller tumors compared with wild-type (WT) mice. Absence of IL-21 reduced signal transducer and activator of transcription 3 activation in tumor and stromal cells. Administration of a neutralizing IL-21 antibody to WT mice after the last DSS cycle decreased the colonic T cell infiltrate and the production of IL-6 and IL-17A and reduced the number of tumors. These observations indicate that IL-21 amplifies an inflammatory milieu that promotes CAC, and suggest that IL-21 blockade may be useful in reducing the risk of UC-associated colon cancer.
The management of moderate to severe ulcerative colitis has undergone significant changes over the past 15 years due to the regulatory approval of several new drugs. In particular, following the ...approval of the first biological, i.e. infliximab, a number of further biological drugs, such as adalimumab, golimumab, vedolizumab and ustekinumab, and small molecules, such as tofacitinib, have been approved, thus enriching the therapeutic armamentarium for ulcerative colitis. Choice of therapy must take into consideration not only the need to induce and maintain disease remission according to the patient's profile, but also age, co-morbidities, and prior treatments. To guide these decisions, the Italian Group for the Study of Inflammatory Bowel Disease has developed clinical guidelines that supersede its earlier document from 2011. These new guidelines were developed following the GRADE methodology for rating the quality of the evidence and for determining the strength of the recommendations. This article presents the methodology and results, in the form of 20 statements with commentary on the use of the five biologics and tofacitinib for managing the intestinal manifestations of active ulcerative colitis and for maintaining remission. A separate technical review reports the analyses of the evidence upon which the present recommendations are based.
Background: Only limited information is available on cost efficacy of the advanced therapies for the treatment of ulcerative rectocolitis. We evaluated the efficacy and the treatment costs of these ...advanced therapies in the treatment of bio-exposed (primary failure to a biological agent) patients with moderately to severely active ulcerative rectocolitis. Methods: Data from a previous network meta-analysis (NMA) in the treatment of bio-exposed patients with moderately to severely active ulcerative rectocolitis was used. The analysis involved three therapies approved in Italy for the treatment of moderately to severely active ulcerative rectocolitis: upadacitinib (UPA), ustekinumab (UST) and vedolizumab (VDZ). According to the NMA results, the analysis was conducted considering two different timepoints: induction and maintenance. The pharmacoeconomic comparison between advanced therapies was carried out to estimate the respective cost for the NNT (Number Needed to Treat) compared to placebo using the clinical response (CRes) for the induction and clinical remission (CRem) and endoscopic improvement (EI) for the maintenance. Only the ex-factory price of each advanced therapy was considered. The cost per NNT was adopted as a cost-effectiveness indicator. Results: Independently of the timepoint considered (induction or maintenance) and the clinical (CRem and CRes) or endoscopic endpoint (EI) evaluated, UPA had always the lower cost per NNT than UST and VDZ. For example, considering the induction and the CRes, the cost per NNT for upadacitinib (45 mg) was € 7,862.07 compared to € 30,459.38 for ustekinumab (6 mg/kg) and to € 67,868.00 for vedolizumab. Conclusion: Upadacitinib is a cost-effective therapeutic option compared to ustekinumab and vedolizumab in the treatment of bio-exposed patients with moderately to severely active ulcerative rectocolitis.
Anti-TNF therapies infliximab (IFX), adalimumab (ADA), and golimumab (GOL) are approved for treating moderate to severe ulcerative colitis (UC). In UC, only the switch from IFX to ADA has been ...investigated, reaching no more than 10–43% remission rates at 12 months.
Of the present study was to investigate disease outcome after a switch from subcutaneous (SC) agents to the intravenous (IV) agent (IFX).
In this retrospective multicentre study, we analysed the charts of UC patients unresponsive/intolerant or with secondary loss of response (LOR) to ADA or GOL who were switched to IFX. We evaluated clinical response and remission together with adverse events at 3, 6, and 12 months follow-up.
Seventy-six patients were included; 38 patients started ADA and 38 started GOL for a mean therapy duration of 6 ± 6 months. Indications for switch were adverse events in 3%, primary failure in 79%, and LOR in 18% of patients. Clinical remission was reached by 47%, 50%, and 77% of patients, respectively. Patients that switched for LOR did numerically, but not statistically, better than patients who switched for primary failure.
Our data show a superior remission rate in SC to IV anti-TNF switch in UC compared to the IV to SC switch reported in literature.
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