Infliximab preferentially induces clinical remission and mucosal healing in short course Crohn's disease with luminal lesions through balancing abnormal immune response in gut mucosa

Development and validation of a novel therapeutic drug monitoring-based nomogram for prediction of primary endoscopic response to anti-TNF therapy in active Crohn's disease

Background

Anti-tumor necrosis factor (TNF) monoclonal antibodies, especially infliximab (IFX) and adalimumab (ADA), are considered the first-line treatment for active Crohn's disease (CD). However, the predictive role of therapeutic drug monitoring (TDM) of serum anti-TNF in monitoring the treatment of inflammatory bowel disease (IBD) remains controversial.

Objectives

To explore the correlation between serum anti-TNF levels and early endoscopic response in active CD using a TDM-based nomogram.

Design

Cross-sectional study.

Methods

The simplified endoscopic activity score for CD (SES-CD), Crohn's disease activity index (CDAI), laboratory parameters, and the serum trough levels of IFX and ADA were assessed.

Results

The trough levels of IFX or ADA were significantly higher in patients with endoscopic response compared to non-responders in the development cohort (p < 0.001). The IFX and ADA levels showed a weak but significantly negative correlation with SES-CD (p < 0.001), CDAI (p < 0.001), and C-reactive protein (CRP) (p < 0.001) at week 14 post-IFX therapy in the development cohort. Furthermore, the receiver operating characteristic curve revealed that an optimal level of IFX (4.80 μg/mL) and ADA (8.80 μg/mL) exhibited the best performance in predicting endoscopic response. Concomitantly, we developed a novel nomogram prediction model based on the results of multivariate logistic regression analysis, which consisted of CRP, albumin (Alb), and anti-TNF trough levels at week 14. The nomogram showed significant discrimination and calibration for both IFX and ADA in the development cohort and performed well in the external validation cohort.

Conclusion

This study demonstrates a robust association between serum concentrations of IFX, ADA, Alb, and CRP and primary endoscopic response in active CD patients. Importantly, the TDM- and laboratory marker-based nomogram may be used to evaluate the primary endoscopic response to anti-TNF therapy, especially for optimizing treatment strategies and switching therapy in CD patients.

Histological Hallmarks of Mucosal Healing in Inflammatory Bowel Diseases in the Era of Monoclonal Antibodies Therapy: New Insights and Perspectives

BACKGROUND

Chronic inflammatory bowel diseases (IBDs) are gaining increasing attention, both because they can severely reduce the quantity and quality of life, and because the advent of monoclonal antibodies has profoundly changed the natural history of these diseases. In recent years, the concept of mucosal healing has assumed a certain importance, and there are more and more clinical and pharmacological trials that consider this parameter among their endpoints, so much so that it may soon be included among the desirable clinical outcomes of patients with IBD.

METHODS

We performed a literature review of the Pubmed, Medline, and Web of Science (WoS) databases.

RESULTS

We selected 88 articles and then removed 6 duplicates; the final sample after accurate application of the inclusion criteria numbered 73 articles, with a level of evidence rating of three or four, according to Oxfords Evidence-based medicine. Our aim was to study the histological impact of monoclonal antibody therapies on mucosal healing, taking into consideration the few studies present in the literature. To perform this review, we compared studies that examined patients with Crohn's disease (CD) and/or ulcerative colitis (UC) undergoing monoclonal therapy versus patients undergoing other non-biological therapies (PICO statements).

CONCLUSIONS

We try to delineate how monoclonal antibodies have changed the natural history of IBD, acting at the microscopic level, and we believe that a careful analysis of the histopathology and the definition of the objective criteria for "Mucosa Healing" should enable this concept to be included among the clinical endpoints of patients affected by IBD, thus contributing to a better therapeutic management of these patients.

Systematic review and meta-analysis: real-world data rates of deep remission with anti-TNFα in inflammatory bowel disease

BACKGROUND

Deep remission (DR) is a treatment target in IBD associated with reduced hospitalization and improved outcome. Randomized control trial (RCT) data demonstrates efficacy of anti-TNFα agents in achieving DR; however, real-world data (RWD) can provide information complementary to RCTs, specifically regarding treatment duration. In this systematic review with meta-analysis, we use real-world data (RWD) to determine rates of DR in IBD treated with anti-TNFα.

METHODS

We completed a systematic search of MEDLINE and EMBASE on July 8, 2019 with review of major gastrointestinal conference abstracts from 2012 to 2019. Studies utilizing RWD (data not from phase I-III RCTs) of adult IBD patients treated with anti-TNFα agents were included. DR was defined by clinical and endoscopic remission at minimum. DR was assessed at 8 weeks, 6 months, 1 year, and 2 years. Risk of bias was assessed with the Newcastle Ottawa Scale.

RESULTS

29,033 publications were identified. Fifteen publications, nine manuscripts and six conference abstracts, were included encompassing 1212 patients (769 Crohn's disease-CD, 443 ulcerative colitis-UC), and analyzed using Comprehensive Meta-Analysis. Rate of DR was 36.4% (95% CI 12.6-69.4%) at 8 weeks, 39.1% (95% CI 10.4-78%) at 6 months, 44.4% (95% CI 34.6-54.6%) at 1 year, and 36% (95% CI 18.7-58%) at 2 years. DR in CD at 1 year was 48.6% (95% CI 32.8-64.7%) and in UC was 43.6% (95% CI 32.8-55.1%).

CONCLUSIONS

The rate of DR was highest after 1 year of therapy, in nearly 45% of IBD patients treated with anti-TNFα. Similar rates were achieved between patients with UC and CD. The findings highlight the efficacy of anti-TNFα in real-world setting. Future studies using RWD can determine efficacy of newer IBD therapeutics in routine clinical practice.

A Novel Radiomics Nomogram for the Prediction of Secondary Loss of Response to Infliximab in Crohn's Disease

Purpose

The prediction of the loss of response (LOR) to infliximab (IFX) is crucial for optimizing treatment strategies and shifting biologics. However, a secondary LOR is difficult to predict by endoscopy due to the intestinal stricture, perforation, and fistulas. This study aimed to develop and validate a radiomic nomogram for the prediction of secondary LOR to IFX in patients with Crohn’s disease (CD).

Patients and Methods

A total of 186 biologic-naive patients diagnosed with CD between September 2016 and June 2019 were enrolled. Secondary LOR was determined during week 54. Computed tomography enterography (CTE) texture analysis (TA) features were extracted from lesions and analyzed using LIFEx software. Feature selection was performed by least absolute shrinkage and selection operator (LASSO) and ten-fold cross validation. A nomogram was constructed using multivariable logistic regression, and the internal validation was approached by ten-fold cross validation.

Results

Predictors contained in the radiomics nomogram included three first-order and five second-order signatures. The prediction model presented significant discrimination (AUC, 0.880; 95% CI, 0.816–0.944) and high calibration (mean absolute error of = 0.028). Decision curve analysis (DCA) indicated that the nomogram provided clinical net benefit. Ten-fold cross validation assessed the stability of the nomogram with an AUC of 0.817 and an accuracy of 0.819.

Conclusion

This novel radiomics nomogram provides a predictive tool to assess secondary LOR to IFX in patients with Crohn’s disease. This tool will help physicians decide when to switch therapy.

Efficacy of drug and endoscopic treatment of Crohn's disease strictures: A systematic review

BACKGROUND AND AIMS

Strictures are the commonest complication in Crohn's disease. Surgery and endoscopic dilation are the mainstays of treatment, while drug therapy has often been considered contraindicated. The benefit of nonsurgical treatments, particularly drug and endoscopic therapy, need to be defined.

METHODS

Ovid MEDLINE, Embase, Emcare, PsycINFO, CINAHL and the Cochrane Library (inception until August 30, 2019) were searched. Studies with ≥ 10 patients with Crohn's disease strictures, reporting on outcomes following medication or endoscopic treatment, were included.

RESULTS

Of 3480 records, 85 studies met inclusion criteria and formed the basis of this analysis. Twenty-five studies assessed drug therapy; none were randomized trials. Despite study heterogeneity anti-tumor necrosis factor (TNF) therapy appeared effective, with 50% of patients avoiding surgery after 4 years of follow up. No other drug therapy was of demonstrable benefit. Sixty studies assessed endoscopic therapy including 56 on endoscopic balloon dilation, two assessed needle knife stricturotomy, and two stent insertion. Dilation was equally effective for de novo and anastomotic strictures ≤ 5 cm in length, with most studies reporting a subsequent surgical rate of 30% to 50%. Repeat dilation was required in approximately half of all patients.

CONCLUSIONS

Anti-TNF drug therapy and endoscopic balloon dilation are effective strategies for avoiding surgery in patients with stricturing Crohn's disease. Additional endoscopic therapies require further evaluation. Early data suggest that combining these therapies may provide greater benefit than individual therapies. Optimization of current drug and endoscopic therapy, and the incorporation of newer therapies, are needed for stricturing Crohn's disease.

CircRNA_103765 acts as a proinflammatory factor via sponging miR-30 family in Crohn's disease

Increasing evidence suggests that circular RNAs (circRNAs) play critical roles in various pathophysiological activities. However, the role of circRNAs in inflammatory bowel disease (IBD) remains unclear. Here we report the potential roles of hsa_circRNA_103765 in regulating cell apoptosis induced by TNF-α in Crohn’s disease (CD). We identify that CircRNA_103765 expression was significantly upregulated in peripheral blood mononuclear cells (PBMCs) of patients with active IBD. A positive correlation with TNF-α significantly enhanced circRNA_103765 expression in CD, which was significantly reversed by anti-TNF-α mAb (infliximab) treatment. In vitro experiments showed that TNF-α could induce the expression of circRNA_103765, which was cell apoptosis dependent, while silencing of circRNA_103765 could protect human intestinal epithelial cells (IECs) from TNF-α-induced apoptosis. In addition, circRNA_103765 acted as a molecular sponge to adsorb the miR-30 family and impair the negative regulation of Delta-like ligand 4 (DLL4). Collectively, CircRNA_103765 is a novel important regulator of the pathogenesis of IBD via sponging miR-30 family-mediated DLL4 expression changes. Blockade of circRNA_103765 could serve as a novel approach for the treatment of IBD patients.

Efficacy and safety of adalimumab in Chinese patients with moderately to severely active Crohn's disease: results from a randomized trial

BACKGROUND AND AIMS

Efficacy of adalimumab in Crohn's disease (CD) has not been shown in China. The aim of this study was to evaluate the efficacy and safety of adalimumab in Chinese patients with CD.

METHODS

This 26-week, multicenter, phase III study evaluated patients with moderately to severely active CD and elevated high-sensitivity C-reactive protein (⩾3 mg/l) who were naïve to anti-tumor necrosis factor therapy. Patients were randomized to double-blind adalimumab 160/80 mg at weeks 0/2 and 40 mg at weeks 4/6 or placebo at weeks 0/2 followed by blinded adalimumab 160/80 mg at weeks 4/6. At week 8, all patients received open-label 40 mg adalimumab every other week through week 26. The primary endpoint was clinical remission [CD activity index (CDAI) <150] at week 4. Clinical remission at week 26 was assessed in week-8 responders (decrease in CDAI ⩾70 points at week 8 from baseline) and compared with a clinically meaningful threshold of 30%. Adverse events (AEs) were recorded throughout the study.

RESULTS

At baseline, 205 patients were enrolled, with mean [standard deviation (SD)] age of 32.9 (9.9) years and CD duration of 2.7 (3.0) years. At week 4, 38/102 patients (37%) receiving adalimumab and 7/103 (7%) receiving placebo (p < 0.001) achieved clinical remission. Among week-8 responders, 93/144 (65%) achieved clinical remission at week 26 (p < 0.001). No unexpected AEs and no malignancies, active tuberculosis, or deaths were reported.

CONCLUSIONS

Adalimumab induced and maintained remission in Chinese patients with CD. Safety results were consistent with the known safety profile of adalimumab.

CLINICALTRIALSGOV IDENTIFIER

NCT02499783.

Systematic review and meta-analysis: efficacy and safety of early biologic treatment in adult and paediatric patients with Crohn's disease

BACKGROUND

There is an increasing body of evidence showing that earlier use of biologics improves clinical outcomes in Crohn's disease (CD).

AIM

To perform a systematic review and meta-analysis to assess the impact of early biologic use in the treatment of CD.

METHODS

PubMed and Embase databases were searched for English language papers and conference abstracts published through April 30, 2019. Studies were selected for inclusion if patients initiated biologics within 2 years of a CD diagnosis or if earlier biologics use (top-down) was compared with a conventional step-up strategy. Random-effects meta-analyses were conducted to compare clinical remission (CR), relapse and endoscopic healing rates between early biologic treatment (<2 years of disease duration or top-down treatment strategy) and late/conventional treatment (biologic use after >2 years of disease duration or conventional step-up treatment strategy).

RESULTS

A total of 3069 records were identified, of which 47 references met the selection criteria for systematic review. A total of 18 471 patients were studied, with a median follow-up of 64 weeks (range 10-416). Meta-analysis found that early use of biologics was associated with higher rates of clinical remission (OR 2.10 [95% CI: 1.69-2.60], n = 2763, P < .00001), lower relapse rates (OR 0.31 [95% CI: 0.14-0.68], n = 596, P = .003) and higher mucosal healing rates (OR 2.37 [95% CI: 1.78-3.16], n = 994, P < .00001) compared with late/conventional management.

CONCLUSIONS

Early biologic treatment is associated with improved clinical outcomes in both adult and paediatric CD patients, not only in prospective clinical trials but also in real-world settings.

Risk Factors Associated with Infusion Reactions to Infliximab in Chinese Patients with Inflammatory Bowel Disease: A Large Single-Center Study

BACKGROUND This study investigated the risk factors of infliximab (IFX)-related infusion reactions (IR) in Chinese patients with inflammatory bowel disease (IBD). MATERIAL AND METHODS The medical records of 330 consecutive IBD patients treated with IFX between 2009 and 2017 were reviewed. The incidence of IR and adverse effects were recorded in detail, and the potential risk factors related to IR were analyzed by univariate and logistic regression analysis. RESULTS The 330 patients received a total of 2108 IFX infusions, with a median follow-up of 29 months. Eighteen patients (5.5%) experienced IR: 15 were immediate (2 severe) and 3 were late (0 severe). The patients who were treated with episodic IFX without concomitant IM therapy and at the 2nd IFX series (all P<0.001) had higher incidence of IR. Logistic regression revealed the 2nd IFX treatment series (OR=0.017, P<0.001) and episodic use of IFX (OR=0.113, P<0.001) as the significant predictors. Antibodies against infliximab (ATI) were highly positive in 10 of 14 patients (71%) with IR. Sixty-seven percent of patients finished infusions after IR through appropriate management. CONCLUSIONS IFX infusions were accompanied by IR in about 5% of Chinese IBD patients. Severe IR was rare. The patients with the 2nd series or episodic use of IFX should be monitored closely during infusion.

Food-specific IgGs Are Highly Increased in the Sera of Patients with Inflammatory Bowel Disease and Are Clinically Relevant to the Pathogenesis

Objective Dietary antigens are common luminal antigens in the gastrointestinal tract and have been considered to contribute to the pathogenesis of inflammatory bowel disease (IBD). We analyzed the levels of food-specific IgGs against a variety of dietary antigens, explored the clinical relevance of food allergy to the pathogenesis of IBD, and investigated whether or not infliximab (IFX) treatment could regulate the immune responses induced by dietary antigens. Methods A total of 301 IBD patients, including 201 patients with Crohn's disease (CD) and 100 patients with ulcerative colitis (UC), were recruited, and their serum food-specific IgGs against 14 food antigens were detected by a semi-quantitative enzyme linked immunosorbent assay (ELISA). Total serum IgG and IgE levels were measured by immunonephelometry and fluorescent enzyme immunoassay, respectively. Simultaneously, the relevant medical records and clinical data were collected for further analyses. Results Food-specific IgGs against egg, milk, wheat, corn, rice, tomato, codfish, and soybean antigens were found to be significantly increased in the sera of CD patients compared with UC patients and healthy controls (p<0.01). The levels of total serum IgG and IgE were also significantly higher in CD patients than in healthy controls (p<0.01). The titers of corn- and tomato-specific IgGs were found to be significantly correlated with total serum IgG in CD patients (p<0.05), while the titers of egg-, milk-, and wheat-specific IgGs were correlated with total serum IgE (p<0.05). Interestingly, IFX therapy was able to down-regulate the food-specific IgG-mediated immune response markedly in active CD patients. Conclusion Food-specific IgGs against egg, milk, wheat, corn, rice, tomato, codfish, and soybean are highly increased in the sera of CD patients. IFX treatment was able to down-regulate the levels of food-specific IgGs by suppressing intestinal inflammation and promoting mucosal healing. Therefore, food-specific IgGs may serve as an important approach in the diagnosis and management of food allergy in IBD.

Current, experimental, and future treatments in inflammatory bowel disease: a clinical review

Inflammatory bowel diseases (IBDs) may result from dysregulated mucosal immune responses directed toward the resident intestinal microbiota. This review describes the hallmark immunobiology of Crohn's disease and ulcerative colitis as well as therapeutic targets and mechanisms of action for current, experimental, and future treatments in IBD. Conventional therapies include 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and methotrexate. Since 1997, monoclonal antibodies have gained widespread use. These consist of antibodies directed against pro-inflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-12, and IL-23, or anti-homing antibodies directed against α4β7 integrin. Emerging oral therapies include modulators of intracellular signal transduction such as Janus kinase inhibitors. Vitamin D may help to regulate innate and adaptive immune responses. Modulation of the intestinal microbiota, using live microorganisms (probiotics), substrates for the colonic microbiota (prebiotics), or fecal microbiota transplantation (FMT), is in development. Dietary supplements are in widespread use, but providing evidence for their benefit is challenging. Stem cell treatment and nervous stimulation are promising future treatments.

Effects of Anti-TNFα Treatment on Mucosal Expression of IL-17A, IL-21, and IL-22 and Cytokine-Producing T Cell Subsets in Crohn's Disease

T helper 17 (Th17) cells produce interleukin (IL) 17-A. In addition, Th17 cells produce IL-21 and IL-22. Th17 cells have a disease-promoting role in Crohn's disease (CD). We investigated the effects of anti-TNFα treatment on mucosal gene expression (qPCR) of IL-17A, IL-21, and IL-22 as well as on the frequency of lamina propria (LP) T cell subsets producing these cytokines (flow cytometry) in 12 active CD patients before and after 4 weeks of anti-TNFα treatment with adalimumab. At baseline, in inflamed mucosa we found increased gene expression of IL-17A and IL-22 but not IL-21 when compared to noninflamed mucosa. There were increased frequencies of IL-21-producing LP T cells but no differences in the frequencies of IL-17A- or IL-22-producing LP T cells when comparing inflamed versus noninflamed mucosa at baseline. There were no changes in the mucosal gene expression of IL-17A, IL-21, and IL-22 or the frequencies of IL-17A-, IL-21- and IL-22-producing LP T cell subsets between baseline and following 4 weeks of adalimumab initiation. Our results do not support the hypothesis that anti-TNFα treatment has an early effect on the mucosal levels of IL-17A, IL-21, and IL-22 or LP T cell production of these cytokines in CD.

Evaluating IL-21 as a Potential Therapeutic Target in Crohn's Disease

Background and Aim

Interleukin-21 (IL-21) is primarily a T cell-derived cytokine; it is upregulated in patients with Crohn's Disease (CD) and could be a potential new therapeutic target in CD.

Methods

In human material, IL-21 and IL-21R expression was investigated by in situ hybridization (ISH) and immunohistochemistry (IHC) in noninflammatory bowel disease (non-IBD) controls and patients with CD. The pathologic role of IL-21 was examined in murine models of T cell-dependent and T cell-independent colitis, either with a neutralizing monoclonal antibody against IL-21 or with the transfer of CD4⁺CD45RB^highIL-21R^-/- T cells. Colonic pathology was examined by endoscopy, histopathology, IHC, ELISA, and Luminex.

Results

In the human intestine, IL-21 and IL-21R mRNA and protein-expressing cells were observed in the mucosa, in lymphoid aggregates of submucosa in non-IBD controls, and in lymphoid aggregates of muscularis externa in patients with CD. IL-21 expression was most abundant in germinal centers (GCs) of the lymphoid aggregates, and IL-21R expression assessed semiquantitatively, was significantly higher in patients with CD compared to non-IBD controls. Following prophylactic and interventive anti-IL-21 mAb treatment in the adoptive transfer (AdTr) model, clinical and pathological parameters were significantly reduced. The most persistent finding was a reduction in colonic infiltrating neutrophils. As well, Rag2^-/- mice receiving CD4⁺CD45RB^highIL-21R^-/- T cells developed less severe colitis compared to Rag2^-/- mice receiving CD4⁺CD45RB^highIL-21R^+/+ T cells. No effect of reduced IL-21 signalling was observed in T cell-independent colitis.

Conclusion

Our study shows that patients with CD have significant expression of IL-21 and IL-21R in the gut. As well, we show that neutralization of IL-21 in experimental T cell-driven colitis is associated with a reduction in clinical and pathological findings. This amelioration seems to be associated with a reduction in colon-infiltrating neutrophils.

Accurate cut-offs for predicting endoscopic activity and mucosal healing in Crohn's disease with fecal calprotectin

BACKGROUND

Fecal biomarkers, especially fecal calprotectin, are useful for predicting endoscopic activity in Crohn's disease; however, the cut-off point remains unclear. The aim of this paper was to analyze whether faecal calprotectin and M2 pyruvate kinase are good tools for generating highly accurate scores for the prediction of the state of endoscopic activity and mucosal healing.

METHODS

The simple endoscopic score for Crohn's disease and the Crohn's disease activity index was calculated for 71 patients diagnosed with Crohn's. Fecal calprotectin and M2-PK were measured by the enzyme-linked immunosorbent assay test.

RESULTS

A fecal calprotectin cut-off concentration of ≥ 170 µg/g (sensitivity 77.6%, specificity 95.5% and likelihood ratio +17.06) predicts a high probability of endoscopic activity, and a fecal calprotectin cut-off of ≤ 71 µg/g (sensitivity 95.9%, specificity 52.3% and likelihood ratio -0.08) predicts a high probability of mucosal healing. Three clinical groups were identified according to the data obtained: endoscopic activity (calprotectin ≥ 170), mucosal healing (calprotectin ≤ 71) and uncertainty (71 > calprotectin < 170), with significant differences in endoscopic values (F = 26.407, p < 0.01). Clinical activity or remission modified the probabilities of presenting endoscopic activity (100% vs 89%) or mucosal healing (75% vs 87%) in the diagnostic scores generated. M2-PK was insufficiently accurate to determine scores.

CONCLUSIONS

The highly accurate scores for fecal calprotectin provide a useful tool for interpreting the probabilities of presenting endoscopic activity or mucosal healing, and are valuable in the specific clinical context.

miR-301a promotes intestinal mucosal inflammation through induction of IL-17A and TNF-α in IBD

OBJECTIVE

MicroRNA (miR)-301a is known to be involved in the tumourigenesis and pathogenesis of several autoimmune diseases, but it remains unclear whether miR-301a is associated with the pathogenesis of IBD.

METHODS

miR-301a expression was assessed in peripheral blood mononuclear cells (PBMC) and inflamed mucosa of patients with IBD by quantitative real-time-PCR. Peripheral blood CD4+ T cells were transduced with lentivirus-encoding pre-miR-301a (LV-miR-301a) or a reverse complementary sequence of miR-301a (LV-anti-miR-301a), and their differentiation and activation were investigated in vitro. Antisense miR-301a was administered into mice during trinitrobenzene sulphonic acid (TNBS)-induced colitis to determine its role in colitis.

RESULTS

miR-301a expression was significantly upregulated in PBMC and inflamed mucosa of patients with IBD compared with healthy controls. Stimulation with tumour necrosis factor-α (TNF-α) significantly enhanced miR-301a expression in IBD CD4+ T cells, which was markedly reversed by anti-TNF-α mAb (Infliximab) treatment. Transduction of LV-miR-301a into CD4+ T cells from patients with IBD promoted the Th17 cell differentiation and TNF-α production compared with the cells with expression of LV-anti-miR-301a. SNIP1 as a functional target of miR-301a was reduced in miR-301a expression but increased in LV-anti-miR-301a expression. Knockdown of SNIP1 could enhance Th17 cell differentiation. Furthermore, intracolonical administration of antisense miR-301a in TNBS-induced mouse colitis model significantly decreased numbers of interleukin (IL)-17A+ cells and amounts of pro-inflammatory cytokines (eg, IL-17A, TNF-α) in inflamed colon.

CONCLUSIONS

Our data reveal a novel mechanism in which the elevated miR-301a in PBMC and inflamed mucosa of IBD promotes Th17 cell differentiation through downregulation of SNIP1. Blockade of miR-301a in vivo may serve as a novel therapeutic approach in the treatment of IBD.

Blockade of PLD2 Ameliorates Intestinal Mucosal Inflammation of Inflammatory Bowel Disease

Background. Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronically remittent and progressive inflammatory disorders. Phospholipase D2 (PLD2) is reported to be involved in the pathogenesis of several inflammatory diseases. However, the exact role of PLD2 in IBD is obscure. Methods. PLD2 expression was determined in peripheral blood cells and inflamed mucosa from patients with IBD by qRT-PCR. Colonic biopsies were also obtained from CD patients before and after infliximab (IFX) treatment to examine PLD2 expression. PLD2 selective inhibitor (CAY10594) was administrated daily by oral gavage in DSS-induced colitis mice. Bone marrow neutrophils from colitis mice were harvested to examine the migration using Transwell plate. Results. PLD2 was found to be significantly increased in peripheral blood cells and inflamed mucosa in patients with active IBD. Treatment with IFX could significantly decrease PLD2 expression in intestinal mucosa in patients with CD. Moreover, blockade of PLD2 with CAY10594 could markedly ameliorate DSS-induced colitis in mice and promote neutrophil migration. Conclusions. PLD2 plays a critical role in the pathogenesis of IBD. Blockade of PLD2 may serve as a new therapeutic approach for treatment of IBD.

Systematic review with meta-analysis: mucosal healing is associated with improved long-term outcomes in Crohn's disease

BACKGROUND

Clinical manifestations of Crohn's disease (CD) do not reliably correlate with endoscopic activity. While treating to achieve clinical remission (CR) has neither proven to improve CD outcomes nor alter the natural disease course, it is unclear whether targeting objective measures like mucosal healing (MH) is associated with improved long-term outcomes.

AIM

To perform a systematic review and meta-analysis comparing long-term outcomes in active CD patients who achieve MH compared to those who do not.

METHODS

We performed a systematic literature search to identify studies with prospective cohorts of active CD patients that included outcomes of patients who achieved MH at first endoscopic assessment (MH1) compared to those who did not. The primary outcome was long-term (≥50 weeks) CR. Secondary outcomes included CD-related surgery-free rate, hospitalisation-free rate and long-term MH rate. Pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

Twelve studies with 673 patients met inclusion criteria. Patients achieving MH1 had a pooled OR of 2.80 (95%CI, 1.91-4.10) for achieving long-term CR, 2.22 (95%CI, 0.86-5.69) for CD-related surgery-free rate, and 14.30 (95%CI, 5.57-36.74) for long-term MH. Sensitivity analyses suggested no difference in outcomes if MH1 was achieved on biologics vs. non-biologics. No significant publication bias or heterogeneity was detected.

CONCLUSIONS

Achieving MH1 is associated with increased rates of long-term clinical remission, and maintenance of mucosal healing in active Crohn's disease and may therefore be a reasonable therapeutic target.

Divalent metal-ion transporter 1 is decreased in intestinal epithelial cells and contributes to the anemia in inflammatory bowel disease

Divalent metal-ion transporter 1 (DMT1) has been found to play an important role in the iron metabolism and hemogenesis. However, little is known about the potential role of DMT1 in the pathogenesis of anemia from patients with inflammatory bowel disease (IBD). Herein, we investigated expression of DMT1 in the intestinal mucosa by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry, and found that DMT1 was significantly decreased in the inflamed mucosa of active IBD patients compared with that in those patients at remission stage and healthy controls. To further study the mechanism, we cultured HCT 116 cell line in vitro. Expression of DMT1 in HCT116 was demonstrated to be markedly decreased under stimulation with TNF for 24 and 48 h, while JNK inhibitor (JNK-IN-7) could significantly reverse the decrease. Interestingly, anti-TNF therapy successfully improved anemia in clinical responsive Crohn’s disease patients, and DMT1 was found to be markedly up-regulated in intestinal mucosa. Taken together, our studies demonstrate that decreased expression of DMT1 in intestinal mucosa leads to compromised absorption and transportation of iron and that blockade of TNF could rescue anemia and promote DMT1 expression in gut mucosa. This work provides a therapeutic approach in the management of anemia in IBD.