Prophylactic versus endoscopy-driven treatment of Crohn's postoperative recurrence: A retrospective, multicentric European study (PORCSE study).

BACKGROUND AND AIMS: No consensus exists on optimal strategy to prevent postoperative recurrence (POR) after ileocecal resection (ICR) for Crohn's disease (CD).We compared early medical prophylaxis versus expectant management with treatment driven by findings at elective endoscopy 6-12 months after ICR. METHODS: A retrospective, multicentric, observational study was performed. CD-patients undergoing first ICR were assigned to cohort1 if a biologic or immunomodulator was (re)started prophylactically after ICR, or to cohort2 if no postoperative prophylaxis was given and treatment was started as reaction to elective endoscopic findings. Primary endpoint was rate of endoscopic POR (Rutgeerts>i1). Secondary endpoints were severe endoscopic POR (Rutgeerts i3/i4), clinical POR, surgical POR and treatment burden during follow-up. RESULTS: Of 346 included patients, 47.4% received prophylactic postoperative treatment (proactive/cohort1) and 52.6% did not (reactive/cohort2).Endoscopic POR (Rutgeerts>i1) rate was significantly higher in cohort2 (41.5% vs 53.8%, OR1.81, P=0.039) at endoscopy 6-12 months after surgery. No significant difference in severe endoscopic POR was found (OR1.29, P=0.517). Cohort2 had significantly higher clinical POR rates (17.7% vs 35.7%, OR3.05, P=0.002) and numerically higher surgical recurrence rates (6.7% vs 13.2%, OR2.59, P=0.051). Cox proportional hazards regression analysis showed no significant difference in time to surgical POR of proactive versus expectant/reactive approach (HR2.50, P=0.057). Quasi-Poisson regression revealed a significantly lower treatment burden for immunomodulator use in cohort2 (mean ratio 0.53, P=0.002), but no difference in burden of biologics or combination treatment. CONCLUSIONS: The PORCSE study showed lower rates of endoscopic POR with early postoperative medical treatment compared to expectant management after first ileocecal resection for Crohn's disease.

Safety and Effectiveness of Vedolizumab and Ustekinumab in Elderly Patients with Inflammatory Bowel Disease: A Real-Life Multicentric Cohort Study.

BACKGROUND: Data on ustekinumab and vedolizumab in the elderly inflammatory bowel disease (IBD) population are limited. The aim of the current study was to assess the safety and effectiveness of both in an elderly real-life population. METHODS: A multicentric retrospective study was performed on IBD patients who started vedolizumab or ustekinumab between 2010 and 2020. Clinical and endoscopic remission rates and (serious) adverse events (AE) were assessed. RESULTS: A total of 911 IBD patients were included, with 171 (19%) aged above 60 (111 VDZ, 60 UST). Elderly patients treated with vedolizumab or ustekinumab had an increased risk for non-IBD hospitalization (10.5% vs. 5.7%, p = 0.021) and malignancy (2.3% vs. 0.5%, p = 0.045) compared to the younger population. Corticosteroid-free clinical (50% vs. 44%; p = 0.201) and endoscopic remission rates (47.9% vs. 31%, p = 0.07) at 1 year were similar. Comparing vedolizumab to ustekinumab in the elderly population, corticosteroid-free (47.9% vs. 31%, p = 0.061) and endoscopic remission rates (66.7% vs. 64.4%, p = 0.981) were similar. Vedolizumab- and ustekinumab-treated patients had comparable infection rates (13.5% vs. 10.0%, p = 0.504), IBD flare-ups (4.5% vs. 5%, p = 1.000), the occurrence of new EIMs (13.5% vs. 10%, p = 0.504), a risk of intestinal surgery (5.4% vs. 6.7%, p = 0.742), malignancy (1.8% vs. 3.3%, p = 0.613), hospitalization (9.9% vs. 11.7%, p = 0.721), and mortality (0.9% vs. 1.7%, p = 1.000). AE risk was associated only with corticosteroid use. CONCLUSIONS: Ustekinumab and vedolizumab show comparable effectiveness and safety in the elderly IBD population. Elderly IBD patients have an increased risk for non-IBD hospitalizations and malignancy compared to the younger IBD population, with corticosteroid use as the main risk factor.

Outcome of Biological Therapies and Small Molecules in Ulcerative Proctitis: A Belgian Multicenter Cohort Study.

BACKGROUND & AIMS: Several advanced therapies (biologic therapies and small molecules) have been approved for the treatment of moderate-to-severe ulcerative colitis. The registration trials for these agents typically excluded patients with isolated proctitis, leaving an evidence gap. We evaluated efficacy and safety of advanced therapies in patients with ulcerative proctitis (UP). METHODS: This multicenter retrospective cohort study included consecutive patients with active UP (Mayo endoscopy subscore of ≥2, rectal inflammation up to 15 cm) initiating advanced therapy, after failing conventional therapy. The primary end point was short-term steroid-free clinical remission (total Mayo score ≤2 with no individual subscore >1). In addition, drug persistence and relapse-free and colectomy-free survival were assessed. Both binary logistic and Cox regression analyses were performed. RESULTS: In total, 167 consecutive patients (52.0% female; median age 41.0 years; 82.0% bionaive) underwent 223 courses of therapy for UP (38 adalimumab, 14 golimumab, 54 infliximab, 9 ustekinumab, 99 vedolizumab, 9 tofacitinib). The primary end point was achieved with 36.3% of the treatment courses, and based on multivariate analysis, more commonly attained in bionaive patients (P = .001), patients treated with vedolizumab (P = .001), patients with moderate endoscopic disease activity (P = .002), and a body mass index <25 kg/m2 (P = .018). Drug persistence was significantly higher in patients treated with vedolizumab (P < .001) and patients with a shorter disease duration (P = .006). No new safety signals were observed. CONCLUSIONS: Advanced therapies are also efficacious and safe in patients with ulcerative colitis limited to the rectum. Therefore, the inclusion of patients with UP in future randomized-controlled trials should be considered.

Early versus Late Use of Vedolizumab in Ulcerative Colitis: Clinical, Endoscopic, and Histological Outcomes.

BACKGROUND AND AIMS: We explored the potential for differential efficacy of vedolizumab between "early" and "late" ulcerative colitis (UC) with evaluation of clinical, endoscopic, and histological endpoints. METHODS: This was a multicentre, multinational open-label study in patients with moderately-to-severely active UC, defining "early" UC by a disease duration <4 years and bio-naïve and "late" UC by a disease duration >4 years and additional exposure to tumour necrosis factor antagonists. Patients received standard treatment with intravenous vedolizumab for 52 weeks (300 mg weeks 0-2-6, every 8 weeks thereafter without escalation). The primary endpoint was corticosteroid-free clinical remission with endoscopic improvement (total Mayo score ≤2 with no subscore >1) at both week 26 and 52. RESULTS: A total of 121 patients were included: in the "early" group 25/59 (42.4%) achieved the primary endpoint versus 19/62 (30.6%) in the "late" group (P = 0.18). There were no significant differences between the two groups in endoscopic improvement (week 26: "early" 32/59 [54.2%] vs. "late" 29/62 [46.8%]; P = 0.412; week 52: 27/59 [45.8%] vs. 25/62 [40.3%]; P = 0.546) or histological remission (Robarts Histopathology Index <3 without neutrophils in the epithelium and lamina propria) (week 26: 24/59 [40.7%] vs. 21/62 [33.9%]; P = 0.439; week 52: 22/59 [37.3%] vs. 22/62 [35.5%]; P = 0.837). CONCLUSIONS: No significant differences in clinical, endoscopic, and histological outcomes were observed between "early" and "late" disease.

Effect of 5-Hydroxytryptophan on Fatigue in Quiescent Inflammatory Bowel Disease: A Randomized Controlled Trial.

BACKGROUND & AIMS: Fatigue is highly prevalent among patients with inflammatory bowel disease (IBD), and only limited treatment options are available. Based on the hypothetical link between low serum tryptophan concentrations and fatigue, we determined the effect of 5-hydroxytryptophan supplementation on fatigue in patients with inactive IBD. METHODS: A multicenter randomized controlled trial was performed at 13 Belgian hospitals, including 166 patients with IBD in remission but experiencing fatigue, defined by a fatigue visual analog scale (fVAS) score of ≥5. Patients were treated in a crossover manner with 100 mg oral 5-hydroxytryptophan or placebo twice daily for 2 consecutive periods of 8 weeks. The primary end point was the proportion of patients reaching a ≥20% reduction in fVAS after 8 weeks of intervention. Secondary outcomes included changes in serum tryptophan metabolites, Functional Assessment of Chronic Illness Therapy Fatigue scale, and scores for depression, anxiety, and stress. The effect of the intervention on the outcomes was evaluated by linear mixed modeling. RESULTS: During 5-hydroxytryptophan treatment, a significant increase in serum 5-hydroxytryptophan (estimated mean difference, 52.66 ng/mL; 95% confidence interval [CI], 39.34-65.98 ng/mL; P < .001) and serotonin (3.0 ng/mL; 95 CI, 1.97-4.03 ng/mL; P < .001) levels was observed compared with placebo. The proportion of patients reaching ≥20% reduction in fVAS was similar in placebo- (37.6%) and 5-hydroxytryptophan (35.6%)-treated patients (P = .830). The fVAS reduction (-0.18; 95% CI, -0.81 to 0.46; P = .581) and Functional Assessment of Chronic Illness Therapy Fatigue scale increase (0.68; 95% CI, -2.37 to 3.73; P = .660) were both comparable between 5-hydroxytryptophan and placebo treatment as well as changes in depression, anxiety, and stress scores. CONCLUSIONS: Despite a significant increase in serum 5-hydroxytryptophan and serotonin levels, oral 5-hydroxytryptophan did not modulate IBD-related fatigue better than placebo. (Trial Registration: Belgian Federal Agency for Medication and Health Products, EudraCT number: 2017-005059-10 and ClinicalTrials.gov: NCT03574948, https://clinicaltrials.gov/ct2/show/NCT03574948.).

The Impact of Vedolizumab and Ustekinumab on Articular Extra-Intestinal Manifestations in Inflammatory Bowel Disease Patients: A Real-Life Multicentre Cohort Study.

BACKGROUND AND AIMS: Extra-intestinal manifestations are frequently reported in inflammatory bowel diseases. However, data comparing the effect of vedolizumab and ustekinumab on articular extra-intestinal manifestations are limited. The aim here was to evaluate differences in new-onset and the evolution of pre-existing joint extra-intestinal manifestations during both treatments. METHODS: An international multicentre retrospective study was performed on inflammatory bowel disease patients who started vedolizumab or ustekinumab between May 2010 and December 2020. Extra-intestinal manifestations were assessed at baseline and joint extra-intestinal manifestations were evaluated throughout the 2-year follow-up. Arthropathy was defined by joint inflammation [arthritis/sacroiliitis], diagnosed by a rheumatologist, and arthralgia as articular pain without confirmed inflammation. Additionally, skin, ocular and hepatic extra-intestinal manifestations were assessed at baseline. Uni- and multivariate analyses were performed. RESULTS: In total, 911 patients [vedolizumab: 584; ustekinumab: 327] were included. Deterioration of pre-existing arthropathy and rate of new-onset arthropathy were not significantly associated with vedolizumab over ustekinumab. Arthropathy was used as reason to stop treatment in six vedolizumab and two ustekinumab patients. The odds of developing new arthralgia within 6 months was higher in patients who took vedolizumab compared to ustekinumab (adjusted odds ratio [aOR]: 2.28 [1.01-5.15], p = 0.047). However, this effect was not sustained during the 2-year follow-up (aOR: 1.35 [0.80-2.29], p = 0.259). Deterioration of pre-existing arthralgia was comparable between ustekinumab and vedolizumab-treated patients. In two vedolizumab-treated patients arthralgia was given as the reason to stop treatment. CONCLUSIONS: Vedolizumab and ustekinumab can be used safely in patients with articular extra-intestinal manifestations. Only a temporary increased risk for developing arthralgia has been observed under vedolizumab.

Ultra-proactive Therapeutic Drug Monitoring of Infliximab Based on Point of Care Testing in Inflammatory Bowel Disease: Results of a Pragmatic Trial.

BACKGROUND: With point of care testing [POCT] for infliximab [IFX], ultraproactive therapeutic drug monitoring [TDM] with ad-hoc dose optimisation is possible in patients with inflammatory bowel disease [IBD]. AIM: To compare the clinical outcomes of an ultraproactive TDM algorithm of IFX based on POCT with reactive TDM in patients with IBD, in a pragmatic clinical trial. METHODS: All patients with IBD and maintenance IFX treatment were included between June and August 2018 in two centres. Centre A applied an ultra-proactive TDM algorithm incorporating POCT, and centre B applied reactive TDM. Primary endpoint was failure of IFX therapy after 1 year. Secondary endpoints included sustained clinical remission and mucosal remission. RESULTS: In total 187 patients [n = 115/72 cohort A/B] were included. Cohort A had more trough level [TL] measurements compared with cohort B [8.8 vs 1/patient/year; p <0.0001], leading to a significant higher number of dose optimisations. POCT testing was required in 27% after the first round of ultra-proactive TDM and in a mean of 6.3% (standard deviation [SD] 1.9) in the subsequent rounds. Ad-hoc extra dosing was needed in 13% of the POCT. After 1 year, no difference was seen between cohort A and cohort B in IFX failure [19% vs 10%; p = 0.08], nor in sustained clinical remission [75% vs 83%; p = 0.17]. Mucosal remission was evaluated in 71 patients [38%], and was more frequent in the reactive TDM cohort [p = 0.02]. CONCLUSIONS: Ultra-proactive TDM in patients with IBD and maintenance IFX treatment leads to equal clinical outcomes as reactive TDM after 1 year of follow-up.

Translational research into the effects of cigarette smoke on inflammatory mediators and epithelial TRPV1 in Crohn's disease.

Crohn's disease is a pathological condition of the gastro-intestinal tract, causing severe transmural inflammation in the ileum and/or colon. Cigarette smoking is one of the best known environmental risk factors for the development of Crohn's disease. Nevertheless, very little is known about the effect of prolonged cigarette smoke exposure on inflammatory modulators in the gut. We examined the effect of cigarette smoke on cytokine profiles in the healthy and inflamed gut of human subjects and in the trinitrobenzene sulphonic acid mouse model, which mimics distal Crohn-like colitis. In addition, the effect of cigarette smoke on epithelial expression of transient receptor potential channels and their concurrent increase with cigarette smoke-augmented cytokine production was investigated. Active smoking was associated with increased IL-8 transcription in ileum of controls (p < 0,001; n = 18-20/group). In the ileum, TRPV1 mRNA levels were decreased in never smoking Crohn's disease patients compared to healthy subjects (p <0,001; n = 20/group). In the colon, TRPV1 mRNA levels were decreased (p = 0,046) in smoking healthy controls (n = 20/group). Likewise, healthy mice chronically exposed to cigarette smoke (n = 10/group) showed elevated ileal Cxcl2 (p = 0,0075) and colonic Kc mRNA levels (p = 0,0186), whereas TRPV1 mRNA and protein levels were elevated in the ileum (p = 0,0315). Although cigarette smoke exposure prior to trinitrobenzene sulphonic acid administration did not alter disease activity, increased pro-inflammatory cytokine production was observed in the distal colon (Kc: p = 0,0273; Cxcl2: p = 0,104; Il1-ß: p = 0,0796), in parallel with the increase of Trpv1 mRNA (p < 0,001). We infer that CS affects pro-inflammatory cytokine expression in healthy and inflamed gut, and that the simultaneous modulation of TRPV1 may point to a potential involvement of TRPV1 in cigarette smoke-induced production of inflammatory mediators.

Belgian IBD Research Group [BIRD] Position Statement 2019 on the Use of Adalimumab Biosimilars in Inflammatory Bowel Diseases.

The emergence of biosimilars is generally considered as an opportunity to guarantee accessibility to affordable treatments and to enhance financial sustainability of national health systems. Since 2017, five biosimilars of adalimumab were approved by the European Medicines Agency [EMA] for use in inflammatory bowel disease: ABP 510, SB5, GP2017, FKB327, and MSB11022. In this position statement, the available efficacy and safety data of the different adalimumab biosimilars in immune-mediated inflammatory diseases are summarised. Furthermore, the Belgian IBD research group [BIRD] formulates statements concerning the use of adalimumab biosimilars in inflammatory bowel disease.

Beclomethasone dipropionate in microscopic colitis: Results of an exploratory open-label multicentre study (COLCO).

Background: Budesonide has been proven to be an effective treatment for microscopic colitis (MC). However, the two current commercially available preparations are released in the ileum. Beclomethasone dipropionate (Clipper®) is a synthetic corticosteroid with topical colonic release. Objective: This study aimed to explore whether an open-label treatment with beclomethasone dipropionate is an effective treatment for MC. Methods: Prospectively collected data of 30 patients from six centres were retrospectively analysed. All patients had a confirmed diagnosis of idiopathic MC (lymphocytic and collagenous colitis) and were symptomatic (i.e. ≥ 21 loose stools over a seven-day period). Treatment consisted of 10 mg beclomethasone daily for four weeks, followed by 5 mg daily for another four weeks. The primary end point was the proportion of patients in remission (i.e. a mean of < 3 stools/day and a mean of <1 watery stool per day) after an eight-week treatment period. Secondary end points were the proportion of patients responding to therapy at weeks 4 and 8, remission at weeks 4 and 12 and relapse at week 12. Reported adverse events were collected. Results: Overall, at week 8, remission was achieved in 70%, and 77% of patients were responding to treatment. After four weeks of treatment, 80% were responding, and 67% were in remission. Four weeks after stopping treatment, 60% were still in remission. Conclusion: This open-label study suggests that an eight-week course of beclomethasone could be a promising and relatively safe treatment for MC. A randomised controlled study is warranted.

Long-term Clinical Effectiveness of Ustekinumab in Patients with Crohn's Disease Who Failed Biologic Therapies: A National Cohort Study.

BACKGROUND: Ustekinumab [UST] was recently approved in Europe for the treatment of moderate to severe Crohn's disease [CD]. Long-term real-world data are currently scarce for CD patients previously exposed to several biologics. METHODS: This is an observational, national, retrospective multicentre study. Patients received intravenous UST ~6 mg/kg at baseline, with 90 mg subcutaneously thereafter every 8 weeks. Response and remission rates were assessed at Weeks 8, 16, and 52. RESULTS: Data from 152 patients were analysed. All patients were exposed to at least one anti-TNFα agent, with 69.7% were exposed to even two anti-TNFα and vedolizumab. After 1 year, 42.1% and 25.7% of patients had experienced clinical response and clinical remission, respectively, and 38.8% and 24.3% had achieved steroid-free clinical response and remission, respectively; 38.8% of patients discontinued therapy during the 12 months of follow-up. Colonic location was predictive of clinical response at 1 year, and low body mass index [BMI] at baseline was a negative predictor of clinical remission. Resolution of arthralgia was associated with clinical response over time. De novo arthralgia was reported by 17.9% of patients at Week 8 and 13.5% of patients at Week 52. No impact of UST on arthralgia was observed in patients with concomitant ankylosing spondylitis [n = 17]. Others adverse events were reported in 7.2% of patients. CONCLUSIONS: This real-world cohort study confirms the effectiveness of UST in CD patients previously exposed to several biologics. Ustekinumab was well tolerated with respect to adverse events. PODCAST: This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

Long-term Outcomes with Anti-TNF Therapy and Accelerated Step-up in the Prospective Pediatric Belgian Crohn's Disease Registry (BELCRO).

BACKGROUND: Accelerated step-up or anti-tumor necrosis factor (TNF) before first remission is currently not recommended in pediatric Crohn's disease. METHODS: Five-year follow-up data from a prospective observational cohort of children diagnosed with Crohn's disease in Belgium were analyzed. Disease severity was scored as inactive, mild, or moderate to severe. Remission or inactive disease was defined as sustained if lasting ≥2 years. Univariate analyses were performed between anti-TNF-exposed versus naive patients and anti-TNF before versus after first remission and correlations assessed with primary outcomes average disease severity and sustained remission. RESULTS: A total of 91 patients (median [IQR] age 12.7 [10.9-14.8] yrs, 53% male) were included. Disease location was 12% L1, 23% L2, and 64% L3 with 76% upper gastrointestinal and 30% perianal involvement. Disease severity was 25% mild and 75% moderate to severe. Of 66 (73%) anti-TNF-exposed patients, 34 (52%) had accelerated step-up. Anti-TNF use was associated with age (13.1 [11.5-15.2] versus 11.8 [8.7-13.8] yrs; P < 0.05), L2 (29% versus 8%; P = 0.04), and average disease severity (1.7 [1.4-1.9] versus 1.4 [1.3-1.6]; P < 0.001). Duration of anti-TNF correlated with average disease severity (r = 0.32, P = 0.002). Accelerated step-up was also associated with age (13.3 [12.1-15.9] versus 12.5 [10.2-14.1]; P = 0.02) and average disease severity (1.8 [1.6-1.9] versus 1.6 [1.3-1.8]; P = 0.002). Duration of sustained remission was similar in all patients, and no serious infections, cancer, or deaths were reported. CONCLUSIONS: Anti-TNF therapy and accelerated step-up in older patients with more severe disease leads to beneficial long-term outcomes.

C-ANCA/proteinase 3-positive colitis in children: a distinctive form of inflammatory bowel disease or vasculitis with colitis as initial presentation?

AIM: Anti-neutrophil cytoplasmic antibodies (ANCAs) detected by indirect immunofluorescence have been found in patients with inflammatory bowel disease (IBD). Nevertheless, specific antibodies against proteinase-3 (PR3) are rare in this context. METHODS: Sera from 30 consecutive pediatric patients with IBD were evaluated for ANCA-indirect immunofluorescence and its specific antibodies to investigate whether PR3-ANCA positivity (PR3-ANCA+) identifies a distinct IBD subtype. RESULTS: The 5 PR3-ANCA+ patients (17%) showed significantly more concomitant biliary disease and severe anal blood loss (P < 0.05). None had vasculitis features at diagnosis nor during follow-up. CONCLUSIONS: This pilot study demonstrates significant clinical differences between the PR3-ANCA-positive and -negative IBD subset.

Adalimumab dose escalation and dose de-escalation success rate and predictors in a large national cohort of Crohn's patients.

BACKGROUND AND AIMS: Adalimumab is efficacious in inducing and maintaining remission in Crohn's disease but dose escalation is needed in 30-40% after 1 year. Attempts for dose de-escalation have not been studied. This study aimed to assess the need for, predictors, and outcome of dose escalation and de-escalation in a large cohort of adalimumab treated Crohn's patients. METHODS: All consecutive patients treated with open label adalimumab for active Crohn's disease from the participating centres were included in this cohort study. A detailed retrospective chart review was performed to look for possible factors predicting outcome. RESULTS: Eighty four percent of 720 patients had a primary response and were followed up for a median of 14 months. Thirty four percent needed escalation after a median of 7 months (0-55 months). Multivariate predictors for dose escalation were the following: prior anti-TNF use (p<0.0001), no concomitant azathioprine or <3 m (p<0.02) and abnormal CRP at start (p<0.05). Dose escalation re-induced response for at least 6 months in 67%. Only abnormal CRP at start correlated with failure of dose escalation (p=0.02). Dose de-escalation was attempted in 54% and was successful in 63%. After a median follow-up of 14 m adalimumab was discontinued in 29% of patients. CONCLUSION: In this study real life nationwide cohort of Crohn's patients treated with adalimumab dose escalation was needed in 34% and was successful in 67%. Dose de-escalation was attempted in 54% and was successful in 63%. Overall 71% of patients maintained long term response on adalimumab.

Microscopic gut inflammation in axial spondyloarthritis: a multiparametric predictive model.

OBJECTIVE: To assess the rates and explore predictors of microscopic gut inflammation in a cohort of patients with axial and peripheral spondyloarthritis (SpA). METHODS: Ileocolonoscopy was performed in 65 patients with axial and peripheral SpA from the Gent Inflammatory Arthritis and spoNdylitis cohorT. Histopathological analysis and scoring were performed by an experienced pathologist. RESULTS: Overall, 46.2% of the patients with SpA showed microscopic gut inflammation. In axial SpA, the following parameters were independently associated with gut involvement: male sex (OR=8.9, p=0.035); high disease activity measured by the Bath Ankylosing Spondylitis Disease Activity Index (OR=2.05, p=0.032); restricted spinal mobility measured by the Bath Ankylosing Spondylitis Metrology Index (OR=1.94, p=0.009); and younger age (OR=0.85, p=0.013). No clear association was found for human leucocyte antigen-B27 status, presence of peripheral arthritis, enthesitis, uveitis, psoriasis, intake of non-steroidal anti-inflammatory drugs and family history of SpA. The prevalence of gut inflammation in non-radiographic axial SpA and ankylosing spondylitis was comparable. CONCLUSIONS: The prevalence of microscopic gut inflammation in SpA remains unaltered over time. Younger age (shorter symptom duration), progressive disease, male sex and higher disease activity are independently associated with microscopic gut inflammation in axial SpA.

Inverse correlation between metallothioneins and hypoxia-inducible factor 1 alpha in colonocytes and experimental colitis.

A positive-feedback mechanism between hypoxia-inducible factor 1 alpha (HIF-1α) and metallothioneins (MTs) has been identified in different diseases. Both proteins have been independently proposed in the pathogenesis of inflammatory bowel disease (IBD); however, their relation has never been studied in the gut. In this study, we investigated the interaction between HIF-1α and MTs in colonic epithelial cells and during experimental colitis. Dimethyloxalylglycine (DMOG) was used to subject colonocytes to hydroxylase inhibition and HIF-1α stabilization in three experimental models (in vitro, in vivo and ex vivo). Small interfering RNA targeting HIF-1α (siRNA-HIF) and MT (siRNA-MT) together with zinc-mediated MT induction were used to study the interaction between HIF-1α and MT in HT29 cells. Acute colitis was induced in C57BL/6 mice using dextran sulphate sodium. MT expression and HIF-1α protein levels were measured using quantitative real-time PCR and ELISA, respectively. Vascular endothelial growth factor (VEGF) expression was quantified as an indirect measure of HIF-1 transcriptional activity. DMOG down-regulated MT expression in HT29 cells, in freshly isolated human colonocytes and in colonocytes isolated from mice treated with DMOG (p<0.05). SiRNA-HIF-treated cells displayed significant higher basal MT levels (p<0.05) and an attenuated MT down-regulation after DMOG treatment. In turn, HIF-1α stabilization was significantly lower in zinc-treated control cells, displaying high MT levels, compared to siRNA-MT cells treated with DMOG (p<0.05). In the course of experimental colitis, MT and VEGF mRNA expression were inversely related. MTs were induced in the acute phase and down-regulated during recovery. Opposing results were observed for VEGF expression levels (p<0.05). The present study underscores the inverse relation between HIF-1α and MT expression in colonocytes and during experimental colitis. The manipulation of MTs may represent a novel therapeutic strategy for patients suffering from IBD.

Involvement of endoplasmic reticulum stress in inflammatory bowel disease: a different implication for colonic and ileal disease?

BACKGROUND: Endoplasmic reticulum (ER) stress has been suggested to play a role in inflammatory bowel disease (IBD). The three branches (ATF6, IRE1 and PERK) of the unfolded protein response (UPR) have different roles and are not necessarily activated simultaneously. METHODOLOGY/PRINCIPAL FINDINGS: Expression of UPR-related genes was investigated in colonic and ileal biopsies of 23 controls, 15 ulcerative colitis (UC) and 54 Crohn's disease (CD) patients. This expression was confirmed at protein level in colonic and ileal samples of five controls, UC and CD patients. HSPA5, PDIA4 and XBP1s were significantly increased in colonic IBD at mRNA and/or protein levels, indicating activation of the ATF6 and IRE1 branch. Colonic IBD was associated with increased phosphorylation of EIF2A suggesting the activation of the PERK branch, but subsequent induction of GADD34 was not observed. In ileal CD, no differential expression of the UPR-related genes was observed, but our data suggested a higher basal activation of the UPR in the ileal mucosa of controls. This was confirmed by the increased expression of 16 UPR-related genes as 12 of them were significantly more expressed in ileal controls compared to colonic controls. Tunicamycin stimulation of colonic and ileal samples of healthy individuals revealed that although the ileal mucosa is exhibiting this higher basal UPR activation, it is still responsive to ER stress, even more than colonic mucosa. CONCLUSIONS/SIGNIFICANCE: Activation of the three UPR-related arms is seen in colonic IBD-associated inflammation. However, despite EIF2A activation, inflamed colonic tissue did not increase GADD34 expression, which is usually involved in re-establishment of ER homeostasis. This study also implies the presence of a constitutive UPR activation in healthy ileal mucosa, with no further activation during inflammation. Therefore, engagement of the UPR differs between colon and ileum and this could be a factor in the development of ileal or colonic disease.

Intrarectal administration of oxygenated perfluorodecalin promotes healing of murine colitis by targeting inflammatory hypoxia.

Intestinal inflammation is associated with enhanced mucosal hypoxia, which contributes to the ongoing inflammatory process and hampers appropriate mucosal healing. We questioned whether local treatment with an oxygen (O(2))-carrying and -releasing molecule (oxygenated perfluorodecalin, O(2)-PFD) could positively influence the course of experimental colitis. The impact of intrarectal (IR) treatment with O(2)-PFD was tested using the murine dextran sodium sulfate (DSS)-induced model of distal colitis, both in preventive and therapeutic settings. Colonic mucosal hypoxia was visualized by pimonidazole staining. Colonic permeability was evaluated with FITC-dextran. In the preventive study, mice treated with O(2)-PFD were protected against DSS colitis compared with saline-treated mice, as demonstrated by reduced shortening of colon length, reduced colonic tumor necrosis factor-alpha levels and a lower histological inflammation score (P<0.05 for all parameters). In the therapeutic study, administration of O(2)-PFD resulted in accelerated recovery of colitis compared with saline-treated littermates, and this was reflected by a better weight evolution, lower myeloperoxidase activity and a lower histological inflammation score (P<0.05 for all parameters). It was found that O(2)-PFD established its therapeutic effects through (1) intrinsic anti-inflammatory effects of the PFD molecule and (2) O(2)-induced preservation and healing of the intestinal epithelial surface. Further in vitro and in vivo studies showed that the barrier-protective activity of O(2)-PFD was obtained through prevention of colonocyte apoptosis and stimulation of colonocyte proliferation during inflammatory hypoxia. These data show that IR treatment with O(2)-PFD promotes colitis healing by the combined actions of direct anti-inflammatory effects and O(2)-induced restitution of the epithelial barrier. As such, O(2)-PFD enemas could be an attractive treatment option for patients with distal inflammatory bowel disease.

Differential mucosal expression of Th17-related genes between the inflamed colon and ileum of patients with inflammatory bowel disease.

BACKGROUND: Immunological and genetic findings implicate Th17 effector cytokines in the pathogenesis of inflammatory bowel disease (IBD). Expression of Th17 pathway-associated genes is mainly studied in colonic disease. The present study assessed the mRNA expression levels of Th17 effector cytokines (IL17A, IL17F, IL21, IL22 and IL26) and genes involved in differentiation (IL6, IL1B, TGFB1, IL23A and STAT3) and recruitment of Th17 cells (CCR6 and CCL20) by quantitative real-time PCR analysis of colonic and ileal biopsies from 22 healthy control subjects, 26 patients with Crohn's disease (CD) and 12 patients with ulcerative colitis (UC). Inflammation was quantified by measuring expression of the inflammatory mediators IL8 and TNF. RESULTS: Evaluation of mRNA expression levels in colonic and ileal control samples revealed that TNF, TGFB1, STAT3 and CCR6 were expressed at higher levels in the ileum than in the colon. Expression of all the Th17 pathway-associated genes was increased in inflamed colonic samples. The increased expression of these genes was predominantly observed in samples from UC patients and was associated with more intense inflammation. Although increased expression of IL17A, IL17F, IL21 and IL26 was detected in inflamed ileal samples, expression of the indispensable Th17 cell differentiation factors TGFB1 and IL23A, the signaling molecule STAT3 and the Th17 recruitment factors CCR6 and CCL20 were unchanged. CONCLUSIONS: Our findings suggest that immune regulation is different in colonic and ileal disease, which might have important consequences for therapeutic intervention.