Updates on the management of inflammatory bowel disease from periconception to pregnancy and lactation

Inflammatory bowel disease (IBD) affects reproductive planning due to psychological effects and mechanical problems related to surgery. Children of people with IBD have an increased risk of about 10% if one parent has IBD and up to 33% if both parents have IBD. The fertility of people with IBD is similar to the general population, but fertility might be reduced in individuals with active IBD, ileal pouch-anal anastomosis, or perianal Crohn's disease. Flaring disease during pregnancy increases complications, such as preterm birth. Thus, disease management with appropriate medications can optimise outcomes. As most medications have minimal fetal risks, people with IBD should be informed about the risks of stopping medications and the importance of maintaining remission. A period of disease remission is advisable before pregnancy and could reduce the risks for both the pregnant person and the fetus. Flexible endoscopy, intestinal ultrasound, and gadolinium-free magnetic resonance enterography are safe during pregnancy. We provide state-of-the-art knowledge on the basis of the latest evidence to ensure successful pregnancy outcomes in controlled IBD.

IAPs and RIPK1 mediate LPS-induced cytokine production in healthy subjects and Crohn's disease

Innate immune activity fuels intestinal inflammation in Crohn's disease (CD), an inflammatory bowel disease. Identification and targeting of new molecular regulators of the innate activity are warranted to control the disease. Inhibitor of apoptosis proteins (IAPs) regulate both cell survival and inflammatory signaling. We investigated the effects of IAP inhibition by second mitochondria-derived activator of caspases (SMAC) mimetics (SMs) on innate responses and cell death to pathogen-associated molecular patterns in peripheral blood mononuclear cells (PBMCs) and monocytes. IAPs inhibited lipopolysaccharide (LPS)-induced expression of proinflammatory interleukin (IL)-1β, IL-6. Likewise, LPS (but not muramyl dipeptide or Escherichia coli) induced TNF-α was inhibited in CD and control PBMCs. The SM effect was partially reversed by inhibition of receptor-interacting serine/threonine-protein kinase 1 (RIPK1). The effect was mainly cell death independent. Thus, IAP inhibition by SMs leads to reduced production of proinflammatory cytokines and may be considered in the efforts to develop new therapeutic strategies to control CD.

Diagnosis and Pharmacological Management of Microscopic Colitis in Geriatric Care

Microscopic colitis, a diagnosis under the umbrella term of inflammatory bowel disease, is a prevalent cause of watery diarrhea, often with symptoms of urgency and bloating, typically observed in older adults aged ≥ 60 years. Its incidence has been reported to exceed those of ulcerative colitis and Crohn's disease in some geographical areas. Although nonpathognomonic endoscopic abnormalities, including changes of the vascular mucosal pattern; mucosal erythema; edema; nodularity; or mucosal defects, e.g., "cat scratches" have been reported, a colonoscopy is typically macroscopically normal. As reliable biomarkers are unavailable, colonoscopy using random biopsies from various parts of the colon is compulsory. Based on the histological examination under a microscope, the disease is divided into collagenous (with a thickened subepithelial collagenous band) and lymphocytic (with intraepithelial lymphocytosis) colitis, although incomplete forms exist. In routine clinical settings, the disease has a high risk of being misdiagnosed as irritable bowel syndrome or even overlooked. Therefore, healthcare providers should be familiar with clinical features and rational management strategies. A 6-8-week oral budesonide treatment course (9 mg/day) is considered the first-line therapy, but patients often experience relapse when discontinued, or might become intolerant, dependent, or even fail to respond. Consequently, other therapeutic options (e.g., bismuth subsalicylate, biologics, loperamide, bile acid sequestrants, and thiopurines) recommended by available guidelines may be prescribed. Herein, clinically meaningful data is provided based on the latest evidence that may aid in reaching a diagnosis and establishing rational therapy in geriatric care to control symptoms and enhance the quality of life for those affected.

Paternal Medications in Inflammatory Bowel Disease and Male Fertility and Reproductive Outcomes: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Studies evaluating reproductive outcomes among male patients with inflammatory bowel disease (IBD) are limited. We evaluated use of IBD medications and association with semen parameters, a proxy of male fertility, and adverse pregnancy outcomes (early pregnancy loss [EPL], preterm birth [PB], congenital malformations [CM]).

METHODS

We searched Medline, Embase, Scopus, and Web of Science (PROSPERO CRD42020197098) from inception to April 2022 for studies reporting semen parameters and adverse pregnancy outcomes among male patients exposed to biologics, thiopurine, or methotrexate. Standardized mean difference, prevalence, and odds ratios (ORs) of outcomes were pooled and analyzed using a random effects model.

RESULTS

Ten studies reporting semen parameters (268 patients with IBD) and 16 studies reporting adverse pregnancy outcomes (over 25,000 patients with IBD) were included. Biologic, thiopurine, or methotrexate use were not associated with decreased sperm count, motility, or abnormal morphology compared with nonexposed patients. The prevalence of adverse pregnancy outcomes with paternal biologic (5%), thiopurine (6%), or methotrexate (6%) exposure was comparable to nonexposed patients (5%). Biologic use was not associated with risk of EPL (OR, 1.26; I2 = 0%; P = .12), PB (OR, 1.10; I2 = 0%; P = .17), or CM (OR, 1.03; I2 = 0%; P = .69). Thiopurine use was not associated with risk of EPL (OR, 1.31; I2 = 19%; P = .17), PB (OR, 1.05; I2 = 0%; P = .20), or CM (OR, 1.07; I2 = 7%; P = .34). Methotrexate use was not associated with risk of PB (OR, 1.06; I2 = 0%; P = .62) or CM (OR, 1.03; I2 = 0%; P = .81).

CONCLUSIONS

Biologic, thiopurine, or methotrexate use among male patients with IBD are not associated with impairments in fertility or with increased odds of adverse pregnancy outcomes.

Effectiveness of Non-Budesonide Therapies in Management of Microscopic Colitis: A Systematic Review and Meta-analysis

BACKGROUND

Budesonide is accepted as first-choice therapy for microscopic colitis (MC); however, symptoms often recur and some patients may be dependent, intolerant, or even fail budesonide. We performed a systematic review and meta-analysis to determine the effectiveness of non-budesonide therapies (thiopurines, bismuth subsalicylate [BSS], bile acid sequestrants [BAS], loperamide and biologics) for MC suggested by international guidelines.

METHODS

We searched the CENTRAL, MEDLINE, and EMBASE databases from their inception to 18 April 2023 for the above-mentioned therapeutics in MC. We pooled the response and remission rates by medication using a random-effects model.

RESULTS

Twenty-five studies comprising 1475 patients were included in the meta-analysis. Treatment with BSS showed the highest response rate of 75% (95% confidence interval [CI] 0.65-0.83; I² = 70.12%), with 50% achieving remission of symptoms (95% CI 0.35-0.65; I² = 71.06%). Treatment with tumor necrosis factor (TNF) inhibitors (infliximab and adalimumab) demonstrated a response rate of 73% (95% CI 0.63-0.83; I² = 0.00%), with a remission rate of 44% (95% CI 0.32-0.56; I² = 0.00%). The response rate for those treated with vedolizumab was similar; 73% responded to treatment (95% CI 0.57-0.87; I² = 35.93%), with a remission rate of 56% (95% CI 0.36-0.75; I² = 46.30%). Loperamide was associated with response and remission rates of 62% (95% CI 0.43-0.80; I² = 92.99%) and 14% (95% CI 0.07-0.25), respectively, whereas BAS use was associated with response and remission rates of 60% (95% CI 0.51-0.68; I² = 61.65%) and 29% (95% CI 0.12-0.55), respectively. Finally, the outcomes for thiopurine use were 49% (95% CI 0.27-0.71; I² = 81.45%) and 38% (95% CI 0.23-0.54; I² = 50.05%), respectively DISCUSSION: The present systematic review and meta-analysis provides rates of effectiveness of non-budesonide therapies for MC based on available data in the field. Studies in the meta-analysis showed a large amount of heterogeneity due to the variability in assessing the clinical effects of intervention between the studies caused by differences in the definitions of response or remission rates between the studies included. This may likely result in overestimating the benefit of a treatment. Furthermore, the number of participants and drug dosages varied, and only a few studies applied disease-specific activity indices. Only one randomized controlled trial (RCT) was identified. All other 24 included studies were either case series or (retrospective) cohort studies, which complicated efforts to perform further sensitivity analyses to adjust for potential confounders and risk of bias. In addition, the overall evidence on the effect of these treatment options was judged as low, mostly due to comparability bias and the observational nature of the available studies, which limited statistically robust comparisons of rates of effectiveness of the different non-budesonide agents ranked against each other. However, our observational findings may inform clinicians regarding the most rational selection of non-budesonide therapies to patients with MC.

CLINICAL TRIALS REGISTRATION

PROSPERO protocol #CRD42020218649.

Comparative onset of effect of biologics and small molecules in moderate-to-severe ulcerative colitis: a systematic review and network meta-analysis

BACKGROUND

Onset of effect of advanced therapies is an important parameter due to symptom load and risk of disease complications in moderate-to-severe ulcerative colitis (UC), but comparative data are lacking. Therefore, we aimed to assess the comparative onset of efficacy of biological therapies and small molecules for this patient population.

METHODS

In this systematic review and network meta-analysis, we searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to 24 August 2022, for randomised controlled trials or open-label studies assessing the efficacy of biologics or small molecule drugs within the first six weeks of treatment in adults with UC. The co-primary outcomes were the induction of clinical response and clinical remission at week 2. Network meta-analyses was conducted under the Bayesian framework. This study is registered with PROSPERO: CRD42021250236.

FINDINGS

The systematic literature search identified 20,406 citations, of which 25 studies comprising 11,074 patients fulfilled the eligibility criteria. Upadacitinib ranked highest for induction of clinical response and clinical remission at week 2 and was significantly superior to all agents but tofacitinib, which ranked second highest. Although the rankings remained consistent, no differences between upadacitinib and biological therapies were demonstrated in the sensitivity analyses of partial Mayo clinic score response or resolution of rectal bleeding at week 2. Tumor necrosis factor-α (TNF) inhibitors were significantly superior to vedolizumab and ustekinumab for patient-reported outcome-2 (PRO-2) remission at week 2 in bio-naïve patients. Filgotinib 100 mg, ustekinumab, and ozanimod ranked lowest across all endpoints.

INTERPRETATION

In this network meta-analysis, we found upadacitinib to be significantly superior to all agents but tofacitinib for the induction of clinical response and clinical remission two weeks after treatment initiation. In contrast, ustekinumab and ozanimod ranked lowest. Our findings help to establish the evidence regarding the onset of efficacy of advanced therapies.

FUNDING

None.

Selective JAK1 inhibitors for the treatment of inflammatory bowel disease

Janus kinase (JAK) inhibitors, also known as jakinibs, are third-generation oral small molecules that have expanded the therapeutic options for the management of chronic inflammatory diseases, including inflammatory bowel disease (IBD). Tofacitinib, a pan-JAK inhibitor, has spearheaded the new JAK class for IBD treatment. Unfortunately, serious adverse effects, including cardiovascular complications such as pulmonary embolism and venous thromboembolism or even death from any cause, have been reported for tofacitinib. However, it is anticipated that next-generation selective JAK inhibitors may limit the development of serious adverse events, leading to a safer treatment course with these novel targeted therapies. Nevertheless, although this drug class was recently introduced, following the launch of second-generation biologics in the late 1990s, it is breaking new ground and has been shown to efficiently modulate complex cytokine-driven inflammation in both preclinical models and human studies. Herein, we review the clinical opportunities for targeting JAK1 signaling in the pathophysiology of IBD, the biology and chemistry underpinning these target-selective compounds, and their mechanisms of actions. We also discuss the potential for these inhibitors in efforts to balance their benefits and harms.

COLAR: open-label clinical study of IL-6 blockade with tocilizumab for the treatment of immune checkpoint inhibitor-induced colitis and arthritis

Background

Immune-related adverse events due to immune checkpoint inhibitors (ICIs) are not always effectively treated using glucocorticoids and it may negatively affect the antitumor efficacy of ICIs. Interventional studies of alternatives to glucocorticoids are lacking. We examined whether interleukin-6 blockade by tocilizumab reduced ICI-induced colitis and arthritis.

Patients and methods

Patients with solid cancer experiencing Common Terminology Criteria for Adverse Events (CTCAE v5.0) grade >1 ICI-induced colitis/diarrhea (n=9), arthritis (n=9), or both (n=2) were recruited and treated with tocilizumab (8 mg/kg) every 4 weeks until worsening or unacceptable toxicity. Patients were not allowed to receive systemic glucocorticoids and other immunosuppressive drugs within the 14-day screening period. The primary endpoint was clinical improvement of colitis and arthritis, defined as ≥1 grade CTCAE reduction within 8 weeks. Secondary endpoints were improvements and glucocorticoid-free remission at week 24; safety; radiologic, endoscopic, and histological changes; and changes in plasma concentrations of C reactive protein, cytokines (IL-6, IL-8, and IL-17), and YKL-40.

Results

Nineteen patients were available for efficacy analysis; one patient was excluded due to pancreatic insufficiency-induced diarrhea. Patients received treatment with pembrolizumab (n=10) or nivolumab (n=4) as monotherapy or ipilimumab and nivolumab (n=5) combined. Seven patients had been initially treated with glucocorticoids, and two of them also received infliximab. Ten patients continued ICI therapy during tocilizumab treatment. The primary endpoint was achieved in 15 of 19 (79%) patients. Additional one patient had ≥1 grade reduction at week 10, and another patient had stabilized symptoms. At week 24, ongoing improvement without glucocorticoids (n=12), including complete remission (n=10), was noted. Five patients had grades 3–4 treatment-related adverse events, which were manageable and reversible.

Conclusions

Tocilizumab showed promising clinical efficacy and a manageable safety profile in the treatment of ICI-induced colitis and arthritis. Our findings support the feasibility of randomized trials of immune-related adverse events.

Trial registration number

NCT03601611.

Microscopic colitis: Etiopathology, diagnosis, and rational management

Microscopic colitis is an inflammatory bowel disease divided into two subtypes: collagenous colitis and lymphocytic colitis. With an increasing incidence of microscopic colitis exceeding those of ulcerative and Crohn's disease among elderly people in some countries, microscopic colitis is a debilitating life experience. Therefore, physicians should be familiar with its clinical features and management strategies because the disease deserves the same attention as the classical inflammatory bowel diseases. Here, state-of-the-art knowledge of microscopic colitis is provided from a global perspective with reference to etiopathology and how to establish the diagnosis with the overall aim to create awareness and improve rational management in clinical practice. The immune system and a dysregulated immune response seem to play a key role combined with risk factors (e.g. cigarette smoking) in genetically predisposed individuals. The symptoms are characterized by recurrent or chronic nonbloody, watery diarrhea, urgency, weight loss, and a female preponderance. As biomarkers are absent, the diagnosis relies on colonoscopy with a histological assessment of biopsy specimens from all parts of the colon. Although the disease is not associated with a risk of colorectal cancer, a recent nationwide, population-based cohort study found an increased risk of lymphoma and lung cancer. Budesonide is the first-line therapy for management, whereas immunomodulatory drugs (including biologics) and drugs with antidiarrheal properties may be indicated in those failing, dependent, or intolerant to budesonide. In microscopic colitis induced by checkpoint inhibitors, a drug class used increasingly for a wide range of malignancies, a more aggressive therapeutic approach with biologics introduced early seems reasonable. However, particular attention needs to be drawn to the existence of incomplete forms of microscopic colitis with the risk of being overlooked in routine clinical settings.

Gut Microbiome in Inflammatory Bowel Disease: Role in Pathogenesis, Dietary Modulation, and Colitis-Associated Colon Cancer

The gut microbiome has increasingly been recognized as a critical and central factor in inflammatory bowel disease (IBD). Here, we review specific microorganisms that have been suggested to play a role in the pathogenesis of IBD and the current state of fecal microbial transplants as a therapeutic strategy in IBD. We discuss specific nutritional and dietary interventions in IBD and their effects on gut microbiota composition. Finally, we examine the role and mechanisms of the gut microbiome in mediating colitis-associated colon cancer.

Selective tyrosine kinase 2 inhibitors in inflammatory bowel disease

Recent significant advances have been made in the treatment of chronic inflammatory diseases with initiation of the era of biologics. However, an unmet medical need still exists for novel targeted therapies. Compared with biologics, Janus kinase inhibitors (JAKis) are a new drug class of orally administered small molecules that have been shown to efficiently modulate complex cytokine-driven inflammation in preclinical models and human studies. Unfortunately, serious adverse effects have been reported with the first introduced pan-JAKi, tofacitinib. Here, we review tyrosine kinase 2 (TYK2) signaling in the pathophysiology of inflammatory bowel disease (IBD), examine mechanisms of action of selective TYK2 inhibitors (TYK2is), and discuss the potential for these inhibitors in efforts to balance benefits and harms.

Molecular manipulations and intestinal stem cell-derived organoids in inflammatory bowel disease

The pathogenesis of inflammatory bowel diseases (IBD) involves genetic predisposition, environmental factors, and a broadly dysregulated intestinal immune response to the commensal intestinal microflora. The interface between genetic predisposition and environmental factors is reflected in the epigenetic regulation at the transcriptional level. Treatment targets now involve mucosal and histological healing, but the future might additionally include normalization of intestinal cellular functions also at the molecular level, for example comprising complete restoration of phenotypic, genotypic, and epigenetic states. Recent developments in patient-derived epithelial intestinal stem cell (ISC) organoid technologies have opened exciting new therapeutic opportunities to potentially attain molecular healing by combining stem cell therapy with molecular manipulations using (epi)drugs and/or CRISPR/Cas9 genome editing. Here, we are the first to discuss the possibility for phenotypic, genotypic, and epigenetic restoration via molecular manipulations and stem cell therapy in IBD from a clinical perspective.

Tuft Cells and Their Role in Intestinal Diseases

The interests in intestinal epithelial tuft cells, their basic physiology, involvement in immune responses and relevance for gut diseases, have increased dramatically over the last fifteen years. A key discovery in 2016 of their close connection to helminthic and protozoan infection has further spurred the exploration of these rare chemosensory epithelial cells. Although very sparse in number, tuft cells are now known as important sentinels in the gastrointestinal tract as they monitor intestinal content using succinate as well as sweet and bitter taste receptors. Upon stimulation, tuft cells secrete a broad palette of effector molecules, including interleukin-25, prostaglandin E2 and D2, cysteinyl leukotriene C4, acetylcholine, thymic stromal lymphopoietin, and β-endorphins, some of which with immunomodulatory functions. Tuft cells have proven indispensable in anti-helminthic and anti-protozoan immunity. Most studies on tuft cells are based on murine experiments using double cortin-like kinase 1 (DCLK1) as a marker, while human intestinal tuft cells can be identified by their expression of the cyclooxygenase-1 enzyme. So far, only few studies have examined tuft cells in humans and their relation to gut disease. Here, we present an updated view on intestinal epithelial tuft cells, their physiology, immunological hub function, and their involvement in human disease. We close with a discussion on how tuft cells may have potential therapeutic value in a clinical context.

Biologics for Inflammatory Bowel Disease and Their Safety in Pregnancy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Biologics are used routinely in pregnant women with inflammatory bowel disease (IBD), but large-scale data reporting adverse pregnancy outcomes among biologic users are lacking. We sought to estimate the prevalence of adverse pregnancy outcomes in women with IBD on biologic therapies.

METHODS

We searched major databases from inception to June 2020 for studies estimating the prevalence of adverse pregnancy outcomes in IBD when using biologics (anti-tumor necrosis factor [TNF], anti-integrins, and anticytokines). Prevalence and relative risk (RR) were pooled using a random-effects model.

RESULTS

Forty-eight studies were included in the meta-analysis comprising 6963 patients. Biologic therapy in IBD pregnancies was associated with a pooled prevalence of 8% (95% CI, 6%-10%; I2 = 87.4%) for early pregnancy loss, 9% (95% CI, 7%-11%; I2 = 89.9%) for preterm birth, 0% (95% CI, 0%-0%; I2 = 0%) for stillbirth, 8% (95% CI, 5%-10%; I2 = 87.0%) for low birth weight, and 1% (95% CI, 1%-2%; I2 = 78.3%) for congenital malformations. These rates are comparable with those published in the general population. In subgroup analyses of a small number of studies, the prevalence of early pregnancy loss and preterm birth were higher in vedolizumab vs anti-TNF users. Meta-regression did not show an association of disease activity or concomitant thiopurine on adverse outcomes. Continued TNF inhibitor use during the third trimester was not associated with risk of preterm birth (RR, 1.41; 95% CI, 0.77-2.60; I2 = 0%), low birth weight (RR, 1.32; 95% CI, 0.80-2.18; I2 = 0%), or congenital malformations (RR, 1.28; 95% CI, 0.47-3.49; I2 = 0%).

CONCLUSIONS

Adverse pregnancy outcomes among pregnant IBD women using biologics are comparable with that of the general population. PROSPERO protocol #CRD42019135721.

Multiparametric and accurate functional analysis of genetic sequence variants using CRISPR-Select

Determining the functional role of thousands of genetic sequence variants (mutations) associated with genetic diseases is a major challenge. Here we present clustered regularly interspaced short palindromic repeat (CRISPR)-Select^TIME, CRISPR-Select^SPACE and CRISPR-Select^STATE, a set of flexible knock-in assays that introduce a genetic variant in a cell population and track its absolute frequencies relative to an internal, neutral control mutation as a function of time, space or a cell state measurable by flow cytometry. Phenotypically, CRISPR-Select can thereby determine, for example, pathogenicity, drug responsiveness/resistance or in vivo tumor promotion by a specific variant. Mechanistically, CRISPR-Select can dissect how the variant elicits the phenotype by causally linking the variant to motility/invasiveness or any cell state or biochemical process with a flow cytometry marker. The method is applicable to organoids, nontransformed or cancer cell lines. It is accurate, quantitative, fast and simple and works in single-well or 96-well higher throughput format. CRISPR-Select provides a versatile functional variant assay for research, diagnostics and drug development for genetic disorders.

Lipidomic Trajectories Characterize Delayed Mucosal Wound Healing in Quiescent Ulcerative Colitis and Identify Potential Novel Therapeutic Targets

Improving the long-term prognosis of ulcerative colitis (UC) requires sustained deep mucosal colonic healing with histologic remission, making the study of colonic tissue regeneration essential. In experimental colitis models, lipid metabolites are recognized as pivotal components of this process. This study aimed to describe the kinetics of wound healing and lipid metabolites engaged in regeneration in the normal colonic mucosa and how they are affected in UC to reveal new therapeutic targets. Experimental colonic wounds were created endoscopically in quiescent UC (n=21) and controls (n=9), and the healing process was surveilled by serial endoscopies and cross-sectional wound biopsies post-wounding. Biopsies were analyzed by liquid chromatography coupled with mass spectrometry. Endoscopic wound scores were significantly higher in UC at day two (p=0.001) and seven (p<0.0001) post-wounding, demonstrating a prolonged wound healing process. The wound scores were correlated with lipid mediators crucial for normal regeneration and sustained UC-specific changes in key phospholipids and eicosanoids, i.e., lysophosphatidylcholine, phosphatidylcholine, lysophosphatidic acid, phosphatidylglycerol, phosphatidylinositol, prostaglandin D₂, and prostaglandin E₁, were observed. A prolonged wound healing process is identified in quiescent UC with altered disease specific lipidomic trajectories providing potential novel therapeutic avenues for stimulating mucosal regeneration as an add-on to the traditional immune suppression treatment.

Telomere dysfunction activates YAP1 to drive tissue inflammation

Germline telomere maintenance defects are associated with an increased incidence of inflammatory diseases in humans, yet whether and how telomere dysfunction causes inflammation are not known. Here, we show that telomere dysfunction drives pATM/c-ABL-mediated activation of the YAP1 transcription factor, up-regulating the major pro-inflammatory factor, pro-IL-18. The colonic microbiome stimulates cytosolic receptors activating caspase-1 which cleaves pro-IL-18 into mature IL-18, leading to recruitment of interferon (IFN)-γ-secreting T cells and intestinal inflammation. Correspondingly, patients with germline telomere maintenance defects exhibit DNA damage (γH2AX) signaling together with elevated YAP1 and IL-18 expression. In mice with telomere dysfunction, telomerase reactivation in the intestinal epithelium or pharmacological inhibition of ATM, YAP1, or caspase-1 as well as antibiotic treatment, dramatically reduces IL-18 and intestinal inflammation. Thus, telomere dysfunction-induced activation of the ATM-YAP1-pro-IL-18 pathway in epithelium is a key instigator of tissue inflammation.

Mucosal vitamin D signaling in inflammatory bowel disease

Epidemiological studies have identified vitamin D (25(OH)D) deficiency to be highly prevalent among patients with inflammatory bowel disease (IBD), and low serum levels correlate with a higher disease activity and a more complicated disease course. The link to IBD pathogenesis has been subject of investigations, primarily due to the distinct immunological functions of vitamin D signaling, including anti-inflammatory and anti-fibrotic actions. Vitamin D is a pleiotropic hormone that executes its actions on cells through the vitamin D receptor (VDR). A leaky gut, i.e. an insufficient intestinal epithelial barrier, is thought to be central for the pathogenesis of IBD, and emerging data support the concept that vitamin D/VDR signaling in intestinal epithelial cells (IECs) has an important role in controlling barrier integrity. Here we review the latest evidence on how vitamin D promotes the interplay between IECs, the gut microbiome, and immune cells and thereby regulate the intestinal immune response. On the cellular level, vitamin D signaling regulates tight junctional complexes, apoptosis, and autophagy, leading to increased epithelial barrier integrity, and promotes expression of antimicrobial peptides as part of its immunomodulating functions. Further, intestinal VDR expression is inversely correlated with the severity of inflammation in patients with IBD, which might compromise the positive effects of vitamin D signaling in patients with flaring disease. Efforts to reveal the role of vitamin D in the pathophysiology of IBD will pave the road for the invention of more rational treatment strategies of this debilitating disease in the future.

A fully defined 3D matrix for ex vivo expansion of human colonic organoids from biopsy tissue

Intestinal organoids have widespread research and biomedical applications, such as disease modeling, drug testing and regenerative medicine. However, the transition towards clinical use has in part been hampered by the dependency on animal tumor-derived basement membrane extracts (BMEs), which are poorly defined and ill-suited for regulatory approval due to their origin and batch-to-batch variability. In order to overcome these limitations, and to enable clinical translation, we tested the use of a fully defined hydrogel matrix, QGel CN99, to establish and expand intestinal organoids directly from human colonic biopsies. We achieved efficient de novo establishment, expansion and organoid maintenance, while also demonstrating sustained genetic stability. Additionally, we were able to preserve stemness and differentiation capacity, with transcriptomic profiles resembling normal colonic epithelium. All data proved comparable to organoids cultured in the BME-benchmark Matrigel. The application of a fully defined hydrogel, completely bypassing the use of BMEs, will drastically improve the reproducibility and scalability of organoid studies, but also advance translational applications in personalized medicine and stem cell-based regenerative therapies.

Efficacy and safety of methotrexate in the management of inflammatory bowel disease: A systematic review and meta-analysis of randomized, controlled trials

BACKGROUND

The therapeutic role of methotrexate (MTX) for management of inflammatory bowel disease (IBD) remains unclear.

METHODS

We systematically reviewed randomized, controlled trials (RCTs) of MTX for induction and maintenance of remission in IBD until January 2020 in accordance with PROSPERO protocol (#CRD42018115047). Relative risk (RR) of maintenance of remission, induction of remission, endoscopic disease activity, and adverse events were combined in a meta-analysis.

FINDINGS

MTX monotherapy was not superior to placebo for induction of clinical remission in Crohn's disease (CD). However, MTX was superior to placebo in maintaining clinical remission of CD. Concomitant therapy with MTX and the TNF inhibitor infliximab (IFX) was not superior to IFX monotherapy in CD. In ulcerative colitis (UC), MTX monotherapy was not superior to placebo neither for induction of clinical remission, nor for maintenance of clinical remission. MTX did not result in superior endoscopic outcomes during induction or maintenance therapy compared with placebo. Regarding adverse events (AEs), our meta-analysis on CD studies showed a significantly higher risk of AEs when comparing MTX versus placebo in studies investigating induction of remission, but not in maintenance of remission. In UC, no such differences in AEs between MTX or placebo were observed.

INTERPRETATION

Current data support the efficacy of parenteral MTX monotherapy for maintenance of clinical remission in CD. MTX is not confirmed to be effective for treatment of UC or for induction of remission in CD. No evidence supports concomitant MTX to improve efficacy of IFX (no other biologics investigated).

SMAC mimetics and RIPK inhibitors as therapeutics for chronic inflammatory diseases

New therapeutic approaches for chronic inflammatory diseases such as inflammatory bowel disease, rheumatoid arthritis, and psoriasis are needed because current treatments are often suboptimal in terms of both efficacy and the risks of serious adverse events. Inhibitor of apoptosis proteins (IAPs) are E3 ubiquitin ligases that inhibit cell death pathways and are themselves inhibited by second mitochondria-derived activator of caspases (SMAC). SMAC mimetics (SMs), small-molecule antagonists of IAPs, are being evaluated as cancer therapies in clinical trials. IAPs are also crucial regulators of inflammatory pathways because they influence both the activation of inflammatory genes and the induction of cell death through the receptor-interacting serine-threonine protein kinases (RIPKs), nuclear factor κB (NF-κB)-inducing kinase, and mitogen-activated protein kinases (MAPKs). Furthermore, there is an increasing interest in specifically targeting the substrates of IAP-mediated ubiquitylation, especially RIPK1, RIPK2, and RIPK3, as druggable nodes in inflammation control. Several studies have revealed an anti-inflammatory potential of RIPK inhibitors that either block inflammatory signaling or block the form of inflammatory cell death known as necroptosis. Expanding research on innate immune signaling through pattern recognition receptors that stimulate proinflammatory NF-κB and MAPK signaling may further contribute to uncovering the complex molecular roles used by IAPs and downstream RIPKs in inflammatory signaling. This may benefit and guide the development of SMs or selective RIPK inhibitors as anti-inflammatory therapeutics for various chronic inflammatory conditions.

Systematic review with meta-analysis: association of vitamin D status with clinical outcomes in adult patients with inflammatory bowel disease

BACKGROUND

Vitamin D deficiency is highly prevalent among patients with IBD, however, data on its association with clinical outcomes are conflicting.

AIM

To perform a systematic review and meta-analysis to explore the association of low vitamin D status with clinical outcomes in patients with IBD.

METHODS

We searched PubMed, Embase, Scopus and Web of Science from inception to February 2018 for observational studies evaluating the association of low 25(OH)D status on IBD disease activity, mucosal inflammation, clinical relapse and quality of life. Odds ratios (ORs) were pooled and analysed using a random effects model.

RESULTS

Twenty-seven studies were eligible for inclusion comprising 8316 IBD patients (3115 ulcerative colitis, 5201 Crohn's disease). Among IBD patients, low 25(OH)D status was associated with increased odds of disease activity (OR 1.53, 95% CI 1.32-1.77, I²  = 0%), mucosal inflammation (OR 1.25, 95% CI 1.06-1.47, I²  = 0%), low quality of life (QOL) scores (OR 1.30, 95% CI 1.06-1.60, I²  = 0%) and future clinical relapse (OR 1.23, 95% CI 1.03-1.47, I²  = 0%). In subgroup analysis, low vitamin D status was associated with Crohn's disease activity (OR 1.66, 95% CI 1.36-2.03, I²  = 0%), mucosal inflammation (OR 1.39, 95% CI 1.03-1.85, I²  = 0%), clinical relapse (OR 1.35, 95% CI 1.14-1.59, I²  = 0%), and low QOL scores (OR 1.25, 95% CI 1.04-1.50, I²  = 0%) and ulcerative colitis disease activity (OR 1.47, 95% CI 1.03-2.09, I²  = 0%) and clinical relapse (OR 1.20, 95% 1.01-1.43, I²  = 0%).

CONCLUSIONS

Low 25(OH)D status is a biomarker for disease activity and predictor of poor clinical outcomes in IBD patients.

Managing vitamin D deficiency in inflammatory bowel disease

Management of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is generally cumbersome for patients and is a massive health-economic burden. In recent years, the immunomodulating effects of vitamin D have gained a huge interest in its possible pathogenic influence on the pathophysiology of IBD. Vitamin D deficiency is frequent among patients with IBD. Several clinical studies have pointed to a critical role for vitamin D in ameliorating disease outcomes. Although causation versus correlation unfortunately remains an overwhelming issue in the illusive chicken versus egg debate regarding vitamin D and IBD, here we summarise the latest knowledge of the immunological effects of vitamin D in IBD and recommend from available evidence that physicians regularly monitor serum 25(OH)D levels in patients with IBD. Moreover, we propose an algorithm for optimising vitamin D status in patients with IBD in clinical practice. Awaiting well-powered controlled clinical trials, we consider vitamin D supplementation to be an affordable and widely accessible therapeutic strategy to ameliorate IBD clinical outcomes.

Fluorescence-based tracing of transplanted intestinal epithelial cells using confocal laser endomicroscopy

Background

Intestinal stem cell transplantation has been shown to promote mucosal healing and to engender fully functional epithelium in experimental colitis. Hence, stem cell therapies may provide an innovative approach to accomplish mucosal healing in patients with debilitating conditions such as inflammatory bowel disease. However, an approach to label and trace transplanted cells, in order to assess engraftment efficiency and to monitor wound healing, is a key hurdle to overcome prior to initiating human studies. Genetic engineering is commonly employed in animal studies, but may be problematic in humans due to potential off-target and long-term adverse effects.

Methods

We investigated the applicability of a panel of fluorescent dyes and nanoparticles to label intestinal organoids for visualization using the clinically approved imaging modality, confocal laser endomicroscopy (CLE). Staining homogeneity, durability, cell viability, differentiation capacity, and organoid forming efficiency were evaluated, together with visualization of labeled organoids in vitro and ex vivo using CLE.

Results

5-Chloromethylfluorescein diacetate (CMFDA) proved to be suitable as it efficiently stained all organoids without transfer to unstained organoids in co-cultures. No noticeable adverse effects on viability, organoid growth, or stem cell differentiation capacity were observed, although single-cell reseeding revealed a dose-dependent reduction in organoid forming efficiency. Labeled organoids were easily identified in vitro using CLE for a duration of at least 3 days and could additionally be detected ex vivo following transplantation into murine experimental colitis.

Conclusions

It is highly feasible to use fluorescent dye-based labeling in combination with CLE to trace intestinal organoids following transplantation to confirm implantation at the intestinal target site.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1246-5) contains supplementary material, which is available to authorized users.

Targeting JAK-STAT signal transduction in IBD

An unmet medical need exists for novel targeted therapies for inflammatory bowel disease (IBD) as many patients experience inadequate responses to antibody-based biologics. An oral drug formulation with reduced production costs and redundancy for healthcare staff to administer therapy ideally should result in diminished healthcare expenses and improved patient compliance. A new drug class of small molecules, the Janus kinase (JAK) inhibitors (jakinibs), fulfills these criteria and has recently shown efficacy in IBD. Here we provide an overview of the mode of action of jakinibs and provide a comprehensive overview of existing clinical studies. Convincing clinical data show that a complex cytokine-driven inflammation can efficiently be modulated by therapeutic inhibition of the JAK proteins.

Putative biomarkers of vedolizumab resistance and underlying inflammatory pathways involved in IBD

Objectives

Characterise the circulating inflammatory cytokine pattern among patients failing consecutive anti-tumour necrosis factor (anti-TNF) and anti-integrin treatments to identify predictors of response.

Methods

A retrospective single-centre cohort study of 28 patients with inflammatory bowel disease (IBD) receiving anti-integrin therapy (vedolizumab) subsequent to the failure of anti-TNF treatment was conducted. Blood samples were obtained immediately prior to initiation of vedolizumab therapy, and the response to treatment was evaluated after completion of the 14-week induction regimen. Multiplex ELISA was applied to quantify 47 preselected plasma proteins based on their putative involvement in the inflammatory process in IBD.

Results

Anti-TNF and vedolizumab non-responders (n=20) had significantly higher levels of circulating interleukin (IL)-6 than anti-TNF non-responders with subsequent response to vedolizumab (n=8): median 9.5 pg/mL versus 5.9 pg/mL, p<0.05. Following stratification by diagnosis, patients with Crohn's disease who failed vedolizumab therapy (n=7) had higher soluble CD40 ligand (sCD40L) than responders (n=4): 153.0 pg/mL versus 45.5 pg/mL, p<0.01; sensitivity 100% (95% CI 59% to 100%), specificity 100% (95% CI 40% to 100%). Osteocalcin was higher among patients with ulcerative colitis responding to vedolizumab (n=4) compared with those not responding (n=13): 4219 pg/mL versus 2823 pg/mL, p=0.01; sensitivity 85% (95% CI 55% to 98%), specificity 100% (95% CI 40% to 100%).

Conclusions

Patients with IBD failing vedolizumab induction and anti-TNF therapy have persistent IL-6 pathway activity, which could be a potential alternative treatment target. sCD40L, osteocalcin and the IL-6 pathway activity might be predictors for response to vedolizumab.

Role of Vitamin D in the Natural History of Inflammatory Bowel Disease

Inflammatory bowel disease [IBD], including ulcerative colitis and Crohn's disease, is a chronic and unpredictable condition characterised by alternating periods of remission interspersed with relapses. In recent years, accumulating support for an immunomodulating effect of vitamin D on both the innate and the adaptive immune systems has been presented. Through the vitamin D receptor, the active form of vitamin D, 1,25[OH]2D, induces antimicrobial peptide secretion, decreases dendritic cell activity, and promotes Th2 and regulatory T cell development and activity. In addition, vitamin D promotes an increased ratio of anti-inflammatory cytokines to pro-inflammatory cytokines. Studies in IBD point to a role for vitamin D in ameliorating disease outcome. Suboptimal circulating levels of 25-hydroxyvitamin D are common in IBD and appear to be associated with an increased risk of flares, IBD-related hospitalisations and surgeries, an inadequate response to tumour necrosis factor [TNF] inhibitors, a deterioration in quality of life, and low bone mineral density. With only few available randomised double-blind, placebo-controlled studies investigating therapeutic effects of vitamin D related to IBD, further research is necessary to determine the true therapeutic potential of vitamin D, as well as to define its optimal range in serum to achieve and maintain quiescence of disease. This review aims to summarise the latest knowledge on the extraskeletal effects of vitamin D in IBD, and outlines the potential deleterious consequences of vitamin D deficiency in this patient cohort.

Characterization of the enhancer and promoter landscape of inflammatory bowel disease from human colon biopsies

Inflammatory bowel disease (IBD) is a chronic intestinal disorder, with two main types: Crohn’s disease (CD) and ulcerative colitis (UC), whose molecular pathology is not well understood. The majority of IBD-associated SNPs are located in non-coding regions and are hard to characterize since regulatory regions in IBD are not known. Here we profile transcription start sites (TSSs) and enhancers in the descending colon of 94 IBD patients and controls. IBD-upregulated promoters and enhancers are highly enriched for IBD-associated SNPs and are bound by the same transcription factors. IBD-specific TSSs are associated to genes with roles in both inflammatory cascades and gut epithelia while TSSs distinguishing UC and CD are associated to gut epithelia functions. We find that as few as 35 TSSs can distinguish active CD, UC, and controls with 85% accuracy in an independent cohort. Our data constitute a foundation for understanding the molecular pathology, gene regulation, and genetics of IBD.

Many SNPs associated with inflammatory bowel disease are located in non-coding genomic regions. Here, the authors perform CAGE-sequencing on descending colon biopsies of Crohn’s disease and ulcerative colitis patients to map transcription start sites and enhancer activity for analysis of regulatory regions.

Inflammatory bowel disease with primary sclerosing cholangitis: A Danish population-based cohort study 1977-2011

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) may be complicated by primary sclerosing cholangitis (PSC). We aimed to assess the characteristics of Danish PSC-IBD patients and to compare their prognosis with IBD patients without PSC.

METHODS

A retrospective nationwide population-based cohort of 257 PSC-IBD patients was assessed through Danish national registries and manual scrutiny of patient files.

RESULTS

For all PSC-IBD patients diagnosed after 1976 (n = 222) and 8231 IBD controls (ie, without PSC), the cumulative probability of resective surgery, liver transplantation, cancer, and survival from 1977 through 2011 was estimated and compared by log-rank test and Cox regression. PSC-IBD patients primarily had ulcerative colitis (UC) (72%), were diagnosed in young adulthood (median age at IBD diagnosis, 23 years), and 9% were smokers. Among PSC-UC patients 78% had pancolitis at diagnosis. Among patients with PSC and Crohn's disease (CD) 91% had colonic involvement. The PSC-IBD patients had a significantly higher probability of receiving resective surgery (HR; 2.13, 95% CI: 1.50-3.03); of developing colorectal cancer (CRC) (HR; 21.4, 95% CI: 9.6-47.6), of cholangiocarcinoma (HR; 190, 95% CI: 54.8-660), and of dying (HR; 4.39, 95% CI: 3.22-6.00) as compared to non-PSC-IBD controls. The 25-year cumulative risk of liver transplantation was high (53%).

CONCLUSIONS

This unselected population-based study shows that PSC-IBD patients not only have an extensive phenotype of IBD, they are also treated more intensively than other patients with IBD. However, the prognosis remains poor and without any apparent improvement over calendar time.

Impact of red and processed meat and fibre intake on treatment outcomes among patients with chronic inflammatory diseases: protocol for a prospective cohort study of prognostic factors and personalised medicine

INTRODUCTION

Chronic inflammatory diseases (CIDs) are frequently treated with biological medications, specifically tumour necrosis factor inhibitors (TNFi)). These medications inhibit the pro-inflammatory molecule TNF alpha, which has been strongly implicated in the aetiology of these diseases. Up to one-third of patients do not, however, respond to biologics, and lifestyle factors are assumed to affect treatment outcomes. Little is known about the effects of dietary lifestyle as a prognostic factor that may enable personalised medicine. The primary outcome of this multidisciplinary collaborative study will be to identify dietary lifestyle factors that support optimal treatment outcomes.

METHODS AND ANALYSIS

This prospective cohort study will enrol 320 patients with CID who are prescribed a TNFi between June 2017 and March 2019. Included among the patients with CID will be patients with inflammatory bowel disease (Crohn's disease and ulcerative colitis), rheumatic disorders (rheumatoid arthritis, axial spondyloarthritis, psoriatic arthritis), inflammatory skin diseases (psoriasis, hidradenitis suppurativa) and non-infectious uveitis. At baseline (pretreatment), patient characteristics will be assessed using patient-reported outcome measures, clinical assessments of disease activity, quality of life and lifestyle, in addition to registry data on comorbidity and concomitant medication(s). In accordance with current Danish standards, follow-up will be conducted 14-16 weeks after treatment initiation. For each disease, evaluation of successful treatment response will be based on established primary and secondary endpoints, including disease-specific core outcome sets. The major outcome of the analyses will be to detect variability in treatment effectiveness between patients with different lifestyle characteristics.

ETHICS AND DISSEMINATION

The principle goal of this project is to improve the quality of life of patients suffering from CID by providing evidence to support dietary and other lifestyle recommendations that may improve clinical outcomes. The study is approved by the Ethics Committee (S-20160124) and the Danish Data Protecting Agency (2008-58-035). Study findings will be disseminated through peer-reviewed journals, patient associations and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT03173144; Pre-results.

Rational Management of Iron-Deficiency Anaemia in Inflammatory Bowel Disease

Anaemia is the most frequent, though often neglected, comorbidity of inflammatory bowel disease (IBD). Here we want to briefly present (1) the burden of anaemia in IBD, (2) its pathophysiology, which mostly arises from bleeding-associated iron deficiency, followed by (3) diagnostic evaluation of anaemia, (4) a balanced overview of the different modes of iron replacement therapy, (5) evidence for their therapeutic efficacy and subsequently, (6) an updated recommendation for the practical management of anaemia in IBD. Following the introduction of various intravenous iron preparations over the last decade, questions persist about when to use these preparations as opposed to traditional and other novel oral iron therapeutic agents. At present, oral iron therapy is generally preferred for patients with quiescent IBD and mild iron-deficiency anaemia. However, in patients with flaring IBD that hampers intestinal iron absorption and in those with inadequate responses to or side effects with oral preparations, intravenous iron supplementation is the therapy of choice, although information on the efficacy of intravenous iron in patients with active IBD and anaemia is scare. Importantly, anaemia in IBD is often multifactorial and a careful diagnostic workup is mandatory for optimized treatment. Nevertheless, limited information is available on optimal therapeutic start and end points for treatment of anaemia. Of note, neither oral nor intravenous therapies seem to exacerbate the clinical course of IBD. However, additional prospective studies are still warranted to determine the optimal therapy in complex conditions such as IBD.

Inflammatory Bowel Disease and Small Bowel Cancer Risk, Clinical Characteristics, and Histopathology: A Population-Based Study

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) may increase risk of small bowel cancer (SBC). However, little is known of the characteristics and features of IBD-SBC, due to a low number of cases worldwide. We performed a population-based study of IBD and SBC to calculate risk and increase our understanding of clinical characteristics and histopathological and molecular features.

METHODS

The study population consisted of all individuals aged 16 years or older living in Denmark during 1978-2010. Through linkage between national registers and subsequent scrutiny of medical records and pathology descriptions, we identified 40 cases of IBD-SBC. Risk was calculated by standardized incidence ratio (SIR) (observed/expected); patient characteristics were derived from medical files, and surgery specimens were obtained from hospitals nationwide for histopathological and molecular analyses.

RESULTS

During 241,620 person-years of follow-up, 23 patients with Crohn's disease developed small bowel adenocarcinoma (SIR, 14.38; 95% confidence interval, 8.78-22.20) and 9 developed neuroendocrine tumors (SIR, 6.83; 95% confidence interval, 3.13-12.97). No significantly increased risk of SBC was found among patients with ulcerative colitis. Most patients with SBC had moderate-to-severe Crohn's disease with small bowel and upper gastrointestinal involvement. Assessment of surgical specimens of small bowel adenocarcinomas revealed a clear transition from inflammation to dysplasia and cancer, whereas no tumors had evidence of microsatellite instability.

CONCLUSIONS

In a population-based study of patients in Denmark with IBD and SBC, we found risk of adenocarcinomas and neuroendocrine tumors to be increased among persons with Crohn's disease. Most patients with IBD-SBC had extensive IBD of moderate-to-severe activity. Adenocarcinomas appeared to develop via an inflammation-dysplasia-carcinoma pathway, but differed from IBD-related colorectal adenocarcinomas in their molecular features.

Metabonomics uncovers a reversible proatherogenic lipid profile during infliximab therapy of inflammatory bowel disease

BACKGROUND

One-third of inflammatory bowel disease (IBD) patients show no response to infliximab (IFX) induction therapy, and approximately half of patients responding become unresponsive over time. Thus, identification of potential treatment response biomarkers are of great clinical significance. This study employs spectroscopy-based metabolic profiling of serum from patients with IBD treated with IFX and healthy subjects (1) to substantiate the use of spectroscopy as a semi-invasive diagnostic tool, (2) to identify potential biomarkers of treatment response and (3) to characterise the metabolic changes during management of patients with tumour necrosis factor-α inhibitors.

METHODS

Successive serum samples collected during IFX induction treatment (weeks 0, 2, 6 and 14) from 87 IBD patients and 37 controls were analysed by ¹H nuclear magnetic resonance (NMR) spectroscopy. Data were analysed with principal components analysis and orthogonal projection to latent structures discriminant analysis using SIMCA-P+ v12 and MATLAB.

RESULTS

Metabolic profiles were significantly different between active ulcerative colitis and controls, active Crohn's disease and controls, and quiescent Crohn's disease and controls. Metabolites holding differential power belonged primarily to lipids and phospholipids with proatherogenic characteristics and metabolites in the pyruvate metabolism, suggestive of an intense inflammation-driven energy demand. IBD patients not responding to IFX were identified as a potentially distinct group based on their metabolic profile, although no applicable response biomarkers could be singled out in the current setting.

CONCLUSION

¹H NMR spectroscopy of serum samples is a powerful semi-invasive diagnostic tool in flaring IBD. With its use, we provide unique insights into the metabolic changes taking place during induction treatment with IFX. Of distinct clinical relevance is the identification of a reversible proatherogenic lipid profile in IBD patients with active disease, which partially explains the increased risk of cardiovascular disease associated with IBD.

Characterization of Growth Hormone Resistance in Experimental and Ulcerative Colitis

Growth hormone (GH) resistance may develop as a consequence of inflammation during conditions such as inflammatory bowel disease, encompassing ulcerative colitis (UC). However, the specific role of the GH–insulin growth factor (IGF)-1-axis and/or the functional consequences of GH resistance in this condition are unclear. In situ hybridization targeting the GH receptor (GHR) and relevant transcriptional analyses were performed in patients with UC and in IL-10 knock-out mice with piroxicam accelerated colitis (PAC). Using cultured primary epithelial cells, the effects of inflammation on the molecular mechanisms governing GH resistance was verified. Also, the therapeutic potential of GH on mucosal healing was tested in the PAC model. Inflammation induced intestinal GH resistance in UC and experimental colitis by down-regulating GHR expression and up-regulating suppressor of cytokine signalling (SOCS) proteins. These effects are driven by pro-inflammatory mediators (tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6) as confirmed using primary epithelial cells. Treatment of experimental colitis with GH increased IGF-1 and body weight of the mice, but had no effects on colonic inflammation or mucosal healing. The high transcriptional similarity between UC and experimental colitis accentuates the formation of intestinal GH resistance during inflammation. Inflammation-induced GH resistance not only impairs general growth but induces a state of local resistance, which potentially impairs the actions of GH on mucosal healing during colitis when using long-acting GH therapy.

Impact of feedback and monitoring on colonoscopy withdrawal times and polyp detection rates

Background

Previous studies have shown colonoscopy withdrawal time (WT) to be a reliable surrogate indicator for polyp detection rate (PDR) and adenoma detection rate (ADR) in colonoscopy. Our aim was to assess the impact of feedback and monitoring of WT on PDR in routine colonoscopies with long-term follow-up.

Materials and methods

A total of 307 colonoscopies were performed in three separate clinical scenarios. First, PDR and WT were recorded without the staff being aware of the specific objective of the study. Before the second scenario, the staff was given interventional information and feedback on WTs and PDRs from the first scenario and was encouraged to aim for a minimum WT of 8 min. Retention of knowledge gained was reassessed in the third scenario 1 year later.

Results

The PDR in the first two scenarios differed significantly (p<0.01), with a more than 90% increase in PDR after intervention from 22% to 42% (95% CI 1.44 to 4.95), although the mean WT did not change (6.8 vs 7.2 min; p>0.05). The increase in PDR between the first and second scenarios was retained in the third follow-up scenario 1 year later where the WT of both polyp-positive and polyp-negative colonoscopies was found to be longer.

Conclusions

PDR almost doubled from the first to the second scenario of a real-life colonoscopy setting, indicating that awareness of WT is crucial. The knowledge gained from this intervention in routine practice was even retained after a year.

A Proposal for a Study on Treatment Selection and Lifestyle Recommendations in Chronic Inflammatory Diseases: A Danish Multidisciplinary Collaboration on Prognostic Factors and Personalised Medicine

Chronic inflammatory diseases (CIDs), including Crohn’s disease and ulcerative colitis (inflammatory bowel diseases, IBD), rheumatoid arthritis, psoriasis, psoriatic arthritis, spondyloarthritides, hidradenitis suppurativa, and immune-mediated uveitis, are treated with biologics targeting the pro-inflammatory molecule tumour necrosis factor-α (TNF) (i.e., TNF inhibitors). Approximately one-third of the patients do not respond to the treatment. Genetics and lifestyle may affect the treatment results. The aims of this multidisciplinary collaboration are to identify (1) molecular signatures of prognostic value to help tailor treatment decisions to an individual likely to initiate TNF inhibitor therapy, followed by (2) lifestyle factors that support achievement of optimised treatment outcome. This report describes the establishment of a cohort that aims to obtain this information. Clinical data including lifestyle and treatment response and biological specimens (blood, faeces, urine, and, in IBD patients, intestinal biopsies) are sampled prior to and while on TNF inhibitor therapy. Both hypothesis-driven and data-driven analyses will be performed according to pre-specified protocols including pathway analyses resulting from candidate gene expression analyses and global approaches (e.g., metabolomics, metagenomics, proteomics). The final purpose is to improve the lives of patients suffering from CIDs, by providing tools facilitating treatment selection and dietary recommendations likely to improve the clinical outcome.

Relation between NOD2 genotype and changes in innate signaling in Crohn's disease on mRNA and miRNA levels

Crohn’s disease is associated with an altered innate immune response of pathogenic importance. This altered response can be associated to loss-of-function polymorphisms in the NOD2 (nucleotide-binding oligomerization domain-containing protein 2) gene, but also changes in transcriptional and post-transcriptional regulatory layers, including microRNA activity. Here, we characterized the link between NOD2 genotype and inflammatory-mediated changes in innate signaling by studying transcriptional and post-transcriptional activity in response to NOD2-agonist muramyl dipeptide in monocytes from healthy controls, and Crohn’s disease patients with and without NOD2 loss-of-function polymorphisms. We measured the expression of genes and microRNAs in monocytes from these subjects after stimulation with muramyl dipeptide. Gene expression profiles mainly distinguished the actual muramyl dipeptide response, but not the genotype. A hyper-responsive phenotype was found in Crohn’s disease patients without NOD2 mutations, characterized by upregulated cytokine receptors and general downregulation of microRNA expression. Conversely, microRNA expression could identify genotype-specific differences between subject groups but exhibited little change upon muramyl dipeptide treatment. Only two microRNAs showed muramyl dipeptide-induced response, including miR-155, which was found to regulate multiple genes and whose host gene was one of the highest muramyl dipeptide responders. miR-155 was upregulated in Crohn’s disease patients with NOD2 mutations following lipopolysaccharide and Escherichia coli treatment, but the upregulation was substantially reduced upon muramyl dipeptide treatment. While Crohn’s disease patients with NOD2 mutations on average showed a reduced muramyl dipeptide response, the cohort exhibited large individual variance: a small subset had inflammatory responses almost comparable to wild-type patients on both gene and miR-155 regulatory levels.

The genetics of people with Crohn’s disease affects the molecular drivers of their dysregulated immune responses. Some individuals with Crohn’s harbor mutations in the NOD2 gene, which encodes a pathogen recognition receptor that binds to a molecule called muramyl dipeptide (MDP). To better understand how alternations in NOD2 can lead to increased susceptibility to gut inflammation, Yun Chen, Mohammad Salem and colleagues from the University of Copenhagen and Herlev Hospital, Denmark, analyzed the expression patterns of both genes and small, regulatory microRNAs in blood cells from healthy controls and from Crohn’s patients with and without NOD2 mutations. They exposed the cells to MDP, and saw that although gene acticity changed dramatically as a response, there was little difference between subjects, regardless of genetics. Conversely, microRNA expression showed genotype-specific differences that weren not impacted by MDP treatment. The findings underscore the importance of microRNAs in Crohn’s disease.

An open prospective study evaluating efficacy and safety of a new medical device for rectal application of activated carbon in the treatment of chronic, uncomplicated perianal fistulas

PURPOSE

It has been proposed that biological/chemical substances in the intestine might play a role in the occurrence and deterioration of perianal fistulas. Elimination of such unidentified factors from the lower gastrointestinal tract might offer a new strategy for the management of anal fistulas. The aim of this study was to evaluate the clinical effects on non-Crohn's disease perianal fistula healing, and the safety and tolerability of a new medical device that applies high-purity, high-activity granular activated carbon locally into the rectum twice daily of patients with perianal fistulas without any concomitant medication.

METHODS

An open, single-arm, prospective study with active treatment for 8 weeks and an optional follow-up until week 24 ( ClinicalTrial.gov identifier NCT01462747) among patients with chronic, uncomplicated perianal fistulas scheduled for surgery was conducted.

RESULTS

Of 28 patients included, 10 patients (35.7%) showed complete fistula healing (closed, no discharge on palpation) after 8 weeks; seven of these patients, corresponding to 25% of the enrolled patients, remained in remission for up to 31 weeks. At week 8, there was a statistically significant reduction in the discharge visual analog scale (p = 0.04), a significant improvement in the patient-perceived quality of life for the category of embarrassment (p = 0.002), and a trend toward improvement in the other assessment categories.

CONCLUSIONS

The treatment was well tolerated, and patient acceptance was high. The results support the efficacy and safety of locally administered activated carbon for the treatment of patients with chronic uncomplicated perianal fistulas not receiving any other medication for fistula problems.

Novel Targeted Therapies for Inflammatory Bowel Disease

Our growing understanding of the immunopathogenesis of inflammatory bowel disease (IBD) has opened new avenues for developing targeted therapies. These advances in treatment options targeting different mechanisms of action offer new hope for personalized management. In this review we highlight emerging novel and easily administered therapeutics that may be viable candidates for the management of IBD, such as antibodies against interleukin 6 (IL-6) and IL-12/23, small molecules including Janus kinase inhibitors, antisense oligonucleotide against SMAD7 mRNA, and inhibitors of leukocyte trafficking to intestinal sites of inflammation (e.g., sphingosine 1-phosphate receptor modulators). We also provide an update on the current status in clinical development of these new classes of therapeutics.

Pharmacology and Optimization of Thiopurines and Methotrexate in Inflammatory Bowel Disease

Improving the efficacy and reducing the toxicity of thiopurines and methotrexate (MTX) have been areas of intense basic and clinical research. An increased knowledge on pharmacodynamics and pharmacokinetics of these immunomodulators has optimized treatment strategies in inflammatory bowel disease (IBD). This review focuses on the metabolism and mode of action of thiopurines and MTX, and provides an updated overview of individualized treatment strategies in which efficacy in IBD can be increased without compromising safety. The patient-based monitoring instruments adapted into clinical practice include pretreatment thiopurine S-methyltransferase testing, thiopurine metabolite monitoring, and blood count measurements that may help guiding the dosage to improve clinical outcome. Other approaches for optimizing thiopurine therapy in IBD include combination therapy with allopurinol, 5-aminosalicylates, and/or biologics. Similar strategies are yet to be proven effective in improving the outcome of MTX therapy. Important challenges for the management of IBD in the future relate to individualized dosing of immunomodulators for maximal efficacy with minimal risk of side effects. As low-cost conventional immunomodulators still remain a mainstay in pharmacotherapy of IBD, more research remains warranted, especially to substantiate these tailored management strategies in controlled clinical trials.

Incidence of, phenotypes of and survival from small bowel cancer in Denmark, 1994-2010: a population-based study

BACKGROUND

Small bowel cancer (SBC) is a rare and highly heterogeneous disease in respect to both anatomical distribution and histological morphology. We aimed to conduct a Danish nationwide population-based cohort study of the incidence of, phenotypes of, stage of, synchronous/metachronous cancer occurrence of and survival from SBC during 1994-2010.

METHODS

The study population included all individuals aged 16 years or older living in Denmark during 1994-2010 (n = 7,070,142). Patients with SBC were identified through the Danish Cancer Registry. Incidence rates were calculated overall and according to the anatomical origin and morphological subtype. Patients were followed up from the date of cancer diagnosis to the date of emigration, death or the end of the study (31 December 2010).

RESULTS

SBC was diagnosed in 1088 patients during 1994-2010. The total annual incidence of SBC was 1.10 per 100,000 [95 % confidence interval (CI) 1.04 to 1.17 per 100,000], with an annual percentage change of 1.9 % (95 % CI 0.6-3.1 %, p = 0.003) during the observation period. This increase was mainly explained by an increase in the occurrence of duodenal adenocarcinomas, with an annual percentage change of 7.5 % (95 % CI 4.9-10.2 %, p < 0.001). Further, 29 % of all SBC patients had metastatic cancer at the time of diagnosis and 32 % had one or more synchronous/metachronous cancers. All morphological subtypes were associated with poor 5-year prognoses, in particular duodenal adenocarcinomas, with a 5-year survival rate of only 16 % (95 % CI 12-22 %).

CONCLUSIONS

The incidence of SBC has increased in recent decades, mainly because of a large increase in the incidence of duodenal adenocarcinomas, which are also associated with the poorest prognosis.

Systemic and intestinal levels of factor XIII-A: the impact of inflammation on expression in macrophage subtypes

BACKGROUND

Subunit A of coagulation factor XIII (FXIII-A) is important for clot stability and acts in the subsequent wound healing process. Loss of plasma FXIII-A has been reported after surgery, sepsis, and inflammatory conditions. In the intestinal mucosa, FXIII-A is expressed by macrophages and cellular FXIII-A has been associated with phagocytosis and migration of macrophages. The objective was to evaluate the consequences of intestinal inflammation on resident mucosal macrophages, focusing on the level and distribution of FXIII-A.

METHODS

Plasma and colonic biopsies were collected from 67 patients with ulcerative colitis and controls. Intestinal samples were stained using immunohistochemistry for FXIII-A and macrophages (CD68, CD163 and iNOS). In situ hybridization were used to assess the intestinal expression of FXIII-A. FXIII-A antigen and activity levels were measured in plasma.

RESULTS

Increased infiltration of CD68 positive macrophages in the inflamed mucosa coincided with increased extracellular deposited FXIII-A and decreased expression and intracellular protein levels of FXIII-A. A decreased proportion of FXIII-A/CD68/CD163 triple-positive macrophages was observed in inflamed mucosa, indicating a reduction of the M2 phenotype with consequent loss of FXIII-A. No induction of iNOS positive macrophages was observed. Stimulation of naïve monocytes with physiological concentrations of pro-inflammatory mediators negatively affected the expression of FXIII-A. Measurements in plasma confirmed the loss of both FXIII antigen and activity during active disease.

CONCLUSIONS

Intestinal inflammation in UC induces loss of M2 macrophages with subsequent loss of FXIII-A synthesis. The loss of cellular FXIII-A may impact migration and phagocytosis, and hence limit pathogen eradication in UC.

How genetic testing can lead to targeted management of XIAP deficiency-related inflammatory bowel disease

X-linked lymphoproliferative disease type 2 (XLP-2, OMIM 300635) is a primary immunodeficiency caused by the loss of X chromosome-linked inhibitor of apoptosis (XIAP), the X-linked inhibitor of apoptosis gene at Xq25. XLP-2 individuals are susceptible to several specific and potentially fatal infections, such as Epstein-Barr virus (EBV). Children with XIAP-related XLP-2 may present with either familial hemophagocytic lymphohistiocytosis, often triggered in response to EBV infection, or with a treatment-refractory severe pediatric form of inflammatory bowel disease (IBD) that might be diagnosed as Crohn disease. However, this monogenic cause of IBD is distinct from adult Crohn disease (a polygenic and multifactorial disease) in its etiology and responsiveness to therapy. XLP-2 and the associated IBD symptoms are managed by a reduced-intensity conditioning regimen with an allogeneic hematopoietic stem cell transplantation that causes resolution of gastrointestinal symptoms. Exome sequencing has enabled identification of XIAP-deficient diseased individuals and has altered their morbidity by providing potentially lifesaving strategies in a timely and effective manner. Here, we summarize XLP-2 IBD treatment history and patient morbidity/mortality since its original identification in 2006. Since XLP-2 is rare, cases are probably undergiagnosed or misdiagnosed. Consideration of XLP-2 in children with severe symptoms of IBD can prevent serious morbidities and mortality, avoid unnecessary procedures, and expedite specific targeted therapy.Genet Med 19 2, 133-143.