Inflammatory bowel disease: towards a personalized medicine

MMX mesalamine in ulcerative colitis: Major advantages towards classical mesalamine formulations

Medical therapy is the cornerstone of ulcerative colitis (UC) management and aims to induce and maintain remission. In case of mild-to-moderate UC, mesalamine (5-ASA) is the first-line option. 5-ASA requires local release at the level of the inflamed mucosa to exert its therapeutic action. While rectal preparations are useful in distal colitis, in cases of UC of at least rectosigmoid extent, guidelines suggest the association of oral and rectal 5-ASA. Mesalamine with Multi Matrix System® technology (MMX mesalamine) is an oral, high-strength (1.2 g/tablet), once-daily formulation of 5-ASA, designed to provide delayed and prolonged release throughout the entire colon. Clinical trials demonstrated a strong efficacy in inducing and maintaining clinical and endoscopic remission in active mild-to-moderate UC. The efficacy is related to specific colonic drug-delivery, to its high-dosage and once-daily administration, thus improving patients' adherence and outcomes. The specific colonic-delivery is also associated with very low rates of systemic absorption and adverse events (AEs). With this comprehensive review we aimed to summarize current knowledge on MMX mesalamine in mild-to-moderate UC, in terms of clinical pharmacology, efficacy and safety, also compared to other 5-ASA products. In addition we provided an expert opinion on the topic, examining the implications on clinical practice.

Baseline Expression of Immune Gene Modules in Blood is Associated With Primary Response to Anti-TNF Therapy in Crohn's Disease Patients

BACKGROUND AND AIMS

Anti-tumour necrosis factor [anti-TNF] therapy is widely used for the treatment of inflammatory bowel disease, yet many patients are primary non-responders, failing to respond to induction therapy. We aimed to identify blood gene expression differences between primary responders and primary non-responders to anti-TNF monoclonal antibodies [infliximab and adalimumab], and to predict response status from blood gene expression and clinical data.

METHODS

The Personalised Anti-TNF Therapy in Crohn's Disease [PANTS] study is a UK-wide prospective observational cohort study of anti-TNF therapy outcome in anti-TNF-naive Crohn's disease patients [ClinicalTrials.gov identifier: NCT03088449]. Blood gene expression in 324 unique patients was measured by RNA-sequencing at baseline [week 0], and at weeks 14, 30, and 54 after treatment initiation [total sample size = 814].

RESULTS

After adjusting for clinical covariates and estimated blood cell composition, baseline expression of major histocompatibility complex, antigen presentation, myeloid cell enriched receptor, and other innate immune gene modules was significantly higher in anti-TNF responders vs non-responders. Expression changes from baseline to week 14 were generally of consistent direction but greater magnitude [i.e. amplified] in responders, but interferon-related genes were upregulated uniquely in non-responders. Expression differences between responders and non-responders observed at week 14 were maintained at weeks 30 and 54. Prediction of response status from baseline clinical data, cell composition, and module expression was poor.

CONCLUSIONS

Baseline gene module expression was associated with primary response to anti-TNF therapy in PANTS patients. However, these baseline expression differences did not predict response with sufficient sensitivity for clinical use.

The effectiveness of continuity of care in patients with inflammatory bowel disease: a systematic review

AIM

To investigate the effectiveness of continuity of care in patients with inflammatory bowel disease.

BACKGROUND

The prevalence of inflammatory bowel disease(IBD) is increasing by years, especially in China. Moreover, IBD is prolonged and difficult to heal, which seriously impairs the quality of life of patients. Some studies have identified that continuity of care could contribute to the improvement of the quality of life, but the results remains inconclusive in patients with IBD.

METHODS

PRISMA guidelines was the outline of this study. Review Manager Software (version 5.3) was used to carry out the data analysis. Outcome assessments included quality of life (QoL), remission rates, number of outpatient clinic visits, and medication adherence.

RESULTS

Ultimately, 12 studies involving 2415 patients were brought into this meta-analysis. The results indicated there was no significant difference for continuity of care to improve the QoL in intervention group (SMD = 0.02, 95% CI: -0.08, 0.12). Besides, the remission rates of disease had no difference with those patients in the two groups (OR = 1.07, 95% CI: 0.72, 1.60). However, continued care could contribute to the number of outpatient clinic visits (MD = -0.84, 95% CI: -1.19, -0.49) and patients' adherence to medication significantly (OR = 2.40, 95% CI: 1.16, 4.95).

CONCLUSIONS

IBD patients could benefited from continuity of care with reducing their number of clinic visits and improving medication adherence. Nonetheless, there was no evidence of continuity of care contribute to QoL and remission of disease for these patients.

Telemedicine in inflammatory bowel disease from its origin to the post pandemic golden age: A narrative review

Inflammatory bowel disease (IBD), a chronic intestinal inflammatory disorder encompassing ulcerative colitis and Crohn's disease can be disabling and often requires lifelong treatment and follow-up. Digital health technologies and distance-management tools are less costly alternatives for IBD management and clinical monitoring. This review discusses how telephone/videoconference appointments enable treatment optimization from an early disease stage, provide complementary value-based patient care and educational resources, and allow consistent follow-up with a high standard of care. Replacing/supplementing traditional clinical consultations with telemedicine reduces healthcare utilization costs and the need for in-person consultations. The COVID-19 pandemic has accelerated the evolution of telemedicine in IBD, with several studies conducted since 2020 reporting high levels of patient satisfaction. Home-based injectable formulations coupled with telemedicine may become permanently embedded in healthcare systems in the post-pandemic period. While telemedicine consultations are well-accepted by many patients with IBD, they do not suit all patients or are not preferred (e.g., by elderly who do not have the means or ability to understand the associated technology). Ultimately, use of telemedicine should be decided by the patient and careful consideration is required to ensure that the patient is willing and capable of a successful remote visit.

Baseline Peripheral Blood Mononuclear Cell Transcriptomics Before Ustekinumab Treatment Is Linked With Crohn's Disease Clinical Response at 1 Year

INTRODUCTION

Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin (IL)-12 and IL-23, is used for Crohn's disease (CD), and the documented clinical remission rate after 1 year was observed in approximately 50% of patients. We aimed to identify predictors for a clinical response using peripheral blood obtained from patients with CD just before ustekinumab treatment initiation.

METHODS

RNA extraction from peripheral blood mononuclear cells was followed by mRNA paired-end sequencing. Differential gene expression was performed using DESeq2.

RESULTS

We processed samples from 36 adults with CD (13 men, 36%) obtained at baseline before starting ustekinumab treatment. Twenty-two of 36 (61%) were defined as responders and 14/36 (39%) as nonresponders after 1 year based on Physician Global Assessment. Differential gene expression between responders (n = 22) and nonresponders (n = 14) did not show a gene expression signature that passed false discovery rate (FDR) correction. However, the analyses identified 68 genes, including CXCL1/2/3, which were induced in nonresponders vs responders with P < 0.05 and fold change above 1.5. Functional annotation enrichments of these 68 genes using ToppGene indicated enrichment for cytokine activity (FDR = 1.98E-05), CXCR chemokine receptor binding (FDR = 2.11E-05), IL-10 signaling (FDR = 5.03E-07), genes encoding secreted soluble factors (FDR = 1.73E-05), and myeloid dendritic cells (FDR = 1.80E-08).

DISCUSSION

No substantial differences were found in peripheral blood mononuclear cell transcriptomics between responders and nonresponders. However, among the nonresponders, we noted an increased inflammatory response enriched for pathways linked with cytokine activity and chemokine receptor binding and innate myeloid signature. A larger cohort is required to validate and further explore these findings.

Precision medicine in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease characterized by remission-relapse cycles throughout its course. Both Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of IBD, exhibit tendency to develop complications and substantial heterogeneity in terms of frequency and severity of relapse, thus posing great challenges to the clinical management for IBD. Current treatment strategies are effective in different ways in induction and maintenance therapies for IBD. Recent advances in studies of genetics, pharmacogenetics, proteomics and microbiome provide a strong driving force for identifying molecular markers of prognosis and treatment response, which should help clinicians manage IBD patients more effectively, and then, improve clinical outcomes and reduce treatment costs of patients. In this review, we summarize and discuss precision medicine in IBD, focusing on predictive markers of disease course and treatment response, and monitoring indices during therapeutic drug monitoring.

Epidemiological, Clinical, Patient-Reported and Economic Burden of Inflammatory Bowel Disease (Ulcerative colitis and Crohn's disease) in Spain: A Systematic Review

INTRODUCTION

This study describes the epidemiological, clinical, patient-reported and economic burden of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), in Spain.

METHODS

A systematic review was performed of observational studies reporting the epidemiological, clinical, patient-reported and economic burden of IBD in the Spanish population, from 2011 to 2021. Original articles and conference abstracts published in English or Spanish were eligible.

RESULTS

A total of 45 publications were included in the review. The incidence of IBD in adults ranged from 9.6 to 44.3 per 100,000 inhabitants (4.6 to 18.5 for CD and 3.4 to 26.5 for UC). The incidence increased between 1.5- and twofold from 2000 to 2016 (regionally). Up to 6.0% (CD) and 3.0% (UC) IBD-associated mortality was reported. Disease onset predominantly occurs between 30 and 40 years (more delayed for UC than CD). Most frequently reported gastrointestinal manifestations are rectal bleeding in UC and weight loss in CD. Extraintestinal manifestations (EIM) have been described in up to 47.4% of patients with CD and 48.1% of patients with UC. Psychiatric comorbidities were frequently reported in both CD and UC (depression up to 20% and anxiety up to 11%). Reduced health-related quality of life (HRQoL) compared to the general population was reported. Significant symptomatology was associated with high levels of anxiety, depression, stress and lower HRQoL. Main healthcare resources reported were emergency department visits (24.0%), hospitalization (14.7%), surgery (up to 11%) and use of biologics (up to 60%), especially in CD. Direct and indirect annual costs per patient with UC were €1754.1 and €399.3, respectively.

CONCLUSION

Patients with CD and UC present a high disease burden which negatively impacts their HRQoL, leading to elevated use of resources.

Pretreatment serum monocyte chemoattractant protein-1 as a predictor of long-term outcome by ustekinumab in patients with Crohn's disease

BACKGROUND AND AIMS

Ustekinumab has been proven to be effective for treatment of patients with Crohn's disease; however, 30-40% of patients have been reported to lose clinical response within 2 years. We aimed to evaluate the efficacy of ustekinumab and identify predictors of short-term and long-term efficacy in Crohn's disease.

METHODS

Patients with Crohn's disease receiving their first ustekinumab infusion in our hospital between June 2017 and September 2020 were prospectively enrolled. Concentrations of serum cytokines and chemokines were measured using a multiplex bead array assay.

RESULTS

Fifty-nine Crohn's disease patients were enrolled in this study. Among 34 clinically active patients, 38.2% achieved a clinical response at week 8. None of the assayed factors were associated with short-term clinical response. Cumulative persistence rates of ustekinumab were 77.6% at 1 year and 58.9% at 2 years. Univariate Cox regression analysis revealed that Harvey-Bradshaw Index scores at baseline, concomitant immunomodulator treatment, and concentrations of interferon gamma-induced protein-10, monocyte chemoattractant protein-1 (MCP-1), and interleukin (IL)-1RA, IL-4, IL-6, and IL-8 were significantly associated with loss of efficacy. Multivariate Cox regression analysis found that biologic naïve status (hazard ratio [HR]: 0.1191, 95% confidence interval [CI]: 0.02458-0.5774) and MCP-1 concentrations (HR: 1.038, 95% CI: 1.015-1.062) were significantly and associated with loss of sustained efficacy for ustekinumab treatment.

CONCLUSIONS

Our findings suggest that pretreatment serum MCP-1 analysis, combined with a history of biologic use, could be a novel biomarker for predicting the long-term efficacy of ustekinumab in patients with Crohn's disease.

Current status of novel biologics and small molecule drugs in the individualized treatment of inflammatory bowel disease

Treatment strategies for inflammatory bowel disease (IBD) are rapidly evolving with the development of biologics and small molecule drugs (SMDs). However, these drugs are not guaranteed to be effective in all patients, and a “ceiling effect” of biologic monotherapy may occur. This issue highlights an unmet need for optimizing the use of biologics and predicting therapeutic responses. Thus, the development of new drugs with novel mechanisms of action is urgently needed for patients with primary nonresponse and secondary loss of response to conventional biologics and SMDs. In addition, combining different biologics or SMDs has been proposed as a novel strategy to enhance treatment efficacy in IBD, which theoretically has multidimensional anti-inflammatory potential. Based on the current evidence available for IBD, dual targeted therapy may be a promising strategy for refractory IBD patients who have failed in multiple biologic trea-tments or who have extraintestinal manifestation. Additionally, identifying the subgroup of IBD patients who are responding to biological combination therapies is also equally important in stable disease remission. In this review, we sum-marize the newly developed biologics and SMDs and the current status of bio-logics/SMDs to highlight the development of individualized treatment in IBD.

Early Diagnosis, Early Stratification, and Early Intervention to Deliver Precision Medicine in IBD

Despite huge advances in understanding the molecular basis of IBD, clinical management has continued to rely on a "trial and error" approach. In addition, a therapeutic ceiling has emerged whereby even the most effective interventions are only beneficial for approximately 30% of patients. Consequently, several tools have been developed to aid stratification and guide treatment-decisions. We review the potential application for many of these precision medicine approaches, which are now almost within reach. We highlight the importance of early action (and avoiding inaction) to ensure the best outcomes for patients and how combining early action with precision tools will likely ensure the right treatment is delivered at the right time and place for each individual person living with IBD. The lack of clinical impact to date from precision medicine, despite much hype and investment, should be tempered with the knowledge that clinical translation can take a long time, and many promising breakthroughs might be ready for clinical implementation in the near future. We discuss some of the remaining challenges and barriers to overcome for clinical adoption. We also highlight that early recognition, early diagnosis, early stratification, and early intervention go hand in hand with precision medicine tools. It is the combination of these approaches that offer the greatest opportunity to finally deliver on the promise of precision medicine in IBD.

Management of Non-response and Loss of Response to Anti-tumor Necrosis Factor Therapy in Inflammatory Bowel Disease

Anti-tumor necrosis factor (anti-TNF) therapy has been successfully used as first-line biologic treatment for moderate-to-severe inflammatory bowel disease (IBD), in both “step-up” and “top-down” approaches, and has become a cornerstone of IBD management. However, in a proportion of patients the effectiveness of anti-TNF therapy is sub-optimal. Either patients do not achieve adequate initial response (primary non-response) or they lose response after initial success (loss of response). Therapeutic drug monitoring determines drug serum concentrations and the presence of anti-drug antibodies (ADAbs) and can help guide treatment optimization to improve patient outcomes. For patients with low drug concentrations who are ADAb-negative or display low levels of ADAbs, dose escalation is recommended. Should response remain unchanged following dose optimization the question whether to switch within class (anti-TNF) or out of class (different mechanism of action) arises. If ADAb levels are high and the patient has previously benefited from anti-TNF therapy, then switching within class is a viable option as ADAbs are molecule specific. Addition of an immunomodulator may lead to a decrease in ADAbs and a regaining of response in a proportion of patients. If a patient does not achieve a robust therapeutic response with an initial anti-TNF despite adequate drug levels, then switching out of class is appropriate. In conjunction with the guidance above, other factors including patient preference, age, comorbidities, disease phenotype, extra-intestinal manifestations, and treatment costs need to be factored into the treatment decision. In this review we discuss current evidence in this field and provide guidance on therapeutic decision-making in clinical situations.

Alterations and Potential Applications of Gut Microbiota in Biological Therapy for Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a chronic immune-mediated inflammatory disorder of the gastrointestinal tract that is closely associated with dysbiosis of the intestinal microbiota. Currently, biologic agents are the mainstream therapies for IBD. With the increasing incidence of IBD, limitations of biologic agents have gradually emerged during treatment. Recent studies have indicated that gut microbiota is highly correlated with the efficacy of biologic agents. This review focuses on alterations in both the components and metabolites of gut microbiota during biological therapy for IBD, systematically summarises the specific gut microbiota closely related to the clinical efficacy, and compares current predictive models for the efficacy of biologics, further highlighting the predictive value of intestinal microbiota. Based on the mechanistic analysis of faecal microbiota transplantation (FMT) and biologic agents, a new therapeutic strategy, comprising a combination of FMT and biologics, has been proposed as a promising treatment for IBD with improved efficacy.

A systematic review and functional bioinformatics analysis of genes associated with Crohn's disease identify more than 120 related genes

BACKGROUND

Crohn's disease is one of the two categories of inflammatory bowel diseases that affect the gastrointestinal tract. The heritability estimate has been reported to be 0.75. Several genes linked to Crohn's disease risk have been identified using a plethora of strategies such as linkage-based studies, candidate gene association studies, and lately through genome-wide association studies (GWAS). Nevertheless, to our knowledge, a compendium of all the genes that have been associated with CD is lacking.

METHODS

We conducted functional analyses of a gene set generated from a systematic review where genes potentially related to CD found in the literature were analyzed and classified depending on the genetic evidence reported and putative biological function. For this, we retrieved and analyzed 2496 abstracts comprising 1067 human genes plus 22 publications regarding 133 genes from GWAS Catalog. Then, each gene was curated and categorized according to the type of evidence associated with Crohn's disease.

RESULTS

We identified 126 genes associated with Crohn's disease risk by specific experiments. Additionally, 71 genes were recognized associated through GWAS alone, 18 to treatment response, 41 to disease complications, and 81 to related diseases. Bioinformatic analysis of the 126 genes supports their importance in Crohn's disease and highlights genes associated with specific aspects such as symptoms, drugs, and comorbidities. Importantly, most genes were not included in commercial genetic panels suggesting that Crohn's disease is genetically underdiagnosed.

CONCLUSIONS

We identified a total of 126 genes from PubMed and 71 from GWAS that showed evidence of association to diagnosis, 18 to treatment response, and 41 to disease complications in Crohn's disease. This prioritized gene catalog can be explored at http://victortrevino.bioinformatics.mx/CrohnDisease .

Cytokine responses in nonlesional psoriatic skin as clinical predictor to anti-TNF agents

BACKGROUND

A major issue with the current management of psoriasis is our inability to predict treatment response.

OBJECTIVE

Our aim was to evaluate the ability to use baseline molecular expression profiling to assess treatment outcome for patients with psoriasis.

METHODS

We conducted a longitudinal study of 46 patients with chronic plaque psoriasis treated with anti-TNF agent etanercept, and molecular profiles were assessed in more than 200 RNA-seq samples.

RESULTS

We demonstrated correlation between clinical response and molecular changes during the course of the treatment, particularly for genes responding to IL-17A/TNF in keratinocytes. Intriguingly, baseline gene expressions in nonlesional, but not lesional, skin were the best marker of treatment response at week 12. We identified USP18, a known regulator of IFN responses, as positively correlated with Psoriasis Area and Severity Index (PASI) improvement (P = 9.8 × 10^-4) and demonstrate its role in regulating IFN/TNF responses in keratinocytes. Consistently, cytokine gene signatures enriched in baseline nonlesional skin expression profiles had strong correlations with PASI improvement. Using this information, we developed a statistical model for predicting PASI75 (ie, 75% of PASI improvement) at week 12, achieving area under the receiver-operating characteristic curve value of 0.75 and up to 80% accurate PASI75 prediction among the top predicted responders.

CONCLUSIONS

Our results illustrate feasibility of assessing drug response in psoriasis using nonlesional skin and implicate involvement of IFN regulators in anti-TNF responses.

Tumour necrosis factor inhibitors in inflammatory bowel disease: the story continues

In the 1990s, tumour necrosis factor-α inhibitor therapy ushered in the biologic therapy era for inflammatory bowel disease, leading to marked improvements in treatment options and patient outcomes. There are currently four tumour necrosis factor-α inhibitors approved as treatments for ulcerative colitis and/or Crohn's disease: infliximab, adalimumab, golimumab and certolizumab pegol. Despite the clear benefits of tumour necrosis factor-α inhibitors, a subset of patients with inflammatory bowel disease either do not respond, experience a loss of response after initial clinical improvement or report intolerance to anti-tumour necrosis factor-α therapy. Optimizing outcomes of these agents may be achieved through earlier intervention, the use of therapeutic drug monitoring and thoughtful switching within class. To complement these approaches, evolving predictive biomarkers may help inform and optimize clinical decision making by identifying patients who might potentially benefit from an alternative treatment strategy. This review will focus on the current use of tumour necrosis factor-α inhibitors in inflammatory bowel disease and the application of personalized medicine to improve future outcomes for all patients.

Novel Gut Microbiota Patterns Involved in the Attenuation of Dextran Sodium Sulfate-Induced Mouse Colitis Mediated by Glycerol Monolaurate via Inducing Anti-inflammatory Responses

Inflammatory bowel disease (IBD) is a type of immune-mediated chronic and relapsing inflammatory gastrointestinal symptoms. IBD cannot be completely cured because of the complex pathogenesis. Glycerol monolaurate (GML), naturally found in breast milk and coconut oil, has excellent antimicrobial, anti-inflammatory, and immunoregulatory functions. Here, the protective effect of GML on dextran sodium sulfate (DSS)-induced mouse colitis and the underlying gut microbiota-dependent mechanism were assessed in C57BL/6 mice pretreated or cotreated with GML and in antibiotic-treated mice transplanted with GML-modulated microbiota. Results showed that GML pretreatment has an advantage over GML cotreatment in alleviating weight loss and reducing disease activity index (DAI), colonic histological scores, and proinflammatory responses. Moreover, the amounts of Lactobacillus and Bifidobacterium and fecal propionic acid and butyric acid were elevated only in mice pretreated with GML upon DSS induction. Of note, fecal microbiota transplantation (FMT) from GML-pretreated mice achieved faster and more significant remission of DSS-induced colitis, manifested as reduced DAI, longer colon, decreased histological scores, and enhanced colonic Foxp3+ regulatory T cells (Tregs) and ratio of serum anti-inflammatory/proinflammatory cytokines, as well as the reconstruction of microbial communities, including elevated Helicobacter ganmani and decreased pathogenic microbes. In conclusion, GML-mediated enhancement of Bifidobacterium and fecal short-chain fatty acids (SCFAs) could be responsible for the anticolitis effect. FMT assay confirmed that gut microbiota modulated by GML was more resistant to DSS-induced colitis via elevating beneficial H. ganmani and establishing Treg tolerant phenotype. Importantly, colitis remission induced by GML is associated with novel gut microbiota patterns, even though different microbial contexts were involved. IMPORTANCE The gut microbiota, which can be highly and dynamically affected by dietary components, is closely related to IBD pathogenesis. Here, we demonstrated that food-grade glycerol monolaurate (GML)-mediated enhancement of Bifidobacterium and fecal SCFAs could be responsible for the anticolitis effect. FMT assay confirmed that gut microbiota modulated by GML was more resistant to DSS-induced colitis via elevating beneficial H. ganmani and establishing Treg tolerant phenotype. Collectively, colitis remission induced by GML is associated with novel gut microbiota patterns, even though different microbial contexts were involved, which further provided a perspective to identify specific microbial members and those responsible for the anticolitis effect, such as Bifidobacterium and Helicobacter.

A random forest model predicts responses to infliximab in Crohn's disease based on clinical and serological parameters

BACKGROUND

Infliximab (IFX) has revolutionised the treatment for Crohn's disease (CD) recently, while a part of patients show no response to it at the end of the induction period. We developed a random forest-based prediction tool to predict the response to IFX in CD patients.

METHODS

This observational study retrospectively enrolled the patients diagnosed with active CD and received IFX treatment at the Gastroenterology Department in Xiangya Hospital of Central South University between January 2017 and December 2019. The baseline data were recorded in the beginning and were used as predictor variables to construct models to forecast the outcome of the response to IFX.

RESULTS

Our cohort identified a total of 174 patients finally with a response rate of 29.3% (51/174). The area under the receiver operating characteristic curve (AUC) for the model, based on the random forest was 0.90 (95%CI: 0.82-0.98), compared to the logistic regression model with AUC of 0.68 (95%CI: 0.52-0.85). The optimal cut-off value of the random forest model was 0.34 with the specificity of 0.94, the sensitivity of 0.81 and the accuracy of 0.85. We demonstrated a strong association of IFX response with the levels of complement C3 (C3), high density lipoprotein, serum albumin, Controlling Nutritional Status (CONUT) score and visceral fat area/subcutaneous fat area ratio (VSR).

CONCLUSION

A novel random forest model using the clinical and serological parameters of baseline data was established to identify CD patients with baseline inflammation to achieve IFX response. This model could be valuable for physicians, patients and insurers, which allows individualised therapy.

How to Optimize Treatment With Ustekinumab in Inflammatory Bowel Disease: Lessons Learned From Clinical Trials and Real-World Data

Ustekinumab is a fully human IgG1 monoclonal antibody that has been approved for the treatment of moderate to severe Crohn's disease, and more recently moderate to severe ulcerative colitis. It binds with high affinity to the p40 subunit of human interleukin-12 and 23. This mechanism of action prevents the bioactivity of both interleukins, thus precluding their interaction with the cell surface receptor protein. The pivotal clinical trials (UNITI-1, UNITI-2 and IM-UNITI) demonstrated its clinical efficacy and safety, in naïve patients and also in those previously exposed to immunosuppressants and/or biologics. There is now an extensive experience with its use worldwide, corroborating its favorable profile even in patients with refractory disease. However, the number of medical treatment options available in inflammatory bowel disease are still limited. Hence, we should prioritize the treatments that have a greater probability of response in an individual patient. Our aim was to review and summarize all the available literature regarding the potential predictors of response to ustekinumab that can increase the success rate with this therapy in clinical practice.

IL-1 and CD40/CD40L platelet complex: elements of induction of Crohn's disease and new therapeutic targets

Ulcerative colitis (UC) and Crohn's disease (CD) are chronic and multifactorial diseases that affect the intestinal tract, both characterized by recurrent inflammation of the intestinal mucosa, resulting in abdominal pain, diarrhea, vomiting and, rectal bleeding. Inflammatory bowel diseases (IBD) regroup these two disorders. The exact pathological mechanism of IBD remains ambiguous and poorly known. In genetically predisposed patients, defects in intestinal mucosal barrier are due to an uncontrolled inflammatory response to normal flora. In addition to the genetic predisposition, these defects could be triggered by environmental factors or by a specific lifestyle which is widely accepted as etiological hypothesis. The involvement of the CD40/CD40L platelet complex in the development of IBD has been overwhelmingly demonstrated. CD40L is climacteric in cell signalling in innate and adaptive immunity, the CD40L expression on the platelet cell surface gives them an immunological competence. The IL-1, a major inflammation mediator could be involved in different ways in the development of IBD. Here, we provide a comprehensive review regarding the role of platelet CD40/CD40L in the pathophysiological effect of IL-1 in the development of Crohn's disease (CD). This review could potentially help future approaches aiming to target these two pathways for therapeutic purposes and elucidate the immunological mechanisms driving gut inflammation.

The four epidemiological stages in the global evolution of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a global disease; its evolution can be stratified into four epidemiological stages: Emergence, Acceleration in Incidence, Compounding Prevalence and Prevalence Equilibrium. In 2020, developing countries are in the Emergence stage, newly industrialized countries are in the Acceleration in Incidence stage, and Western regions are in the Compounding Prevalence stage. Western regions will eventually transition to the Prevalence Equilibrium stage, in which the accelerating prevalence levels off as the IBD population ages and possibly as a result of an unexpected rise in mortality during the COVID-19 pandemic. Mitigating the global burden of IBD will require concerted efforts in disease prevention and health-care delivery innovations that respond to changing demographics of the global IBD population. In this Perspective, we summarize the global epidemiology of IBD and use these data to stratify disease evolution into four epidemiological stages.

Review article: how the intestinal microbiota may reflect disease activity and influence therapeutic outcome in inflammatory bowel disease

BACKGROUND

Intestinal bacteria produce metabolites and by-products necessary for homeostasis. Imbalance in this equilibrium is linked to multiple pathologies including inflammatory bowel disease (IBD). The role of the gut microbiota in determining treatment response is becoming apparent, and may act as biomarker for efficacy.

AIM

To describe knowledge about the intestinal microbiota on disease severity and treatment outcomes in IBD METHODS: Descriptive review using PubMed to identify literature on the intestinal microbiota in IBD RESULTS: Severe IBD has a less diverse microbiota with fewer commensal microbiota communities and more opportunistic pathogenic bacteria originating from the oral cavity or respiratory tract. IBD treatments can alter gut microbiota composition, but in vitro/in vivo studies are needed to prove causation. A diversification of the microbiota is observed during remission. Patients with a more diverse baseline microbiome and higher microbial diversity show better response to anti-tumour necrosis factor-α, vedolizumab and ustekinumab therapy. Higher abundance of short chain fatty acid-producing bacteria, fewer mucus-colonising bacteria and lower abundance of pro-inflammatory bacteria have also been associated with a favourable outcome. Predictive models, based on a combination of microbiota, clinical data and serological markers, have good accuracy for treatment outcome and disease severity.

CONCLUSION

The intestinal microbiota in IBD carries a set of promising biomarkers of disease activity and prediction of therapeutic outcome. Current insights may also help in designing microbiota modulation strategies to improve outcomes in IBD.

Discovery and validation of mucosal TNF expression combined with histological score - a biomarker for personalized treatment in ulcerative colitis

Background

There are no accurate markers that can predict clinical outcome in ulcerative colitis at time of diagnosis. The aim of this study was to explore a comprehensive data set to identify and validate predictors of clinical outcome in the first year following diagnosis.

Methods

Treatment naive-patients with ulcerative colitis were included at time of initial diagnosis from 2004 to 2014, followed by a validation study from 2014 to 2018. Patients were treated according to clinical guidelines following a standard step-up regime. Patients were categorized according to the treatment level necessary to achieve clinical remission: mild, moderate and severe. The biopsies were assessed by Robarts histopathology index (RHI) and TNF gene transcripts.

Results

We included 66 patients in the calibration cohort and 89 patients in the validation. Mucosal TNF transcripts showed high test reliability for predicting severe outcome in UC. When combined with histological activity (RHI) scores the test improved its diagnostic reliability. Based on the cut-off values of mucosal TNF and RHI scores from the calibration cohort, the combined test had still high reliability in the validation cohort (specificity 0.99, sensitivity 0.44, PPV 0.89, NPV 0.87) and a diagnostic odds-ratio (DOR) of 54.

Conclusions

The combined test using TNF transcript and histological score at debut of UC can predict severe outcome and the need for anti-TNF therapy with a high level of precision. These validated data may be of great clinical utility and contribute to a personalized medical approach with the possibility of top-down treatment for selected patients.

Fecal Microbiota Transplant in Two Ulcerative Colitis Pediatric Cases: Gut Microbiota and Clinical Course Correlations

Fecal microbiota transplantation (FMT) is a promising strategy in the management of inflammatory bowel disease (IBD). The clinical effects of this practice are still largely unknown and unpredictable. In this study, two children affected by mild and moderate ulcerative colitis (UC), were pre- and post-FMT monitored for clinical conditions and gut bacterial ecology. Microbiota profiling relied on receipts’ time-point profiles, donors and control cohorts’ baseline descriptions. After FMT, the improvement of clinical conditions was recorded for both patients. After 12 months, the mild UC patient was in clinical remission, while the moderate UC patient, after 12 weeks, had a clinical worsening. Ecological analyses highlighted an increase in microbiota richness and phylogenetic distance after FMT. This increase was mainly due to Collinsella aerofaciens and Eubacterium biforme, inherited by respective donors. Moreover, a decrease of Proteus and Blautia producta, and the increment of Parabacteroides, Mogibacteriaceae, Bacteroides eggerthi, Bacteroides plebeius, Ruminococcus bromii, and BBacteroidesovatus were associated with remission of the patient’s condition. FMT results in a long-term response in mild UC, while in the moderate form there is probably need for multiple FMT administrations. FMT leads to a decrease in potential pathogens and an increase in microorganisms correlated to remission status.

Real-world use of therapeutic drug monitoring of CT-P13 in patients with inflammatory bowel disease: A 12-month prospective observational cohort study

BACKGROUND

Whether therapeutic drug monitoring (TDM) of infliximab should be implemented in daily practice is an ongoing controversy.

AIMS

To assess the real-world use of TDM in an observational multicentre cohort study with consecutive patients with inflammatory bowel disease (IBD) treated with CT-P13.

METHODS

Between September 2015 and December 2016, 364 patients with IBD were treated with CT-P13 in 13 gastroenterology departments and were followed up for 54 weeks. Disease activity, CT-P13 trough concentration and anti-CT-P13 antibody (ACA) were recorded.

RESULTS

Steroid-free clinical remission rates at week 54 were 67.0% and 56.4% in patients with CD and UC, respectively. CT-P13 trough concentrations were measured in 70.7% of the patients. The mean CT-P13 trough concentration was 4.2±4.3μg/mL. The presence of ACA was observed in 53 (15.9%) patients. CT-P13 trough concentration was collected in a proactive approach in 62.8% of cases and in a reactive approach in 37.2%. Among patients who submitted to TDM, CT-P13 therapy was optimized in 88.7% of the reactive group and in 22.5% of the proactive group (P<0.001).

CONCLUSION

In a real-world cohort of patients with IBD treated with CT-P13, more than two-thirds of the patients underwent TDM. CT-P13 optimization was much less common in the proactive approach than in the reactive approach.

Patient's profiling for therapeutic management of inflammatory bowel disease: a tailored approach

Introduction: Several biological drugs and a new small molecule are available for the treatment of Crohn's disease and ulcerative colitis. However, to date, no reliable predictors of response to treatment have yet been identified. Areas covered: We focused on studies evaluating the therapeutic management of patients with chronic inflammatory bowel diseases in order to identify any predictive factors of response to drugs and to guide therapeutic decisions based on patient and disease characteristics. Expert opinion: The heterogeneity of literature data, the main retrospective nature of the scientific evidence, and the lack of comparative head-to-head trials are the most relevant limitations for identifying factors predicting drug response. In the near future, a personalized approach to patients with chronic inflammatory diseases will be based on patient's profile to define not only the best drug to use, but also the appropriate follow-up, and the possibility of home care.

Predictors of Primary Response to Biologic Treatment [Anti-TNF, Vedolizumab, and Ustekinumab] in Patients With Inflammatory Bowel Disease: From Basic Science to Clinical Practice

BACKGROUND

Inflammatory bowel diseases [IBD]-ulcerative colitis and Crohn's disease-are commonly treated with biologic drugs. However, only approximately two-thirds of patients have an initial response to these therapies. Personalised medicine has the potential to optimise efficacy, decrease the risk of adverse drug events, and reduce costs by establishing the most suitable therapy for a selected patient.

AIM

The present study reviews the potential predictors of short-term primary response to biologic treatment, including not only anti-tumour necrosis factor [TNF] agents [such as infliximab, adalimumab, certolizumab, and golimumab] but also vedolizumab and ustekinumab.

METHODS

We performed a systematic bibliographical search to identify studies investigating predictive factors of response to biologic therapy.

RESULTS

For anti-TNF agents, most of the evaluated factors have not demonstrated usefulness, and many others are still controversial. Thus, only a few factors may have a potential role in the prediction of the response, including disease behaviour/phenotype, disease severity, C-reactive protein, albumin, cytokine expression in serum, previous anti-TNF therapy, some proteomic markers, and some colorectal mucosa markers. For vedolizumab, the availability of useful predictive markers seems to be even lower, with only some factors showing a limited value, such as the expression of α4β7 integrin in blood, the faecal microbiota, some proteomic markers, and some colorectal mucosa markers. Finally, in the case of ustekinumab, no predictive factor has been reported yet to be helpful in clinical practice.

CONCLUSION

In summary, currently no single marker fulfils all criteria for being an appropriate prognostic indicator of response to any biologic treatment in IBD.

Predicted efficacy of a pharmacogenetic passport for inflammatory bowel disease

BACKGROUND

High inter-individual variability in therapeutic response to drugs used in the management of Inflammatory Bowel Disease (IBD) leads to high morbidity and high costs. Genetic variants predictive of thiopurine-induced myelosuppression, thiopurine-induced pancreatitis and immunogenicity of Tumour Necrosis Factor alpha (TNFα) antagonists have been identified, but uptake of pre-treatment pharmacogenetic testing into clinical guidelines has been slow.

AIM

To explore the efficacy of a pharmacogenetic passport for IBD that includes multiple pharmacogenetic predictors of response.

METHODS

Patients with IBD exposed to thiopurines and/or TNFα antagonists were retrospectively evaluated for the presence of thiopurine toxicity and/or immunogenicity of TNFα antagonists. All patients were genotyped using both whole-exome sequencing and the Illumina Global Screening Array. An in-house-developed computational pipeline translated genetic data into an IBD pharmacogenetic passport that predicted risks for thiopurine toxicity and immunogenicity of TNFα antagonists per patient. Using pharmacogenetic-guided treatment guidelines, we calculated clinical efficacy estimates for pharmacogenetic testing for IBD.

RESULTS

Among 710 patients with IBD exposed to thiopurines and/or TNFα antagonists, 150 adverse drug responses occurred and our pharmacogenetic passport would have predicted 54 (36%) of these. Using a pharmacogenetic passport for IBD that includes genetic variants predictive of thiopurine-induced myelosuppression, thiopurine-induced pancreatitis, and immunogenicity of TNFα antagonists, 24 patients need to be genotyped to prevent one of these adverse drug responses.

CONCLUSIONS

This study highlights the clinical efficacy of a pharmacogenetic passport for IBD. Implementation of such a pharmacogenetic passport into clinical management of IBD may contribute to a reduction in adverse drug responses.

Usefulness of therapeutic drug monitoring of infliximab during the induction period in patients with inflammatory bowel disease

INTRODUCTION

previous studies have shown that higher infliximab trough levels are associated with favorable short-term and long-term therapeutic outcomes in inflammatory bowel disease. There is a need to determine which patients could benefit from proactive therapeutic drug monitoring in the induction phase. The aim of this study was to evaluate the pharmacokinetic variability of infliximab, determine the factors associated with achieving target infliximab trough levels in the induction phase and analyze the clinical and biochemical response at week 26 of treatment.

PATIENTS AND METHODS

a retrospective observational study was performed of patients with inflammatory bowel disease and data available on serum levels of infliximab during the induction period. The percentage of patients that achieved target infliximab trough levels at week 6 was determined. Clinical remission and response and biochemical remission were evaluated at week 26.

RESULTS

thirty patients were included and only 13 (43.3 %) had infliximab trough levels > 15 µg/mL at week 6. A clinical response was observed during the maintenance period in 71.4 % of patients, their infliximab levels were significantly higher than in non-responders (6.3 µg/mL [IQR: 6.7] vs 1.0 µg/mL [IQR: 5.0], respectively; p = 0.016). Likewise, 53.6 % of patients achieved biochemical remission (responders 6.2 µg/mL [IQR: 5.2] vs non-responders 3.2 µg/mL [IQR: 5.0]; p = 0.031).

CONCLUSION

less than half of patients had target infliximab levels during the induction period. Therapeutic drug monitoring during this period is related to the achievement of therapeutic levels of infliximab and may lead to a better clinical response in these patients.

Plasma Oncostatin M, TNF-α, IL-7, and IL-13 Network Predicts Crohn's Disease Response to Infliximab, as Assessed by Calprotectin Log Drop

BACKGROUND

Cytokines emerge as possible biomarkers of response in Crohn's disease (CD). We aimed to determine the plasmatic cytokine profiles of active CD patients who started infliximab (IFX) treatment and their capacity to predict the response to IFX.

METHODS

A total of 30 active CD patients receiving an induction therapy of IFX were enrolled in the study. Peripheral blood samples pretreatment were collected. Concentrations of 15 cytokines were measured by Luminex technology. Responses to IFX were evaluated by the drop in fecal calprotectin based on its logarithm-transformed values. A random forest (RF) predictive model was used for data analyses.

RESULTS

Samples of 22 patients were analyzed. The RF model ranked the following cytokines as the top predictors of the response: tumor necrosis factor alpha (TNFα), interleukin (IL)-13, oncostatin M (OSM), and IL-7 (p < 0.005). Partial dependency plots showed that high levels of IL-13 pretreatment, low TNFα levels, and low IL-7 levels were associated with a favorable IFX response. Increased levels of OSM and TNFα predicted unfavorable responses to IFX.

CONCLUSIONS

We here show that a log drop in calprotectin strongly correlates with clinical parameters and it can be proposed as a useful objective clinical response predictor. Plasma TNFα, IL-13, Il-7, and OSM network could predict CD response to IFX before induction therapy, as assessed by calprotectin log drop.

Real-World Experience with AGA Guidelines in the Management of Crohn's Disease following Ileocolonic Resection: A Retrospective Cohort Study

BACKGROUND

Postoperative endoscopic recurrence (PER) is common in patients with Crohn's disease (CD) after surgery. The impact of the American Gastroenterological Association (AGA) guideline adherence on PER in real life remains unclear.

METHODS

The postoperative management of CD patients undergoing ileocolonic resection with anastomosis from 2017 to 2018 was conducted based on the AGA guidelines. Colonoscopies were performed within one year after surgery. Clinical data and risk factors for endoscopic recurrence were analyzed focusing on postoperative pharmacological prophylaxis.

RESULTS

All patients were at a high risk of postoperative recurrence according to the AGA guidelines. PER occurred in 29 (28.7%) of these patients. The overall PER rate was 39.2% at one year. The PER rate in patients treated with nitroimidazole, thiopurines, infliximab, or a combination of thiopurines and infliximab for postoperative prophylaxis was 88.1%, 34.1%, 20.5%, and 0%, respectively. Cox regression showed that smoking at the time of surgery and AGA guideline adherence were independent factors associated with PER (HR: 3.75, 95% CI: 1.36-10.33, P = 0.01; HR: 0.36, 95% CI: 0.15-0.86, P = 0.02). In addition, further investigation revealed that educational background was the main factor related to patients' nonadherence to AGA guidelines.

CONCLUSIONS

The majority of CD patients who undergo surgery in clinical practice may be at a high risk of disease recurrence. Thiopurines and infliximab are effective in preventing endoscopic recurrence. Guideline nonadherence is associated with PER at one year, thus indicating that there is room for improvement in adherence to the AGA guidelines.

Oral Delivery of Biologics for Precision Medicine

The emerging field of precision medicine is rapidly growing, fostered by the advances in genome mapping and molecular diagnosis. In general, the translation of these advances into precision treatments relies on the use of biological macromolecules, whose structure offers a high specificity and potency. Unfortunately, due to their complex structure and limited ability to overcome biological barriers, these macromolecules need to be administered via injection. The scientific community has devoted significant effort to making the oral administration of macromolecules plausible thanks to the implementation of drug delivery technologies. Here, an overview of the current situation and future prospects in the field of oral delivery of biologics is provided. Technologies in clinical trials, as well as recent and disruptive delivery systems proposed in the literature for local and systemic delivery of biologics including peptides, antibodies, and nucleic acids, are described. Strategies for the specific targeting of gastrointestinal regions-stomach, small bowel, and colon-cell populations, and internalization pathways, are analyzed. Finally, challenges associated with the clinical translation, future prospects, and identified opportunities for advancement in this field are also discussed.

Etiology and Management of Lack or Loss of Response to Anti-Tumor Necrosis Factor Therapy in Patients With Inflammatory Bowel Disease

The management of patients with moderate to severe inflammatory bowel disease was transformed with the arrival of anti-tumor necrosis factor (TNF) therapy. Nevertheless, a considerable number of patients do not respond to anti-TNF induction therapy (primary nonresponse) or lose response to treatment over time after initially experiencing clinical improvement (secondary loss of response). Studies suggest that these outcomes are often due to inadequate drug concentrations. Therapeutic drug monitoring (TDM) is a practical tool that can be used to better define the etiologies of and help manage primary nonresponse or secondary loss of response. Proactive TDM, or drug titration to a target trough concentration, can improve the efficacy of anti-TNF treatment and lead to favorable clinical outcomes. However, in patients with adequate anti-TNF drug concentrations and active disease, alternate pathways of inflammation (not driven by TNFa agents) are at play, and therapies with another mechanism of action should be employed.

Review article: the genetics of the human leucocyte antigen region in inflammatory bowel disease

BACKGROUND

The human leucocyte antigen (HLA) complex, located at chromosome 6p21.3 is a highly polymorphic region containing the classical class I and II HLA genes. The region is highly associated with inflammatory bowel disease (IBD), largely through genome-wide association studies (GWAS).

AIMS

To review the role of HLA in immune function, summarise data on risk/protective HLA genotypes for IBD, discuss the role of HLA in IBD pathogenesis, treatment and examine limitations that might be addressed by future research.

METHODS

An organised search strategy was used to collate articles describing HLA genes in IBD, including Crohn's disease and ulcerative colitis.

RESULTS

All classical HLA genes with variation (including HLA-A, B, C, DRB1, DQA1, DQB1, DPA1 and DPB1) harbour IBD-associated genotypes. The most implicated gene is HLA-DRB1, with HLA-DRB1*03:01 the most associated risk allele in both Crohn's disease and ulcerative colitis. Elucidating precise disease associations is challenging due to high linkage disequilibrium between HLA genotypes. The mechanisms by which risk alleles cause disease are multifactorial, with the best evidence indicating structural and electrostatic alteration impacting antigen binding and downstream signalling. Adverse medication events have been associated with HLA genotypes including with thiopurines (pancreatitis) and anti-TNF agents (antibody formation).

CONCLUSIONS

The HLA complex is associated with multiple risk/protective alleles for IBD. Future research utilising long-read technology, ascertainment of zygosity and integration in disease modelling will improve the functional understanding and clinical translation of genetic findings.

The use of Tofacitinib in the treatment of inflammatory bowel disease

Major advances in pharmacology of the 21st century include the development of a new class of drugs, which are low-molecular, chemically synthesized molecules (the so-called "small molecules"), the point of application of which is Janus kinase (Janus kinase, JAK) involved in intracellular cytokine signaling. The review examines the molecular aspects of the JAK-STAT signaling pathway, justifying the use of the JAK-kinase inhibitor (tofacitinib) in the treatment of inflammatory bowel disease.

De-escalation of IBD Therapy: When, Who, and How?

When patients with inflammatory bowel disease reach clinical remission with biologic therapy, a question that often comes up is, “when can I stop my biologic medication?” This is a question fraught with challenges for both physicians and patients. For physicians, there are valid concerns that stepping down from a successful therapy will lead to relapse and disease exacerbation, and that stepping down could lead to anti-biologic antibodies. For patients, the question is often driven by concerns about long-term side effects and costs of biologics. This review provides an overview of the rationale for, and risks of, withdrawal of IBD therapy. Selected studies have shown how to identify subsets of patients in whom de-escalation can be performed with low risk of relapse. Practical guidance on when and how to de-escalate IBD therapy is provided.

Mucosal IL13RA2 expression predicts nonresponse to anti-TNF therapy in Crohn's disease

BACKGROUND

Ileocolonic expression of IL13RA2 has been identified as a predictive marker for nonresponsiveness to infliximab (IFX) in patients with Crohn's disease (CD).

AIM

To validate the IL13RA2 biomarker, study its anti-TNF specificity and get a better understanding of the underlying biology driving its expression.

METHODS

IL13RA2 mucosal expression was studied in a cohort of adalimumab and vedolizumab treated patients. To identify the upstream regulators of anti-TNF nonresponsiveness, weighted gene co-expression network analysis was applied on publicly available microarray data of IFX-treated patients. Selected serum proteins, including TNF, were measured prior to first IFX exposure and compared between healers and nonhealers.

RESULTS

Increased mucosal IL13RA2 expression prior to start of biological therapy was predictive for anti-TNF nonresponsiveness specifically (AUROC, area under the curve = 0.90, P < 0.001 in anti-TNF vs AUROC = 0.63, P = 0.30 in vedolizumab treated patients). In baseline biopsies, TNF-driven pathways were significantly enriched in future anti-TNF nonhealers (P = 5.0 × 10^-34 ). We found an increased baseline mucosal TNF burden in nonhealers (P = 0.02), and TNF mRNA correlated significantly with IL13RA2 expression (ρ = 0.55, P = 0.02). Baseline serum TNF levels were significantly lower in nonhealers (P = 0.04), and correlated inversely with IFX serum induction levels (r = -0.45, P = 0.002 at week 6).

CONCLUSIONS

Increased mucosal IL13RA2 expression is associated with an increased mucosal TNF burden in CD patients. In view of its specificity for prediction of anti-TNF therapy resistance, mucosal IL13RA2 expression is a potential biomarker for therapy selection and/or for the need of increased anti-TNF drug dosing.

Low TREM1 expression in whole blood predicts anti-TNF response in inflammatory bowel disease

Background

With the changed therapeutic armamentarium for Crohn's disease (CD) and ulcerative colitis (UC), biomarkers predicting treatment response are urgently needed. We studied whole blood and mucosal expression of genes previously reported to predict outcome to anti-TNF therapy, and investigated if the signature was specific for anti-TNF agents.

Methods

We prospectively included 54 active IBD patients (24CD, 30UC) initiating anti-TNF therapy, as well as 22 CD patients initiating ustekinumab and 51 patients initiating vedolizumab (25CD, 26UC). Whole blood expression of OSM, TREM1, TNF and TNFR2 was measured prior to start of therapy using qPCR, and mucosal gene expression in inflamed biopsies using RNA-sequencing. Response was defined as endoscopic remission (SES-CD ≤ 2 at week 24 for CD and Mayo endoscopic sub-score ≤ 1 at week 10 for UC).

Findings

Baseline whole blood TREM1 was downregulated in future anti-TNF responders, both in UC (FC = 0.53, p = .001) and CD (FC = 0.66, p = .007), as well as in the complete cohort (FC = 0.67, p < .001). Receiver operator characteristic statistics showed an area under the curve (AUC) of 0.78 (p = .001). A similar accuracy could be achieved with mucosal TREM1 (AUC 0.77, p = .003), which outperformed the accuracy of serum TREM1 (AUC 0.58, p = .31). Although differentially expressed in tissue, OSM, TNF and TNFR2 were not differentially expressed in whole blood. The TREM1 predictive signal was anti-TNF specific, as no changes were seen in ustekinumab and vedolizumab treated patients.

Interpretation

We identified low TREM-1 as a specific biomarker for anti-TNF induced endoscopic remission. These results can aid in the selection of therapy in biologic-naïve patients.

Personalising medicine in inflammatory bowel disease-current and future perspectives

Up to 25% of inflammatory bowel disease (IBD) presents during childhood, often with severe and extensive disease, leading to significant morbidity including delayed growth and nutritional impairment. The classical approach to management has centred on differentiation into Crohn's disease (CD) or ulcerative colitis (UC), with subsequent treatment based on symptoms, results and complications. However, IBD is a heterogeneous condition with substantial variation in phenotype, disease course and outcome, so whilst effective treatment exists one size does not fit all. The ability to predict disease course at diagnosis, alongside tailoring medications based on response gives the potential for a more 'personalised approach'. The move to a pre-emptive strategy to prevent IBD-related complications, whilst simultaneously minimising side effects and long-term toxicity from therapy, particularly in those with relatively indolent disease, has the potential to revolutionise care. In very early-onset IBD, personalised approaches to diagnosis and management have become the standard of treatment enabling clinicians to significantly alter the outcomes of the few children with monogenic disease. However, the promise of discoveries in genomics, microbiome and transcriptomics in paediatric IBD has not yet translated to clinical application for the vast majority of patients. Despite this, the opportunity presents itself to apply data gathered at diagnosis and follow-up to predict which patients are likely to progress to complicated disease, which will respond well and which will require additional therapy. Using complex mathematics and innovative, cutting-edge machine learning (ML) techniques gives the potential to use this data to develop personalised clinical care algorithms to treat patients more effectively, reduce toxicity and improve outcome. In this review, we will consider current management of paediatric IBD, discuss how precision medicine is making inroads into clinical practice already, examine the contemporary studies applying data to stratify patients and explore how future management may be revolutionised by personalisation with clinical, genomic and other multi-omic data.

Effects of Epithelial IL-13Rα2 Expression in Inflammatory Bowel Disease

Background: Mucosal IL-13 Receptor alpha 2 (IL13RA2) mRNA expression is one of the best predictive markers for primary non-responsiveness to infliximab therapy in patients with inflammatory bowel disease (IBD). The objective of this study was to understand how IL-13Rα2, a negative regulator of IL-13 signaling, can contribute to IBD pathology. Methods:IL13RA2 knockout (KO) and wild type (WT) mice were exposed to dextran sodium sulfate (DSS) in drinking water to induce colitis. Furthermore, mucosal biopsies and resection specimen of healthy individuals and IBD patients before the start of anti-tumor necrosis factor (anti-TNF) therapy were obtained for immunohistochemistry and gene expression analysis. Results: After induction of DSS colitis, IL13RA2 KO mice had similar disease severity, but recovered more rapidly than WT animals. Goblet cell numbers and mucosal architecture were also more rapidly restored in IL13RA2 KO mice. In mucosal biopsies of active IBD patients, immunohistochemistry revealed that IL-13Rα2 protein was highly expressed in epithelial cells, while expression was restricted to goblet cells in healthy controls. Mucosal IL13RA2 mRNA negatively correlated with mRNA of several goblet cell-specific and barrier genes, and with goblet cell numbers. Conclusions: The data suggest that IL-13Rα2 on epithelial cells contributes to IBD pathology by negatively influencing goblet cell recovery, goblet cell function and epithelial restoration after injury. Therefore, blocking IL-13Rα2 could be a promising target for restoration of the epithelial barrier in IBD.

A Bronze-Tomato Enriched Diet Affects the Intestinal Microbiome under Homeostatic and Inflammatory Conditions

Inflammatory bowel diseases (IBD) are debilitating chronic inflammatory disorders that develop as a result of a defective immune response toward intestinal bacteria. Intestinal dysbiosis is associated with the onset of IBD and has been reported to persist even in patients in deep remission. We investigated the possibility of a dietary-induced switch to the gut microbiota composition using Winnie mice as a model of spontaneous ulcerative colitis and chow enriched with 1% Bronze tomato. We used the near isogenic tomato line strategy to investigate the effects of a diet enriched in polyphenols administered to mild but established chronic intestinal inflammation. The Bronze-enriched chow administered for two weeks was not able to produce any macroscopic effect on the IBD symptoms, although, at molecular level there was a significant induction of anti-inflammatory genes and intracellular staining of T cells revealed a mild decrease in IL17A and IFNγ production. Analysis of the microbial composition revealed that two weeks of Bronze enriched diet was sufficient to perturb the microbial composition of Winnie and control mice, suggesting that polyphenol-enriched diets may create unfavorable conditions for distinct bacterial species. In conclusion, dietary regimes enriched in polyphenols may efficiently support IBD remission affecting the intestinal dysbiosis.

Reproducing the human mucosal environment ex vivo: inflammatory bowel disease as a paradigm

PURPOSE OF REVIEW

The medical management of inflammatory bowel disease (IBD) remains problematic with a pressing need for innovation in drug development as well as delivery of personalized therapies. Both the disease's inherent pathophysiologic complexity and heterogeneity in its etiology conspire in making it difficult to accurately model for either the purposes of basic research or drug development. Multiple attempts at creating meaningful experimental models have fallen short of adequately recapitulating the disease and most do not capture any aspect of the cause or the effects of patient heterogeneity that underlays most of the difficulties faced by physicians and their patients. In vivo animal models, tissue culture systems, and more recent synthetic biology approaches are all too simplistically reductionist for the task. However, ex vivo culture platforms utilizing patient biopsies offer a system that more closely mimics end-stage disease processes that can be studied in detail and subjected to experimental manipulations.

RECENT FINDINGS

Recent studies describe further optimization of mucosal explant cultures in order to increase tissue viability and maintain a polarized epithelial layer. Current applications of the platform include studies of the interplay between the epithelial, immune and stromal compartment of the intestinal tissue, investigation of host-microbial interactions, preclinical evaluation of candidate drugs and uncovering mechanisms of action of established or emerging treatments for IBD.

SUMMARY

Patient explant-based assays offer an advanced biological system in IBD that recapitulates disease complexity and reflects the heterogeneity of the patient population. In its current stage of development, the system can be utilized for drug testing prior to the costlier and time-consuming evaluation by clinical trials. Further refinement of the technology and establishment of assay readouts that correlate with therapeutic outcomes will yield a powerful tool for personalized medicine approaches in which individual patient responses to available treatments are assessed a priori, thus reducing the need for trial and error within the clinical setting.

Proteomics and Lipidomics in Inflammatory Bowel Disease Research: From Mechanistic Insights to Biomarker Identification

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. Ulcerative colitis and Crohn's disease are the major manifestations of IBD. While our understanding of IBD has progressed in recent years, its etiology is far from being fully understood, resulting in suboptimal treatment options. Complementing other biological endpoints, bioanalytical "omics" methods that quantify many biomolecules simultaneously have great potential in the dissection of the complex pathogenesis of IBD. In this review, we focus on the rapidly evolving proteomics and lipidomics technologies and their broad applicability to IBD studies; these range from investigations of immune-regulatory mechanisms and biomarker discovery to studies dissecting host⁻microbiome interactions and the role of intestinal epithelial cells. Future studies can leverage recent advances, including improved analytical methodologies, additional relevant sample types, and integrative multi-omics analyses. Proteomics and lipidomics could effectively accelerate the development of novel targeted treatments and the discovery of complementary biomarkers, enabling continuous monitoring of the treatment response of individual patients; this may allow further refinement of treatment and, ultimately, facilitate a personalized medicine approach to IBD.

A Noninvasive Method to Assess Mucosal Healing in Patients* With Crohn's Disease

Ongoing inflammation in the gastrointestinal tract and loss of the mucosal barrier are key components of Crohn's disease. Current treatment paradigms, including treat-to-target, are based on improvement of both clinical and endoscopic symptoms. Endoscopy is an essential tool for the evaluation of mucosal healing, but patients may be reluctant to undergo repeated procedures. Surrogate markers of inflammation, such as C-reactive protein and fecal calprotectin, are being used, yet they have several limitations in the assessment of mucosal healing. A new strategy, known as the Monitr test, assesses mucosal healing status by evaluating serum levels of 13 biomarkers in patients with Crohn's disease. The 13 biomarkers are associated with cell adhesion, inflammation, angiogenesis, extracellular matrix remodeling, cell proliferation and repair, and immune cell recruitment. Monitr testing yields a mucosal healing index score that reflects disease severity. Validation of the test showed an overall accuracy of 90%, with a negative predictive value of 92% and a positive predictive value of 87% for identifying patients with endoscopic evidence of Crohn's disease. Use of this noninvasive test may aid in the monitoring and management of patients with Crohn's disease, while potentially reducing the need for repeated endoscopy.

Evaluation of IL-12A, IL-12B, IL-23A and IL-27 mRNA expression level genes in peripheral mononuclear cells of inflammatory bowel disease patients in an Iranian population

AIM

Aim of this study was to compare the gene expression of Interleukin 12 members in two phase of IBD.

BACKGROUND

Inflammatory bowel disease (IBD) is a well-known gastrointestinal disorder in the world that fluctuates between remission and flare-up phases. Each of these phases has an individual immune system response profile. Therefore, analyzing the interleukins (IL) expression status improves the diagnosis and the classification of the IBD cases.

METHODS

In this a case-control study, among 400 patients whom admitted to the IBD clinic, forty nine IBD patients were included. Patients were divided into three categories based on 1) the phase of the disease, 2) the type of IBD, Ulcerative colitis (UC) or Crohn's disease (CD), and 3) the therapeutic pathways. Using the real-time PCR method, the expression levels of IL-12A, IL-12B, IL-23A, and IL-27 were examined in the peripheral blood mononuclear cell (PBMC) and compared to the pre-described subgroups.

RESULTS

the data showed upregulation in the expression levels of IL-12A and IL-12B in the remission phase in comparison with the flare-up. However, no significant changes were obtained from the evaluation of IL-23A and IL-27. In addition, the mRNA levels of the target genes in the subgroups of Category 2 as well as Category 3 were similar.

CONCLUSION

Our results showed that expression patterns of the IL-12A and IL-12B genes varied between the remission and flare-up phases for the IBD patients, and may be considered as potential biomarkers for the detection and the classification of IBD cases.