An analysis of factors influencing short-term and sustained response to infliximab treatment for Crohn's disease

A nomogram to predict stoma creation in elective surgical resection for penetrating Crohn's disease

BACKGROUNDS

The decision to perform a stoma during surgical resection of penetrating Crohn's disease (CD) is a critical consideration. The objective of this study was to identify factors that influence stoma creation and develop a predictive nomogram model to assist surgeons in making optimal surgical decisions.

METHODS

A retrospective study was conducted at a tertiary center from December 1, 2012, to December 1, 2021, involving consecutive patients with penetrating CD who underwent elective surgical resection. The LASSO regression method was used to select preoperative predictors, and a nomogram was constructed using multivariate logistic regression. The performance of the nomogram was validated in an internal cohort by assessing its discrimination, calibration, and clinical usefulness.

RESULTS

The study included 405 cases in the training group and 135 cases in the validation group. Nine risk factors for stoma formation were identified, including disease location, fistula resulted from previous anastomosis, absence of preoperative exclusive enteral nutrition support, albumin levels below 35 g/L, C-reactive protein levels above 10 mg/L, hemoglobin levels below 100 g/L, perianal disease, internal fistula, and surgical approach. These risk factors were selected using the LASSO regression method, and a nomogram was developed based on them. The area under the curve and the coefficient of determination (R2) of the nomogram were 0.821 and 0.394, respectively. And the nomogram demonstrated good performance in the validation cohort.

CONCLUSIONS

The nomogram exhibited good predictive ability for stoma formation during elective surgical resection for penetrating CD, which can assist surgeons in making informed clinical decisions.

Apoptosis and inflammatory genes variants in primary non-response to anti-TNF therapy in Crohn's disease patients

Anti-TNF therapy has indeed revolutionized the treatment of Crohn's disease, leading to higher rates of response and remission in patients. However, a significant proportion of 20-40% of patients do not respond to the initial therapy, others experience a secondary loss of response with ongoing treatment. Adverse drug reactions also occur in some patients. The effectiveness of anti-TNF treatment may be influenced by genetic variability, including FCGR3A, ADAM17, TNFRSF1A, TNFRSF1B, FAS, FASL, IL1B, CASP9 , and MIF genes. In this article, we provide an overview of the current knowledge and findings in the pharmacogenetics of anti-TNF drugs in CD focusing on the aspect of apoptosis and inflammatory genes variants in primary non-response. Pharmacogenetic investigations have been conducted to identify genetic markers that can predict response to anti-TNF therapy. However, large multi-center validation studies and multi-loci algorithms development are required to effectively prognose the treatment effect. The identification of predictive markers of response to anti-TNF therapy can help clinicians make informed decisions about treatment options and minimize adverse drug reactions in patients.

Comparison of Clinical Outcomes in Pediatric Patients with Ileocolonic Crohn Disease Treated with Infliximab Versus Adalimumab

OBJECTIVES

Infliximab is considered superior to adalimumab in patients with ulcerative colitis, especially in severe cases. Whether this is true for Crohn disease (CD) patients with colonic involvement is unclear. Our aim was to compare the clinical effectiveness of infliximab versus adalimumab in pediatric ileocolonic (L3) CD.

METHODS

This retrospective study included patients <18 years with ileocolonic CD treated with infliximab or adalimumab between 2014 and 2021. Primary outcome was steroid-free clinical remission by week 52. Secondary outcomes were treatment modifications, drug discontinuation, inflammatory bowel disease (IBD)-associated hospitalizations, and surgery during the first year of treatment.

RESULTS

We identified 74 patients treated with adalimumab and 41 with infliximab, with comparable demographic features. Concomitant immunomodulator therapy at biologic initiation was significantly lower in the adalimumab group (28% vs 85%, P < 0.001). Rates of drug intensification were higher in the infliximab group at end of induction (EOI) and at 52 weeks (55% vs 32% and 88% vs 46%, P < 0.001). Given significant differences between initial median Pediatric Crohn Disease Activity Index scores (20.0 [interquartile range, IQR 15.0-27.5] vs 11.0 [IQR 7.5-20.0] for infliximab and adalimumab groups, respectively, P < 0.001), propensity score matching was performed. Following matching, the rate of patients in steroid-free clinical remission by EOI was significantly higher in the adalimumab group (93.8% vs 46.9%, P < 0.001), but comparable by 1 year. Moreover, inflammatory markers and fecal calprotectin values were also similar at these time points. Rates of drug discontinuation, IBD-associated admissions, and surgery were similar between groups.

CONCLUSIONS

In a retrospective study of patients with ileocolonic CD, adalimumab and infliximab had comparable outcomes by 52 weeks.

The importance of predicting patient responses to monoclonal antibodies for Crohn's disease

INTRODUCTION

Crohn's disease (CD) is a chronic immune-mediated inflammatory bowel disease that results in relapsing and remitting symptoms but progressive transmural bowel damage leading to significant morbidity. CD results from dysregulation of the immune system related to genetic and environmental factors. While the use of monoclonal antibodies targeting cytokines and adhesion molecules has been shown to improve outcomes in CD patients, their widespread use has been limited due to high costs as well as variable access. Here, we summarize the factors that have been shown to correlate with responsiveness to biologic agents for use in practice.

AREAS COVERED

We summarize the current literature regarding factors that have been shown to influence patient response to various biologic agents including: patient-related factors (e.g. age, gender, weight smoking history); disease-specific factors (e.g. disease duration, location/extension, behavior/phenotype, severity); genetic markers; transcription factors, and the gut microbiome. Finally, we review the utility of prediction models and present data supporting the use of recently developed decision support tools.

EXPERT OPINION

Clinical decision support tools developed by machine learning are currently available for the selection of biologic agents in CD patients. We expect these models to become an integral tool for clinicians in the treatment of CD in the coming years.

Serum TGF-β1 and CD14 Predicts Response to Anti-TNF-α Therapy in IBD

Background

Tumor necrosis factor-alpha (TNF-α) agonists revolutionized therapeutic algorithms in inflammatory bowel disease (IBD) management. However, approximately every third IBD patient does not respond to this therapy in the long term, which delays efficient control of the intestinal inflammation.

Methods

We analyzed the power of serum biomarkers to predict the failure of anti-TNF-α. We collected serum of 38 IBD patients at therapy prescription and 38 weeks later and analyzed them with relation to therapy response (no-, partial-, and full response). We used enzyme-linked immunosorbent assay to quantify 16 biomarkers related to gut barrier (intestinal fatty acid-binding protein, liver fatty acid-binding protein, trefoil factor 3, and interleukin (IL)-33), microbial translocation, immune system regulation (TNF-α, CD14, lipopolysaccharide-binding protein, mannan-binding lectin, IL-18, transforming growth factor-β1 (TGF-β1), osteoprotegerin (OPG), insulin-like growth factor 2 (IGF-2), endocrine-gland-derived vascular endothelial growth factor), and matrix metalloproteinase system (MMP-9, MMP-14, and tissue inhibitors of metalloproteinase-1).

Results

We found that future full-responders have different biomarker profiles than non-responders, while partial-responders cannot be distinguished from either group. When future non-responders were compared to responders, their baseline contained significantly more TGF-β1, less CD14, and increased level of MMP-9, and concentration of these factors could predict non-responders with high accuracy (AUC = 0.938). Interestingly, during the 38 weeks, levels of MMP-9 decreased in all patients, irrespective of the outcome, while OPG, IGF-2, and TGF-β1 were higher in non-responders compared to full-responders both at the beginning and the end of the treatment.

Conclusions

The TGF-β1 and CD14 can distinguish non-responders from responders. The changes in biomarker dynamics during the therapy suggest that growth factors (such as OPG, IGF-2, and TGF-β) are not markedly influenced by the treatment and that anti-TNF-α therapy decreases MMP-9 without influencing the treatment outcome.

Precision medicine and drug optimization in adult inflammatory bowel disease patients

Inflammatory bowel diseases (IBD) encompass two main entities including ulcerative colitis and Crohn's disease. Although having a common global pathophysiological mechanism, IBD patients are characterized by a significant interindividual heterogeneity and may differ by their disease type, disease locations, disease behaviours, disease manifestations, disease course as well as treatment needs. Indeed, although the therapeutic armamentarium for these diseases has expanded rapidly in recent years, a proportion of patients remains with a suboptimal response to medical treatment due to primary non-response, secondary loss of response or intolerance to currently available drugs. Identifying, prior to treatment initiation, which patients are likely to respond to a specific drug would improve the disease management, avoid unnecessary side effects and reduce the healthcare expenses. Precision medicine classifies individuals into subpopulations according to clinical and molecular characteristics with the objective to tailor preventative and therapeutic interventions to the characteristics of each patient. Interventions would thus be performed only on those who will benefit, sparing side effects and expense for those who will not. This review aims to summarize clinical factors, biomarkers (genetic, transcriptomic, proteomic, metabolic, radiomic or from the microbiota) and tools that could predict disease progression to guide towards a step-up or top-down strategy. Predictive factors of response or non-response to treatment will then be reviewed, followed by a discussion about the optimal dose of drug required for patients. The time at which these treatments should be administered (or rather can be stopped in case of a deep remission or in the aftermath of a surgery) will also be addressed. IBD remain biologically complex, with multifactorial etiopathology, clinical heterogeneity as well as temporal and therapeutic variabilities, which makes precision medicine especially challenging in this area. Although applied for many years in oncology, it remains an unmet medical need in IBD.

Active smoking is associated with the development of adverse events of biological therapy in patients with inflammatory bowel disease

INTRODUCTION

Smoking has been associated with lower levels of anti-TNF agents, higher antibodies and a reduced response to anti-TNF in patients with inflammatory bowel disease (IBD). The aim of this study was to investigate the possible association between smoking and adverse events (AEs) of biologics in patients with IBD.

MATERIAL AND METHODS

Consecutive IBD patients under biologics from a prospective, longitudinal registry of a tertiary center were included. A specially designed questionnaire including a wide range of AEs associated with biologics was also used.

RESULTS

A total of 147 patients with IBD under biologics [median age (IQR) 46 (32.5-56) years, Crohn's disease (CD) 109 (74%), female 51 (35%), under combination with immunosuppressants 60 (41 %), under intensified biologic therapy 50 (34%), under anti-TNF 132 (89%), vedolizumab 11 (7.5%), ustekinumab 3 (2%)] who had completed the questionnaire forms for AEs were included. There were 52 (35%) active smokers and 33 (22.5%) ex-smokers. The prevalence of all AEs was 88% in smokers, 87% in ex-smokers and 79% in nonsmokers. Active smoking was significantly associated with the presence of arthralgias and skin rashes ( P = 0.01 and 0.002, respectively). These correlations were the same for the CD and ulcerative colitis (UC), except for arthralgias where there was a significant correlation only with CD ( P = 0.001). There were no significant associations between smoking and other AEs ( P > 0.05).

CONCLUSION

Active smoking is associated with the development of dermatological manifestations (both in UC and CD) and arthralgias (in CD) in IBD patients under biologics.

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.

Ileal and colonic Crohn'´s disease: Ddoes location makes a difference in therapy efficacy?

Within the IBD entity of Crohn's disease, there is currently no differentiation between ileal and colonic manifestation for recruitment of patients in clinical trials, well-powered analysis of study results or therapeutic decisions in daily clinical practice. However, there is accumulating evidence from epidemiological, genetic, microbial, immunological, and clinical characteristics that clearly indicate that ileal Crohn's disease represents a distinct disease entity, which differentiates itself from colonic Crohn's disease. This is also reflected by lower efficacy of targeted therapies in isolated ileal compared to colonic Crohn's disease. The distinct site-specific mechanisms that drive heightened non-response in ileal disease need to be analysed in-depth in the future, to enable optimized therapy in the individual Crohn's disease patient.

Smoking Behaviour Changes After Diagnosis of Inflammatory Bowel Disease and Risk of All-cause Mortality

BACKGROUND AND AIMS

We examined smoking behaviour changes after diagnoses of Crohn's disease [CD] and ulcerative colitis [UC] and evaluated their impact on mortality.

METHODS

Study population included incident CD or UC cases from three cohorts of the Nurses' Health Study [NHS], NHSII, and Health Professionals Follow-up Study. Smoking and other risk factors were prospectively assessed. Smoking behaviour changes were categorised as never, former [i.e., quit smoking before diagnosis], quitters [i.e., quit smoking after diagnosis], and current [i.e., continue smoking after diagnosis]. Follow-up for date and cause of death was completed through linkage to the National Death Index. Cox proportional hazard regression was used to estimate hazard ratios [HRs] and 95% confidence intervals [CIs].

RESULTS

Among 909 eligible CD and UC cases, 45% were never smokers, 38% were past smokers, and 16% were active smokers at the time of diagnosis. Among active smokers, 70% of patients with CD and 44% of patients with UC continued to smoke after diagnosis. In patients with CD, compared with current smokers, the multivariable-adjusted HRs [95% CI] of death were 0.19 [0.10 to 0.38] for never smokers, 0.31 [0.16 to 0.57] for former smokers, and 0.41 [0.18 to 0.93] for quitters. Similarly for UC, compared with current smokers, we observed a reduced risk of mortality for never smokers [HR = 0.23, 95% CI 0.10 to 0.51], former smokers [HR = 0.23, 95% CI 0.11 to 0.48], and quitters [HR = 0.28, 95% CI 0.11 to 0.72].

CONCLUSIONS

In three cohorts of health professionals, a substantial proportion of patients with new diagnosis of CD and UC and history of smoking continued to smoke after diagnosis. Smoking cessation around the time of diagnosis was associated with a significant reduction in mortality.

Genetic association of primary nonresponse to anti-TNFα therapy in patients with inflammatory bowel disease

OBJECTIVES

Primary nonresponse (PNR) to antitumor necrosis factor-α (TNFα) biologics is a serious concern in patients with inflammatory bowel disease (IBD). We aimed to identify the genetic variants associated with PNR.

PATIENTS AND METHODS

Patients were recruited from outpatient GI clinics and PNR was determined using both clinical and endoscopic findings. A case-control genome-wide association study was performed in 589 IBD patients and associations were replicated in an independent cohort of 293 patients. Effect of the associated variant on gene expression and TNFα secretion was assessed by cell-based assays. Pleiotropic effects were investigated by Phenome-wide association study (PheWAS).

RESULTS

We identified rs34767465 as associated with PNR to anti-TNFα therapy (odds ratio: 2.07, 95% CI, 1.46-2.94, P = 2.43 × 10-7, [replication odds ratio: 1.8, 95% CI, 1.04-3.16, P = 0.03]). rs34767465 is a multiple-tissue expression quantitative trait loci for FAM114A2. Using RNA-sequencing and protein quantification from HapMap lymphoblastoid cell lines (LCLs), we found a significant decrease in FAM114A2 mRNA and protein expression in both heterozygous and homozygous genotypes when compared to wild type LCLs. TNFα secretion was significantly higher in THP-1 cells [differentiated into macrophages] with FAM114A2 knockdown versus controls. Immunoblotting experiments showed that depletion of FAM114A2 impaired autophagy-related pathway genes suggesting autophagy-mediated TNFα secretion as a potential mechanism. PheWAS showed rs34767465 was associated with comorbid conditions found in IBD patients (derangement of joints [P = 3.7 × 10-4], pigmentary iris degeneration [P = 5.9 × 10-4], diverticulum of esophagus [P = 7 × 10-4]).

CONCLUSIONS

We identified a variant rs34767465 associated with PNR to anti-TNFα biologics, which increases TNFα secretion through mechanism related to autophagy. rs34767465 may also explain the comorbidities associated with IBD.

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.

Location is important: differentiation between ileal and colonic Crohn's disease

Crohn's disease can affect any part of the gastrointestinal tract; however, current European and national guidelines worldwide do not differentiate between small-intestinal and colonic Crohn's disease for medical treatment. Data from the past decade provide evidence that ileal Crohn's disease is distinct from colonic Crohn's disease in several intestinal layers. Remarkably, colonic Crohn's disease shows an overlap with regard to disease behaviour with ulcerative colitis, underlining the fact that there is more to inflammatory bowel disease than just Crohn's disease and ulcerative colitis, and that subtypes, possibly defined by location and shared pathophysiology, are also important. This Review provides a structured overview of the differentiation between ileal and colonic Crohn's disease using data in the context of epidemiology, genetics, macroscopic differences such as creeping fat and histological findings, as well as differences in regard to the intestinal barrier including gut microbiota, mucus layer, epithelial cells and infiltrating immune cell populations. We also discuss the translation of these basic findings to the clinic, emphasizing the important role of treatment decisions. Thus, this Review provides a conceptual outlook on a new mechanism-driven classification of Crohn's disease.

Improving prediction of disease outcome for inflammatory bowel disease: progress through systems medicine

Introduction: Inflammatory bowel diseases (IBDs) are lifelong conditions causing relapsing inflammation of the intestine. In the absence of a cure, clinical management of IBDs is extremely challenging since they present with a wide range of phenotypes and disease behaviors. Hence, there is an urgent need for markers that could guide physicians in making the right choice of the rapidly growing treatment options toward a personalized care that could improve the overall outcome.Areas covered: In this review, the authors summarize existing biomarkers in IBD, discuss the challenges with the development of prognostic biomarkers and propose alternative options such as focusing on the prediction of the response to individual treatments, i.e. predictive biomarkers. The problems related to developing disease prognostic and predictive biomarkers in the field of IBDs are discussed including the difficulties in dealing with phenotypic heterogeneity particularly when performing studies in a real-life setting. The authors reviewed literature from PubMed.Expert opinion: Systems biology provides potential solutions to this problem by offering an unbiased, holistic approach to adjusting for variation in larger datasets thereby increasing the chances of identifying true associations between molecular profiles and clinical phenotypes.

Passive Smoking Increases the Risk for Intestinal Surgeries in Patients With Crohn's Disease

BACKGROUND

Despite substantial evidence on the negative effect of active smoking, the impact of passive smoking on the course of Crohn's disease (CD) remains largely unclear. Our aim was to assess passive smoking as a risk factor for intestinal surgeries in CD.

METHODS

The study was conducted in a university-based, monocentric cohort of 563 patients with CD. Patients underwent a structured interview on exposure to passive and active smoking. For clinical data, chart review was performed. Response rate was 84%, leaving 471 cases available for analysis. For evaluation of the primary objective, which was the impact of exposure to passive smoking on the risk for intestinal surgery, only never actively smoking patients were included.

RESULTS

Of 169 patients who never smoked actively, 91 patients (54%) were exposed to passive smoking. Exposed patients were more likely to undergo intestinal surgery than nonexposed patients (67% vs 30%; P < 0.001). Multivariate Cox regression analysis revealed that passive smoking was an independent risk factor for intestinal surgeries (hazard ratio, 1.7; 95% CI, 1.04-2.9; P = 0.034) after adjustment for ileal disease at diagnosis (hazard ratio, 2.9; 95% CI, 1.9-4.5; P < 0.001) and stricturing or penetrating behavior at diagnosis (hazard ratio, 1.9; 95% CI, 1.2-3.1; P = 0.01). Passive smoking during childhood was a risk factor for becoming an active smoker in later life (odds ratio, 2.2; 95% CI, 1.5-3.2; P < 0.001).

CONCLUSION

Passive smoking increases the risk for intestinal surgeries in patients with CD.

Smoking May Reduce the Effectiveness of Anti-TNF Therapies to Induce Clinical Response and Remission in Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Cigarette smoking worsens prognosis of Crohn's disease [CD]. We conducted a systematic review and meta-analysis to examine the association between smoking and induction of clinical response or remission with anti-tumour necrosis factor [TNF] therapy.

METHODS

MEDLINE, EMBASE, PubMed, and Cochrane CENTRAL [June 2019] were searched for studies reporting the effect of smoking on short-term clinical response and remission to anti-TNF therapy [≤16 weeks following the first treatment] in patients with CD. Risk ratios [RR] with 95% confidence intervals [CI] were calculated using random-effects models.

RESULTS

Eighteen observational studies and three randomised controlled trials [RCT] were included. Current smokers and non-smokers [never or former] had similar rates of clinical response [observational studies RR: 0.96; 95% CI: 0.88, 1.05; RCTs RR: 1.09; 95% CI: 0.84, 1.41]. When restricted to studies clearly defining the smoking exposure, smokers treated with anti-TNF were less likely to achieve clinical response than non-smokers [smokers defined as having ≥5 cigarettes/day for ≥6 months RR: 0.63; 95% CI: 0.48, 0.83; lifetime never smokers vs ever smokers excluding former smokers RR: 0.81; 95% CI: 0.71, 0.93]. Current smokers were also less likely to achieve clinical remission in observational studies [RR: 0.75; 95% CI: 0.57, 0.98], though this association was not seen in RCTs [RR: 1.04; 95% CI: 0.89, 1.21].

CONCLUSIONS

Smoking is significantly associated with a reduction in the ability of infliximab or adalimumab to induce short-term clinical response and remission when pooling studies where smoking status was clearly defined. When patients with CD are treated with highly effective therapy, including anti-TNF agents, concurrent smoking cessation may improve clinical outcomes.

The impact of tobacco smoking on treatment choice and efficacy in inflammatory bowel disease

Smoking significantly increases the risk of developing and worsens Crohn's disease (CD), yet protects against the development and reduces the severity of ulcerative colitis. It is less clear whether smoking impacts the efficacy of therapeutics in inflammatory bowel disease (IBD). We review the literature regarding the relationship between smoking and the efficacy of medical and surgical therapy in IBD. Smoking is associated with alterations in thiopurine metabolism and may affect time to disease relapse. The outcomes of anti-tumor necrosis factor therapy in active smokers appear neutral with data lacking for newer biologics. Smoking increases the risk of postoperative recurrence in those requiring resection for CD, likely attributable to perturbations of the gut microbiota although further implications of these for disease onset/progression and treatment efficacy remain unclear. Multiple lifestyle and psychosocial confounders are likely under-recognized cofactors in the association between smoking and IBD. Despite the widely promulgated risks associated with cigarette smoking in CD, more incisive data are required to further elucidate the actual relationship between smoking and disease pathways, while accounting for the several negative cofactors prevalent in smokers which cast uncertainty on the magnitude of the direct effect of smoking on disease pathophysiology and the efficacy of therapy.

Personalizing Treatment in IBD: Hype or Reality in 2020? Can We Predict Response to Anti-TNF?

The advent of anti-TNF agents as the first approved targeted therapy in the treatment of inflammatory bowel disease (IBD) patients has made a major impact on our existing therapeutic algorithms. They have not only been approved for induction and maintenance treatment in IBD patients, but have also enabled us to define and achieve novel therapeutic outcomes, such as combination of clinical symptom control and endoscopic remission, as well as mucosal healing. Nevertheless, approximately one third of treated patients do not respond to initiated anti-TNF therapy and these treatments are associated with sometimes severe systemic side-effects. There is therefore the currently unmet clinical need do establish predictive markers of response to identify the subgroup of IBD patients, that have a heightened probability of response. There have so far been approaches from different fields of IBD research, to descry markers that would empower us to apply TNF-inhibitors in a more rational manner. These markers encompass findings from disease-related and clinical factors, pharmacokinetics, biochemical markers, blood and stool derived parameters, pharmacogenomics, microbial species, metabolic compounds, and mucosal factors. Furthermore, changes in the intestinal immune cell composition in response to therapeutic pressure of anti-TNF treatment have recently been implicated in the process of molecular resistance to these drugs. Insights into factors that determine resistance to anti-TNF therapy give reasonable hope, that a more targeted approach can then be utilized in these non-responders. Here, IL-23 could be identified as one of the key factors determining resistance to TNF-inhibitors. Growing insights into the molecular mechanism of action of TNF-inhibitors might also enable us to derive critical molecular markers that not only mediate the clinical effects of anti-TNF therapy, but which level of expression might also correlate with its therapeutic efficacy. In this narrative review, we present an overview of currently identified possible predictive markers for successful anti-TNF therapy and discuss identified molecular pathways that drive resistance to these substances. We will also point out the necessity and difficulty of developing and validating a diagnostic marker concerning clinically relevant outcome parameters, before they can finally enter daily clinical practice and enable a more personalized therapeutic 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.

Opening a Window on Attention: Adjuvant Therapies for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), most commonly known as Crohn's disease (CD) and ulcerative disease (UC), is a chronic and relapsing intestinal disease which cannot be cured completely. The prevalence of IBD in Europe and in North America has increased over the past 20 years. As most IBD patients are young at onset, their quality of life (QOL) can be influenced to varying degrees. Thus, current treatment goals are typically focused on preventing complications, including maintaining clinical remission and improving the QOL. Adjuvant therapies have been widely concerned as an effective treatment in alleviating IBD symptoms, including dietary intervention, traditional Chinese medicine, smoking, alcohol, and physical activities. This review focuses on different ancillary therapies for IBD treatments, in particular the mechanism of reducing inflammation based on the actual data from research studies. Moreover, comparing the latest data, this review also presented potential future prospect for adjuvant therapies.

Personalised medicine in Crohn's disease

Similar to many immune-mediated diseases, Crohn's disease follows a relapsing-remitting pattern, with a variable disease course and heterogeneous clinical outcomes. Frequency of flare-ups, development of complications, and response to treatment collectively determine the effect on a patient's quality of life, which can vary from minimal disruption to profound disability or death. Despite recent advances in the understanding of complex disease pathogenesis, including for Crohn's disease, management decisions are still typically made using a one-size-fits-all approach. Indeed, the inability to reliably predict clinical outcomes in a way that could guide future therapy represents a major unmet need. Recently, several important insights have been made into the biology underlying outcomes in Crohn's disease. In this Review, we will summarise these insights and discuss how greater understanding of these disease mechanisms can be used to develop clinically useful biomarkers, identify novel approaches to optimise disease control, and help deliver the goal of personalised medicine.

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.

The effect of a multidisciplinary approach for smoking cessation in patients with Crohn's disease: Results from an observational cohort study

INTRODUCTION

Cigarette smoking is the most important risk factor for Crohn’s disease (CD). The effectiveness of smoking cessation programs (SCPs) in patients with CD is still poorly understood.

METHODS

This was a retrospective, observational, single-centre, cohort study of 136 active smokers with mean age 55 years (SD=11), 58% males, including 27 (19.8%) patients with CD who entered the multidisciplinary SCP of the Luigi Sacco University Hospital of Milan from January 2017 through January 2019. A pulmonologist was responsible for the clinical and pharmacological management, while a psychiatrist and a psychologist conducted the counselling and assessed the motivation to quit, anxiety and depression using the Brief Psychiatric Rating Scale (BPRS) and the nicotine dependence with the Fagerström test. Patients were defined as quitters after 12 months.

RESULTS

Demographic and clinical characteristics, and Fagerström score, did not differ in patients with and without CD. At baseline, patients with CD had a higher BPRS (median: 27, IQR: 22–32; vs 25 and 22–28.5; p=0.03), and a lower motivation to quit score (median: 10, IQR: 9–13; vs 14 and 12–15; p<0.001). After 12 months, the quitting rate of smokers with CD was significantly lower (14.8% vs 36.7%; p<0.022) and the chance of quitting was negatively associated with the baseline BPRS (r=-0.256; p<0.003). Varenicline and nicotine replacement therapy tended to be less effective in patients with CD.

CONCLUSIONS

The lower efficacy of SCPs in patients with CD might be secondary to a higher prevalence of anxiety and depression. Psychological issue recognition and support should be enhanced to increase SCP effectiveness in CD.

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

BACKGROUND

Ustekinumab [UST] was recently approved in Europe for the treatment of moderate to severe Crohn's disease [CD]. Long-term real-world data are currently scarce for CD patients previously exposed to several biologics.

METHODS

This is an observational, national, retrospective multicentre study. Patients received intravenous UST ~6 mg/kg at baseline, with 90 mg subcutaneously thereafter every 8 weeks. Response and remission rates were assessed at Weeks 8, 16, and 52.

RESULTS

Data from 152 patients were analysed. All patients were exposed to at least one anti-TNFα agent, with 69.7% were exposed to even two anti-TNFα and vedolizumab. After 1 year, 42.1% and 25.7% of patients had experienced clinical response and clinical remission, respectively, and 38.8% and 24.3% had achieved steroid-free clinical response and remission, respectively; 38.8% of patients discontinued therapy during the 12 months of follow-up. Colonic location was predictive of clinical response at 1 year, and low body mass index [BMI] at baseline was a negative predictor of clinical remission. Resolution of arthralgia was associated with clinical response over time. De novo arthralgia was reported by 17.9% of patients at Week 8 and 13.5% of patients at Week 52. No impact of UST on arthralgia was observed in patients with concomitant ankylosing spondylitis [n = 17]. Others adverse events were reported in 7.2% of patients.

CONCLUSIONS

This real-world cohort study confirms the effectiveness of UST in CD patients previously exposed to several biologics. Ustekinumab was well tolerated with respect to adverse events.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

A nomogram for predicting the response to exclusive enteral nutrition in adult patients with isolated colonic Crohn's disease

BACKGROUND

Isolated colonic Crohn's disease (cCD) responds less well to induction therapy with exclusive enteral nutrition (EEN) compared with ileal or ileocolonic disease in adult patients; therefore, we aimed to identify the factors that influence the response to EEN and develop a predictive nomogram model to optimize the use of EEN in cCD patients.

MATERIALS AND METHODS

Eighty-five cCD patients treated with EEN as first-line therapy at our center between 1 June 2012 and 30 June 2018 were retrospectively analyzed as the primary cohort. The primary endpoint was clinical remission after EEN therapy. Potential predictive factors for the efficacy of EEN were assessed by univariate and multivariate analyses, and a nomogram to predict the response to EEN therapy in cCD patients was designed. Another 19 cCD patients were retrospectively included in the validation cohort to verify the accuracy of the nomogram model.

RESULTS

The clinical remission rates for the primary cohort and validation cohort were 52.9% and 47.4%, respectively. Pancolitis was the greatest contributor to the risk of failure to respond to EEN [odds ratio (OR) = 4.896; 95% confidence interval (CI) = 1.223-19.607; p = 0.025], lean body mass index (LBMI), colonic lesion features, simple endoscopic scores for Crohn's disease, C-reactive protein before treatment and ∆prealbumin were also related to the efficacy of EEN in cCD. The nomogram model showed robust discrimination, with an area under the receiving operating characteristic curve of 0.906.

CONCLUSION

Several predictive factors for response to EEN therapy in cCD adult patients were identified, and a promising nomogram that can predict the effect of EEN in cCD was developed.

Elevated Pretreatment Plasma Oncostatin M Is Associated With Poor Biochemical Response to Infliximab

Background

We hypothesized that elevations of plasma Oncostatin M (OSM) would be associated with infliximab nonresponse.

Methods

Plasma OSM was measured in Crohn disease patients pre-infliximab with biochemical response (>50% reduction in fecal calprotectin) as the primary outcome.

Results

The median OSM in biochemical responders was 86 (69-148) pg/mL compared with 166 (74-1766) pg/mL in nonresponders (P = 0.03). Plasma OSM > 143.5 pg/mL was 71% sensitive and 78% specific for biochemical nonresponse (area under the curve 0.71). Early biochemical nonremission was also associated with an elevated neutrophil CD64 expression (odds ratio 8.9, P = 0.011).

Conclusions

Elevated preinfliximab plasma OSM and nCD64 surface expression were both associated with poor biochemical outcomes.

Novel Pharmacological Therapy in Inflammatory Bowel Diseases: Beyond Anti-Tumor Necrosis Factor

Inflammatory bowel diseases (IBDs) are chronic conditions of the gastrointestinal tract in which dysregulated immune responses cause persistent inflammation of the gut mucosa. Biologic therapy with anti-TNF blockers has revolutionized the therapeutic management of IBD for their remarkable efficacy and potential impact on disease course and for many years has represented the sole treatment option for patients refractory or intolerant to conventional therapy. In recent years, more molecules, both biologically and chemically synthetized, have been developed as potential therapeutic options for IBD that target different molecular pathways aside from TNF blockade, and which have been proposed as targets for novel drugs. This is particularly relevant for the present, as well as future, management of IBD, considering that some patients are refractory to anti-TNF. This review will summarize the pharmacological options, either currently available or in the pipeline, for market approval to treat IBD, besides anti-TNF strategies, based on their mechanism(s) of action. We will also analyze the current evidence for effectiveness and safety, as well as offer perspective, regarding the potential implementation for such therapies in the future.

Predicting (side) effects for patients with inflammatory bowel disease: The promise of pharmacogenetics

Inflammatory bowel disease (IBD) is a chronic and heterogeneous intestinal inflammatory disorder. The medical management of IBD aims for long-lasting disease remission to prevent complications and disease progression. Early introduction of immunosuppression forms the mainstay of medical IBD management. Large inter-individual variability in drug responses, in terms of both efficacy and toxicity, leads to high rates of therapeutic failure in the management of IBD. Better patient stratification is needed to maximize patient benefit and minimize the harm caused by adverse events. Pre-treatment pharmacogenetic testing has the potential to optimize drug selection and dose, and to minimize harm caused by adverse drug reactions. In addition, optimizing the use of cheap conventional drugs, and avoiding expensive ineffective drugs, will lead to a significant reduction in costs. Genetic variation in both TPMT and NUDT15, genes involved in thiopurine metabolism, is associated to an increased risk of thiopurine-induced myelosuppression. Moreover, specific HLA haplotypes confer risk to thiopurine-induced pancreatitis and to immunogenicity to tumor necrosis factor-antagonists, respectively. Falling costs and increased availability of genetic tests allow for the incorporation of pre-treatment genetic tests into clinical IBD management guidelines. In this paper, we review clinically useful pharmacogenetic associations for individualized treatment of patients with IBD and discuss the path from identification of a predictive pharmacogenetic marker to implementation into IBD clinical care.

Mechanisms of molecular resistance and predictors of response to biological therapy in inflammatory bowel disease

Biological therapy has led to marked improvements in treatment of patients with inflammatory bowel disease, and an increasing number of drugs has been approved for treatment. However, only a subgroup of patients responds to therapy, highlighting the need to identify biomarkers for therapeutic response to allow personalised medicine in inflammatory bowel disease. Potential markers of response to biological therapy have been identified; however, studies also suggest that changes in the composition of immune cell infiltrates in response to therapeutic pressure lead to molecular resistance to these drugs. For instance, the cytokine interleukin 23 has been identified as a driver of evasion of apoptosis in response to anti-tumour necrosis factor drugs in patients with Crohn's disease, leading to expansion of apoptosis-resistant T cells and drug resistance. In this Review, we examine the concept of molecular resistance to biological therapy and discuss implications for future therapy.

Endoscopic response to tumor necrosis factor inhibitors predicts long term benefits in Crohn’s disease

BACKGROUND

Identifying predictors of therapeutic response is the cornerstone of personalized medicine.

AIM

To identify predictors of long-term mucosal healing (MH) in patients with Crohn’s disease (CD) treated with tumor necrosis factor α (TNF-α) inhibitors.

METHODS

Prospective single center study. Consecutive patients with clinically active CD requiring treatment with a TNF-α inhibitor were included. A baseline segmental CD Endoscopic Index of Severity (CDEIS) ≥ 10 in at least one segment or the presence of ulcerations were required for inclusion. Clinical, biological and endoscopic data were obtained at baseline, weeks 14 and 46. Endoscopic response (ER) was defined as a decrease ≥ 50% from baseline CDEIS and MH as partial CDEIS ≤ 5 in all segments.

RESULTS

Of 62 patients were included. At baseline, median CD Activity Index and CDEIS were 201 and 6.7, respectively with a significant reduction after one year of treatment (53 and 3.0 respectively, P < 0.001). At week 14, 56% of patients achieved ER and 34% MH. At week 46, the corresponding percentages were 52% and 44%. Baseline disease characteristics or biomarkers did not predict MH. A decrease from baseline CDEIS at week 14 of at least 80% was the best predictor of MH at week 46 (59% sensitivity and 91% specificity; area under the curve = 0.778).

CONCLUSION

Clinical and biomarker data are not useful predictors of response to TNF-α inhibitors in CD, whereas ER to induction therapy, defined as 80% reduction in global CDEIS, is a robust predictor of long-term MH. Achievement of this endoscopic endpoint may be considered as a therapeutic target for anti-TNF-α therapy.

Identifying demographic, social and clinical predictors of biologic therapy effectiveness in psoriasis: a multicentre longitudinal cohort study

Background

Biologic therapies have revolutionized the treatment of moderate‐to‐severe psoriasis. However, for reasons largely unknown, many patients do not respond or lose response to these drugs.

Objectives

To evaluate demographic, social and clinical factors that could be used to predict effectiveness and stratify response to biologic therapies in psoriasis.

Methods

Using a multicentre, observational, prospective pharmacovigilance study (BADBIR), we identified biologic‐naive patients starting biologics with outcome data at 6 (n = 3079) and 12 (n = 3110) months. Associations between 31 putative predictors and outcomes were investigated in univariate and multivariable regression analyses. Potential stratifiers of treatment response were investigated with statistical interactions.

Results

Eight factors associated with reduced odds of achieving ≥ 90% improvement in Psoriasis Area and Severity Index (PASI 90) at 6 months were identified (described as odds ratio and 95% confidence interval): demographic (female sex, 0·78, 0·66–0·93); social (unemployment, 0·67, 0·45–0·99); unemployment due to ill health (0·62, 0·48–0·82); ex‐ and current smoking (0·81, 0·66–0·99 and 0·79, 0·63–0·99, respectively); clinical factors (high weight, 0·99, 0·99–0·99); psoriasis of the palms and/or soles (0·75, 0·61–0·91); and presence of small plaques only compared with small and large plaques (0·78, 0·62–0·96). White ethnicity (1·48, 1·12–1·97) and higher baseline PASI (1·04, 1·03–1·04) were associated with increased odds of achieving PASI 90. The findings were largely consistent at 12 months. There was little evidence for predictors of differential treatment response.

Conclusions

Psoriasis phenotype and potentially modifiable factors are associated with poor outcomes with biologics, underscoring the need for lifestyle management. Effect sizes suggest that these factors alone cannot inform treatment selection.

What's already known about this topic?

Biologic therapy used in the treatment of moderate‐to‐severe psoriasis differs in its effectiveness across patients.

Previous research has indicated that patients with a higher body mass index, who smoke or who have smoked, and with a lower baseline Psoriasis Area and Severity Index (PASI) are less likely to have a good outcome with biologic therapy for the treatment of moderate‐to‐severe psoriasis.

What does this study add?

This large‐scale study in a real‐world setting confirms that weight, smoking status and baseline PASI are associated with effectiveness of biologic therapy.

There is evidence that non‐white ethnicity, female sex, unemployment, psoriasis of the palms and soles and the presence of small chronic plaques are associated with poor outcomes with biologics.

There is some evidence that men have a comparatively worse response to etanercept, relative to adalimumab, than women. Otherwise, most factors do not appear to be predictors of differential treatment response.

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How to predict response to anti-tumour necrosis factor agents in inflammatory bowel disease

Anti-tumor necrosis factor (TNF) agents have changed the therapeutic approach to inflammatory bowel disease (IBD). However, a considerable proportion of patients either do not primarily respond or lose response to treatment. Despite the long-standing experience in the use of these drugs, still there is the need of identifying the possible predictors of efficacy. Areas covered: We critically review the current knowledge on predictors of response to anti-TNF therapy - both those available in clinical practice and those still under investigation. Multiple factors are involved in treatment success, including disease phenotype and severity, adherence to medications, and pharmacogenomic, pharmacokinetic, and immunologic factors. Literature search was conducted in PubMed using keywords 'inflammatory bowel disease,' 'Crohn's disease,' and 'ulcerative colitis,' matched with 'antitumor necrosis factor,' 'biologic therapy,' 'clinical response,' 'predictors,' and 'efficacy,' Relevant articles were selected for review. Expert commentary: While the role of several factors in clinical practice is clearly established, other investigational markers have been proposed, mostly in small studies, yet for many of them little external validation exists. Therapeutic drug monitoring is emerging as a pivotal strategy to guide decisions in clinical practice. In the near future, novel markers could improve our ability to direct treatment and personalize therapy.

Visceral Fat Is Associated With Mucosal Healing of Infliximab Treatment in Crohn's Disease

BACKGROUND

Visceral fat is the pathogenesis of Crohn's disease and is associated with disease status.

OBJECTIVE

This study aimed to evaluate the effect of the visceral fat on mucosal healing in patients with Crohn's disease after infliximab induction therapy DESIGN:: This was a retrospective study.

SETTINGS

The study was conducted in a tertiary referral hospital.

PATIENTS

Between 2011 and 2017, 97 patients with Crohn's disease with the presence of ulcers underwent infliximab therapy.

MAIN OUTCOME MEASURES

We studied them retrospectively. Mucosal healing was the end point. Patients composed 2 groups: mucosal healing and no mucosal healing. Univariate, multivariate, and receiver operating characteristic curve analyses determined the predictive value of the visceral fat area.

RESULTS

Univariate analysis showed a statistically significant difference in the smoking history between the groups. Mucosal healing rates after infliximab were lower among active smokers (p = 0.022). Healed patients had significantly less visceral fat area before therapy (47.76 ± 4.94 vs 75.88 ± 5.55; p = 0.000) and a lower mesenteric fat index (0.52 ± 0.04 vs 0.89 ± 0.07; p = 0.000). There was no significant difference in the subcutaneous fat area (87.39 ± 5.01 vs 93.31 ± 6.95; p = 0.500). Multivariate analysis showed that only visceral fat area (OR = 0.978 (95% CI, 0.964-0.992); p = 0.002) and smoking history (OR = 0.305 (95% CI, 0.089-0.996); p = 0.041) were independent factors for mucosal healing. Receiver operating characteristic curve analysis showed predictive cutoff values of 61.5 cm and 0.62 for visceral fat area and mesenteric fat index.

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

There was an association between increased visceral fat area and attenuated mucosal healing after infliximab therapy in biologically naive patients with Crohn's disease, indicating a need for earlier increased infliximab doses among patients with increased visceral fat. See Video Abstract at http://links.lww.com/DCR/A590.

Evidence-based clinical practice guidelines for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disorder involving mainly the intestinal tract, but possibly other gastrointestinal and extraintestinal organs. Although etiology is still uncertain, recent knowledge in pathogenesis has accumulated, and novel diagnostic and therapeutic modalities have become available for clinical use. Therefore, the previous guidelines were urged to be updated. In 2016, the Japanese Society of Gastroenterology revised the previous versions of evidence-based clinical practice guidelines for ulcerative colitis (UC) and Crohn's disease (CD) in Japanese. A total of 59 clinical questions for 9 categories (1. clinical features of IBD; 2. diagnosis; 3. general consideration in treatment; 4. therapeutic interventions for IBD; 5. treatment of UC; 6. treatment of CD; 7. extraintestinal complications; 8. cancer surveillance; 9. IBD in special situation) were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases. The guidelines were developed with the basic concept of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Recommendations were made using Delphi rounds. This English version was produced and edited based on the existing updated guidelines in Japanese.

Inflammatory bowel disease: towards a personalized medicine

The management of inflammatory bowel disease (IBD) has been transformed over the last two decades by the arrival of tumor necrosis factor (TNF) antagonist agents. Recently, alternative drugs have been approved, directed at leukocyte-trafficking molecules (vedolizumab) or other inflammatory cytokines (ustekinumab). New therapeutics are currently being developed in IBD and represent promising targets as they involve other mechanisms of action (JAK molecules, Smad 7 antisense oligonucleotide etc.). Beyond TNF antagonist agents, these alternative drugs are needed for early-stage treatment of patients with aggressive IBD or when the disease is resistant to conventional therapy. Personalized medicine involves the determination of patients with a high risk of progression and complications, and better characterization of patients who may respond preferentially to specific therapies. Indeed, more and more studies aim to identify factors predictive of drug response (corresponding to a specific signaling pathway) that could better manage treatment for patients with IBD. Once treatment has started, disease monitoring is essential and remote patient care could in some circumstances be an attractive option. Telemedicine improves medical adherence and quality of life, and has a positive impact on health outcomes of patients with IBD. This review discusses the current application of personalized medicine to the management of patients with IBD and the advantages and limits of telemedicine in IBD.

Immunogenicity and loss of response to TNF inhibitors: implications for rheumatoid arthritis treatment

The availability of monoclonal antibodies has revolutionized the treatment of an increasingly broad spectrum of diseases. Inflammatory diseases are among those most widely treated with protein-based therapeutics, termed biologics. Following the first large-scale clinical trials with monoclonal antibodies performed in the 1990s by rheumatologists and clinical immunologists, the approval of these agents for use in daily clinical practice led to substantial progress in the treatment of rheumatic diseases. Despite this progress, however, only a proportion of patients achieve a long-term clinical response. Data on the use of agents blocking TNF, which were among the first biologics introduced into clinical practice, provide ample evidence of primary and secondary treatment inefficacy in patients with rheumatoid arthritis (RA). Important issues relevant to primary and secondary failure of these agents in RA include immunogenicity, methodological problems for the detection of antidrug antibodies and trough drug levels, and the implications for treatment strategies. Although there is no strong evidence to support the routine estimation of antidrug antibodies or serum trough levels during anti-TNF therapy, these assessments might be helpful in a few clinical situations; in particular, they might guide decisions on switching the therapeutic biologic in certain instances of secondary clinical failure.

The role of smoking and alcohol behaviour in the management of inflammatory bowel disease

In the era of increasing use of immunosuppressive and biologic therapy for inflammatory bowel disease, environmental influences remain important independent risk factors to modify the course of the disease, affect the need for surgery and recurrence rates post-surgical resection. The effect of smoking on inflammatory bowel disease has been established over the decades, however the exact mechanism of how smoking affects remains as area of research. Alcohol is also among the socio-environmental factors which has been recognised to cause a flare of symptoms in inflammatory bowel disease patients. Nonetheless, the exact relation to date is not fully understood, and various paradoxical results from different studies are still a point of controversy.

Time to clinical response and remission for therapeutics in inflammatory bowel diseases: What should the clinician expect, what should patients be told?

An awareness of the expected time for therapies to induce symptomatic improvement and remission is necessary for determining the timing of follow-up, disease (re)assessment, and the duration to persist with therapies, yet this is seldom reported as an outcome in clinical trials. In this review, we explore the time to clinical response and remission of current therapies for inflammatory bowel disease (IBD) as well as medication, patient and disease related factors that may influence the time to clinical response. It appears that the time to therapeutic response varies depending on the indication for therapy (Crohn's disease or ulcerative colitis). Agents with the most rapid time to clinical response included corticosteroids, calcineurin inhibitors, exclusive enteral nutrition, aminosalicylates and anti-tumor necrosis factor therapy which will work in most patients within the first 2 mo. Vedolizumab, methotrexate and thiopurines had a longer time to clinical response and can take several months to achieve maximal efficacy. Factors affecting the time to clinical response of therapies included use of concomitant therapy, disease duration, smoking status, disease phenotype and advanced age. There appears to be marked variation in time to clinical response for therapies used in IBD which is further influenced by disease and patient related factors. Understanding the expected time to therapeutic response is integral to inform further decision making, maintain a patient-centered approach and ensure treatment is given an appropriate timeframe to achieve maximal benefit prior to cessation.

Can We Predict the Efficacy of Anti-TNF-α Agents?

The use of biologic agents, particularly anti-tumor necrosis factor (TNF)-α, has revolutionized the treatment of inflammatory bowel diseases (IBD), modifying their natural history. Several data on the efficacy of these agents in inducing and maintaining clinical remission have been accumulated over the past two decades: their use avoid the need for steroids therapy, promote mucosal healing, reduce hospitalizations and surgeries and therefore dramatically improve the quality of life of IBD patients. However, primary non-response to these agents or loss of response over time mainly due to immunogenicity or treatment-related side-effects are a frequent concern in IBD patients. Thus, the identification of predicting factors of efficacy is crucial to allow clinicians to efficiently use these therapies, avoiding them when they are ineffective and eventually shifting towards alternative biological therapies with the end goal of optimizing the cost-effectiveness ratio. In this review, we aim to identify the predictive factors of short- and long-term benefits of anti-TNF-α therapy in IBD patients. In particular, multiple patient-, disease- and treatment-related factors have been evaluated.

Modifiable Environmental Factors in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Environmental factors may influence predisposition to develop inflammatory bowel diseases (Crohn's disease, ulcerative colitis) or alter its natural history by modification of both the host immune response and intestinal microbial composition. The purpose of this review is to translate such evidence into clinical practice by a focus on interventional studies that have modified such environmental influences to improve disease outcomes.

RECENT FINDINGS

Several environmental influences have been identified in the recent literature including tobacco use, diet, antibiotics, vitamin D deficiency, stress, appendectomy, and oral contraceptive use. Some risk factors have similar influences on both Crohn's disease and ulcerative colitis while others are disease-specific or have divergent effects. Emerging epidemiologic evidence has confirmed the association of many of these factors with incident disease using prospective data. In addition, laboratory data has supported their mechanistic plausibility and relevance to intestinal inflammation.

ACG Clinical Guideline: Preventive Care in Inflammatory Bowel Disease

Recent data suggest that inflammatory bowel disease (IBD) patients do not receive preventive services at the same rate as general medical patients. Patients with IBD often consider their gastroenterologist to be the primary provider of care. To improve the care delivered to IBD patients, health maintenance issues need to be co-managed by both the gastroenterologist and primary care team. Gastroenterologists need to explicitly inform the primary care provider of the unique needs of the IBD patient, especially those on immunomodulators and biologics or being considered for such therapy. In particular, documentation of up to date vaccinations are crucial as IBD patients are often treated with long-term immune-suppressive therapies and may be at increased risk for infections, many of which are preventable with vaccinations. Health maintenance issues addressed in this guideline include identification, safety and appropriate timing of vaccinations, screening for osteoporosis, cervical cancer, melanoma and non-melanoma skin cancer as well as identification of depression and anxiety and smoking cessation. To accomplish these health maintenance goals, coordination between the primary care provider, gastroenterology team and other specialists is necessary.

Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition. We have therefore systematically reviewed its epidemiology, pathophysiology and treatment. Key findings include a higher incidence in females (65%) and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites. Diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischaemic colitis, segmental colitis associated with diverticular disease and tuberculosis. Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately.

Infliximab therapy reverses the increase of allograft inflammatory factor-1 in serum and colonic mucosa of rats with inflammatory bowel disease

OBJECTIVE

Our purpose was to study the molecular basis of infliximab (IFX) effect on colon mucosa in a colitis model and to identify new biomarkers of mucosal healing.

METHODS

Healthy rats and rats which were subjected to experimental colitis induced by dextran sulfate sodium, with or without IFX treatment (in the short- and long-term), were studied along with forty-seven IBD patients. Colon mucosal integrity by periodic acid Schiff (PAS) staining, intestinal damage by immunohistochemistry (proliferating cell nuclear antigen, β-catenin, E-cadherin, phosphotyrosine, p-p38, allograft inflammatory factor-1 (AIF-1) and colonic mucosal apoptosis by TUNEL staining were evaluated in rats while serum and colon AIF-1 levels were determined in IBD patients.

RESULTS

In rats with colitis, IFX reestablished the epithelial barrier integrity, recovered mucus production and decreased colon inflammation, as verified by reduced serum and colon AIF-1 levels; colon and serum AIF-1 levels were also lower in inactive IBD patients compare to active ones. P38 activation after IFX treatment tended to induce differentiation/proliferation of epithelial cells along the colonic crypt-villous axis.

CONCLUSIONS

These findings support AIF-1 as a new biomarker of mucosal healing in experimental colitis and suggest that p38 activation is involved in the mucosal healing intracellular mechanism induced by IFX treatment.

Prognostic factors for long-term infliximab treatment in Crohn's disease patients: a 20-year single centre experience

BACKGROUND

The long-term efficacy of infliximab in patients with Crohn's disease is suboptimal.

AIM

To study prognostic factors for real-life long-term effcacy of infliximab in Crohn's disease.

METHODS

All consecutive Crohn's disease patients treated with infliximab at a tertiary centre were retrospectively analysed. Only patients who received scheduled infliximab maintenance treatment were considered. Patient- and disease-related factors were used to identify independent predictors of infliximab failure-free survival using Cox proportional hazards regression.

RESULTS

Of 1031 patients with Crohn's disease, 261 were eligible for inclusion. Median time on infliximab was 2.4 [IQR 1.4-4.7] years, and 65 (24.9%) patients experienced infliximab failure. Estimated 5-year infliximab failure-free survival was 65.9% (95% CI 58.3-73.5). Multivariate Cox regression identified disease duration ≥1 year (HR 2.5 (95% CI 1.2-5.2), P = 0.02), L1 disease location [HR 2.0 (1.1-3.5), P = 0.02], prior anti-TNF use [HR 2.3 (1.1-4.8), P = 0.03], haemoglobin <13.5 g/dL [HR 2.3 (1.2-4.4), P = 0.02], not using therapeutic drug monitoring [HR 8.0 (4.1-15.6), P = 1 × 10(-9) ], and first dose optimisation within first year [HR 3.7 (2.1-6.6), P = 5 × 10(-6) ] as independent predictors of infliximab failure-free survival. Stratifying patients into risk groups resulted in estimated 3-year infliximab failure-free survival rates ranging from 95.3% (94.2-96.4) to 26.3% (8.6-44.0) depending on the number of risk factors (P = 8 × 10(-13) ).

CONCLUSIONS

This study identified several easy to obtain predictors of infliximab failure in patients with Crohn's disease, and these are in line with previous reports. Those with a high-risk profile for infliximab failure in whom infliximab initiation is considered, should be treated as early as possible making use of therapeutic drug monitoring.

Optimizing Treatment with TNF Inhibitors in Inflammatory Bowel Disease by Monitoring Drug Levels and Antidrug Antibodies

BACKGROUND

Biological tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of inflammatory bowel disease and redefined treatment goals to include mucosal healing. Clinicians are faced with challenges such as inadequate responses, treatment failures, side effects, and high drug costs. The objective is to review optimization of anti-TNF therapy by use of personalized treatment strategies based on circulating drug levels and antidrug antibodies (Abs), i.e. therapeutic drug monitoring (TDM). Furthermore, to outline TDM-related pitfalls and their prevention.

METHODS

Literature review.

RESULTS

Circulating anti-TNF drug trough level is a marker for the pharmacokinetics (PK) of TNF inhibitors. Because of a number of factors, including antidrug antibodies, PK varies between and within patients across time leading to variable clinical outcomes. Differences in intestinal inflammatory phenotype influencing the pharmacodynamic (PD) responses to TNF inhibitors also affect treatment outcomes. As an alternative to handling anti-TNF-treated patients by empiric strategies, TDM identifies underlying PK and PD-related reasons for treatment failure and aids decision making to secure optimal clinical and economic outcomes. Although promising, evidence does not the support use of TDM to counteract treatment failure in quiescent disease. Use of TDM is challenged by methodological biases, difficulties related to differentiation between PK and PD problems, and temporal biases due to lack of chronology between changes in PK versus symptomatic and objective disease activity manifestations. Biases can be accommodated by knowledgeable interpretation of results obtained by validated assays with clinically established thresholds, and by repeated assessments over time using complimentary techniques.

CONCLUSIONS

TDM-guided anti-TNF therapy at treatment failure has been brought from bench to bedside.

Identifying Patients at High Risk of Loss of Response to Infliximab Maintenance Therapy in Paediatric Crohn's Disease

BACKGROUND AND AIMS

Loss of response to infliximab resulting in discontinuation of therapy is a frequent problem encountered in paediatric Crohn's disease. Although identifying patients at risk of failure could have important implications for follow-up, literature in this area remains sparse. Our primary aim was to identify predictors of loss of response to infliximab among patients who were responders to induction. The secondary aim was to identify predictors of non-response to induction.

METHODS

A retrospective cohort of patients with paediatric Crohn's disease treated with infliximab between 2000 and 2013 was followed until loss of response to infliximab or transfer to adult care. Predictors of response to induction therapy were studied by multivariate logistic regression. Time to treatment failure was analysed with a multivariate Cox model.

RESULTS

Two-hundred and forty-eight patients were eligible for the study. Of these, 196 (79%) were responders to induction (57% clinical remission and 22% clinical response) and 52 (21%) were non-responders. Steroid resistance was the only variable independently associated with primary non-response (odds ratio [OR] 4.57, 95% confidence interval [CI] 1.67-12.50, p = 0.002). Thirty-one of the 196 responders discontinued infliximab due to loss of response after a mean of 1.6±1.3 years of treatment. Predictors of loss of response were level of response to induction (clinical response vs clinical remission, hazard ratio [HR] 3.74, 95% CI 1.80-7.80, p = 0.0004) and isolated colonic disease (HR 2.72, 95% CI 1.30-5.71, p = 0.008).

CONCLUSIONS

Patients who fail to achieve clinical remission after induction and/or who have isolated colonic disease are at increased risk of loss of response to infliximab.

Predicting durable response or resistance to antitumor necrosis factor therapy in inflammatory bowel disease

Monoclonal antibodies to tumor necrosis factor (TNF) have become a mainstay of the therapeutic armamentarium in inflammatory bowel disease (IBD) over the last 15 years. Although highly effective, primary and secondary nonresponse are common and associated with poor clinical outcomes and significant costs. Multiple clinical, genetic and immunopharmacological factors may impact the response to anti-TNFs. Early stratification of IBD patients by the expected risk of therapeutic failure during the induction and maintenance phases of treatment may allow for treatment optimization and potentially optimal short- and long-term outcomes. The aim of this review is to summarize the current data concerning the potential predictors of therapeutic success and failure of anti-TNFs in IBD.

Review article: acute severe ulcerative colitis - evidence-based consensus statements

BACKGROUND

Acute severe ulcerative colitis (ASUC) is a potentially life-threatening complication of ulcerative colitis.

AIM

To develop consensus statements based on a systematic review of the literature of the management of ASUC to improve patient outcome.

METHODS

Following a literature review, the Delphi method was used to develop the consensus statements. A steering committee, based in Australia, generated the statements of interest. Three rounds of anonymous voting were carried out to achieve the final results. Acceptance of statements was pre-determined by ≥80% votes in 'complete agreement' or 'agreement with minor reservation'.

RESULTS

Key recommendations include that patients with ASUC should be: hospitalised, undergo unprepared flexible sigmoidoscopy to assess severity and to exclude cytomegalovirus colitis, and be provided with venous thromboembolism prophylaxis and intravenous hydrocortisone 100 mg three or four times daily with close monitoring by a multidisciplinary team. Rescue therapy such as infliximab or ciclosporin should be started if insufficient response by day 3, and colectomy considered if no response to 7 days of rescue therapy or earlier if deterioration. With such an approach, it is expected that colectomy rate during admission will be below 30% and mortality less than 1% in specialist centres.

CONCLUSION

These evidenced-based consensus statements on acute severe ulcerative colitis, developed by a multidisciplinary group, provide up-to-date best practice recommendations that improve and harmonise management as well as provide auditable quality assessments.