Impact of Smoking Cessation on the Clinical Course of Crohn's Disease Under Current Therapeutic Algorithms: A Multicenter Prospective Study

Duration of smoking cessation in patients with inflammatory bowel disease

BACKGROUND AND OBJECTIVES

Smoking can worsen inflammatory bowel disease (IBD), although evidence regarding the duration of cessation is scarce. The objectives of the study were to determine the duration of abstinence and identify the characteristics of relapse in IBD patients.

PATIENTS AND METHODS

Using the local database of a nationwide registry of patients with IBD, we identified patients who were active smokers at the time of IBD diagnosis and invited them to participate in the study. Patients were asked about their smoking habit and those who were ex-smokers constituted the study cohort. We obtained clinical and smoking-related data of ex-smokers from medical records and telephone interviews. We measured nicotine dependence using the Fagerström Test for Nicotine Dependence (FTND).

RESULTS

We enrolled 121 IBD patients who were ex-smokers: 89 patients with Crohn's disease (CD) and 33 patients with ulcerative colitis (UC). The median age at cessation was lower in patients with CD (38 years) than in patients with UC (46 years) (p=0.002). Follow-up time was shorter in CD patients than in UC patients (114 vs. 168 months, p=0.035). No difference was found in the FTND score. Relapse was more common in CD patients (46%) than in UC patients (24%) (p=0.029), although time to first relapse was similar in both groups of patients (12 and 15 months, respectively; p=0.056). Nicotine dependence was the only independent factor associated with relapse.

CONCLUSIONS

The risk of smoking relapse was high, especially in CD patients, although their dependence level was similar to that of UC patients.

Assessing Progression of Biologic Therapies Based on Smoking Status in Patients With Crohn's Disease

BACKGROUND

Active smoking is a well-established risk factor for developing Crohn's disease (CD) and negatively impacts overall disease progression. Patients who start or continue smoking after CD diagnosis are at risk for poor outcomes, higher therapeutic requirements, and have higher rates of relapse. However, it remains unclear if the exposure to smoking leads to increased sequencing through treatment therapies, especially biologics.

METHODS

The Study of Prospective Adult Research Cohort with IBD (SPARC IBD) registry has been collecting patient-reported outcomes data in real-time, as well as laboratory, endoscopic, and pathologic samples from 17 tertiary referral centers since 2016. In this study, we conducted a retrospective review of the SPARC clinical registry collected between December 2016 and January 2021 from 1 participating site, the University of Maryland School of Medicine's Inflammatory Bowel Disease Program. A total of 619 patients were enrolled in the SPARC IBD database. Four hundred twenty-five patients with CD were included for initial review of completeness of data; of these, 144 patients were excluded due to missing data on smoking status and/or biologic treatment, resulting in a final cohort of 281 patients. We collected and analyzed baseline demographic and clinical characteristics. The final cohort was categorized into 3 exposure groups: current, former, and never smokers. Our outcome of interest was number biologics used, categorized into 3 groups: 0, 1, or ≥2 biologics.

RESULTS

One hundred seventy-two never smokers, 70 former smokers, and 39 current smokers were identified. Current, former, and never smokers had no statistically significant differences in number of biologics used (ie, biologic sequencing). However, statistically significant independent risk factors for increased sequencing of biologics were identified. These risk factors included female sex, ileocolonic disease location, younger age at diagnosis, and prolonged disease duration; none of these factors remained significant in adjusted analyses.

CONCLUSION

To date, this is the first study assessing the association of smoking and sequencing of biologics. Although current or former smokers were not found to sequence through more biologics when compared with never smokers, smoking is a well-established risk factor for poor health outcomes, and efforts should be made to counsel patients to quit. Further, additional research must be done to stratify risk to patients based on amount of tobacco exposure.

Bowel Stiffness Assessed by Shear-Wave Ultrasound Elastography Predicts Disease Behavior Progression in Patients With Crohn's Disease

INTRODUCTION

There is a lack of reliable predictors of disease behavior progression in patients with Crohn's disease (CD). Real-time shear-wave elastography (SWE) is a novel method for evaluating tissue stiffness. However, its value for assessing CD has not yet been investigated. We aimed to explore the value of SWE and other ultrasound parameters at diagnosis in predicting CD behavior progression.

METHODS

We retrospectively collected data from patients with CD with the nonstenotic nonpenetrating disease (B1 phenotype based on the Montreal classification). All patients underwent intestinal ultrasound at baseline and were followed up. The end point was defined as disease behavior progression to stricturing (B2) or penetrating (B3) disease. Cox regression analysis was performed for the association between baseline characteristics and subsequent end points. In addition, a multivariate nomogram was established to predict the risk of disease behavior progression quantitatively.

RESULTS

A total of 130 patients with CD with B1 phenotype were enrolled. Twenty-seven patients (20.8%) developed B2 or B3 disease, with a median follow-up of 33 months. Multivariate analysis identified that SWE was the only independent predictor of disease behavior progression (hazard ratio 1.08, 95% confidence interval 1.03-1.12, P = 0.001). A reverse of the HR appeared at the cutoff 12.75 kPa. The nomogram incorporating SWE and other clinical characteristics showed a good prediction performance (area under the curve = 0.792).

DISCUSSION

Intestinal stiffness assessed using SWE is an independent predictor of disease behavior progression in patients with CD. Patients with CD with SWE >12.75 kPa at diagnosis are prone to progress toward stricturing or penetrating diseases.

Discontinuation of Anti-Tumour Necrosis Factor Therapy in Patients with Perianal Fistulizing Crohn's Disease: Individual Participant Data Meta-Analysis of 309 Patients from 12 Studies

BACKGROUND

The risk of relapse after anti-tumour necrosis factor [TNF] therapy discontinuation in Crohn's disease patients with perianal fistulas [pCD] is unclear. We aimed to assess this risk.

METHODS

A systematic literature search was conducted to identify cohort studies on the incidence of relapse following anti-TNF discontinuation in pCD patients. Individual participant data were requested from the original study cohorts. Inclusion criteria were age ≥16 years, pCD as a (co)indication for start of anti-TNF therapy, more than three doses, and remission of luminal and pCD at anti-TNF discontinuation. The primary outcome was the cumulative incidence of CD relapse using Kaplan-Meier estimates. Secondary outcomes included response to re-treatment and risk factors associated with relapse as assessed by Cox regression analysis.

RESULTS

In total, 309 patients from 12 studies in ten countries were included. The median duration of anti-TNF treatment was 14 months [interquartile range 5.8-32.5]. Most patients were treated for pCD without active luminal disease [89%], received first-line anti-TNF therapy [87%], and continued immunomodulatory therapy following anti-TNF discontinuation [78%]. The overall cumulative incidence of relapse was 36% (95% confidence interval [CI] 25-48%) and 42% [95% CI 32-53%] at 1 and 2 years after anti-TNF discontinuation, respectively. Risk factors for relapse included smoking (hazard ratio [HR] 1.5 [1.0, 2.1]) and history of proctitis (HR 1.7 [1.1, 2.5]). The overall re-treatment response rate was 82%.

CONCLUSIONS

This individual participant data meta-analysis, on predominantly patients with pCD without active luminal disease and first-line anti-TNF therapy, shows that over half of patients remain in remission 2 years after anti-TNF discontinuation. Therefore, anti-TNF discontinuation may be considered in this subgroup.

Effectiveness of smoking cessation interventions for smokers with Crohn's disease: a systematic review

Aims

Smoking cessation (SC) in Crohn's disease (CD) is widely accepted to be the most important modifiable factor to improve outcomes in these patients. We aimed in this review to provide a summary of the evidence base regarding the effectiveness of SC interventions in patients with CD.

Materials & methods

The following databases were systematically searched from inception to February 2022: PubMed, Google Scholar and Cochrane Library.

Results

Overall, five articles met the research criteria. Studies sample size ranged from 17 to 474 patients. At the outcome level, the abstinence rates ranged from 14.8 to 42% and was ≤25% in four studies. The three studies with control groups did not report statistically higher SC rates in the intervention groups. No predictors of interventions success were identified in this review.

Conclusion

Implementation and evaluation of tailored SC interventions for CD patients must be promptly addressed in further studies.

Surgical Strategies to Reduce Postoperative Recurrence of Crohn's Disease After Ileocolic Resection

Postoperative recurrence after ileocaecal resection for fibrostenotic terminal ileal Crohn's disease is a significant issue for patients as it can result in symptom recurrence and requirement for further surgery. There are very few modifiable factors, aside from smoking cessation, that can reduce the risk of postoperative recurrence. Until relatively recently, the surgical technique used for resection and anastomosis had little or no impact on postoperative recurrence rates. Novel surgical techniques such as the Kono-S anastomosis and extended mesenteric excision have shown promise as ways to reduce postoperative recurrence rates. This manuscript will review and discuss the evidence regarding a range of surgical techniques and their potential role in reducing disease recurrence. Some of the techniques have been shown to be associated with significant benefits for patients and have already been integrated into the routine clinical practice of some surgeons, while other techniques remain under investigation. Current techniques such as resection of the mesentery close to the intestine and stapled side to side anastomosis are being challenged. It is looking more likely that surgeons will have a major role to play when it comes to reducing recurrence rates for patients undergoing ileocaecal resection for Crohn's disease.

Post-surgical recurrence of Crohn's disease: Situational analysis and future prospects

Surgery retains a major role in the treatment of Crohn's disease, and the prevention of post-operative recurrence is an essential issue. In fact, despite the increasing use of biotherapies, almost all of the patients who undergo surgery will present with a recurrence, initially endoscopic and then clinical, eventually leading to a second intervention in 15 to 20% of cases. Certain risk factors for recurrence such as smoking, repeated and/or extensive resections, anoperineal involvement, myenteric plexitis, epithelioid granulomas, penetrating disease behaviour and lack of post-operative prophylactic treatment have been well established. Currently, measures to prevent post-operative recurrence are based mainly on smoking cessation in all patients and the prescription of anti-TNFα medications for patients with a high risk of recurrence (at least two risk factors for recurrence). However, new surgical techniques have recently been described which could modify post-operative prevention strategies. Kono's lateral anti-mesenteric anastomosis could significantly reduce clinical and endoscopic recurrence compared to conventional anastomosis techniques. Long latero-lateral isoperistaltic stricturoplasties have been shown to be feasible and are associated with a low rate of long-term symptomatic recurrence requiring surgery. In a preliminary series, intestinal resections with extensive mesenteric resection reduced the rate of recurrence in comparison with patients operated on conventionally (3% vs. 40% at five years). If the results of these new surgical techniques are confirmed, the indications for post-operative immunomodulatory treatments could be downgraded in patients currently considered to be at high risk of recurrence.

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.

Real-world disease activity and sociodemographic, clinical and treatment characteristics of moderate-to-severe inflammatory bowel disease in Brazil

BACKGROUND

Understanding the treatment landscape of inflammatory bowel diseases (IBD) is essential for improving disease management and patient outcomes. Brazil is the largest Latin American country, and it presents socioeconomic and health care differences across its geographical regions. This country has the highest increase in IBD incidence and prevalence in Latin America, but information about the clinical and treatment characteristics of IBD is scarce.

AIM

To describe the sociodemographic, clinical, and treatment characteristics of IBD outpatients in Brazil overall and in the Southeast, South and Northeast/Midwest regions.

METHODS

Multicenter, cross-sectional study with a 3-year retrospective chart review component. Patients with moderate-to-severe Crohn's disease (CD) or ulcerative colitis (UC) were consecutively enrolled between October 2016 and February 2017. Active CD at enrollment was defined as a Harvey Bradshaw Index ≥ 8 or a CD Activity Index ≥ 220 or a calprotectin level > 200 μg/g or an active result based on colonoscopy suggestive of inadequate control during the previous year; active UC was defined as a partial Mayo score ≥ 5. Descriptive statistics were used to analyze all variables.

RESULTS

In a total of 407 included patients, CD was more frequent than UC, both overall (264 CD/143 UC patients) and by region (CD:UC ratios of 2.1 in the Southeast, 1.6 in the South and 1.2 in the Northeast/Midwest). The majority of patients were female (54.2% of CD; 56.6% of UC), and the mean ages were 45.9 ± 13.8 years (CD) and 42.9 ± 13.0 years (UC). The median disease duration was 10.0 (range: 0.5-45) years for both IBD types. At enrollment, 44.7% [95% confidence interval (CI): 38.7-50.7] of CD patients and 25.2% (95%CI: 18.1-32.3) of UC patients presented with active disease. More than 95% of IBD patients were receiving treatment at enrollment; CD patients were commonly treated with biologics (71.6%) and immunosuppressors (67.4%), and UC patients were commonly treated with mesalazine [5-Aminosalicylic acid (5-ASA)] derivates (69.9%) and immunosuppressors (44.1%). More than 50% of the CD patients had ileocolonic disease, and 41.7% presented with stricturing disease. One-quarter of CD patients had undergone CD-related surgery in the past 3 years, and this proportion was lower in the Northeast/Midwest region (2.9%).

CONCLUSION

In Brazil, there are regional variations in IBD management. CD outweighs UC in both frequency and disease activity. However, one-quarter of UC patients have active disease, and most are receiving 5-ASA treatment.

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.

Prevention of Postoperative Recurrence in CD: Tailoring Treatment to Patient Profile

Crohn's disease (CD) is an immune-mediated condition characterized by the transmural inflammation of the gut tissue, associated with progressive bowel damage often leading to surgical intervention. As operative resection of the damaged segment is not curative, a majority of patients undergoing intestinal resections for complicated CD present disease recurrence within 3 years after the intervention. Postoperative recurrence can be defined as endoscopic, clinical, radiological or surgical. Endoscopic recurrence rates within 1 year exceed 60% and the severity, according to the Rutgeerts' score, is associated with worse prognosis and can predict clinical recurrence (in up to 1/3 of the patients). Most importantly, about 50% of patients will undergo a reoperation after 10 years of their first intestinal resection. Therefore, the prevention of postoperative recurrence in CD remains a challenge in clinical practice and should be properly managed. We aim to summarize the most recent data on the definition, risk factors, assessment and treatment of postoperative CD recurrence.

Development of a uniform, very aggressive disease phenotype in all homozygous carriers of the NOD2 mutation p.Leu1007fsX1008 with Crohn's disease and active smoking status resulting in ileal stenosis requiring surgery

BACKGROUND

NOD2 variants are the strongest genetic predictors for susceptibility to Crohn's disease (CD). However, the clinical value of NOD2 on an individual patient level remains controversial. We aimed to define the predictive power of the major NOD2 mutations regarding complicated CD in a large single center cohort.

METHODS

1076 CD patients were prospectively genotyped for the three common CD-associated NOD2 mutations rs2066844, rs2066845, and rs2066847, followed by detailed genotype-phenotype analyses.

RESULTS

Overall, 434 CD patients (40.3%) carried at least one of the three main NOD2 mutations. A significantly higher minor allele frequency (15.6%) of the NOD2 frameshift mutation p.Leu1007fsX1008 (rs2066847) was seen in patients with aggressive disease compared to 8.2% in patients with mild disease (p = 2.6 x 10-5). Moreover, a total of 54 CD patients (5.0%) were homozygous for this NOD2 frameshift mutation. 100% of these patients had ileal disease compared to 82% of NOD2 wild-type carriers (p<0.0001). In homozygous carriers of the NOD2 frameshift mutation, 87% presented with ileal stenosis, 68.5% had fistulas, and 72.2% required CD-related surgery despite immunosuppressive therapy in 87% of these patients. All homozygous carriers of the 1007fs mutation who were active smokers had ileal stenosis and required CD-related surgery.

CONCLUSION

Homozygosity for Leu1007fsX1008 is an excellent biomarker for predicting complicated CD on an individual patient level. Active smoking and homozygosity for this mutation is associated with a 100% risk for developing ileal stenosis requiring CD-related surgery. In these patients, smoking cessation and early initiation of immunosuppressive strategies may be beneficial.

Precision nicotine metabolism-informed care for smoking cessation in Crohn's disease: A pilot study

INTRODUCTION

Smoking is a strong risk factor for disease severity in Crohn's disease (CD) and cessation improves outcomes. The nicotine metabolite ratio (NMR) predicts cessation success with pharmacotherapy: varenicline doubles cessation over nicotine replacement therapy (NRT) for "normal", but not "slow" metabolizers. Varenicline side effects are heightened in slow metabolizers. Methods using NMR to optimize cessation pharmacotherapy have not been evaluated in CD.

AIMS

We aim to determine the prevalence of smoking in a CD population and then assess these smokers' attitudes toward a personalized metabolism-informed care (MIC) approach to cessation.

METHODS

In this observational study, we surveyed 1098 patients visiting an inflammatory bowel disease center about their smoking history. We then evaluated a subgroup of individuals with CD (n = 32) who participated in a randomized controlled trial of smoking cessation using MIC versus usual care. For MIC, medication selection was informed by the NMR (normal ≥0.31 vs. slow <0.31). The primary outcomes were intervention satisfaction and match rates between NMR and medication choice.

RESULTS

The baseline prevalence of smoking in our CD population was 13%. Intervention participants reported high rates of satisfaction (85%) and chose a medication that matched their NMR result more often in the MIC group (100% vs. 64%, p = 0.01). Six of 16 (37.5%) patients prescribed varenicline discontinued due to side effects.

CONCLUSION

MIC produced high rates of satisfaction and matching between NMR and medication in CD patients, supporting patient acceptance and feasibility of precision smoking cessation in this population. To reduce smoking in CD, therapies such as MIC are needed to maximize efficacy and minimize side effects.

Does Smoking Cessation Reduce Surgical Recurrence After Primary Ileocolic Resection for Crohn's Disease?

BACKGROUND

Tobacco smoking is a known risk factor for recurrence of Crohn's disease after surgical resection.

OBJECTIVE

This study assessed the effect of smoking cessation on long-term surgical recurrence after primary ileocolic resection for Crohn's disease.

DESIGN

A retrospective review of a prospectively maintained database was conducted.

SETTINGS

Patient demographic data and medical and surgical details were combined from 2 specialist centers. After ethical approval, patients were contacted in case of missing data regarding smoking habit.

PATIENTS

All patients undergoing ileocolic resection between 2000 and 2012 for histologically confirmed Crohn's disease were included. Those with previous intestinal resection, strictureplasty for Crohn's disease, leak after ileocolic resection, or who were never reversed were excluded.

MAIN OUTCOME MEASURES

The primary end point was surgical recurrence measured by Kaplan-Meier survival analysis and secondary medical therapy at time of follow-up.

RESULTS

Over a 12-year period, 290 patients underwent ileocolic resection. Full smoking data were available for 242 (83%) of 290 patients. There were 169 nonsmokers (70%; group 1), 42 active smokers at the time of ileocolic resection who continued smoking up to last follow-up (17%; group 2), and 31 (13%) who quit smoking after ileocolic resection (group 3). The median time of smoking exposure after ileocolic resection for group 3 was 3 years (interquartile range, 0-6 y), and median follow-up time for the whole group was 112 months (9 mo; interquartile range, 84-148 mo). Kaplan-Meier survival analysis showed a significantly higher surgical recurrence rate for group 2 compared with group 3 (16/42 (38%) vs 3/31 (10%); p = 0.02; risk ratio = 3.9 (95% CI, 1-12)). In addition, significantly more patients in group 2 without surgical recurrence received immunomodulatory maintenance therapy compared with group 3 (12/26 (46%) vs 4/28 (14%); p = 0.01; risk ratio = 3.2 (95% CI, 1-9)).

LIMITATIONS

The study was limited by its retrospective design and small number of patients.

CONCLUSIONS

Smoking cessation after primary ileocolic resection for Crohn's disease may significantly reduce long-term risk of surgical recurrence and is associated with less use of maintenance therapy. See Video Abstract at http://links.lww.com/DCR/B86. ¿DEJAR DE FUMAR REDUCE LA RECURRENCIA QUIRÚRGICA DESPUÉS DE LA RESECCIÓN ILEOCÓLICA PRIMARIA PARA LA ENFERMEDAD DE CROHN?: Fumar tabaco es un factor de riesgo conocido para la recurrencia de la enfermedad de Crohn después de la resección quirúrgica.Evaluar el efecto de dejar de fumar en la recurrencia quirúrgica a largo plazo después de la resección ileocólica primaria para la enfermedad de Crohn.Revisión retrospectiva de una base de datos mantenida prospectivamente.Se combinaron datos demográficos del paciente, así como detalles médicos y quirúrgicos de dos centros especializados. Después de la aprobación ética, se contactó a los pacientes en caso de falta de datos sobre el hábito de fumar.Todos los pacientes sometidos a resección ileocólica entre 2000 y 2012 por enfermedad de Crohn confirmada histológicamente. Se excluyeron aquellos con resección intestinal previa, estenosis por enfermedad de Crohn, fuga después de resección ileocólica o que nunca se revirtieron.La principal variable fue la recurrencia quirúrgica medida por análisis de supervivencia de Kaplan-Meier, terapia médica secundaria en el momento del seguimiento.Durante un período de 12 años, 290 pacientes fueron sometidos a resección ileocólica. Se dispuso de datos completos sobre el tabaquismo para 242/290 (83%). Hubo 169 no fumadores (70%) (grupo 1), 42 (17%) fumadores activos en el momento de la resección ileocólica que continuaron fumando hasta el último seguimiento (grupo 2) y 31 (13%) que dejaron de fumar después de resección ileocólica (grupo 3). La mediana del tiempo de exposición al tabaquismo después de la resección ileocólica para el grupo 3 fue de 3 años (IQR 0-6) y la mediana del tiempo de seguimiento para todo el grupo fue de 112 meses (9 años) (IQR 84-148). El análisis de supervivencia de Kaplan-Meier mostró una tasa de recurrencia quirúrgica significativamente mayor para el grupo 2 en comparación con el grupo 3 (16/42 (38%) frente a 3/31 (10%), p = 0.02; razón de riesgo 3.9 (IC 95% 1-12)). Además, un número significativamente mayor de pacientes del grupo 2 sin recurrencia quirúrgica recibieron terapia de mantenimiento inmunomoduladora en comparación con el grupo 3 (12/26 (46%) frente a 4/28 (14%), p = 0.01; razón de riesgo 3.2 (IC 95% 1-9)).Diseño retrospectivo y pequeño número de pacientes.Dejar de fumar después de la resección ileocólica primaria para la enfermedad de Crohn puede reducir significativamente el riesgo a largo plazo de recurrencia quirúrgica y se asocia con un menor uso del tratamiento de mantenimiento. Consulte Video Resumen en http://links.lww.com/DCR/B86. (Traducción-Dr. Gonzalo Federico Hagerman).

Risk Factors for Medication Nonadherence to Self-Injectable Biologic Therapy in Adult Patients With Inflammatory Bowel Disease

BACKGROUND

In inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), nonadherence to biologic therapy increases risk of disease flare. The aim of this study was to identify risk factors for nonadherence.

METHODS

This was a single-center retrospective study evaluating patients with IBD treated at a tertiary care center and prescribed self-injectable biologic therapy using the center's specialty pharmacy. Adherence was defined using medication possession ratio (MPR). Nonadherence was defined as MPR <0.86.

RESULTS

Four hundred sixty patients (n = 393 with CD and n = 67 with UC) were evaluated with mean MPR (interquartile range) equaling 0.89 (0.48-1). Overall, 69% of patients were adherent (defined as MPR ≥0.86), 66% of patients with CD and 87% of patients with UC. In univariate analysis, several factors increased risk of nonadherence: CD diagnosis, insurance type, psychiatric history, smoking, prior biologic use, and narcotic use (P < 0.05). In multivariable analysis, Medicaid insurance (odds ratio [OR], 5.5; 95% confidence interval [CI], 1.85-15.6) and CD diagnosis (OR, 2.8; 95% CI, 1.3-6.0) increased risk of nonadherence. In CD, as the number of risk factors increased (narcotic use, psychiatric history, prior biologic use, and smoking), the probability of nonadherence increased. Adherence was 72% in patients with 0-1 risk factors, decreasing to 62%, 61%, and 42% in patients with 2, 3, and 4 risk factors, respectively (P < 0.05).

CONCLUSIONS

This study identified risk factors for nonadherence to biologic therapy. In patients with CD, the probability of nonadherence increased as the number of risk factors increased.

Impact of Genes and the Environment on the Pathogenesis and Disease Course of Inflammatory Bowel Disease

Crohn's disease and ulcerative colitis constitute two major subgroups of inflammatory bowel diseases (IBD), a group of complex polygenic diseases characterized by chronic and progressive inflammation in the gastrointestinal tract. In recent years, methodological advances in genetic analysis have greatly expanded our understanding of the genetic background of IBD. So far, more than 240 genetic risk loci have been identified for IBD. However, these risk alleles explain less than 30% of the susceptibility to disease development, suggesting that environmental factors contribute considerably. The increasing occurrence of IBD in Eastern countries following their 'westernization', as well as the increased risk of disease among those who migrate to high-incidence regions, also suggest that the environment is key in the pathogenesis of IBD. In this review, we summarize the current evidence on the role of genetic and environmental factors in the susceptibility to, and disease course of, IBD, and we suggest how these findings might be applied to clinical practice.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

Occurrence of skin manifestations in patients of the Swiss Inflammatory Bowel Disease Cohort Study

BACKGROUND/AIMS

Extraintestinal cutaneous manifestations of IBD represent a severe disease complication and an early and accurate treatment might positively influence the disease course. Using the patient collective of the Swiss IBD Cohort Study (SIBDCS), we analysed epidemiological as well as clinical factors being associated with the onset of pyoderma gangrenosum, erythema nodosum and aphthous ulcers in IBD patients.

METHODS

We included 3266 SIBDCs patients, 1840 with Crohn's disease (CD) and 1426 with ulcerative colitis (UC) or IBD unclassified (IBDU) and analysed the association of cutaneous manifestations with age, age at diagnosis time, type of disease, gender, family history, HLA-allotype, smoking, intestinal disease activity, therapy and other extraintestinal manifestations (EIM).

RESULTS

354 CD patients and 136 UC/IBDU patients presented with skin manifestations at any time during their disease course. In both, CD and UC, female gender and younger age at IBD diagnosis were significantly associated with extraintestinal skin manifestations. For CD, we also detected a positive family history as associated factor. As an indicator of more intensive intestinal disease activity, patients with cutaneous manifestations of IBD needed more frequently therapy with antibiotics, steroids, immunomodulators and anti-TNF. Multivariate analysis revealed female gender, younger age at diagnosis and presence of other extraintestinal manifestations as factors being associated with skin EIM in IBD patients and anti-TNF as well as immunomodulatory treatment in CD patients.

CONCLUSION

Our results suggest that young females with a positive family history of IBD might be at increased risk for the onset of skin manifestations and require a careful screening for such complications.

Diet and inflammatory bowel disease: The Asian Working Group guidelines

INTRODUCTION

These Asian Working Group guidelines on diet in inflammatory bowel disease (IBD) present a multidisciplinary focus on clinical nutrition in IBD in Asian countries.

METHODOLOGY

The guidelines are based on evidence from existing published literature; however, if objective data were lacking or inconclusive, expert opinion was considered. The conclusions and 38 recommendations have been subject to full peer review and a Delphi process in which uniformly positive responses (agree or strongly agree) were required.

RESULTS

Diet has an important role in IBD pathogenesis, and an increase in the incidence of IBD in Asian countries has paralleled changes in the dietary patterns. The present consensus endeavors to address the following topics in relation to IBD: (i) role of diet in the pathogenesis; (ii) diet as a therapy; (iii) malnutrition and nutritional assessment of the patients; (iv) dietary recommendations; (v) nutritional rehabilitation; and (vi) nutrition in special situations like surgery, pregnancy, and lactation.

CONCLUSIONS

Available objective data to guide nutritional support and primary nutritional therapy in IBD are presented as 38 recommendations.

Assessing mental health and the relation with variables of demographic and clinical in Crohn's disease patients; 2016-2017

Background

Crohn's disease is a group of special diseases that are considered in psychiatric studies because there is a contrast between the physical and psychological diseases among the affected patients.

Aim

The aim of this study was assessing mental health and the relation with variables of demographic and clinical in Crohn's disease patients.

Methods

In this epidemiological study, 96 patients with Crohn's disease who referred to educational hospitals in Ahvaz during 2016--2017 were evaluated by demographic and clinical questionnaires and SCL-90 questionnaires for mental health, and the information was analyzed by SPSS software version 22.

Results

The mean physical complaints in subjects was 24.63 ± 4.08 and the mean mental health was calculated to be 187.75 ± 25.17. Multivariate analysis of mental health showed that steroid consumption (P value < 0.001) and nonsmoking (P value = 0.038) were associated with higher mental health in the individuals.

Conclusions

Crohn's patients suffered from decreased mental parameters in dimensions such as physical complaints, obsession--compulsion behavior, sensitivity to interactions, depression, anxiety, aggression, phobia, psychosis, and paranoid thoughts.

Novel Approaches to Ileocolic and Perianal Fistulising Crohn's Disease

Crohn's disease (CD) is a well-known idiopathic inflammatory bowel disease characterised by transmural inflammation which can ordinarily affect all the gastrointestinal tract. Its true aetiology is unknown, and a causal therapy is not available to date. The most peculiar aspect of CD lies in its absolute heterogeneity, as we might face various scenarios, locations of the disease, pathologic behaviours, and severity of the disease itself. For these reasons, the cornerstone for the treatment of CD lies in a complex multimodal management, requiring close collaborations among surgeons, gastroenterologists, radiologists, and staff nurses. Advances in surgical and medical therapy are changing the course of the disease. Nowadays, the introduction of both laparoscopy and novel surgical techniques, the improvement of recovery pathways, and the opening of new frontiers are allowing healthcare professionals to deal with complex and recurrent scenarios, trying to spare bowel and anal function, thus ensuring a better quality of life for the patient. Given the heterogeneity and complexity of this disease, it would be impractical to encompass all the aspects of surgical management of CD. This review will address areas that are considered to be hot topics, controversies, challenges, and novelties: thus, we will focus on complex ileocecal disease, surgical strategies, and fistulising perianal conditions.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in surgery for inflammatory bowel disease

AIM

There is a requirement of an expansive and up to date review of surgical management of inflammatory bowel disease (IBD) that can dovetail with the medical guidelines produced by the British Society of Gastroenterology.

METHODS

Surgeons who are members of the ACPGBI with a recognised interest in IBD were invited to contribute various sections of the guidelines. They were directed to produce a procedure based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. An editorial board was convened to ensure consistency of style, presentation and quality. Each author was asked to provide a set of recommendations which were evidence based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after 2 votes were included in the guidelines.

RESULTS

All aspects of surgical care for IBD have been included along with 157 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence based summary of the current surgical knowledge in the management of IBD and will serve as a useful practical text for clinicians performing this type of surgery.

Asthma is not associated with the need for surgery in Crohn's disease when controlling for smoking status: a population-based cohort study

Purpose

Growing evidence suggests asthma and Crohn’s disease commonly cooccur. However, the impact of asthma on the prognosis of Crohn’s disease is unknown. The aim of our study was to assess the effect of asthma on the need for intestinal resection in patients with Crohn’s disease while adjusting for smoking status, imputed from a smaller, secondary data set.

Patients and methods

Using health administrative data from a universally funded healthcare plan in Alberta, Canada, we conducted a cohort study to assess the effect of asthma on the need for surgery in patients with Crohn’s disease diagnosed between 2002 and 2008 (N=2,113). Validated algorithms were used to identify incident cases of Crohn’s disease, cooccurring asthma, and intestinal resection. The association between asthma and intestinal resection was estimated using multivariable Cox proportional hazards regression. Smoking status was imputed using a novel method using martingale residuals, derived from a data set of 485 patients enrolled in the Alberta Inflammatory Bowel Disease Consortium (2007 to 2014) who completed environmental questionnaires. All analyses were adjusted for age, sex, rural/urban status, and mean neighborhood income quintile.

Results

Asthma did not increase the risk of surgery in the health administrative data when not adjusting for smoking status (HR 1.03, 95% CI 0.81 to 1.29). The association remained nonsignificant after imputing smoking status in the health administrative data (HR 1.03, 95% CI 0.81 to 1.29).

Conclusion

Although asthma is associated with an increased risk of Crohn’s disease, co-occurring asthma is not associated with the risk of surgery in these patients. This null association persisted after adjusting for smoking status. This study described a novel method to adjust for confounding (smoking status) in time-to-event analyses, even when the confounding variable is unmeasured in health administrative data.

Urbanization and the gut microbiota in health and inflammatory bowel disease

In the 21st century, urbanization represents a major demographic shift in developed and developing countries. Rapid urbanization in the developing world has been associated with an increasing incidence of several autoimmune diseases, including IBD. Patients with IBD exhibit a decrease in the diversity and richness of the gut microbiota, while urbanization attenuates the gut microbial diversity and might have a role in the pathogenesis of IBD. Environmental exposures during urbanization, including Westernization of diet, increased antibiotic use, pollution, improved hygiene status and early-life microbial exposure, have been shown to affect the gut microbiota. The disparate patterns of the gut microbiota composition in rural and urban areas offer an opportunity to understand the contribution of a 'rural microbiome' in potentially protecting against the development of IBD. This Perspective discusses the effect of urbanization and its surrogates on the gut microbiome (bacteriome, virome, mycobiome and helminths) in both human health and IBD and how such changes might be associated with the development of IBD.

Induction with Infliximab and a Plant-Based Diet as First-Line (IPF) Therapy for Crohn Disease: A Single-Group Trial

BACKGROUND

Approximately 30% of patients with Crohn disease (CD) are unresponsive to biologics. No previous study has focused on a plant-based diet in an induction phase of CD treatment.

OBJECTIVE

To investigate the remission rate of infliximab combined with a plant-based diet as first-line (IPF) therapy for CD.

METHODS

This was a prospective single-group trial conducted at tertiary hospitals. Subjects included consecutive adults with a new diagnosis (n = 26), children with a new diagnosis (n = 11), and relapsing adults (n = 9) with CD who were naïve to treatment with biologics. Patients were admitted and administered a standard induction therapy with infliximab (5 mg/kg; 3 infusions at 0, 2, and 6 weeks). Additionally, they received a lacto-ovo-semivegetarian diet. The primary end point was remission, defined as the disappearance of active CD symptoms at week 6. Secondary end points were Crohn Disease Activity Index (CDAI) score, C-reactive protein (CRP) concentration, and mucosal healing.

RESULTS

Two adults with a new diagnosis were withdrawn from the treatment protocol because of intestinal obstruction. The remission rates by the intention-to-treat and per-protocol analyses were 96% (44/46) and 100% (44/44), respectively. Mean CDAI score (314) on admission decreased to 63 at week 6 (p < 0.0001). Mean CRP level on admission (5.3 mg/dL) decreased to 0.2 (p < 0.0001). Mucosal healing was achieved in 46% (19/41) of cases.

CONCLUSION

IPF therapy can induce remission in most patients with CD who are naïve to biologics regardless of age or whether they have a new diagnosis or relapse.

Practices, attitudes, and knowledge about Crohn's disease and smoking cessation among gastroenterologists

OBJECTIVE

Cigarette smoking is one of the most important, modifiable environmental factors in Crohn's disease (CD) and screening for tobacco use is an official recommendation and quality measure in the care of CD patients. The objective of this study was to learn more about gastroenterologists' practices, opinions, and knowledge in this area.

PATIENTS AND METHODS

A 15 question survey was sent through email to two national gastroenterology distribution lists. Questions were written in multiple choice formats and were designed to collect information about gastroenterologists' practices, attitudes, and knowledge regarding smoking cessation in CD patients. Responses were stratified by practice setting, experience, and inflammatory bowel disease-focus. Responses were anonymous and were collected in a secure, online database.

RESULTS

A total of 141 respondents completed the survey. Overall, 89% of participants screened their CD patients for smoking more than 75% of the time. In all, 62% provided smoking cessation counseling more than 75% of the time. Overall, 94% of respondents felt comfortable discussing the benefits of smoking cessation with their patients. In all, 56% felt comfortable discussing smoking cessation strategies with their patients. Overall, 88% of respondents agreed that gastroenterologists should provide smoking cessation counseling; however, 43 and 11% agreed that the gastroenterologist should be the primary counselor and primary prescriber of cessation-related pharmacotherapy, respectively.

CONCLUSION

Surveyed gastroenterologists agree that smoking cessation is an important part of the care of CD patients and this is reflected in their screening practices. Counseling occurs irregularly and many gastroenterologists do not feel comfortable discussing cessation strategies. Future guidelines should provide further guidance on the gastroenterologist's role in smoking cessation counseling for CD patients.

Genetic polymorphisms associated with smoking behaviour predict the risk of surgery in patients with Crohn's disease

BACKGROUND

Smoking is a strong environmental factor leading to adverse outcomes in Crohn's disease, but a more benign course in ulcerative colitis. Several single nucleotide polymorphisms (SNPs) are associated with smoking quantity and behaviour.

AIM

To assess whether smoking-associated SNPs interact with smoking to influence the clinical course of inflammatory bowel diseases.

METHODS

Genetic and prospectively obtained clinical data from 1434 Swiss inflammatory bowel disease cohort patients (821 Crohn's disease and 613 ulcerative colitis) were analysed. Six SNPs associated with smoking quantity and behaviour (rs588765, rs1051730, rs1329650, rs4105144, rs6474412 and rs3733829) were combined to form a risk score (range: 0-12) by adding the number of risk alleles. We calculated multivariate models for smoking, risk of surgery, fistula, Crohn's disease location and ulcerative colitis disease extent.

RESULTS

In Crohn's disease patients who smoke, the number of surgeries was associated with the genetic risk score. This translates to a predicted 3.5-fold (95% confidence interval: 2.4- to 5.7-fold, P<.0001) higher number of surgical procedures in smokers with 12 risk alleles than individuals with the lowest risk. Patients with a risk score >7 had a significantly shorter time to first intestinal surgery. The genetic risk score did not predict surgery in ulcerative colitis or occurrence of fistulae in Crohn's disease. SNP rs6265 was associated with ileal disease in Crohn's disease (P<.05) and proctitis in ulcerative colitis (P<.05).

CONCLUSIONS

SNPs associated with smoking quantity is associated with an increased risk for surgery in Crohn's disease patients who smoke. Our data provide an example of genetics interacting with the environment to influence the disease course of inflammatory bowel disease.

Effect of oral tobacco use and smoking on outcomes of Crohn's disease in India

BACKGROUND AND AIM

Smoking has been linked with adverse outcomes in Crohn's disease (CD); however, it is not known whether oral tobacco (OT) use affects disease outcomes in these patients. The study aimed to assess the association between smoking or OT and outcomes in CD.

METHODS

Retrospective analysis was performed on prospectively maintained records of CD patients from 2004 to 2016. The parameters assessed included disease characteristics at baseline (location, behavior, age at onset, perianal disease, and extraintestinal manifestations), course pattern, and outcomes (surgery, hospitalizations, immunomodulator or biologics use, and steroid requirement).

RESULTS

A total of 426 patients were included (mean age: 39.9 years; 59.9% men; median follow up: 71 months). Forty patients were ever-OT users, and 59 were ever-smokers, ever-use being defined as daily use for at least 2 years. OT use was associated with male sex and smoking. Both OT use and smoking had no effect on baseline characteristics, but upper gastrointestinal disease was less common in ever-smokers. Both OT use and smoking did not have any effect on surgery, immunomodulator, and biologic use. Similarly, no association was found between these outcomes and duration, daily, and cumulative exposure to tobacco. Current but not former tobacco use in both smoked (adjusted odds ratio = 2.59 [1.22-5.49]) and OT (adjusted odds ratio = 2.97 [1.03-8.6]) forms increased risk of hospitalizations.

CONCLUSION

Oral tobacco use and smoking had no significant detrimental effect on disease phenotype or medical and surgical requirements in CD in Indian patients, affirming other non-Caucasian studies that found lack of effect of smoking. However, current tobacco use in any form was associated with hospitalization during follow up.

Outcomes of limited period of adalimumab treatment in moderate to severe Crohn's disease patients: Taiwan Society of Inflammatory Bowel Disease Study

Background/Aims

In Taiwan, due to budget limitations, the National Health Insurance only allows for a limited period of biologics use in treating moderate to severe Crohn's disease (CD). We aimed to access the outcomes of CD patients following a limited period use of biologics, specifically focusing on the relapse rate and remission duration; also the response rate to second use when applicable.

Methods

This was a multicenter, retrospective, observational study and we enrolled CD patients who had been treated with adalimumab (ADA) according to the insurance guidelines from 2009 to 2015.

Results

A total of 54 CD patients, with follow-up of more than 6 months after the withdrawal of ADA, were enrolled. The average period of treatment with ADA was 16.7±9.7 months. After discontinuing ADA, 59.3% patients suffered a clinical relapse. In the univariate analysis, the reason for withdrawal was a risk factor for relapse (P=0.042). In the multivariate analysis, current smoker became an important risk factor for relapse (OR, 3.9; 95% CI, 1.2−14.8; P=0.044) and male sex was another risk factor (OR, 2.9; 95% CI, 1.1−8.6; P=0.049). For those 48 patients who received a second round of biologics, the clinical response was seen in 60.4%, and 1 anaphylaxis occurred.

Conclusions

Fifty-nine percent of patients experienced a relapse after discontinuing the limited period of ADA treatment, and most of them occurred within 1 year following cessation. Male sex and current smoker were risk factors for relapse. Though 60.4% of the relapse patients responded to ADA again.

Communication of alcohol and smoking lifestyle advice to the gastroenterological patient

Effective communication between healthcare staff and patients is central to development of the patient-professional relationship. Many barriers influence this communication, often resulting in patients' lack of understanding and retention of information, particularly affecting advice regarding lifestyle habits, such as alcohol consumption and smoking. Alcohol and smoking misuse are potentially modifiable risk factors known to adversely affect a variety of gastroenterological conditions and improvements in communication with patients regarding this is an important management component. This review discusses the clinical impact of these factors and how healthcare professionals can improve communication. We discuss how enhancing verbal communication skills through medical training leads to greater outcomes in patient satisfaction and adherence to treatment and advice. In addition, with the rapid digitalisation of society, platforms such as social media and smartphone applications may be considered as adjuncts to traditional forms of communication.

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.

Crohn’s disease environmental factors in the developing world: A case-control study in a statewide catchment area in Brazil

AIM

To identify environmental risk factors associated with the development of Crohn’s disease (CD) in order to re-assess the hygiene hypothesis.

METHODS

A hospital-based, case-control study was carried out with CD patients (n = 145) and controls (n = 163) representing a socioeconomically diverse statewide catchment area in Brazil. Controls were recruited from caregivers of patients seen in different outpatient clinics at the same hospital. A multi-item survey with 94 questions regarding family history of CD, perinatal and childhood circumstances, living conditions, tobacco use and familial socioeconomic status was carried out by interviewers.

RESULTS

On the univariate analysis, predictive variables for CD included being male, under age of 40, a high education level, urban dweller, smaller family size, exposure to enteric pathogens and user of treated water (P < 0.005). On the multivariate analysis, variables significantly associated with CD were male gender (OR = 2.09), under age 40 (OR = 3.10), white (OR = 2.32), from a small family in childhood (OR = 2.34) and adulthood (OR = 3.02), absence of viral infections in childhood (OR = 2.23), exposure to enteric pathogens (OR = 2.41), having had an appendectomy (OR = 2.47) and prior or current smoker (OR = 2.83/1.12).

CONCLUSION

Most variables supporting the “hygiene hypothesis” are associated with the development of CD but are not independent predictors of the diagnosis.

Prognostic factors affecting outcomes in fistulating perianal Crohn's disease: a systematic review

BACKGROUND

One in three patients with Crohn's disease will develop a perianal fistulae, and one third of these will achieve long-term healing or closure. A barrier to conducting well-designed clinical trials for these patients is a lack of understanding of prognostic factors. This systematic review sets out to identify factors associated with prognosis of perianal Crohn's fistulae.

METHODS

This review was registered on the PROSPERO database (CRD42016050316) and conducted in line with PRISMA guidelines along a predefined protocol. English-language studies assessing baseline factors related to outcomes of fistulae treatment in adult patients were included. Searches were performed on MEDLINE and Embase databases. Screening of abstracts and full texts for eligibility was performed prior to extraction of data into predesigned forms. Bias was assessed using the QUIPS tool.

RESULTS

Searches identified 997 papers. Following removal of duplicates and secondary searches, 923 were screened for inclusion. Forty-seven papers were reviewed at full-text level and 13, 2 of which were randomised trials, were included in the final qualitative review. Two studies reported distribution of Crohn's disease as a prognostic factor for healing. Two studies found that CARD15 mutations decreased response of fistulae to antibiotics. Complexity of fistulae anatomy was implicated in prognosis by 4 studies.

CONCLUSIONS

This systematic review has identified potential prognostic markers, including genetic factors and disease behaviour. We cannot, however, draw robust conclusions from this heterogeneous group of studies; therefore, we recommend that a prospective cohort study of well-characterised patients with Crohn's perianal fistulae is undertaken.

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.

Anemia at the time of diagnosis of inflammatory bowel disease: Prevalence and associated factors in adolescent and adult patients

BACKGROUND

The prevalence, characteristic and determinants of anemia, at the time of inflammatory bowel disease (IBD) diagnosis have yet to be fully elucidated.

METHODS

Retrospective cross-sectional study. Analytical data and disease characteristics obtained upon diagnosis of 1278 IBD patients [Crohn's disease/ulcerative colitis (CD/UC): 718/560] were collected.

RESULTS

Anemia was present in 41.2% of patients at diagnosis (47% and 33.8% of CD and UC patients, respectively; p<0.001), being severe in 5.5%. Iron deficiency anemia represented 69.6% of cases, with no differences between CD and UC. Female sex was the strongest risk factor for anemia in both CD and UC (OR 7.11; 95%CI 4.18-12.10 and 6.55; 95%CI 3.39-12.63, respectively), followed by elevated (≥2mg/dL) C-reactive protein (OR 4.08; 95%CI 2.39-6.97 and 4.58; 95%CI 2.26-9.27, respectively). Current smoking was a risk factor for anemia in CD (OR 2.23; 95%CI 1.24-4.02), but a protective one in UC (OR 0.36; 95%CI 0.14-0.92). A penetrating CD behavior increased the risk of anemia (OR 3.34; 95%CI 1.36-8.21); in UC, anemia increased with disease extension (E2+E3) (OR 1.80; 95%CI 1.13-2.86).

CONCLUSIONS

Female sex and disease activity are major determinants of anemia at IBD diagnosis. Anemia is associated with disease behavior in CD and with disease extension in UC.

Smoking influences the need for surgery in patients with the inflammatory bowel diseases: a systematic review and meta-analysis incorporating disease duration

Background

Studies examining the association between smoking and the need for surgery in patients with Crohn’s disease and ulcerative colitis have reached inconsistent conclusions. These studies often do not differentiate between patients undergoing early surgery and patients having surgery later in their disease course. Our study examined the association between smoking status and time to first bowel resection in patients with Crohn’s disease and ulcerative colitis.

Methods

We searched MEDLINE and EMBASE for studies (n = 12) reporting on the association between smoking status (current, former, and never) and surgery in IBD, and incorporated disease duration in the analysis. Hazard ratios (HR) with 95% confidence intervals (CI) were pooled across studies using random effects models.

Results

Current smokers with Crohn’s disease were at increased risk of intestinal resection compared to never smokers (HR 1.27, 95% CI 1.08 to 1.49); however, there was no difference in the need for surgery when comparing former and never smokers (HR 1.11, 95% CI 0.95 to 1.30). In patients with ulcerative colitis, there was no difference in the need for colectomy when comparing current smokers to never smokers (HR 0.98, 95% CI 0.67 to 1.44). Former smokers with ulcerative colitis were at increased risk of colectomy (HR 1.38, 95% CI 1.04 to 1.83) compared to never smokers.

Conclusions

Current smokers with Crohn’s disease are at increased risk of surgery, while former smokers with ulcerative colitis have increased risk of colectomy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0555-8) contains supplementary material, which is available to authorized users.

Preventive health measures in inflammatory bowel disease

We aim to review the literature and provide guidance on preventive health measures in inflammatory bowel disease (IBD). Structured searches were performed in PubMed, MEDLINE, EMBASE, Web of Science and Cochrane Library from January 1976 to June 2016 using the following keywords: (inflammatory bowel disease OR Crohn’s disease OR ulcerative colitis) AND (health maintenance OR preventive health OR health promotion). Abstracts of the articles selected from each of these multiple searches were reviewed, and those meeting the inclusion criteria (that is, providing data regarding preventive health or health maintenance in IBD patients) were recorded. Reference lists from the selected articles were manually reviewed to identify further relevant studies. Patients with IBD are at increased risk of developing adverse events related to the disease course, therapeutic interventions, or non-adherence to medication. Recent studies have suggested that IBD patients do not receive preventive services with the same thoroughness as patients with other chronic diseases. Preventive health measures can avert morbidity and improve the quality of life of patients with IBD. Gastroenterologists and primary care physicians (PCPs) should have an up to date working knowledge of preventive health measures for IBD patients. A holistic approach and better communication between gastroenterologists and PCPs with explicit clarification of roles will prevent duplication of services and streamline care.

Gut Microbial Diversity Is Reduced in Smokers with Crohn's Disease

BACKGROUND

Smoking has a negative impact on Crohn's disease (CD), but the mechanisms underlying this association are unclear. We compared the gut microbiota composition of smoking with nonsmoking patients with CD using a metagenomic approach.

METHODS

Stool samples and clinical data were collected from current smokers and nonsmokers with CD from France and the Netherlands, matched for country, gender, age, disease activity, and body mass index. Fecal DNA was sequenced on an Illumina HiSeq 2500. On average, 40 million paired-end reads were generated per sample. Gene richness and the Shannon index were computed to assess microbial diversity. Wilcoxon's signed-rank tests for paired samples were performed to detect differences between the 2 groups.

RESULTS

In total, 21 smoking and 21 nonsmoking patients with CD were included. Compared with nonsmoking patients, gut microbial gene richness (P = 0.01), genus diversity (P < 0.01), and species diversity (P = 0.01) were decreased in smoking patients. This was accompanied by a reduced relative abundance of the genera Collinsella (P = 0.02), Enterorhabdus (P = 0.02), and Gordonibacter (P = 0.02) in smokers. No statistically significant differences at the species level were observed, although smokers had lower proportions of Faecalibacterium prausnitzii (P = 0.10).

CONCLUSIONS

Gut microbial diversity is reduced in smokers with CD compared with nonsmokers with CD. The microbial profile differs between these groups at the genus level. Future studies should evaluate whether intestinal microbes mediate the adverse effects of smoking in CD.

Environmental risk factors for inflammatory bowel diseases: Evidence based literature review

AIM: Advances in genetics and immunology have contributed to the current understanding of the pathogenesis of inflammatory bowel diseases (IBD).

METHODS: The current opinion on the pathogenesis of IBD suggests that genetically susceptible individuals develop intolerance to dysregulated gut microflora (dysbiosis) and chronic inflammation develops as a result of environmental insults. Environmental exposures are innumerable with varying effects during the life course of individuals with IBD. Studying the relationship between environmental factors and IBD may provide the missing link to increasing our understanding of the etiology and increased incidence of IBD in recent years with implications for prevention, diagnosis, and treatment. Environmental factors are heterogeneous and genetic predisposition, immune dysregulation, or dysbiosis do not lead to the development of IBD in isolation.

RESULTS: Current challenges in the study of environmental factors and IBD are how to effectively translate promising results from experimental studies to humans in order to develop models that incorporate the complex interactions between the environment, genetics, immunology, and gut microbiota, and limited high quality interventional studies assessing the effect of modifying environmental factors on the natural history and patient outcomes in IBD.

CONCLUSION: This article critically reviews the current evidence on environmental risk factors for IBD and proposes directions for future research.