Evolution of Clinical Behavior in Crohn's Disease: Factors Associated with Complicated Disease and Surgery

Upper Gastrointestinal Involvement in Crohn's Disease as an Independent Predictor of New-Onset Strictures: Insights from an Extensive Retrospective Cohort Analysis

BACKGROUND/AIMS

Crohn's Disease (CD) can affect the entire gastrointestinal tract, including the upper sections (UGI), which is often overlooked, especially in Asian populations. There's a notable gap in research regarding the impact of UGI involvement on the intricate landscape of ensuing complications. This study aims to address this gap.

METHODS

Conducting a retrospective study at Chang Gung Memorial Hospital from January 2001 to September 2023, we compared CD patients with UGI (Montreal L4) involvement against non-L4 counterparts, focusing on baseline characteristics, post-diagnosis complications, and overall outcomes. Routine UGI endoscopy was performed around the time of diagnosis in all patients followed in our inflammatory bowel disease (IBD) center, and all CD patients with adequate follow-up were included in this study.

RESULTS

The study included 212 CD patients, 111 in the L4 group and 101 in the non-L4 group, with an average follow-up of 40.8 ± 15.1 months. At baseline, individuals in the L4 category demonstrated elevated smoking rates, increased Crohn's Disease Activity Index scores, a higher prevalence of strictures, and a more prevalent usage of biologics and proton pump inhibitors. Moreover, this group was characterized by reduced albumin levels. Upon concluding the follow-up, those with L4 involvement continued to show escalated CDAI scores and hospitalization frequencies, alongside heightened C-reactive protein levels and diminished albumin concentrations. Additionally, the occurrence of UGI involvement, stricturing disease at the time of diagnosis, and a younger age at the onset of CD were pinpointed as independent predictors for the development of new-onset strictures.

CONCLUSIONS

CD patients with UGI involvement exhibit elevated disease activity and serve as independent predictors for the development of intestinal strictures. Thorough UGI evaluations at the time of diagnosis, coupled with assertive treatment strategies, are essential for managing these patients effectively.

Strictureplasty may lead to increased preference in the surgical management of Crohn's disease: a case-matched study

BACKGROUND

Resection and strictureplasty are the two surgical modalities used in the management of Crohn's disease (CD). The objective of this study was to compare morbidity and clinical recurrence between patients who underwent strictureplasty and patients who underwent resection.

METHODS

Patients with CD who underwent strictureplasty between January 2012 and December 2022 were enrolled. The patients were well matched with patients who underwent resection without strictureplasty. Patient- and disease-specific characteristics, postoperative morbidity, and clinical recurrence were also analyzed.

RESULTS

A total of 118 patients who underwent a total of 192 strictureplasties were well matched to 118 patients who underwent resection. The strictureplasty group exhibited significantly less blood loss (30 ml versus 50 ml, p < 0.001) and stoma creation (2.5% versus 16.9%, p < 0.001). No significant difference was found regarding postoperative complications or length of postoperative stay. At the end of the follow-up, the overall rate of clinical recurrence was 39.4%, and no difference was observed between the two groups. Postoperative prophylactic use of biologics (odds ratio = 0.2, p < 0.001) was the only protective factor against recurrence.

CONCLUSION

Strictureplasty does not increase the risk of complications or recurrence compared with resection. It represents a viable alternative to resection in selected patients, and as such, it should have a broader scope of indications and greater acceptance among surgeons.

Incidence of Inflammatory Bowel Disease in New Zealand Remains High, Findings in the Manawatū Region

BACKGROUND

New Zealand (NZ) has one of the world's highest rates of inflammatory bowel diseases (IBD), however available data are limited to southern, urban regions.

AIMS

To determine the incidence and prevalence of IBD in the Manawatū region of NZ.

METHODS

Patients in the Manawatū region, with a diagnosis of IBD made between 2011 and 2015 were identified. Demographic, diagnostic and disease data were collected, fulfilment of diagnostic criteria was assessed, and incidence rates were calculated. Comparison of disease phenotype and observed diagnostic criteria was made between diagnosis and 12-months following diagnosis. All resident patients with a diagnosis of IBD current on 5 March 2013 were identified, and prevalence rates were calculated.

RESULTS

The mean annual age-standardised incidence rates of UC, CD, and IBD were 10.2, 17.0, and 27.2 per 100,000. IBD incidence was highest among those of European ethnicity (24.8 per 100,000), followed by Asian (1.4), and Māori (1.1). IBD incidence in the urban population was 34.0 per 100,000 (95% CI 24.1-46.0) compared to the rural population of 5.6 (95% CI 0.4-22.4). The age-standardised point prevalence of UC, CD, and IBD on 5 March 2013 was 157.7, 231.8, and 397.9 per 100,000, respectively.

CONCLUSIONS

The incidence and prevalence of IBD in the Manawatū region are comparable to those reported in other Australasian studies. Incidence was lower in Māori, and in the rural population. Follow-up is required to identify any changes in incidence and phenotype, and whether rural residence remains protective.

A systematic review and meta-analysis of prevalence and clinical features of upper gastrointestinal (UGI) tract Crohn's disease in adults compared to non-UGI types

Background and Aim

Crohn's disease is an inflammatory condition that affects the gastrointestinal (GI) system. This study aimed to determine the prevalence of upper gastrointestinal Crohn's disease (UGICD) and compare its features to non-UGICD types.

Methods

We conducted a systematic search in the databases PubMed, Web of Science, Scopus, and Google Scholar. The heterogeneity of prevalence estimates was examined, subgroup analyses were carried out, and meta-analyses were conducted using random-effects modeling. Prognostic data were qualitatively reviewed and combined.

Results

Two-thousand nine-hundred and forty studies were retrieved and 32 studies were included in the final analysis. Pooled prevalence of UGICD was 15% (CI: 11-18%) among 14 509 patients. UGICD prevalence did not show any significant increase with time (P = 0.45). The most prevalent (38%, CI: 30-47%) behavior of UGICD was B1 (nonstricturing-nonpenetrating), while the most common concurrent location was L3 (ileocolon) with a prevalence of 47% (CI: 34-59%). UGICD patients had higher stricturing phenotype (B2) compared to non-UGICD (0.38 vs 0.30; P = 0.03). There was no significant difference in the prevalence of UGICD between patients classified according to the Montreal or Vienna classification. Stricturing phenotype was more common among Asian patients compared to Western patients (0.44 vs 0.24; P < 0.001). UGICD was a risk factor for surgery and drug therapy and was associated with an aggressive course of the disease and more resections. Pooled prevalence of UGICD was 15%.

Conclusion

Nonstricturing-nonpenetrating type was the most prevalent UGICD. UGICD patients had more complications and worse outcomes compared to non-UGICD patients.

IBD barriers across the continents: a continent-specific analysis: Latin America

Latin America (LATAM) is a large region comprising 47 countries and territories. Each one carries a different cultural and historical background, diverse political systems, and a particular approach to healthcare management. There is a lack of high-quality data on the epidemiology of inflammatory bowel diseases (IBD) in this region, including broad and detailed information about the penetration of biological and advanced therapies as treatment strategies. From an IBD perspective, patients experience, in general, fragmentations and inequities in the healthcare systems, with different and usually delayed access to qualified health services. This review explores the barriers to accessing IBD care throughout LATAM. The authors compiled data from multiple sources, such as studies focusing on epidemiology, biological penetration, and surgical rates. In addition, overall access to IBD treatments was assessed through a questionnaire distributed to physicians in LATAM via email and direct messaging to capture local perspectives.

Differentiation of Isolated Small Bowel Crohn’s Disease from Other Small Bowel Ulcerative Diseases: Clinical Features and Double-Balloon Enteroscopy Characteristics

Background. The diagnosis of isolated small bowel Crohn’s disease (ISBCD) has always been challenging. Aims. This study is aimed at comparing the clinical features and double-balloon enteroscopy (DBE) characteristics of ISBCD with those of other small bowel ulcerative diseases (OSBUD). Methods. Patients with coexisting colonic and/or ileal valve lesions ( $n=45$ ) or whose final diagnosis was not determined ( $n=29$ ) were excluded. One hundred thirty-nine patients with ISBCD and 62 patients with OSBUD found by DBE were retrospectively analyzed. Results. The age of ISBCD onset was lower than that of OSBUD (OR 0.957, 95% CI 0.938-0.977, $p<0.001$ ). Abdominal pain was more common in ISBCD (OR 4.986, 95% CI 2.539-9.792, $p<0.001$ ). Elevated fibrinogen levels (OR 1.431, 95% CI 1.022-2.003, $p=0.037$ ) and lower levels of D-dimer (OR 0.999, 95% CI 0.999-1.000, $p=0.017$ ) were also more supportive of the diagnosis of ISBCD. Nonsteroidal anti-inflammatory drugs (NSAIDs) used for more than two weeks decreased the probability of a diagnosis of ISBCD (OR 0.173, 95% CI 0.043-0.695, $p=0.013$ ). Abdominal computed tomography revealed a higher proportion of skip lesions in ISBCD than in OSBUD (OR 9.728, 95% CI 3.676-25.742, $p<0.001$ ). The ulcers of ISBCD were more distributed in the ileum (111 (79.9%) vs. 29 (46.8%), $p<0.001$ ), and their main morphology differed in different intestinal segments. Longitudinal ulcers (OR 14.293, 95% CI 4.920-41.518, $p<0.001$ ) and large ulcer (OR 0.128, 95% CI 0.044-0.374, $p<0.001$ ) contributed to the differentiation of ISBCD from OSBUD. We constructed a diagnostic model, ISBCD index ( $\text{AUROC}=0.877$ , 95% CI: 0.830-0.925), using multifactorial binary logistic regression to help distinguish between these two groups of diseases. Conclusion. Clinical features, laboratory tests, abdominal computed tomography, DBE characteristics, and pathology help to distinguish ISBCD from OSBUD.

Changes in disease behaviour and location and factor analysis in patients with Crohn's disease undergoing repeated-resections

AIM

Crohn's disease affects the entire gastrointestinal tract and is accompanied by changes in disease location and behaviour. We aimed to analyse changes and the factors in patients with Crohn's disease undergoing intestinal repeated-resection.

METHODS

We included and retrospectively analyzed patients with Crohn's disease who received ≥2 bowel surgeries from a tertiary inflammatory bowel disease centre from January 2008 to December 2019. The Montreal classification was used to describe the disease site and behaviour. Factors were assessed by univariate and multivariate analysis.

RESULTS

A total of 339 patients were included of whom 94 patients received ≥3 bowel resections. The median patient's age at the second and third surgery was 36.4 and 39.6, respectively. Repeated-resection most commonly occurred in the original surgical site. However, disease behaviour progressed with the number of surgical interventions and disease duration, especially for patients with B1 phenotype. Patients with L1 Crohn's disease at a primary resection that progressed to L2 Crohn's disease at a second surgical resection required a resection earlier than patients whose disease remained in L1 or progressed to L3 Crohn's disease. Multivariate analysis showed that history of appendectomy was a predictor of progression from L1 to L3 Crohn's disease at a second surgical resection, while treatment with azathioprine (AZA) may be a protective factor that abated the risk of progression from L1 to L3 Crohn's disease.

CONCLUSION

The original resection site is the most common location for recurrence in patients with Crohn's disease, but disease behaviour progresses with the number of surgeries and disease duration. L1 Crohn's disease patients with a history of appendectomy have a higher risk to progress to L3 Crohn's disease at a second surgical resection, while the AZA may be a protective factor that reduces the risk of progression from L1 to L3.

Prognostic biomarkers to identify patients likely to develop severe Crohn's disease: a systematic review

BACKGROUND

Identification of biomarkers that predict severe Crohn's disease is an urgent unmet research need, but existing research is piecemeal and haphazard.

OBJECTIVE

To identify biomarkers that are potentially able to predict the development of subsequent severe Crohn's disease.

DESIGN

This was a prognostic systematic review with meta-analysis reserved for those potential predictors with sufficient existing research (defined as five or more primary studies).

DATA SOURCES

PubMed and EMBASE searched from inception to 1 January 2016, updated to 1 January 2018.

REVIEW METHODS

Eligible studies were studies that compared biomarkers in patients who did or did not subsequently develop severe Crohn's disease. We excluded biomarkers that had insufficient research evidence. A clinician and two statisticians independently extracted data relating to predictors, severe disease definitions, event numbers and outcomes, including odds/hazard ratios. We assessed risk of bias. We searched for associations with subsequent severe disease rather than precise estimates of strength. A random-effects meta-analysis was performed separately for odds ratios.

RESULTS

In total, 29,950 abstracts yielded just 71 individual studies, reporting 56 non-overlapping cohorts. Five clinical biomarkers (Montreal behaviour, age, disease duration, disease location and smoking), two serological biomarkers (anti-Saccharomyces cerevisiae antibodies and anti-flagellin antibodies) and one genetic biomarker (nucleotide-binding oligomerisation domain-containing protein 2) displayed statistically significant prognostic potential. Overall, the strongest association with subsequent severe disease was identified for Montreal B2 and B3 categories (odds ratio 4.09 and 6.25, respectively).

LIMITATIONS

Definitions of severe disease varied widely, and some studies confounded diagnosis and prognosis. Risk of bias was rated as 'high' in 92% of studies overall. Some biomarkers that are used regularly in daily practice, for example C-reactive protein, were studied too infrequently for meta-analysis.

CONCLUSIONS

Research for individual biomarkers to predict severe Crohn's disease is scant, heterogeneous and at a high risk of bias. Despite a large amount of potential research, we encountered relatively few biomarkers with data sufficient for meta-analysis, identifying only eight biomarkers with potential predictive capability.

FUTURE WORK

We will use existing data sets to develop and then validate a predictive model based on the potential predictors identified by this systematic review. Contingent on the outcome of that research, a prospective external validation may prove clinically desirable.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016029363.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 45. See the NIHR Journals Library website for further project information.

Intestinal mucosa-derived DNA methylation signatures in the penetrating intestinal mucosal lesions of Crohn's disease

The purpose of this study was to evaluate genome-wide DNA methylation changes in intestinal mucosa tissue of adult patients with Crohn's disease comprehensively. DNA methylation chip was used to analyze abnormal methylation sites among penetrating and non-penetrating intestinal mucosa tissue of Crohn's disease and normal intestinal mucosa tissue of healthy controls. Methylation abnormalities of different locus were verified by pyrosequencing and quantitative polymerase chain reaction. Differential DNA methylation sites were participated in the positive regulation of apoptosis and the positive regulation of IL-8 production and were enriched in signaling pathways related to inflammatory bowel disease and extracellular matrix receptor interaction signaling pathways. Correlation analysis showed that the methylation abnormalities of HLA-DRB1 (r = - 0.62, P < 0.001), MUC1 (r = - 0.45, P = 0.01), YPEL5 (r = - 0.55, P = 0.001) and CBLB (r = - 0.62, P < 0.001) were significantly negatively correlated with their relative expression levels. The degree of methylation abnormality of MUC1 was negatively correlated with the disease activity score of Crohn's disease (r = - 0.50, P = 0.01). Apoptosis, interleukin-8 production and abnormal extracellular matrix might be involved in the mechanism of penetrating intestinal mucosal lesions in Crohn's disease. The degree of abnormal methylation of MUC1 was negatively correlated with the disease activity of Crohn's disease.

A watchful waiting approach for newly diagnosed Crohn's disease patients with an inflammatory phenotype

BACKGROUND

An early treat-to-target approach in Crohn's disease (CD) patients is recommended to avoid complications. However, CD may not always progress despite lack of treatment, thus exposing some patients to unnecessary side effects. We aimed to examine whether newly diagnosed CD patients with an inflammatory phenotype can benefit from a watchful waiting approach.

METHODS

This retrospective cohort study followed CD patients with an inflammatory phenotype who were diagnosed between 2010 and 2015 and followed for at least 1 year. A watchful waiting approach was defined as maintenance therapy with 5-ASA medication only or no treatment during the first year of diagnosis or longer. Disease complications were defined as need for surgery or change in disease phenotype.

RESULTS

Eighty-six patients were included and followed-up for 57.0 ± 29.0 months. Thirty-seven patients were managed with a watchful waiting approach and 49 with an early therapeutic intervention. The majority of patients (83.8%) in the watchful waiting group did not develop disease complications. In this group, there was no difference in clinical disease severity (stools per day, 2.7 ± 1.7 vs 3.3 ± 1.0, P = 0.39; abdominal pain, 74.2 vs 50.0%, P = 0.24) between those who did not develop complications and those who did. Smoking was associated with a complicated course (multivariate analysis: OR = 1.98, 95% CI 1.06-3.71, P = 0.03).

CONCLUSIONS

A watchful waiting approach of newly diagnosed CD patients with an inflammatory phenotype may be a feasible option, with low long-term complication rate specifically in nonsmoking patients.

Clinical and Demographic Profile of Inflammatory Bowel Disease Patients in a Reference Center of São Paulo, Brazil

Background

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the gastrointestinal tract with an increasing incidence in developing countries.

Purpose

To report clinical and demographic data of CD and UC at a referral center for inflammatory bowel disease (IBD) in São Paulo.

Patients and Methods

We conducted a retrospective cross-sectional study on adult patients with established IBD. Demographic and clinical data were obtained by medical records analysis from the IBD Outpatient Clinic of EPM-UNIFESP, from October 1997 to October 2017.

Results

Of 658 patients included, 355 had UC (54%) and 303 had CD (46%). UC was more prevalent in women than CD (219 [61.7%] vs 152 [50.2%], p=0.003). The median time between the onset of symptoms and diagnosis was 13 (5-38) months, with a longer duration for CD patients. CD mostly affected the ileocolonic location (47.9%). CD patients with stricture, fistula and/or perianal disease (213/303, 70.3%) were younger at diagnosis, had a longer disease duration, higher rates of corticosteroid, immunomodulatory, and biological therapy, hospitalization, and referral to surgery, compared to patients without complication. Extensive colitis was the most common extension of UC (50.6%), which was more frequently associated with younger age at diagnosis, hepatobiliary disease, increased need for hospitalization, higher use of immunomodulatory, and biologic therapy, compared to patients with less extensive disease. In the last 5 years, CD patients were more frequently on biologic and/or immunomodulatory (70.9%) therapy, and UC patients often received salicylates (78.1%) and immunomodulatory (28.1%) treatments. There was a consistent reduction in salicylate usage for CD in the last 5 years compared to the total period of follow-up.

Conclusion

Despite the increasing incidence, we highlight the diagnostic delay and a more complicated CD and extensive UC in this cohort, reflecting a high need for immunomodulatory and biological treatment, hospitalization, and surgery.

Clinical management for small bowel of Crohn's disease in the treat-to-target era: now is the time to optimize treatment based on the dominant lesion

A treat-to-target strategy, in which treatment is continuously adjusted according to the results of scheduled objective monitoring, is optimal for patients with Crohn's disease (CD) in the era of biologics. The small bowel is a common site of intractable CD, which may result from multiple strictures or expanding lesions. To improve the prognosis of patients with small bowel CD, lesions should be proactively monitored within the subclinical phase. Objective assessment of small bowel lesions is technically difficult, however, due to the relatively poor correlation between endoscopic activity and clinical symptoms or biomarker titers. The presence of proximal small bowel lesions and asymptomatic "Real Silent CD" must be considered. Endoscopy remains the gold standard to assess these lesions. In clinical practice, the advantages and disadvantages of each imaging modality and biomarker must be carefully weighed for appropriate application and reliable monitoring. The prevalence of small bowel lesions depends on the precision of the imaging modality used for detection. Clinical management should be based on the dominant location of the intestinal lesions rather than classical classification. Optimal strategies for detecting and treating small bowel lesions in patients with CD must be developed utilizing reliable, precise, and objective monitoring.

Progression of Inflammatory Bowel Diseases Throughout Latin America and the Caribbean: A Systematic Review

BACKGROUND & AIMS

The incidence of inflammatory bowel diseases (IBD) is increasing in Latin America. We performed a systematic review to identify clinical and epidemiologic features of IBD in Latin America (including Mexico, Central America, and South America) and the Caribbean.

METHODS

We searched MEDLINE, EMBASE, and SciELO databases for clinical or epidemiologic studies of Crohn's disease (CD) or ulcerative colitis (UC) from Latin American and Caribbean countries and territories that reported incidence, prevalence, ratio of UC:CD, IBD phenotype, and treatment, through September 12, 2018. Data were extracted from 61 articles for analysis.

RESULTS

The incidence and prevalence of IBD have been steadily increasing in Latin America and the Caribbean. The incidence of CD in Brazil increased from 0.08 per 100,000 person-years in 1988 to 0.68 per 100,000 person-years in 1991-1995 to 5.5 per 100,000 person-years in 2015. The highest reported prevalence of IBD was in Argentina, in 2007, at 15 and 82 per 100,000 person-years for CD and UC, respectively. The ratio of UC:CD exceeded 1 in all regions throughout Latin America and the Caribbean with the exception of Brazil. Treatment with tumor necrosis factor antagonists increased steadily for patients with CD (43.4% of all patients in Brazil were treated in 2014) but less so for patients with UC (4.5% of all patients were treated in 2014). Surgery for IBD decreased with time. In Chile, surgeries were performed on 57.0% of patients with CD and 18.0% of patients with UC during the period of 1990-2002; these values decreased to 38.0% and 5.0%, respectively, during the period of 2012-2015. In Peru, 6.9% of patients with UC received colectomies in the period of 2001-2003 and 6.2% in 2004-2014.

CONCLUSIONS

In a systematic review, we found the incidence of IBD to be increasing throughout Latin America and the Caribbean. Population-based epidemiology studies are needed to evaluate the increase in IBD in these regions, which differ from other global regions in climate, culture, demographics, diet, healthcare delivery and infrastructure, and socioeconomic status.

BIOLOGICAL THERAPY PENETRATION FOR INFLAMMATORY BOWEL DISEASE IN LATIN AMERICA: CURRENT STATUS AND FUTURE CHALLENGES

ABSTRACT BACKGROUND: The introduction of anti-TNF agents represented a landmark in the management of both Crohn’s disease (CD) and ulcerative colitis (UC), with improved efficacy and safety when compared with conventional treatment. However, significant challenges still exist in Latin America to facilitate the access of biological agents for physicians and patients. OBJECTIVE: The aim of this review was to summarize current evidence on penetration of biological agents for CD and UC in Latin America. METHODS: Data are derived from a previous complete systematic review that explored different characteristics of inflammatory bowel diseases (IBD) in Latin America. The studies fully included in this previous systematic review which contained detailed descriptions of the percentage of use of biological agents in different cohorts throughout Latin American and Caribbean countries were included, and descriptive findings were compiled, describing CD and UC penetration of these drugs in different patient cohorts from different countries. RESULTS: From the 61 studies included in the original systematic review, only 19 included data of the percentage of patients treated with biological agents. Anti-TNF use in CD varied from 1.51% in Mexico up to 46.9% in Colombia, with most of the studies describing anti-TNF use in approximately 20%-40% of CD patients. On the other side, the frequency of the use of biologics was clearly lower in UC, varying from 0% in 2009 to up 16.2% in 2018, according to two different Mexican studies. Only two studies described the penetration of anti-TNF agents in IBD overall: 13.4% in a Colombian and 37.93% in a Brazilian study. No studies described percentage of use of new biologic agents (vedolizumab and ustekinumab). CONCLUSION: Penetration of anti-TNF agents in Latin America is comparable to the rest of the world in CD, but lower in UC. With the increase in the incidence and prevalence of IBD, specific strategies to increase access to anti-TNF agents in UC and new biological agents overall are warranted.

Clinical course in Crohn's disease: factors associated with behaviour change and surgery

BACKGROUND

Crohn's disease (CD) is a chronic and progressive disease that changes its behaviour over time. Transmural inflammation in CD leads to stricturing and/or penetrating complications.

AIM

To evaluate the frequency of long-term progression of CD phenotypes, the need of abdominal surgery, and the main factors associated with these outcomes.

METHODS

A retrospective study was conducted with a prospective follow-up. Montreal classification was assessed at the moment of the diagnosis and at the end of the follow-up period.

RESULTS

Two hundred and ninety patients were included, with mean follow-up duration of nine years. A change in behaviour was observed in 46 patients (15.9%). Ileocolic location (60.9% vs. 45.1%; p = .049), age at diagnosis <16 years (8.7% vs. 2.0%; p = .017), the use of steroids at diagnosis (43.2% vs. 27.0%; p = .031) and shorter exposure time to biological therapy (15.9 months vs 41.3 months; p < .001) were identified as risk factors for phenotype change. Regarding surgery, 70 patients (24.1%) were submitted to abdominal surgery. Smoking habits (41.3% vs. 26.9%; p = .048), stricturing behaviour (50% vs. 18.4%; p < .001), penetrating behaviour 34.8% vs. 7.8%; p < .001), hospitalisations in the first year of diagnosis (52.3% vs. 12.4%; p < .001), and use of steroids at diagnosis (61.4% vs. 23.6%; p < .001) were more frequently seen in patients subjected to surgery. Patients subjected to surgery were less frequently treated with biological therapy (8.7% vs. 23.4%; p < .025).

CONCLUSIONS

A behaviour progression was observed in about one-sixth of the patients. Progression to a stricturing pattern was the most frequent change in behaviour. Stricturing and penetrating behaviour, higher number of hospitalisations in the first year of diagnosis, use of steroids at diagnosis, smoking status, age at diagnosis <16 years and ileocolic disease location were associated with an unfavourable clinical evolution.