Search

Background Previous studies comparing inflammatory bowel disease(IBD) features between migrant and native patients have shown clinical phenotype differences. To date, no study has focused on IBD immigrants(MP) in Spain. The aim of this study was to explore the features of MP in Spain and to compare age of disease onset, IBD phenotype and therapeutic requirements with native-born IBD patients(NP). Methods This was an observational, multicentric and case-control study of the nationwide ENEIDA registry. We selected all IBD patients who were born outside of Spain and compared with a control cohort of NP. All included patients were diagnosed with IBD before 2015. Results A total of 13,524 patients were included(1864 MP and 11660 NP).The most prevalent ethnic migrant group was Caucasian(771, 41%), followed by Latin American(572, 31%) and Arabian(341,18%), whereas Asian represented only 6%. Table 1 summarizes the demographic and phenotypic features. 71% of MP were diagnosed with IBD in Spain. There was not a gender predisposition to IBD in the overall migrant group, however more female UC MP were detected compared to UC NP(52 % vs 45%, p Conclusion In the largest cohort of migrant IBD patients in Spain, immigrants were younger, had a shorter disease duration and required a higher use of biologics than natives, pointing phenotypic differences in this population and a universal access to the healthcare system all over the country.

Background Older age has been confirmed as a risk factor for severe clinical presentation of SARS-CoV-2 disease (COVID-19). The prevalence of confirmed SARS-CoV-2 infection in Catalonia among people over 60 years is 6.6%. Biological agents have not been associated with a higher incidence nor a worse prognosis of COVID-19. However, the role of immunosuppressants (IMS) on this issue is still to be elucidated. Moreover, there are scarce data related about COVID-19 in inflammatory bowel disease (IBD) patients under IMS, and none focusing in elderly IBD. Our aim was to describe and to compare the incidence and severity of COVID-19 in patients over 65 years of age with IBD, particularly in relation to the use of IMS. Methods We performed a retrospective cohort study including IBD patients over 65 years since January 2020, from two referral centres in the Barcelona metropolitan area (Catalonia, Spain). Patients were grouped in two cohorts regarding the use or not of IMS (thiopurines or methotrexate). Patients on biological treatment were excluded. We identified those cases with confirmed infection with SARS-CoV-2 (positive PCR) during the period from 1st of March 2020 (the beginning of the pandemic in Catalonia) to 1st March 2021 (the beginning of vaccination in the elderly). Demographic data, IBD comorbidities, concomitant non-IBD related treatments, and SARS-CoV-2 infection outcomes were recorded. Results Four-hundred and eighteen elderly IBD patients were included. The median age was 74 years (IQR 69–78), 52% were male; 70% had ulcerative colitis, 28% Crohn’s disease and 2% IBD unclassified, 62% had arterial hypertension, 22% diabetes mellitus, 22% cardiovascular disease, 15% chronic obstructive pulmonary disease, 10% chronic renal disease, 5% were active smokers. There were no differences regarding comorbidities and non-IBD treatments between the two study groups. From the whole cohort, 89 (21.3%) patients were on IMS (86 with thiopurines, 3 with methotrexate). The median time on IMS was 121 months (IQR 60–162). During the study period, 32 patients (7.7%) had confirmed SARS-CoV-2 infection (7 of whom were on IST; 7.6% not on IMS vs. 7.9% on IMS, P=0.933). Seventeen (53%) patients required hospital admittance (4% not IMS vs. 4.5% on IMS; P=0.818); 4 of them developed COVID-19 related complications (3 patients not on IMS vs. 1 on IMS), and 7 (22%) patients died (6 not on IMS vs. 1 patient on IMS). Conclusion The rate of SARS-CoV-2 infection among elderly IBD patients is quite similar to that reported in the elderly background population. In elderly IBD patients, SARS-CoV-2 infection was associated with a high admission rate and mortality, regardless of the use of IMS.

Background The information regarding IBD patients with COVID-19 suggests that the factors related to bad outcome are older age and comorbidity whereas immunosuppressants do not have a significant impact worsening the disease evolution. To date, there is no information to assess if there are differences in epidemiological, demographical, and clinical characteristics between infected and non-infected IBD patients. Methods Case-control study in IBD patients with COVID-19 (cases) compared to IBD without COVID-19 (controls) in the period March-July/2020 within the ENEIDA registry (promoted by GETECCU and with more than 60.000 IBD patients included). Cases were matched 1:2 by age (±5y), type of disease (CD/UC), gender, and centre. All controls were selected from only one investigator blind to other clinical characteristics of the patients to avoid selection bias. Results 496 cases and 964 controls from 63 Spanish centres were included. No differences were found within the basal characteristics including CD location, CD behaviour, extraintestinal manifestations, family history of IBD or smoking habits. Cases had ≥ 1 comorbidities (cases:43%vs. controls:36%, p=0.01) and occupational risk (cases:27% vs. controls:10.6%, p Conclusion Comorbidities and epidemiological risk factors are the most relevant aspects for the risk of COVID-19 in IBD patients. This risk of COVID-19 seems to be increased by aminosalicylates but not by immunosuppressants or biologics. The attitude regarding treating IBD patients with aminosalicylates during the COVID-19 pandemic deserves a deeper analysis. Funded by the Carlos III Health Institute COV20/00227.

Background Crohn’s disease (CD) is a chronic inflammatory bowel disease that normally requires bowel surgical resection due to intra-abdominal inflammatory complications such as fistulae and stenosis. However, 90% of patients that underwent surgery and did not receive prophylaxis, suffer from postsurgical endoscopic recurrence within one year. Methods The objective of this study is to understand the de novo postsurgical lesion formation in order to stablish a potential mechanism of action and its derived predictive signals to devise preventive strategies. To achieve it, transcriptome analyses of the inflamed and macroscopically unaffected zone of the ileocecal resection from 20 patients from a hospital cohort and 10 controls were performed. Patients were classified for early postsurgical recurrence by means of Rutgeerts index (i0 Results The transcriptome results showed there were no differences neither between i0, i1 and i2a (anastomotic lesions) nor when comparing i2b (non-anastomotic lesions) vs ≥i3. However, when comparing i0+i1+i2a vs. i2b+i3+i4 there were differently expressed genes highlighting ADIPOQ in the inflamed zone and the FXR/FGF19 axis in the unaffected zone. When replicating the results in the corroborative cohort, we identified FXR and other xenobiotic nuclear receptors as the genes differentially expressed in i2a vs i2b, i3 and/or i4, mainly in the macroscopically unaffected zone. Specifically, the differentially expressed genes were: MOGAT2, PXR, FXR and AHR (i2a vs i4), PPARα and FXR (i2a vs i3), TMIGD1, PPARα, FXR and AHR (i2a vs i3+i4) and FXR (i2a vs i2b+i3+i4). Conclusion Nuclear receptor FXR is activated in the ileum by bile acids action and it is key in the lipid metabolism regulation and in the bile acids production by means of FGF19. Moreover, ileal FXR, as well as other xenobiotic nuclear receptors, actively participates in the enhancement of the intestinal barrier function and in the innate immunity regulation. In conclusion, the results obtained in this study suggest a link between bowel xenobiotic metabolism and the de novo lesion formation in previously unaffected areas in the postsurgical recurrence in CD.

Background Thiopurine (TP) withdrawal in patients with Crohn’s disease (CD) in clinical remission (CR) is controversial. Our aim was to describe the evolution of CD patients in CR who discontinued TP prescribed to maintain a remission previously achieved with medical treatment, and to detect predictors of reactivation after withdrawal. Methods Multicentric observational retrospective study including CD patients in RC under TP treatment, who electively discontinued TP. Relapse was defined as the need to start any specific treatment for CD, including surgery. Informed consent was obtained from the inclusion in the Eneida database. Results We included 78 patients (52.6% females, age 45(19–77) years) of whom 57 presented an inflammatory, 12 a stricturing and 9 a penetrating behaviour; 31 patients had terminal ileum involvement, 9 colonic, 36 ilecolonic, and 2 ileocolonic plus upper gastrointestinal involvement, whilst 17 also had perianal disease. Mean disease duration was 13.47 (3.02–35.02) years. 48.7% had never smoked whilst 24.4% were active smokers. TP was started to maintain remission previously achieved with medical therapies in 78 patients (100%). Median azathioprine dose was 2.11 (1.3–2.6) mg/kg/d, and of 6-mercaptopurine (6MP) 1.44 (1–2) mg/kg/day. The median duration of TP treatment was 52.79 (3–268) months and of steroid-free remission 49.41 (1–177) months. Reasons for TP withdrawal were: patient choice/request in 20 (25.6%), physician proposal in 28 (25.7%), drug-related adverse events in 19 (24.4%) and miscellaneous in 11 (14.1%). By the time of TP discontinuation, median CRP was 5.08 mg/l (0.1–157.9), fecal calprotectin(FC) 282.38 µg/g (2.4-4430) and a mean 0.45 (0–4) in Harvey–Bradshaw Index (HBI); those who relapsed presented median CRP of 15.31 mg/l (0.1–125.31), fecal calprotectin (FC) 462.22 µg/g (90–1240) and a mean 5.46 (0–15) in HBI. These differences were statistically significant. During a 5.08 (0.12–13.05) years follow-up, 38 (48.1%) patients relapsed, with treatment duration being the only factor associated to risk of relapse (Or = 0.659 IC95 0.43–0.98, p = 0.04) in the multivariant analysis (IMAGE1). Conclusion Thiopurine withdrawal in the context of sustained remission in CD is associated with relapse in almost half of the patients after a median follow-up of 5 years. Thiopurine treatment duration of shorter than 5 years was shown to carry greater risk for relapse.

Background Three anti-TNFs (one intravenous and two subcutaneous) are licensed for the treatment of ulcerative colitis (UC). However, it is not known if the efficacy of a second anti-TNF changes on whether it is intravenous or subcutaneous; this could justify the indication of biological agents with a different mechanism of action in second line. The aim of this study was to compare the efficacy of a second subcutaneous or intravenous anti-TNF in UC. Methods Patients from the prospectively maintained ENEIDA registry treated with consecutively intravenous and subcutaneous anti-TNF, who were naïve to biological agents, were identified. Patients were classified according to the administration route of the first anti-TNF in: IVi (intravenous initially) or SCi (subcutaneous initially). Patients treated for extraintestinal manifestations or pouchitis were excluded. Clinical activity and effectiveness were defined based on Partial Mayo Score (PMS) at baseline, 14 and 52 weeks. Loss of response, dose-escalation and treatment discontinuation were also assessed. Results 372 UC patients were included (270 IVi and 102 SCi). Both cohorts were similar in clinical-epidemiological characteristics, except for a higher proportion of patients with moderate-to-severe clinical activity at the beginning of the first anti-TNF in the IVi group (82% vs. 71%; p = 0.017) and at the beginning of the second anti-TNF (62% vs. 74%; p = 0.04). Clinical response and remission rates at week 14 for the second anti-TNF were 41% and 29% in IVi vs. 47% and 25% in SCi, respectively (p = ns). At week 52, clinical response/remission rates of the second anti-TNF were 37%/32% in IVi vs. 40%/29% in SCi (p = ns). A higher response rate at 14 weeks with the second anti-TNF was detected in the SCi group (40% vs. 68%; p = 0.012) when the reason for withdrawal of the first anti-TNF was secondary loss of response. The cumulative persistence of the second anti-TNF treatment in IVi and SCi were 55% and 54% after 1 year, and 41% and 40% after 2 years, respectively (p = ns). The SCi group had lower rates of dose-escalation with the second anti-TNF than IVi (34% and 29% in SCi vs. 57% and 49% in EVi, at 12 and 24 months, respectively -p = 0.004-). Dose-escalation of the first anti-TNF and moderate-to-severe clinical activity at the beginning of the second anti-TNF were associated with a lower probability of remission with the second anti-TNF in the short- and long-term. Conclusion The efficacy of infliximab after failure/intolerance of a subcutaneous anti-TNF is similar to that of subcutaneous anti-TNFs after infliximab failure/intolerance.

Background Crohn disease (CD) and Ulcerative colitis (UC) are characterised by episodes of exacerbations and remissions. Monitoring disease activity based on intestinal lesion is mandatory prior to any change in the therapeutic strategy. Colonoscopy is the gold standard technique to monitor the disease activity in IBD patients, but it is usually discarded because of costs and risk issues. The concentration of Faecal Calprotectin (FC) is widely used as a non-invasive marker of inflammation of the intestinal mucosa, allowing the assessment of the disease activity. Recently, different studies have demonstrated that certain microbial species, part of intestinal microbiota which can be detected in stool samples, are capable of correlating with disease activity in CD and UC patients. The purpose of this study was to analyse the correlation between these microbial indicators and the FC to monitor the disease activity in CD and UC patients. Methods FC levels were used to define inflammatory disease activity, the predetermined cut-off of 250 μg/g of faeces was used, higher values indicated an active inflammation and lower values indicated disease in remission. Two cohorts consisting of 61 patients of CD (25 with active inflammation and 36 with remission) and 90 of UC (42 with active inflammation and 48 with remission) were recruited by the Gastroenterology department of 4 Catalan hospitals. A sample of faeces was collected from each patient. FC and the following markers were quantified by qPCR: Faecalibacterium prausnitzii (Fpra), Escherichia coli (Eco), Akkermansia muciniphila (Akk), Ruminococcus sp. (Rum), Bacteroidetes (Bac) and Methanobrevibacter smithii (Msm) for each sample. Results The bacterial markers presented different behaviour depending on the disease analysed. The abundances of Eco and Bac were higher in CD with active inflammation compared with CD with remission. In contrast, no significant differences were found for Fpra, Akk, Rum, and Msm. Besides, a significant positive correlation between Eco abundance and FC levels (0.280, p = 0.029) and a significant negative correlation between Msm and FC levels (−0.299, p = 0.021) were observed. According UC patients, while the abundance of Eco was higher in patients with active inflammation, the abundance of Rum was significantly less abundant. No significant differences were found for Fpra, Akk, Bac, and Msm. Moreover, we also observed a significant negative correlation between Rum and FC levels (−0.308, p = 0.003, respectively). Conclusion The abundance of Eco and Msm in CD patients and the abundance of Rum in UC patients correlate to FC in order to determine inflammatory disease activity. So, these markers can also be an accurate discriminator of active disease in CD and UC patients.

Background The risk of splanic vein thrombosis (SVT) -as defined as that involving the portal vein and/or its intrahepatic branches, mesenteric, splenic and/or suprahepatic veïns is mainly observed, among others, in inflammatory abdominal conditions. Thromboembolic complications are frequent among patients with inflammatory bowel disease (IBD). However, there is little information on the prevalence, characteristics, risk factors and evolution of SVT in patients with IBD. Our aims were to describe the characteristics of SVT in patients with IBD, diagnostic explorations, treatment and evolution. Methods Retrospective, multicentre, descriptive study of the ENEIDA registry with a diagnosis of SVT. In addition to epidemiological and clinical features of IBD, we recorded specifically diagnosis, treatment, disease activity at the time of SVT and outcome of SVT. Results Over 59,000 IBD patients in the ENEIDA registry, only 49 episodes of SVT were identified (35 Crohn’s / 14 Ulcerative Colitis); 69% men, median age 42 years old, 35% smokers. 37% had a past history of surgery and/or abdominal inflammatory conditions, 16% extra-intestinal neoplasia, 23% baseline immune or hematologic conditions and 14% liver disease. Finally, 16% had a previous episode of venous thrombosis. The most frequent forms of clinical presentation were abdominal pain with/without fever (59%), and radiological findings in the setting of active IBD (25%). ST coincided with IBD activity in 76% of cases. The diagnosis of SVT was based in the findings of an abdominal CT in 82%. The most frequent localition of SVT were intrahepatic portal branches (51%) and superior mesenteric vein (47%). Only 47% had a basic aetiological study, and 37% underwent gastroscopy (median 7 months from the diagnosis of SVT) showing oesophageal varices in 67%. Anticoagulation therapy was prescribed in 94% of the episodes (74% within the first month since diagnosis), for a median of 7 months. In 90% of the cases, there was a further radiological assessment, 61% of which showing the resolution of the SVT (median of 5 months from the beginning anticoagulation treatment). Conclusion SVT seems to be a rare (or underdiagnosed) complication in IBD patients, it is mostly associated with disease activity and evolves suitably when anticoagulation therapy is suitably started.

Background & aims: Disease outcome has been found to be poorer in familial inflammatory bowel disease (IBD) than in sporadic forms, but assessment of phenotypic concordance in familial IBD provided controversial results. We assessed the concordance for disease type and phenotypic features in IBD families. Methods: Patients with familial IBD were identified from the IBD Spanish database ENEIDA. Families in whom at least two members were in the database were selected for concordance analysis (K index). Concordance for type of IBD [Crohn's disease (CD) vs. ulcerative colitis (UC)], as well as for disease extent, localization and behaviour, perianal disease, extraintestinal manifestations, and indicators of severe disease (i.e., need for immunosuppressors, biological agents, and surgery) for those pairs concordant for IBD type, were analyzed. Results: 798 out of 11,905 IBD patients (7%) in ENEIDA had familial history of IBD. Complete data of 107 families (231 patients and 144 consanguineous pairs) were available for concordance analyses. The youngest members of the pairs were diagnosed with IBD at a significantly younger age (p < 0.001) than the oldest ones. Seventy-six percent of pairs matched up for the IBD type (kappa = 0.58; 95%CI: 0.42-0.73, moderate concordance). There was no relevant concordance for any of the phenotypic items assessed in both diseases. Conclusions: Familial IBD is associated with diagnostic anticipation in younger individuals. Familial history does not allow predicting any phenotypic feature other than IBD type. (C) 2013 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Background: Active smoking has been associated with a higher risk of developing Crohn's disease (CD). However, its impact on clinical outcomes has been controversial among studies. Aims: To evaluate the influence of active smoking on initial manifestations of CD, the development of disease-related complications, and therapeutic requirements. Methods: Patients diagnosed with CD within a ten-year period (1994-2003) were identified. Clinical and therapeutic features until October 2008 or loss of follow-up were recorded. Smoking status was assessed at each major disease-related event (e.g. penetrating and stricturing complications, perianal disease, intestinal resection, introduction of immunomodulators or biological agents). Results: A total of 259 patients were included in the study with a median follow-up period of 91 months. At diagnosis, 50.5% were active smokers and only 12% of them quit smoking during follow-up, mostly after a major disease-related event occurred. Smoking at diagnosis was not associated with a particular CD presentation. Active smoking did not influence the development of strictures, intraabdominal and perianal penetrating complications, or increased resectional surgery, biological therapy or immunomodulators requirements. Conclusions: Patients who develop CD while smoking seem to have a similar disease course to those who never smoked. (c) 2012 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Background Few data are available on the efficacy of methotrexate (MTX) in ulcerative colitis (UC). Aim To evaluate the efficacy and safety of MTX in UC patients. Patients and methods UC patients who had been treated with MTX were identified from the databases of 8 Spanish IBD referral hospitals. Patients were included in the study if they received MTX for steroid dependency or steroid refractoriness. Therapeutic success was defined as the absence of UC-related symptoms, complete steroid withdrawal and no requirement of rescue therapies within the first 6months after starting MTX. Results Forty patients were included, 70% treated for steroid dependency and 27% for steroid refractoriness. Thiopurines had been previously attempted in 87.5% of patients. The median dose of MTX used for induction was 25mg (IIQ 17.5–25) weekly given parenterally in 82.5% of cases. Eighty-five percent of patients were on steroids when MTX was started. Forty-five percent of patients met criteria for therapeutic success. Initial treatment failures were mainly due to inefficacy (50%) or intolerance (36%). After a median follow-up of 28months (IQR 22–47), 38% of patients with initial therapeutic success required new steroid courses, 22% started biological therapy, and only 1 patient required colectomy. The cumulative probability of maintaining steroid-free clinical remission was 60%, 48%, and 35% at 6, 12, and 24months after starting MTX, respectively. Eleven patients (27.5%) experienced adverse events, leading to MTX discontinuation in only 8 of them. Conclusions MTX appears to be effective to maintain clinical remission in UC, at least in the short-term, with an acceptable safety profile.

Background: Apoptosis resistance of T-cells is considered an abnormality of immune pathways in Crohn's disease (CD). It has been previously shown that corticosteroids induce apoptosis of cells involved in inflammation. Thus, our aim was to assess the apoptosis of mononuclear cells and pro/antiinflammatory cytokines in the intestinal mucosa of patients with active CD, related to steroid response, and identify cellular and molecular factors that may predict this response to therapy. Methods: Patients with CD (n = 26), ulcerative colitis (UC) (n = 32), and controls (n = 10) were prospectively studied with mucosal biopsies before and 7–10 days after corticosteroid treatment. Immunophenotype and apoptosis of T and B lymphocytes, plasma cells, and macrophages were assessed by flow cytometry, immunohistochemistry, and immunofluorescence. The cytokine expression pattern was evaluated by quantitative polymerase chain reaction (PCR). Results: Apoptosis resistance of T and B lymphocytes was observed only in steroid-refractory and -dependent CD patients as compared to responsive patients (P = 0.032; P = 0.004, respectively), being evident after steroid treatment. Interleukin (IL)-10 was markedly increased at baseline in steroid-responsive patients compared to the nonresponders (P = 0.006; sensitivity: 88.8%; specificity: 66.6% to predict steroid response). Conclusions: Apoptosis resistance of mucosal T and B cells in steroid-refractory and -dependent CD patients appears during the evolution of the acute phase, limiting its clinical application as a predictor marker. In contrast, increased expression of IL-10 at an early stage of active steroid-sensitive CD patients supports its usefulness at predicting a good steroid response. Steroid-dependent and -refractory CD patients share similar molecular and cellular pathophysiological mechanisms. (Inflamm Bowel Dis 2010;)

Results: Overall, 8673 patient met our inclusion criteria of which 479 went on to have a total colectomy during follow up. 52% of patients were male and the median age of the cohort was 46 years. The overall 5 year colectomy rate over the whole period of follow up was 5.9% (95%CI: 5.4 6.5%). Colectomy was more common in males (62.2% vs 37.8%, p < 0.001). The 5 year colectomy rate was 4.2%, 5.1% and 6.9% for era 1, era 2 and era 3 respectively (p = 0.001 via Log-rank testing) (Figure 1). The 5 year probability of receiving a thiopurine was 10.9%, 19.3% and 27.9% for era 1, era 2 and era 3 respectively (p < 0.001, via Log-rank testing) (Figure 2). Furthermore, the proportion of early thiopurine users within the first year of diagnosis increased by era and was 4.6%, 9.6% and 13.4% (c2 p < 0.001).

therefore aimed to find genetic and clinical factors predictive of thiopurine induced AE in patients with CD. Methods: Four hundred and sixty eight CD patients were screened and one hundred and eighty one patients treated with thiopurines were included in our study. Thiopurine AE included were myelosuppression, hepatotoxicity and pancreatitis. Clinical data collected included age, ethnicity, gender and smoking status. Patients’ DNAwas tested for specific polymorphisms in the TPMT, GSTM1and GSTT1 genes. Results: Twenty-seven patients (15%) developed AE requiring thiopurine discontinuation. The most common AE was myelosuppression (12 patients), followed by pancreatitis (9 patients) and hepatotoxicity (6 patients). Univariate analysis showed that patients developing AE were significantly older when receiving thiopurines (mean 34.19±14.0 vs. 27.95±11.7 years old, P= 0.016) and more likely to be current or past smokers (51.9% vs 30.0%, P= 0.044). Specifically, patients who developed thiopurine induced pancreatitis were more likely to be past or present smokers (p = 0.001), and patients who developed hepatotoxicity were older than patients who did not develop AE (p = 0.014). Only four patients (2.2%) were heterozygous for TPMT polymorphisms, and none developed thiopurine induced AE. No association was found between GSTM1 or GSTT1 polymorphisms and the development of AE (p = 0.08 for GSTM1 wild-type). On multi-variant analysis past or current smokers were at increased risk for developing thiopurine related AE (OR 2.84, CI 95%: 1.104 7.296). Conclusions: TPMT, GSTM1 and GSTT1 genotype did not predict development of thiopurine induced AE in our patients. Past or current smokers were at increased risk for thiopurine induced AE, specifically pancreatitis. These findings may have implications for decision making in treating CD patients with thiopurines.

P447 Transcriptomic profile in Crohn’s disease with early post-surgical recurrence shows T and B cell polarisation Y. Zabana Abdo1 *, E. Pedrosa2, J. Mane3, V. Loren3, E. Domenech1, M. Manosa1, J. Troya4, J. Boix5, J. Lozano6, E. Cabre7. 1Hospital Universitari Germans Trias i Pujol, Department of Gastroenterology, Badalona, Spain, 2Germans Trias i Pujol Institute, Functional Genetics Unit, Badalona, Spain, 3Germans Trias i Pujol Institute, Experimental Digestive Pathology Unit, Badalona, Spain, 4Hospital Universitari Germans Trias i Pujol, General Surgery Department, Badalona, Spain, 5Hospital Universitari Germans Trias i Pujol, Endoscopy Department, Badalona, Spain, 6CIBERehd, Bioinformatic Platform, Barcelona, Spain, 7Hospital Universitari Germans Trias i Pujol, Dept. of Gastroenterology, Badalona, Spain

Markov assumption, is an increasingly favoured approach in time-dependent outcomes-analysis in complex diseases. Methods: The European Collaborative Study of Inflammatory Bowel Disease (EC-IBD) Group prospectively incepted European and Israeli patients at diagnosis of Crohn’s disease from 1991 to 1993. Patients with >5 years unbroken tracking from diagnosis were grouped into clinical transition states by: (1) medical and surgical therapies recorded in continuous quarter-year cycles, (2) presence of flare-years in a minority ( 50%) of follow-up years with a 10-year time horizon. Clinical transition states based on medical and surgical therapy (a surrogate for disease severity) were calculated by a Markov model (SPSS 16, STATA 10.1). These transition states were as follows: “remission” (symptomatic treatment), “mild-moderate” (local corticosteroids, budesonide, mesalazine, antibiotics), “severe” (systemic steroids, immunosuppression, biologics), surgery, and death (from Crohn’s disease). Healthcare costs per patient per cycle were calculated and matched to the transition states. Results: 348 patients had 12861 cycles; sample transition state probabilities appear in Table. In 308 minority flare-years patients the probability of worsening (entering a subsequent more severe transition state requiring more medication or surgery, or dying) from the initial “remission state” was 0.0985, from “mild-moderate state” 0.0875, from “severe state” 0.1853. In 40 majority flare-years patients, the corresponding probabilities were: 0.2602, 0.2260, 0.1500. Minority flare-year patients in an initial “surgery state” had probabilities of 0.3176 for subsequent severe disease and 0.0765 for further surgery; in majority flare-year patients these respective probabilities were 0.3651 and 0.1111. The subsequent “surgery state” in minority flare-years patients derived cases mostly from initial “surgery” (probability 0.0765) but in majority flare-years patients from initial “remission” (probability 0.0528), “mildmoderate” (probability 0.0400), and “severe” (probability 0.0355). Mean healthcare costs (euros/patient-cycle, year 2004 values) were: remission 147, mild-moderate 287, severe 967, surgery 7023, death 1225. Surgery accounted for 63% of total healthcare costs in year 1, rising to 90% by follow-up year 6. Conclusions: Markov analysis shows that cases with severe disease (more intensive therapy, frequent flares) have a poor prognosis and engender high healthcare costs. Surgery constitutes the greatest expense. Medical therapy must try to maintain patients in a state of remission and avoid the need for surgery. Transition probabilities, minority flare-years

(L1/L4), 1 with colonic localization (L2). PCDAI was 21.9±11.2. Terminal/neoterminal lesions were detected at SICUS in 23 patients, confirmed at ileo-colonoscopy in 22 and at surgery in 1. Terminal/neoterminal lesions were excluded at SICUS in 1 patient with CD of the colon and in 2 operated patients with no recurrence and confirmed at ileo-colonoscopy. SICUS detected additional jejunal/proximal ileum lesions in 7 pts confirmed at radiology and/or WCE or surgery. At SICUS the extension of the proximal and distal SB lesions was 26±22.8 cm and 17±10 cm respectively. Furthermore SICUS detected extraluminal CD findings, namely nodes enlargement and mesenteric involvement, in 21/26 patients. Conclusions: These findings indicate that the non invasive procedure SICUS: 1) has a high accuracy for diagnosing Crohn’s lesions of the SB, 2) is comparable to endoscopic, radiological and WCE examination, in detecting presence and site of SB lesions, and 3) furthermore enables to assess the extension of the SB lesions. These findings support the use of non-invasive SICUS as a first choice examination in the diagnostic work up and follow up of CD pediatric patients.