S12 Oral presentations Table 1. Similarity of Percentages (SIMPER) analysis of bacterial community similarity (Bray Curtis) between whole metacommunities for siblings and healthy controls. The 9 species with the highest contribution to dissimilarity are shown. Name Siblings mean abundance (%) Healthy mean abundance (%) Average dissimilarity (%) Contribution to dissimilarity (%) Faecalibacterium prausnitzii 23.4 30.0 10.4 18.9 Escherichia fergusonii 9.6 3.9 5.8 10.6 Sutterella wadsworthensis 5.8 8.6 5.2 9.4 Shigella flexneri 6.9 3.5 4.6 8.4 Bacteroides vulgatus 7.3 7.9 4.6 8.4 Eubacterium rectale 6.1 9.5 3.9 7.0 Oscillospira guilliermondii 7.6 8.1 3.9 7.0 Bacteroides dorei 5.5 0.0 3.0 5.4 Ruminococcus gnavus 4.7 4.0 2.2 4.1 Reference(s) [1] Hedin C, McCarthy NE, Louis P, Farquharson F, McCartney S, Taylor K, Prescott NJ, Murrells T, Stagg AJ, Whelan K, Lindsay JO (2013), Siblings of patients with Crohn’s disease have a distinct microbiological and immune phenotype compared to healthy controls: insights into disease pathogenesis. Gastroenterology, Vol. 144, Issue 5, Supplement 1, S57 8. [2] van der Gast CJ, Walker AW, Stressmann FA, Rogers GB, Scott P, Daniels TW et al. (2011), Partitioning core and satellite taxa from within cystic fibrosis lung bacterial communities., ISME J, Vol. 5, 780 791. OP021 Steroid-free remission in adalimumab-treated paediatric patients with moderately to severely active Crohn’s disease in the IMAgINE 1 trial A. Griffiths 1 *, W. Crandall 2 , R. Colletti 3 , F. Ruemmele 4 , W.A. Faubion 5 , J. Hyams 6 , A. Lazar 7 , Y. Li 8 , S. Eichner 8 , R.B. Thakkar 8 . 1 The Hospital for Sick Children, Department of Paediatrics, Toronto, ON, Canada, 2 Nationwide Children’s Hospital, Department of Gastroenterology/Nutrition, Columbus, United States, 3 University of Vermont, Department of Pediatrics, Burlington, United States, 4 Universite Sorbonne Paris-Cite, Hospital Necker-Enfants Malades, APHP, Paris, France, 5 Mayo Clinic, Gastroenterology, Rochester, United States, 6 Connecticut Children’s Medical Center, Division of Digestive Diseases, Hartford, United States, 7 AbbVie Deutschland GmbH & Co, KG, GPRD, Ludwigshafen, Germany, 8 AbbVie Inc, GPRD, North Chicago, United States Background: The efficacy of adalimumab (ADA) in inducing and maintaining remission in paediatric patients with Crohn’s disease (CD) was demonstrated in IMAgINE 1 [1] (NCT00409682). This analysis further investigated corticosteroid (CS)-free re- mission in the subset of patients receiving CS at baseline (BL). Methods: Patients aged 6 17 y with CD resistant or intolerant to conventional therapy, including infliximab (IFX), and BL Paediatric CD Activity Index (PCDAI) >30 received open-label (OL) induction of ADA at weeks (wks) 0/2 by body weight (<40 kg, 80/40 mg; 40 kg, 160/80 mg). At wk 4, patients were stratified by response and prior IFX use, and randomized to double-blind (DB) higher-dose (HD) ADA (<40 kg, 20 mg every other wk [eow]; 40 kg, 40 mg eow) or lower-dose (LD) ADA (<40 kg, 10 mg eow; 40 kg, 20 mg eow) for 48 wks. Patients with disease flare or nonresponse could move to DB weekly dosing after wk 12, then to OL weekly HD ADA for continued flare/nonresponse. Proportions of patients receiving LD ADA vs HD ADA achieving CS-free clinical remission (PCDAI 10) were compared using a logistic regression model overall, by prior IFX use, and by BL disease severity (PCDAI: <40, 40). Nonresponder imputation was used for missing values and patients who moved to weekly dosing. Results: Of 188 patients randomized to ADA, 38 in the LD ADA group and 33 in the HD ADA group were using CS at BL. Of these, 33.3% receiving HD ADA and 26.3% receiving LD ADA achieved CS-free remission at wk 26 (P =0.519) [1] (Table). CS-free remission rates at wk 52 were also numerically higher but did not reach statistical significance for patients receiving HD ADA (27.3%) vs LD ADA (18.4%). Greater proportions of IFX- naïve patients achieved CS-free remission at wk 26 (P = 0.004) compared to patients with prior IFX use (Table). At wk 26, 52.9% of IFX-naïve patients receiving HD ADA were in CS-free remission. BL disease severity did not appear to affect CS-free remission rates. Table. Proportion of patients achieving CS-free clinical remission LD ADA N = 38 HD ADA N = 33 P value* Week 26 Overall, n (%) 10 (26.3) 11 (33.3) 0.519 Prior IFX, n/N (%) IFX-naive 8/22 (36.4) 9/17 (52.9) 0.303 IFX-experienced 2/16 (12.5) 2/16 (12.5) 1.000 BL disease severity, n/N (%) PCDAI <40 3/13 (23.1) 6/13 (46.2) 0.223 PCDAI 40 7/25 (28.0) 5/20 (25.0) 0.821 Week 52 Overall, n (%) 7 (18.4) 9 (27.3) 0.376 Prior IFX, n/N (%) IFX-naive 5/22 (22.7) 7/17 (41.2) 0.221 IFX-experienced 2/16 (12.5) 2/16 (12.5) 1.000 BL disease severity, n/N (%) PCDAI <40 3/13 (23.1) 3/13 (23.1) 1.000 PCDAI 40 4/25 (16.0) 6/20 (30.0) 0.268 ADA, adalimumab; BL, baseline; CS, corticosteroid; HD, higher dose; IFX, infliximab; LD, lower dose; PCDAI, Paediatric Crohn’s Disease Activity Index. *P value is from a logistic regression model with treatment as the only predictor. Conclusions: In paediatric patients with moderately to severely active CD who used CS at BL in IMAgINE 1, trends toward higher CS-free remission rates were observed with HD ADA treatment. CS-free remission rates were higher in IFX-naïve patients than in IFX-experienced patients, but were not clearly affected by BL disease severity [1]. Reference(s) [1] Hyams J, et al., (2012), Safety and efficacy of adalimumab for moderate to severe Crohn’s disease in children. Gastroenterology, 365. OP022 Low microbial gene diversity and depletion of Akkermansia muciniphila is associated with a relapsing course of ulcerative colitis F. Casellas 1 *, N. Borruel 1 , C. Manichanh 1 , E. Varela 1 , M. Antolín 1 , A. Torrej´ on 1 , V. Robles 1 , F. Guarner 1 , on behalf of MetaHIT Consortium 1,2 . 1 Hospital Universitari Vall d’Hebron, Unitat Atenci´ o Crohn-Colitis, Barcelona, Spain, 2 MetaHIT Network, Partner Centres, Paris, France Background: While the precise aetiology of ulcerative colitis (UC) is still unknown, a dysregulated immunologic response against gut bacteria appears to be the key event driving the inflammatory process that generates lesions. We followed UC patients from remission to disease relapse and analysed microbial communities in faecal samples by metagenomic sequencing. Objective: To determine changes in faecal microbiota related with UC clinical course. Methods: Faecal samples from 31 patients with clinically inactive UC and 30 first-degree relatives were obtained for Downloaded from https://academic.oup.com/ecco-jcc/article-abstract/8/Supplement_1/S12/367536 by guest on 29 May 2020