TY - JOUR T1 - Abstracts JF - Gut JO - Gut SP - a1 LP - a119 VL - 55 IS - suppl 2 A2 - , Y1 - 2006/04/01 UR - http://gut.bmj.com/content/55/suppl_2/a1.abstract N2 - 001 CLINICAL AND MOLECULAR CHARACTERISTICS OF ISOLATED COLONIC CROHN’S DISEASE L. Hancock1,2, T. Ahmad1, B. F. Warren3, N. J. Mortensen2, D. P. Jewell1.Departments of 1Gastroenterology, 2Colorectal Surgery, 3Histopathology, University of Oxford, Radcliffe Infirmary, Oxford OX2 6QX, UK Background: Clinical, serological, and molecular data support the existence of discrete subsets of Crohn’s disease (CD) defined by location of disease. Little is known about the epidemiology and natural history of isolated CD of the colon (Montreal Classification L2) because most studies have not accurately distinguished L2 from L3 disease (ileo-caecal). Aims: (1) To describe the clinical features and natural history of isolated colonic CD in a rigorously characterised patient cohort. (2) To confirm the association with HLA-DRB1*0103, reported in smaller cohorts, and to investigate its role in predicting disease course and need for surgery. Methods: Patients with L2 disease were identified from a database of 1318 CD patients. Only patients with a normal small bowel enema (70%), ileoscopy alone (30%), or both (20%) were included. No patients had capsule endoscopy. HLA genotyping was performed using PCR-SSP. Results: 136 (10.3%) patients were classified with L2 disease after a median follow up of 10.8 years (range 1.4–39.8). The mean age at diagnosis was 30.7 years. L2 disease was more common in women (74.3% v 61.0%; p = 0.001; RR = 1.7) and in never smokers (52.2% v 41.3%; p = 0.007; RR = 1.5). 29.4% and 14.0% reported a family history (1st or 2nd degree) of CD and UC respectively. Stricturing colonic disease was noted in 10% of patients. 12% of the entire cohort received ⩾1 Infliximab infusion and 19% underwent colonic resection for severe disease (cumulative risk at 2 years, 10.6%; 5 years, 17.1%; 10 years, 32.8%). We confirmed the association with DRB1*0103 (14.7% cases v 2.7% controls; p = 5.5×10−9; RR = 3.2) and report the novel association … ER -