Predicting complicated Crohn's disease and surgery: phenotypes, genetics, serology and psychological characteristics of a population‐based cohort

Summary Background Predictors of complicated Crohn's disease (CD), defined as stricturing or penetrating behaviour, and surgery have largely been derived from referral centre populations. Aim To investigate whether serological markers, susceptibility genes or psychological characteristics are associated with complicated CD or surgery in a population‐based cohort. Methods One hundred and eighty‐two members of the Manitoba IBD Cohort with CD phenotyped using the Montreal classification underwent genetic and serological analysis at enrolment and after 5 years. One hundred and twenty‐seven had paired sera at baseline and 5 years later and their data were used to predict outcomes at a median of 9.3 years. Serological analysis consisted of a seven antibody panel, and DNA was tested for CD‐associated NOD2 variants (rs2066845,rs2076756,rs2066847), ATG16L1 (rs3828309, rs2241880) and IL23R (rs11465804). Psychological characteristics were assessed using semi‐structured interviews and validated survey measures. Results Sixty‐five per cent had complicated CD and 42% underwent surgery. Multivariate analysis indicated that only ASCA IgG‐positive serology was predictive of stricturing/penetrating behaviour (OR = 3.01; 95% CI: 1.28–7.09; P = 0.01) and ileal CD (OR = 2.2; 95% CI: 1.07–4.54, P = 0.03). Complicated CD behaviour was strongly associated with surgery (OR = 5.6; 95% CI: 2.43–12.91; P