SUMMARYAim: To determine the clinical characteristics, management and outcome of Crohn's fistulas from the time of first presentation. Methods: Patients treated for fistulas 6 years previously were assessed for disease demographics, fistula characteristics and treatment from first presentation to final follow-up. Results: Eighty-seven patients with active Crohn's fistulas were evaluated. The median age was 35 years and the median duration of Crohn's disease was 8 years at study entry. Disease was ileo-colonic or colonic in 85%, and 65% had rectal involvement. A single fistula was present in one-third and multiple fistulas in two-thirds; 65% of fistulas were perianal; 80% of fistulas were complex. After a median follow-up from the last treatment of 5.9 years, 68% of patients showed healing of all fistulas, 18% showed healing of some fistulas and 14% showed no healing of fistulas. The fistula site did not influence healing. Perianal and recto-vaginal fistulas took a median of 2.6 years to heal. Half of the complex fistulas required a stoma, resection or proctectomy. Conclusions: Healing is usually achieved. However, morbidity is great and healing is slow. Proctectomy is required in one-fifth of patients, and perineal healing is often slow. Defining the perianal fistula anatomy as complex or simple determines the likelihood of healing and the type of surgical approach required.

Dendritic cells (DC) in the colon may regulate intestinal immunity but remain poorly characterized. In this study a CD11c+HLA-DR+lin− (CD3−CD14−CD16−CD19−CD34−) population has been identified by flow cytometry in cells obtained by rapid collagenase digestion of human colonic and rectal biopsies. These day 0 (d0) CD11c+HLA-DR+lin− cells comprised ∼0.6% of the mononuclear cells obtained from the lamina propria, were endocytically active, and had the phenotype of immature DC; they were CD40+ and expressed low levels of CD83 and CD86, but little or no CD80 or CD25. Similar d0 DC populations were isolated from the colonic mucosa of healthy controls and from both inflamed and noninflamed tissue from patients with Crohn’s disease. The lamina propria also contained a population of cells capable of migrating out of biopsies during an overnight culture and differentiating into mature DC with lower levels of endocytic activity and high cell surface expression of CD40, CD80, CD86, CD83, and CD25. This mature DC population was a potent stimulator of an allogeneic mixed leukocyte (MLR). Overnight culture of cells isolated by enzymatic digestion on d0 yielded DC with a phenotype intermediate between that of the d0 cells and that of the cells migrating out overnight. Overnight culture of colonic cells in which DC and HLA-DR+lin+ cells were differentially labeled with FITC-dextran suggested that some of the maturing DC might differentiate from HLA-DR+lin+ progenitors. This study presents the first analysis of the phenotype, maturational status, and migratory activity of human gut DC.

SUMMARYAims: To assess fistula track healing after infliximab treatment using magnetic resonance imaging. Methods: Magnetic resonance imaging and clinical evaluation were performed before and after three infliximab infusions given over a 6-week period. Magnetic resonance images were evaluated for abscesses and fistula tracks. Paired magnetic resonance image examinations were rated 'better', 'unchanged' or 'worse'. Magnetic resonance imaging and clinical outcomes were then compared.

Incidence rates, disease phenotype and initial treatment characteristics in the 2011 ECCO-EpiCom cohort were not significantly different from that reported in the 2010 cohort.