Clinical and pathological analysis of colonic Crohn's disease, including a subgroup with ulcerative colitis-like features.

Little is known regarding the clinical and, in particular, pathological manifestations of patients with isolated colonic Crohn's disease. The purpose of this study was to evaluate the clinical and pathological features of patients with Crohn's disease limited to the colon at initial presentation, and to determine whether there are any histological features that are predictive of outcome after surgery. The clinical features, outcome after surgery, and pathological features of colonic resection specimens of 73 patients who presented initially with isolated colonic Crohn's disease were evaluated and compared with 45 Crohn's disease patients who presented initially with both ileal and colonic involvement. Clinically, patients with isolated colonic Crohn's disease presented at a significantly older age at the time of diagnosis, and had a significantly shorter duration of colitis before surgical resection, than did patients with ileocolonic Crohn's disease at disease onset. Pathologically, patients with isolated colonic Crohn's disease showed a significantly higher proportion of cases with subtotal, total, or left-sided colitis, and significantly fewer strictures/stenosis, pericolonic adhesions, pyloric metaplasia, and cases with proximal worse than distal colonic disease. Overall, patients with isolated colonic Crohn's disease showed a trend toward a lower number of major microscopic Crohn's disease features. A small proportion of patients from both Crohn's disease groups (14% and 13%, respectively) showed inflammatory disease limited to the mucosa, without mural involvement, reminiscent of ulcerative colitis, and these were termed 'ulcerative colitis-like Crohn's disease'. These patients were significantly younger than those with mural involvement. Overall, 44% of patients from both Crohn's disease groups developed at least one adverse outcome, and neither the number nor the type of major Crohn's disease features correlated with adverse outcome. Patients with isolated colonic involvement have distinctive clinical and pathological features. A small subgroup of Crohn's patients shows only mucosal involvement reminiscent of ulcerative colitis.

Anti-Saccharomyces cerevisiae antibodies are associated with the development of postoperative fistulas following ileal pouch-anal anastomosis.

Although serologic testing for perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) is reportedly useful in distinguishing ulcerative colitis (UC) from Crohn's disease (CD), there are few and conflicting reports assessing their utility in predicting postoperative complications after ileal pouch-anal anastomosis (IPAA). We examined the associations between postoperative complications such as pouchitis or fistulas and pANCA and ASCA antibodies in a group of patients who underwent IPAA for UC. We conducted a retrospective chart review of 34 patients initially diagnosed with UC (four of these patients had a diagnosis of indeterminate colitis) who underwent IPAA by a single surgeon, and who had pANCA and ASCA antibody levels measured during their clinical course. Study patients were assigned to four groups based on the pattern of antibody reactivity: pANCA+/ASCA- (16 patients), pANCA-/ASCA+ (nine patients), pANCA+/ASCA+ (five patients), and pANCA-/ASCA- (four patients). The median length of follow-up was 16 months (3-144 months). None of the patients (0 of 16) who were pANCA+/ASCA- had their preoperative diagnosis of UC changed after a median follow-up of 14 months (3-118 months). Of the nine patients with a preoperative diagnosis of UC who were pANCA-/ASCA+, four patients (44%) had their diagnosis changed postoperatively to CD based on clinical findings, with a median follow-up: 15 months (5-98 months). Of 16 patients who underwent IPAA and who were pANCA+/ASCA-, 15 of 16 (93.75%), were free of fistulas postoperatively, with a median follow-up of 14 months (3-118 months). Of nine patients with a preoperative diagnosis of UC who underwent IPAA and who were pANCA-/ASCA+, four of nine (44%; p = 0.04) developed fistulas postoperatively, with a median length of follow-up of 55 months (15-67 months). No relationship between serologic profiles or antibody titer levels and the development of pouchitis was identified. In a cohort of patients undergoing IPAA for UC, serologic profiles may be useful in identifying patients at risk of postoperative fistula formation. Patients who were pANCA-/ASCA+ were at increased risk for the development of fistulas postoperatively compared to patients who were pANCA+/ASCA-, and were also more likely to have their diagnosis changed postoperatively to CD. A larger study is needed to validate these observations.