Factors predictive of Crohn disease following colectomy in medically refractory pediatric colitis

Crohn disease (CD) has been diagnosed following colectomy for ulcerative colitis (UC). This study aims to determine the frequency of this occurrence, and to identify predictive factors leading to a CD diagnosis.

A retrospective chart review was performed in patients who have undergone colectomy.

From 1996 to 2006, colectomy was performed in 212 patients, 37 of whom were diagnosed preoperatively with UC. The mean ages at diagnosis and at colectomy were 10.6+/-4.3 years and 13.7+/-3.7 years, respectively. Inflammatory bowel disease serology at diagnosis in 29 patients showed that 26 (90%) were pANCA+. Serology was negative in 3. Ten (27%) had nonspecific inflammation of the upper digestive tract. Radiographs in 25 patients indicated no abnormalities in the small intestine. Before colectomy, patients (n=35) were treated with corticosteroid (97%), 5-ASA (69%), immunomodulator (66%), infliximab (29%), and cyclosporin (11%). The mean postoperative follow-up was 2.6+/-2 years. Six patients (16%) were found to have CD. All 6 patients were pANCA+ with elevated anti-OmpC (n=4), ASCA immunoglobulin A (n=2), and ASCA immunoglobulin G (n=1). The CD group had higher mean anti-OmpC compared with the UC group, 16.9+/-5.2 and 6.2+/-3.4, respectively (P<0.005). Weight z score at time of surgery was lower in the CD group (-1.38+/-0.79) than in the UC group (0.29+/-0.24), P<0.05.

The possibility of CD remains in a small fraction of patients who undergo colectomy for medically refractory UC. A lower weight and a higher anti-OmpC titer may be predictive of CD.