[The phenotype and clinical patterns of Crohn's disease in the Chinese]

To investigate the possibility to classified Chinese patients with Crohn's disease by the Vienna criteria and clinical features between subtypes. To investigate the clinical significance of anti-saccharomyces cerevisiae antibodies (ASCAs) in Crohn's disease.

We identified 71 cases of Crohn's disease in our hospital during the past five years by searching the electronic medical recording system of the hospital. Clinical data were retrieved. All subjects were classified into subtypes by the Vienna classification, which was established on three criteria: the age at diagnosis, the lesion location and the disease behavior. The disease course, medical and surgical treatment, the detection of serum ASCAs were also abstracted for each subject. The clinical features, disease course and management were compared between subgroups.

The lesion location in patients diagnosed at the age of less than 40 years old was different from that in patients diagnosed after 40, although the difference was not significant (P = 0.085). The ileocolon and terminal ileum were the most common lesions in those early-diagnosed patients, while the lesions in terminal ileum and colon dominated in the late-diagnosed ones. The complications (structuring or perforation) were significantly different in subgroups with different lesion locations (L1 90.5%, L2 50.0%, L3 50.0%, L4 85.7%, P = 0.012), among which the terminal ileum involvement had the highest incidence of complications. The subjects with complications had significantly longer courses [B1 (35.39 +/- 37.11) ms, B2 (87.12 +/- 116.66) ms, B3 (90.65 +/- 93.50) ms, B1 vs non B1, P = 0.023] and more surgical treatments (B1 39.1%, B2 54.6%, B3 70.1%) (B1 vs non B1, P = 0.003) than those pure inflammatory ones. No association was found between the disease course and the age at diagnosis or the lesion location. We did not find difference in medical treatments between subgroups either. ASCAs positive subjects had shorter disease course [(54.12 +/- 74.36) ms vs (84.15 +/- 89.72) ms, P = 0.052] but more surgeries (64.7% vs 30.0%, P = 0.037) than those negative ones.

The age at diagnosis is associated with the lesion location, and the lesion location is associated with the disease behavior. The behavior may change during the disease course. ASCAs expression may be related to early onset and severity of Crohn's disease.