Prevalence and clinical features of indeterminate colitis in Mexico: a 17-year study.

BACKGROUND: Indeterminate Colitis (IC) is diagnosed after colectomy when macroscopic and microscopic features were not sufficient to allow a definite diagnosis of either the classical types of Ulcerative Colitis (UC) or Crohn's disease (CD). Epidemiological data from some series have reported that IC is diagnosed in between 9% and 20% of colectomy specimens. AIM: To determine the prevalence of IC in Mexican patients and to describe their clinical features. MATERIAL AND METHODS: We carried out a retrospective database analysis of all patients diagnosed with inflammatory bowel disease (IBD) who underwent colectomy between January of 1990 and December of 2006. Demographic data, clinical, laboratory, and histopathological results were analyzed. RESULTS: We found 80 patients in the database who had undergone total colectomy whose average age was 44.8 years. IC was found in 7 patients (8.7%) from colectomy specimens among Mexican patients with IBD, with a mean age at diagnosis of 33.6 years. Subgroup analysis showed that a younger age at diagnosis and toxic megacolon were factors of statistical significance associated with IC. CONCLUSIONS: The prevalence of IC was 8.7% in our group. A younger age of onset and toxic megacolon were the most important associated factors in patients with IC.

HLA-DRB1 alleles are associated with the clinical course of disease and steroid dependence in Mexican patients with ulcerative colitis.

AIM: The aim of this study was to study the association between the HLA-DRB1 alleles and the clinical course of ulcerative colitis (UC). METHOD: Seventy-five Mexican patients with UC were studied. High resolution HLA typing was performed using Polymerase Chain Reaction-Sequence Specific Oligonucleotide PCR-SSO reverse dot blot and Polymerase Chain Reaction-single specific primer PCR-SSP. Molecular typing techniques were applied to define HLA-DRB1 alleles. RESULTS: Seventy-five patients (36 female patients, 39 male patients) were studied. Significant associations were found between some HLA-DRB1 alleles and the clinical course of disease: initial active and then inactive and the HLA-DRB1*14 allele (P = 0.03; OR = 4.63; 95% CI: 1.08-21.23); and HLA-DRB1*08 allele (P = 0.04; OR = 4.34; 95% CI: 1.9-33.3). On the other hand, the HLA-DRB1*07 (P = 0.001; OR = 9.76 95% CI: 1.55-65.56) was significantly associated with steroid dependence in UC patients. CONCLUSIONS: This study suggests that HLA-DRB1 alleles were associated with the clinical course of disease and steroid dependence in UC patients.