Association of polymorphic alleles of CTLA4 with inflammatory bowel disease in the Japanese

AIM: To examine an association between the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis (UC) and Crohn's disease (CD) in the Japanese.METHODS: We studied 108 patients with UC, 79 patients with CD, and 200 sex-matched healthy controls, with respect to three single nucleotide polymorphisms (SNPs)in CTLA4, such as C-318T in the promoter region, A+49G in exon 1 and G+6230A in the 3' untranslated region (3'-UTR) by a PCR-restriction fragment length polymorphism method, and to an (AT)n repeat polymorphism in 3'-UTR by fragment analysis with fluorescence-labeling on denaturing sequence gels. Frequency of alleles and genotypes and their distribution were compared statistically between patients and controls and among subgroups of patients, using χ2 and Fisher exact tests.RESULTS: The frequency of 'A/A' genotype at the G+6230A SNP site was statistically lower in UC patients than in controls (3.7% vs 11.0%, P= 0.047, odds ratio (OR) = 0.311). Moreover, the frequency of'G/G' genotype at the A+49G SNP site was significantly higher in CD patients with fistula (48.6%) than those without it (26.2%)(P = 0.0388, OR=2.67).CONCLUSION: The results suggest that CTLA4 located at 2q33 is a determinant of UC and responsible for fistula formation in CD in the Japanese.

Crohn's disease in Japanese is associated with a SNP-haplotype of N-acetyltransferase 2 gene

AIM: To investigate the frequency and distribution of N-acetyltransferase 2 (NAT2) and uridine 5′-diphosphate (UDP)-glucuronosyltransferase 1A7 (UGT1A7) genes in patients with ulcerative colitis (UC) and Crohn's disease (CD).METHODS: Frequencies and distributions of NAT2 and UGT1A7SNPs as well as their haplotypes were investigated in 95 patients with UC, 60 patients with CD, and 200gender-matched, unrelated, healthy, control volunteers by PCR-restriction fragment length polymorphism (RFLP),PCR-denaturing high-performance liquid chromatography (DHPLC), and direct DNA sequencing.RESULTS: Multiple logistic regression analysis revealed that the frequency of haplotype, NAT2*7B, significantly increased in CD patients, compared to that in controls (P= 0.0130, OR = 2.802, 95%CI = 1.243-6.316). However,there was no association between NAT2 haplotypes and UC, or between any UGT1A7haplotypes and inflammatory bowel disease (IBD).CONCLUSION: It is likely that the NAT2 gene is one of the determinants for CD in Japanese. Alternatively, a new CD determinant may exist in the 8p22 region, whereNAT2is located.

Endoscopic identification of Peyer's patches of the terminal ileum in a patient with Crohn's disease

We presented a 20-year-old patient with Crohn's disease (CD). Colonoscopy revealed longitudinal ulceratlon in the terminal ileum and rectal aphtoid ulcers, After treatment with mesalamine and total parenteral nutrition, repeat colonoscopy revealed a granular elevated area in the terminal ileum, which appeared as an irregular dome-like elevation with irregularly arranged vill on magnifying endoscopy. Biopsy specimens taken from the region showed microgranulomas and lymphoid hyperplasia, Scanning electron microscopy revealed the presence of M cells, conthming that the area corresponded to Peyer's patches. Peyer's patches by magnifying endoscopy and electron microscopy may provide insights into the pathogenesis oF CD.