Helicobacter pylori infection and inflammatory bowel disease in Asians:A meta-analysis

AIM: To investigate the relationship between Helicobacter pylori infection and inflammatory bowel disease(IBD) in an Asian population.METHODS: The Pub Med, EMBASE, and CochraneLibrary databases were searched for observational studies published up until June 2014, without language restrictions. Additional references were obtained from reviewed articles. RESULTS: Ten studies involving 1299 IBD patients and 1817 controls were included in the meta-analysis(24.9% of IBD patients had H. pylori infection vs 48.3% of the controls). The pooled risk ratio for H. pylori infection in IBD patients compared with controls was 0.48(95%CI: 0.43-0.54; P < 0.001). There was no significant heterogeneity in the included studies(I2= 21%). Egger's linear regression indicated that there was no significant publication bias(P = 0.203).CONCLUSION: The H. pylori infection rate in Asian IBD patients is significantly lower than in non-IBD patients, indicating that infection protects against the development of IBD.

Detection of RASSF1A promoter hypermethylation in serum from gastric and colorectal adenocarcinoma patients

AIM：To evaluate the diagnostic role of serum RASSF1A promoter hypermethylation in gastric and colorectal adenocarcinoma. METHODS：Methylation-specific polymerase chain reaction （MSPCR） was used to examine the promoter methylation status of the serum RASSF1A gene in 47 gastric adenocarcinoma patients, 45 colorectal adenocarcinoma patients, 60 patients with benign gastrointestinal disease （30 with benign gastric disease and 30 with benign colorectal disease）, and 30 healthy donor controls. Apaired study of RASSF1A promoter methylation status in primary tumor, adjacent normal tissue, and postopertive serum were conducted in 25 gastric and colorectal adenocarcinoma patients who later were underwent surgical therapy. RESULTS：The frequencies of detection of serum RASSF1A promoter hypermethylation in gastric （34.0%） and colorectal （28.9%） adenocarcinoma patients were significantly higher than those in patients with benign gastric （3.3%） or colorectal （6.7%） disease or in healthy donors （0%） （P 〈 0.01）. The methylation status of RASSF1A promoter in serum samples was consistent with that in paired primary tumors, and the MSPCR results for RASSF1A promoter methylation status in paired preoperative samples were consistent with those in postoperative serum samples. The serum RASSF1A promoter hypermethylation did not correlate with patient sex, age, tumor differentiation grade, surgical therapy, or serum carcinoembryonic antigen level. Although the serum RASSF1A promoter hypermethylation frequency tended to be higher in patients with distant metastases, there was no correlation between methylation status and metastasis. CONCLUSION：Aberrant CpG island methylation within the promoter region of RASSF1A is a promising biomarker for gastric and colorectal cancer.