Association of NLRP3 single nucleotide polymorphisms with ulcerative colitis: A case-control study

BACKGROUND

Ulcerative colitis (UC) is inflammatory bowel disease (IBD), characterized by chronic inflammation episodes within mucosal layer of the intestine mostly affecting colon and rectum. As the role of innate immunity in pathogenesis of disease and important role of NLRP3, the aim of this study is to investigate the association of NLRP3 SNPs with UC in Iranian patients.

METHODS

Blood samples from 45 UC patients and 56 healthy subjects were tested for single nucleotide polymorphisms in rs10754558, rs3806265, rs4612666, and rs35829419 of NLRP3 gene, using real-time PCR method.

RESULTS

Among the investigated SNPs, "GG" genotype of rs10754558 have been 2.48 times more common among UC patients (P=0.04), while "CG" genotype has indicated protective effect against UC, as more frequently found in healthy subjects.

CONCLUSION

Despite no significant association between three investigated SNPs and disease, "GG" and "CG" genotypes of rs10754558 have been significantly associated with disease.

Cytokine gene polymorphisms are associated with irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Low-grade inflammation has been increasingly implicated in the pathophysiology of irritable bowel syndrome (IBS). Imbalances of pro- and anti-inflammatory cytokines and polymorphisms in cytokine genes have been reported in IBS; however, these findings have not been consistently observed. This may be due to small sample sizes and differences in ethnicities. Therefore, we performed a meta-analysis on the studies that investigated cytokine gene polymorphisms in IBS patients compared to healthy controls.

METHODS

A PubMed and EMBASE search was performed, and cytokine gene polymorphisms, which had been investigated in at least two case-control studies, were evaluated. Pooled odds ratios (OR) for the genotypes were calculated using random- or fixed-effects models.

KEY RESULTS

Five studies that investigated interleukin-10 (IL-10; -1082 G/A), transforming growth factor-β1 (TGF-β1; +869 T/C and +915 G/C) and tumor necrosis factor (TNF; -308 G/A) polymorphisms in IBS patients and controls were included. High producer IL-10 (-1082 G/G; OR: 0.64 [95% CI: 0.48-0.87]) was significantly associated with a decreased risk of IBS. The intermediate producer TGF-β1 (+915 G/C) genotype showed a tendency toward decreasing the risk of IBS. No associations were found between TNF (-308 G/A) genotypes and IBS in the whole meta-analysis although an analysis of Asian studies revealed an association between TNF (-308 G/A and G/G) genotypes and IBS (OR: 0.50 [95% CI: 0.29-0.85]), and 1.82 [95% CI: 1.08-3.07], respectively).

CONCLUSIONS & INFERENCES

This meta-analysis indicates a role for IL-10 polymorphisms in IBS in general and TNF in Asian populations. Whether or not gene polymorphisms are associated with alterations in cytokine levels leading to functional effects at the level of the gut needs further investigation.

The prevalence of cagA and cagE genes in Helicobacter pylori strains isolated from different patient groups by polymerase chain reaction

The aim of this study was to investigate the prevalence of cagA and cagE genes in H. pylori strains isolated from different patient groups with Non-Ulcer Dyspepsia (NUD), Duodenal Ulcer (DU), Gastric Ulcer (GU) and Gastric Cancer (GC). The patients admitted to the gastroenterology unit at Sharyati hospital in Tehran in 2006 were included in this study. Gastric biopsy specimens were obtained from the antrum of the stomach from each patient then cultured for detection of H. pylori. Identification of H. pylori was performed according to the standard bacteriological methods. Genomic DNA was extracted using a commercially available Qia gene kit. PCR was done using primers cagA-F, cagA-R and cagE-F, cagE-R to detect the target genes cagA and cagE, respectively. Amplified products of target genes were confirmed by sequencing. The cagA and cagE were detected among 85 and 86% of H. pylori isolates, respectively. Prevalence of cagA and cagE genes in the patients with NUD, DU, GU and GC were 22 (64.7%), 28 (100%), 18 (90%), 10 (100%) and 25 (73.5%), 27 (96.4%), 19 (95%), 7 (70%), respectively. The current study demonstrated a significant correlation between peptic ulceration and the presence of H. pylori isolates carrying cagE and cagA genes in Iranian patients.