The TNF-α -308 polymorphism may affect the severity of Crohn's disease

Comparative analysis of TNF-α (-308) gene polymorphism in Turkish patients with type 2 diabetes developing nephropathy and/or neuropathy

Type 2 diabetes (T2DM) is a group of chronic and systemic metabolic diseases. Nephropathy (NP) and neuropathy (NR) are two common complications that severely affect the quality of life of patients with T2DM. In this study, our aim was to investigate the association between TNF-alpha (-308) gene polymorphism and the risk of developing NP and NR in patients with T2DM We also aimed to determine the association between TNF-alpha (-308) gene polymorphism and several demographic characteristics and biochemical parameters of patients with T2DM developed NP and/or NR. First, blood samples of patients were collected, and DNA isolation was performed. Then, real-time PCR analysis was used for genotyping the TNF-α (-308) gene utilising fluorescently labelled probes. Patients' demographical data and biochemical parameters were also obtained. Our study did not detect any significant difference in the frequency of possessing the gene polymorphism (A allele) between the groups. Additionally, no significant difference was detected when the data on various biochemical parameters were evaluated in GG, GA, and AA genotypes.

Tumor necrosis factor‑α ‑308 G/A genetic polymorphism in patients with chronic obstructive pulmonary disease presenting with hyperactive airways

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide. COPD is often diagnosed late in the disease leading to a delay in management. Notably, tumor necrosis factor-α (TNF-α) polymorphisms may serve an important role in the development of COPD. A single-center, case-control study was conducted to determine the presence of the TNF-α -308 G/A polymorphism among patients diagnosed with COPD presenting with hyperactive airways, patients without COPD presenting with hyperactive airways, and normal study participants without pulmonary comorbidities. Three genotypes: G/G (94%; 157/167), G/A (5%; 9/167) and A/A (1%; 1/167) were detected by quantitative PCR. The present study showed that the presence of the TNF-α -308 G/A polymorphism reduced the odds of having hyperactive airways with COPD by 29.3% and hyperactive airways without COPD by 26.3%. Multinomial logistic regression analysis showed that having the TNF-α -308 G/A polymorphism did not significantly reduce the odds of having hyperactive airways with COPD and without COPD compared to those with the G/G genotype. In conclusion, the presence of the TNF-α -308 G/A gene polymorphism showed no significant association with patients with COPD with or without hyperactive airways. The presence of the TNF-α -308 G/A polymorphism instead had a weak association with the reduction in the development of COPD regardless of the presence or absence of airway hyperactivity.

Oral administration of Lactobacillus plantarum 06CC2 prevents experimental colitis in mice via an anti‑inflammatory response

Dysbiosis of the enteric microbiota causes gastrointestinal diseases, including colitis. The present study investigated the beneficial effect of Lactobacillus plantarum 06CC2 in experimental colitis in mice. An experimental colitis model in C57BL6 mice was induced using dextran sulfate sodium. Mice were orally administered 06CC2 (06CC2 group) or PBS only (control group) by gavage. The disease activity index (DAI), histological grading, and colon tissue and colonic lamina propria mononuclear cells (LPMCs) were examined macroscopically and histopathologically, and the expression levels of inflammation‑associated cytokines (IL‑6, IL‑12, TNF‑α and IL‑10) in these samples were determined. Compared with the control group, the 06CC2 group exhibited a significantly lower DAI (1.5±0.8 vs. 0.2±0.3, respectively; P<0.05) and pathology score (6.3±1.5 vs. 3.8±1.3, respectively; P<0.05). IL‑10 expression in colonic LPMCs was higher in the 06CC2 group than in the control group, although there was no significant difference in IFN‑γ, IL‑6 or IL‑12 expression in colonic LPMCs between the two groups. In addition, 06CC2 stimulated the production of IL‑10 from CD11b‑positive cells and CD11c‑positive cells in the colon. The 06CC2 strain induced IL‑10 production in the colon and attenuated colon inflammation.

The Unsolved Link of Genetic Markers and Crohn's Disease Progression: A North American Cohort Experience

BACKGROUND

While progress has been made in the identification of Crohn's disease (CD) susceptibility loci, efforts to identify a genetic basis for disease progression have been less fruitful. The specific aim of this study was to build upon the major genetic advances made in IBD by applying genome-wide technologies toward predicting disease progression in CD.

METHODS

Crohn's disease cases (n = 1495) from 3 IBD centers were reviewed by experienced physicians. Clinical and demographic details were collected, focusing on the time to first disease progression. Genome-wide association (GWA) analysis was carried out on 3 clinical outcomes: 1) time to disease progression; 2) time to first abdominal surgery; and 3) a binary analysis of indolent vs progressive disease. Cox-proportional hazard and logistic regression models were used.

RESULTS

A GWA analysis was carried out to determine any genetic variation associated with the time to disease progression; 662 cases were included after quality control (QC) and exclusion of any cases with B2/B3 behavior at baseline (n = 450). There were 1360 cases included after QC in the time to abdominal surgery analysis. No variant reached genome-wide significance in any of the 3 analyses performed. Eight known IBD susceptibility single nucleotide polymorphism (SNPs) were found to be associated with time-to-abdominal surgery SMAD3 (rs17293632), CCR6 (rs1819333), CNTF (rs11229555), TSPAN14 (rs7097656), CARD9 (rs10781499), IPMK (rs2790216), IL10 (rs3024505), and SMURF1 (rs9297145) (P < 0.05).

CONCLUSION

Our GWA study failed to show any SNP-phenotype association reaching genome-wide significance. It is likely that multiple variables affect disease progression, with genetic factors potentially having only a small effect size.

Association of tumor necrosis factor-α and -β gene polymorphisms in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex, multifactorial, chronic inflammatory disorder of the gastrointestinal tract in which immune dysregulation caused by genetic and/or environmental factors plays an important role. The aim of this case–control study was to evaluate the association of tumor necrosis factor-alpha (TNF-α) (308) and -β (+252) polymorphisms with susceptibility of IBD. A total of 379 Saudi subjects including 179 IBD patients (ulcerative colitis (UC) =84 and Crohn’s disease (CD) =95) and 200 age- and sex-matched healthy controls were recruited. TNF-α and TNF-β genes were amplified using an amplification refractory mutation systems polymerase chain reaction methodology to detect TNF-α (−308) and -β (+252) polymorphisms. The frequency of the GA genotype of TNF-α (−308G/A) was higher, and the frequencies of the GG and AA genotypes were significantly lower in IBD patients compared with those in controls, indicating that genotype GA-positive individuals are susceptible to IBD and that the GG and AA genotypes exert a protective effect. The frequency of allele A of TNF-α (−308G/A) was significantly higher and that of allele G was lower in IBD patients compared with those in controls, indicating an association of allele A with IBD risk in Saudi patients. On stratification of IBD patients into UC and CD, an almost similar pattern was noticed in both the groups. The results of TNF-β (+252A/G) polymorphisms showed a significant increase in the frequency of the GG genotype in IBD patients, suggesting a positive association of GG genotype with IBD risk. On stratification of IBD patients into UC and CD, the genotype GG of TNF-β was associated with susceptibility risk to UC but not CD. The frequencies of alleles and genotypes of both TNF-α and-β polymorphisms are not affected by sex or type of IBD (familial or sporadic). TNF-α (−308G/A) and TNF-β (+252A/G) polymorphisms are associated with risk of developing IBD in Saudi population.