Initially, rs1800629 and rs361525 variants show association with T1DM, but after adjusting the data for LD with DRB1-DQB1 and B18-DR3 haplotypes, the association lost its significance [93]. Boraska et al. [95] studied relation of TNF gene promoter polymorphism (rs1800629 and rs361525) with TIDM in a case–control study from South Croatia. Haplotype (rs1800629 A and rs361525 G) was observed more often in patients with TIDM than in controls. SNP rs1800629 was found to be more frequent in patients with TIDM. The author did not find strong evidence of association of TNF promoter polymorphism with TIDM. Independent association of TNF polymorphism
with type 1 diabetes susceptibility have been found in Korean [96]. Seven SNPs in the TNF genes (TNFα and TNFβ) were genotyped in a Korean, along with HLA DRB1, DQB1 and MICA (MHC class I chain–related genes). Three SNPs and two common TNF haplotypes Wnt inhibitor showed significant association with the risk of TIDM. In case of type 2 diabetes, high levels of cytokines have been considered as risk factors. Kubaszek et al. [97] investigated TNF-α and IL-6 polymorphisms and found that TNF-α rs1800629 A-allele was associated with Y-27632 ic50 an approximate twofold higher risk of type 2 diabetes compared with the rs1800629 G. The rs1800629 A-allele of TNF-α rs1800629 polymorphism is a predictor for the
conversion from IGT (impaired glucose tolerance) to type 2 diabetes. In diabetic nephropathy, glucose auto-oxidation and production of free radicals causes protein glycation that increases the concentrations of proinflammatory cytokines. Myeloperoxidase (MPD) is a heme enzyme, participating in microorganism killing by phagocytes. Patients with chronic renal failure results from diabetic nephropathy show a significant reduction in the intracellular myeloperoxidase level and myeloperoxidase gene promoter polymorphism (−463, G/A) causes a decreased gene expression. In a case–control study, no significant differences in TNF genotype and allele
frequencies between the groups and patients with diabetic nephropathy were found. A lower frequency of TNF1/TNF1 genotype has been reported [98]. Significant differences TCL of TNF plasma level in patients with diabetic nephropathy and other renal diseases were reported. A statistically significant difference in MPO genotype frequencies between patients with diabetic nephropathy and patients with other renal diseases was observed. MPO, GG and AA genotypes were significantly more common in patients with diabetic nephropathy. A correlation between the MPO genotype and an earlier onset of the disease was observed while such a relationship was not found for the TNF genotype. It has been found that in patients with diabetic nephropathy, TNF variants were more frequent than in non-diabetic patients with chronic renal failure. Crohn’s disease is a chronic inflammatory disease of the intestines.