Role of Tumor Necrosis Factor-alpha Promoter Polymorphism and Insulin Resistance in the Development of Non-alcoholic Fatty Liver Disease in Obese Children / 대한소아소화기영양학회지

PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) polymorphism has been suggested to play an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) in obese adults, and known to be a mediator of insulin resistance. In this study, we evaluated the role of TNF-alpha promoter polymorphisms and insulin resistance in the development of NAFLD in obese children. METHODS: A total of 111 obese children (M:F=74:37; mean age, 11.1+/-2.0 yrs) were included. The children were divided into 3 groups: controls (group I, n=61), children with simple steatosis (group II, n=17), and children with non-alcoholic steatohepatitis (group III, n=33). Serum TNF-alpha levels, homeostasis model assessment of insulin resistance (HOMA-IR), and TNF-alpha -308 and -238 polymorphisms were evaluated. RESULTS: There were no differences in TNF-alpha polymorphism at the -308 or the -238 loci between group I and group II + III (p=0.134 and p=0.133). The medians of HOMA-IR were significantly different between group I and group II + III (p=0.001), with significant difference between group II and group III (p=0.007). No difference was observed in the HOMA-IR among the genotypes at the -308 locus (p=0.061) or the -238 locus (p=0.207) in obese children. CONCLUSION: TNF-alpha promoter polymorphisms at the -308 and -238 loci were not significantly associated with the development of NAFLD in children; nevertheless, insulin resistance remains a likely essential factor in the pathogenesis of NAFLD in obese children, especially in the progression to NASH.

Polymorphisms of tumor necrosis factor-alpha promotor gene in Kawasaki disease and relation to the risk of coronary artery lesion / 소아과

PURPOSE: The purpose of this study was to investigate the polymorphisms of the TNF-alpha promotor gene, its susceptibility to Kawasaki disease (KD) and to assess whether the TNF-alpha promotor gene polymorphism was related the risk of coronary artery lesions (CALs). METHODS: From January 2003 to January 2007, 51 children (30 boys and 21 girls) with KD and 48 children forming an age-matched control group were studied. DNA from the peripheral blood of all the children was sampled, and the DNA polymorphisms of the 5' flanking regions of the TNF-alpha promoter gene at position -308 [guanine (G) to adenine (A)] were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Then, the relationship between KD and the TNF-alpha promotor gene polymorphisms was evaluated. RESULTS: The A allele frequency of the -308 site of the TNF-alpha promotor gene was 17.6% (9/51) for children with KD and 6.8% (3/48) for the control group children, but this result was not statistically significant. Twenty-four patients experienced CALs within 60 days after the onset of symptoms. KD children with TNF-alpha -308 A allele had lower frequencies of CALs (12.5% versus 22.2%, P>0.05). CONCLUSIONS: The DNA polymorphism of the -308 site TNF-alpha gene was not associated with susceptibility to KD and a risk of CALs. Multicenter, large-scale randomized controlled trials are needed for further study.