Association of Tumor Necrosis Factor and Manganese Superoxide Dismutase Polymorphisms in Patients with Non-Alcoholic Steatohepatitis from Northeast Mexico

Background and Aims: Environmental and genetic factors play a role in the pathogenesis and natural history of non-alcoholic steatohepatitis (NASH). The aim of this study was to determine if the G-238A (allele TNFA) and G-308A (allele TNF2) tumor necrosis factor-alpha (TNF- ) and Ala9Val manganese superoxide dismutase (MnSOD) polymorphisms were associated with NASH in a case-control study of subjects from Northeast Mexico. Methods: We analyzed DNA samples from 68 patients with NASH (50 women and 18 men; mean age ± SD, 33.9 ± 10.8 years; BMI 43.9 ± 7.2 kg/m 2 ) and 100 healthy subjects (44 women and 56 men; mean age ± SD, 27.8 ± 10.8 years; BMI 23 ± 1.6 kg/m 2 ). The diagnosis was based on liver biopsy reviewed by two pathologists blinded to clinical data. The polymorphisms were evaluated using the polymerase chain reaction-restriction fragment length polymorphism method. Results: The frequency of G-238A TNF- and Ala9Val MnSOD polymorphisms in NASH patients was significantly higher in comparison with control subjects (OR = 3.06, 95% CI 1.29-7.33, p = 0.0047 and OR = 6.28, 95% CI 2.95-13.55, p = 0.001, respectively). In contrast, the G-308A TNF- polymorphism did not show a statistical difference between either group (OR = 1.04, 95% CI 0.45-2.38, p = NS). Analyzed populations were in Hardy-Weinberg equilibrium. Conclusions: Our results suggest that G-238A TNF- and Ala9Val MnSOD polymorphisms, which are molecules involved in inflammation and cellular oxidative stress, could be associated with NASH. These data may contribute to understanding the genetic susceptibility to NASH.