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Background & Aims Mutations in the hemochromatosis gene ( HFE ) (C282Y and H63D) lead to parenchymal iron accumulation, hemochromatosis, and liver damage. We investigated whether these factors also contribute to the progression of fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). Methods We studied clinical, histologic (liver biopsy samples for hepatocellular iron accumulation), serologic (iron and enzyme levels), and genetic ( HFE genotype) data from 587 patients from Italy with NAFLD and 184 control subjects. Results Iron accumulation predominantly in hepatocyes was associated with a 1.7-fold higher risk of a fibrosis stage greater than 1 (95% confidence interval [CI]: 1.2–2.3), compared with the absence of siderosis (after adjustment for age, body mass index, glucose tolerance status, and alanine aminotransferase level). Nonparenchymal/mixed siderosis was not associated with moderate/severe fibrosis (odds ratio, 0.72; 95% CI: 0.50–1.01). Hepatocellular siderosis was more prevalent in patients with HFE mutations than in those without; approximately one third of patients with HFE mutations had parenchymal iron accumulation (range, 29.8%–35.7%, depending on HFE genotype). Predominantly hepatocellular iron accumulation occurred in 52.7% of cases of patients with HFE mutations. There was no significant association between either the presence of HFE mutations or specific HFE genotypes and the severity of liver fibrosis. Conclusions Iron deposition predominantly in hepatocyes is associated with more severe liver damage in patients with NAFLD. However, HFE mutations cannot be used to identify patients with hepatocellular iron accumulation.

Background & Aims: Nonalcoholic fatty liver disease, which can range from fatty liver alone to nonalcoholic steatohepatitis and cirrhosis, is related to insulin resistance. Tumor necrosis factor α (TNF-α) may induce insulin resistance, and polymorphisms of its promoter have been associated with an increased release of this cytokine. We analyzed (1) the prevalence of insulin resistance, (2) the prevalence of the 238 and 308 TNF-α polymorphisms, and (3) the relationship among TNF-α polymorphisms, insulin resistance, and the occurrence of steatohepatitis in 99 patients with nonalcoholic fatty liver diagnosed by ultrasonography and confirmed by histologic analysis in the 53 who underwent biopsy. Methods: Insulin resistance was evaluated by the homeostatic metabolic assessment insulin resistance indices and TNF-α polymorphisms by polymerase chain reaction and restriction fragment length polymorphism analysis. Results: Insulin resistance was detected in almost all of the patients and was more severe in those with steatohepatitis. The prevalence of the 238, but not of the 308, TNF-α polymorphism was higher in subjects with nonalcoholic fatty liver than in controls (31% vs. 15%; P < 0.0001), and patients positive for TNF-α polymorphisms had higher insulin resistance indices, a higher prevalence of impaired glucose tolerance, and a lower number of associated risk factors for steatosis. Conclusions: TNF-α polymorphisms could represent a susceptibility genotype for insulin resistance, nonalcoholic fatty liver, and steatohepatitis. GASTROENTEROLOGY 2002;122:274-280