HFE Genotype, Parenchymal Iron Accumulation, and Liver Fibrosis in Patients With Nonalcoholic Fatty Liver Disease
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.
Keywords: Hepatic Fibrosis, hfe Gene, Iron Overload, Nonalcoholic Fatty Liver Disease
Abbreviations used in this paper: BMI, body mass index, GGT, γ-glutamyltranspeptidase, HFE, hemochromatosis gene, NAFLD, nonalcoholic fatty liver disease, NASH, nonalcoholic steatohepatitis
This article has an accompanying continuing medical education activity on page e9. Learning Objective: Upon completion of reading this article, successful learners will be able to differentiate the effect of different patterns of iron overload on liver damage, understand the effect of mutations in the HFE gene of hereditary hemochromatosis in determining the predisposition to develop iron overload, and recognize the lack of utility of HFE mutations assessment in the absence of histological demonstration of hepatocellular iron accumulation in patients with nonalcoholic fatty liver disease.
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Conflicts of interest The authors disclose no conflicts.
Funding Supported by the following grants: FIRST Università di Milano 2007, 2008 (to L.V., S.F., A.L.F.); Ricerca corrente Ospedale Maggiore Policlinico 2006 and 2008 (L.V., S.F.); and Centro per lo Studio delle Malattie del Fegato e del Metabolismo.
PII: S0016-5085(09)02003-4
doi:10.1053/j.gastro.2009.11.013
© 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.
