ABSTRACT: To investigate whether the patatin-like phospholipase domain containing-3 gene (PNPLA3) I148M polymorphism is associated with steatosis, fibrosis stage, and cirrhosis in hereditary hemochromatosis (HH).
We studied 174 consecutive unrelated homozygous for the C282Y HFE mutation of HH (C282Y+/+ HH) patients from Northern Italy, for whom the presence of cirrhosis could be determined based on histological or clinical criteria, without excessive alcohol intake (< 30/20 g/d in males or females) or hepatitis B virus and hepatitis C virus viral hepatitis. Steatosis was evaluated in 123 patients by histology (n = 100) or ultrasound (n = 23). The PNPLA3 rs738409 single nucleotide polymorphism, encoding for the p.148M protein variant, was genotyped by a Taqman assay (assay on demand, Applied Biosystems). The association of the PNPLA3 I148M protein variant (p.I148M) with steatosis, fibrosis stage, and cirrhosis was evaluated by logistic regression analysis.
PNPLA3 genotype was not associated with metabolic parameters, including body mass index (BMI), the presence of diabetes, and lipid levels, but the presence of the p.148M variant at risk was independently associated with steatosis [odds ratio (OR) 1.84 per p.148M allele, 95% confidence interval (CI): 1.05-3.31; P = 0.037], independently of BMI and alanine aminotransaminase (ALT) levels. The p.148M variant was also associated with higher aspartate aminotransferase (P = 0.0014) and ALT levels (P = 0.017) at diagnosis, independently of BMI and the severity of iron overload. In patients with liver biopsy, the 148M variant was independently associated with the severity (stage) of fibrosis (estimated coefficient 0.56 ± 0.27, P = 0.041). In the overall series of patients, the p.148M variant was associated with cirrhosis in lean (P = 0.049), but not in overweight patients (P = not significant). At logistic regression analysis, cirrhosis was associated with BMI ≥ 25 (OR 1.82, 95% CI: 1.02-3.55), ferritin > 1000 ng/mL at diagnosis (OR 19.3, 95% CI: 5.3-125), and with the G allele in patients with BMI < 25 (OR 3.26, 95% CI: 1.3-10.3).
The PNPLA3 I148M polymorphism may represent a permissive factor for fibrosis progression in patients with C282Y+/+ HH.
World Journal of Gastroenterology 06/2012; 18(22):2813-20. · 2.47 Impact Factor
ABSTRACT: Parenchymal liver siderosis is associated with increased fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). The aim of this study was to assess whether a panel of genetic variants previously reported to influence iron metabolism, including the C282Y/H63D HFE, the PiZ/PiS alpha1-antitrypsin, the IVS1-24 ferroportin polymorphisms, and the beta-thalassemia trait, may be able to predict the presence of parenchymal siderosis and of progressive fibrosis in NAFLD.
We considered 274 Italian patients with biopsy-proven NAFLD. Genetic polymorphisms were searched for by sequence allele specific-polymerase chain reaction and restriction analysis, whereas beta-trait was determined according to blood count and HbA(2) determination.
Parenchymal iron deposition was predominantly observed in 32 (11.7%) patients. Heterozygosity for the C282Y (OR 1.87, 95% CI 1.04-3.25), homozygosity for the H63D HFE (OR 2.31, 95% CI 1.04-4) mutations, and the beta-thalassemia trait (OR 2.57 95% CI 1.49-4.47) were all predominantly associated with parenchymal siderosis, independently of age, sex, body mass index, alcohol intake, ferritin, and transferrin saturation. Sixty-three percent of patients with hepatocellular siderosis were positive for at least one of the aforementioned genetic variants. The beta-thalassemia trait had the highest positive and the lowest negative likelihood ratios for predominantly parenchymal iron accumulation (5.05 and 0.74, respectively), and was independently associated with moderate/severe fibrosis (OR 2.50, 95% CI 1.26-5.19).
In patients with NAFLD, predominant hepatocellular iron deposition is often related to genetic factors, among which beta-globin mutations play a major role, predisposing to parenchymal iron accumulation and to progressive liver fibrosis.
Journal of Hepatology 11/2010; 53(5):927-33. · 9.26 Impact Factor
ABSTRACT: Peroxisome proliferator-activated receptors (PPARs) play key roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD).
to assess the effect of functional single nucleotide polymorphisms (SNPs) of PPARα and PPARγ2, previously associated with insulin resistance and dyslipidemia, on liver damage in NAFLD, whose progression is influenced by metabolic abnormalities and inherited factors.
The Leu162Val PPARα and Pro12Ala PPARγ2 SNPs were evaluated by restriction analysis. We considered 202 Italian patients with biopsy-proven NAFLD.
The frequency of the evaluated SNPs did not differ between patients and 346 healthy controls. The presence of the PPARα 162Val allele (prevalence 57%), but not of the PPARγ2 12Ala allele (prevalence 18%), was associated with higher insulin resistance (HOMA-IR index 4.71 ± 3.8 vs. 3.58 ± 2.7, p = 0.026), but not with hyperglycemia. The PPARα 162Val and PPARγ2 12Ala alleles were not associated with the severity of steatosis, necroinflammation, or fibrosis.
The presence of the PPARα 162Val allele was associated with insulin resistance, but not with liver damage in NAFLD. Because of the limited power of the present sample, larger studies are needed to exclude a minor effect of the PPARγ2 12Ala allele on necroinflammation/fibrosis in NAFLD.
BMC Gastroenterology 01/2010; 10:102. · 2.42 Impact Factor