Association of a genetic polymorphism in ectonucleotide pyrophosphatase/phosphodiesterase 1 with hepatitis C virus infection and hepatitis C virus core antigen levels in subjects in a hyperendemic area of Japan.

BACKGROUND: The clinical course of chronic hepatitis C virus (HCV) infection is strongly associated with insulin resistance and obesity. The K121Q polymorphism in the ectonucleotide pyrophosphatase/phosphodiesterase (ENPP)-1 gene and the rs7566605 genotype located near insulin-induced gene 2 have been shown to be associated with insulin resistance and obesity. This study examined whether the K121Q polymorphism in ENPP1 or the rs7566605 genotype is associated with the clinical course of HCV infection. METHODS: The relationships between the clinical characteristics of 469 anti-HCV antibody-seropositive subjects (353 were positive for HCV core antigen or RNA, whereas 116 were negative for HCV RNA) and the polymorphisms were analyzed. RESULTS: No significant differences in body mass index, plasma glucose level, serum insulin level, and other biochemical markers were observed between subgroups of subjects with different genotypes at the K121Q polymorphism or rs7566605. The frequency of the homozygous wild-type genotype at K121Q in HCV carriers, however, was significantly higher than that in subjects who were negative for HCV RNA (84.5% vs. 75.9%; P < 0.05). Moreover, in HCV carriers, HCV core antigen levels in subjects homozygous for the wild-type genotype at K121Q were significantly higher than in heterozygous carriers of K121Q (5358 fmol/l vs. 4002 fmol/l; P = 0.04). In contrast, the rs7566605 genotype was not associated with hepatitis C viremia or with the HCV core antigen level. CONCLUSIONS: The K121Q variant of ENPP1 may be associated with hepatitis C viremia and core antigen levels in HCV carriers.

Alanine aminotransferase flare-up in hepatitis C virus carriers with persistently normal alanine aminotransferase levels in a hyperendemic area of Japan.

BACKGROUND: The clinical features of hepatitis C virus (HCV) carriers with persistently normal alanine aminotransferase (PNALT) levels (ALT < or = 34 IU/l) have not been fully elucidated. We investigated clinical factors associated with ALT flare-up in PNALT individuals in a HCV hyperendemic area of Japan. METHODS: We analyzed 101 HCV carriers who had PNALT between 1993 and 2000. The first occurrence of ALT flare-up (ALT > or = 35 IU/l) between 2001 and 2005 was evaluated by the Kaplan-Meier method. Multivariate analysis of factors predicting ALT flare-up were conducted using Cox proportional hazards models. RESULTS: The mean follow-up period was 2.8 years, and the 5-year cumulative incidence of ALT flare-up was estimated to be 31.8%. In multivariate analysis, an ALT level of 20-34 IU/l and a high serum ferritin level (> or =90 ng/ml) in the most recently available data up to the year 2000, as well as H63D heterozygosity in the HFE gene, were independently and strongly associated with the incidence of ALT flare-up (Hazard ratios = 5.6, 3.1, and 4.8, respectively). In addition, HFE H63D heterozygosity was significantly associated with higher serum ferritin levels in subjects with PNALT (153.8 + or - 73.3 ng/ml in subjects with the 63HD genotype vs. 89.4 + or - 51.3 ng/ml in subjects with the 63HH genotype, P = 0.043). CONCLUSIONS: HCV carriers with PNALT in this population were at risk for ALT flare-up. Basal ALT levels, serum ferritin levels, and HFE polymorphism are potentially important predictors of ALT flare-up.

Repeated intravenous injection of recombinant human hepatocyte growth factor ameliorates liver cirrhosis but causes albuminuria in rats.

Hepatocyte growth factor (HGF) is a promising agent for the treatment of liver cirrhosis because of its mitogenic and anti-fibrotic effects. We investigated the effect of recombinant human HGF (rh-HGF) on cirrhosis development; its pharmacokinetics and nephrotoxicity in rats with liver cirrhosis induced by 4-week treatment with dimethylnitrosamine (DMN). rh-HGF (0.3 mg/kg) was intravenously administered to rats once a day for 4 weeks in parallel with DMN treatment or twice a day for the last 2 weeks of DMN treatment. Repeated doses of rh-HGF increased the liver weight and serum albumin, and reduced serum ALT. The development of hepatic fibrosis was inhibited more efficiently by extended low-dose treatment with rh-HGF. In cirrhotic rats, serum levels of rh-HGF increased and clearance was decreased, leading to an increase in the area under the plasma-concentration time curve and a decrease in the steady-state volume of distribution. Repeated doses of rh-HGF led to increased urinary albumin excretion, but no rh-HGF-treated animals developed increased serum creatinine levels. Urinary albumin excretion returned to baseline after the cessation of rh-HGF. These results suggest that extended treatment with rh-HGF is required for the attenuation of cirrhosis, and repeated doses of rh-HGF cause adverse effects in extra-hepatic organs. These issues must be resolved before the widespread application of rh-HGF in the treatment of liver cirrhosis.

Transgenic expression of osteoactivin in the liver attenuates hepatic fibrosis in rats.

The role of osteoactivin (OA) in liver fibrogenesis remains unclear. After feeding wild-type (WT) and OA transgenic (OA-Tg) rats a choline-deficient, L-amino acid-defined (CDAA) diet for 12 weeks, we evaluated liver fibrosis. Hepatic fibrosis and expression of alpha-smooth muscle actin protein in OA-Tg rats were reduced in comparison to WT rats. Our examination of the expression of 31,100 genes by microarray analysis identified 177 and 256 genes that were upregulated and downregulated, respectively, by at least twofold in OA-Tg rat livers in comparison to WT rat livers. Of these genes, we confirmed a significant downregulation in the expression levels of tissue inhibitor of metalloproteinase-1 and -2, type I collagen, and platelet-derived growth factor receptor-alpha and -beta in the livers of OA-Tg rats. These results indicate that transgenic OA expression attenuates the development of hepatic fibrosis in association with the suppression of specific genes involved in its pathogenesis.

Interleukin-10 or tumor necrosis factor-alpha polymorphisms and the natural course of hepatitis C virus infection in a hyperendemic area of Japan.

We investigated the effects of polymorphisms in interleukin (IL)-10 and tumor necrosis factor (TNF)-alpha on the natural course of hepatitis C virus (HCV) infection in a community-based population in Japan. A total of 460 anti-HCV antibody seropositive individuals were classified into two groups, those who were positive or negative for HCV RNA. In HCV RNA-positive individuals with at least four annual alanine aminotransferase (ALT) measurements taken between 1993 and 2003, 74 exhibited persistently normal ALT levels, while 211 had one or more elevated ALT level tests. We examined the relationships between polymorphisms in the genes encoding IL-10 (-1082, -819, -592) or TNF-alpha (-308, -238) and HCV clearance, ALT abnormalities, or serum level of type IV collagen 7S, a marker of hepatic fibrosis. These polymorphisms were equally distributed among the patient subgroups with differential HCV RNA clearances or ALT abnormalities. Serum levels of type IV collagen 7S, however, were significantly higher in individuals with an A at position -238 or -308 in the TNF-alpha gene promoter than in individuals lacking these polymorphisms. We conclude that, while the relationships between inherited variations in IL-10 or TNF-alpha expression are not associated with alterations in HCV clearance or ALT levels, TNF-alpha polymorphisms may be associated with hepatic fibrosis.