Search

Background/aims: Intercross studies in inbred mice susceptible or resistant to liver fibrosis revealed complement factor 5 as a quantitative trait gene associated with the development of fibrosis. In 277 patients with hepatitis C, two C5 SNPs, rs17611 and rs2300929, have been associated with advanced fibrosis., Methods: We investigated the association of these C5 SNPs with advanced fibrosis in 1435 HCV infected patients and in 1003 patients with other liver diseases. We performed genotyping with melting curve analysis using fluorescence resonance energy transfer probes in the LightCycler., Results: The defined high-risk genotypes (AA and TT) and alleles (A and T) were not associated with advanced fibrosis in HCV patients when Chi square testing and logistic regression analysis were applied (rs17611A 0.45 in F0-1 vs. 0.43 in F2-4, P=0.31; rs2300929T 0.91 F0-1 and 0.91 in F2-4, P=0.82). In the group of patients with liver diseases other than HCV we neither found an association of the C5 SNPs with advanced fibrosis nor an overrepresentation of the SNPs in patients with cirrhosis., Conclusions: We found no evidence that these C5 SNPs are genetic risk factors for the development of advanced fibrosis in chronic HCV infection or other chronic liver diseases.

Background/aims: HCV-infection leads to development of liver fibrosis, causing morbidity and mortality. Multiple factors influence the progression of fibrosis, including genetic factors. Since HCV is an RNA virus, a role for TLR7 in the immune response against HCV is likely. No systematic analysis of TLR7 single nucleotide polymorphisms (SNPs) has been published., Methods: We sequenced TLR7 in 52 women and investigated SNPs with an allele frequency >5% in 807 patients with chronic HCV-infection by melting curve analysis. We analyzed the effect of TLR7 SNPs on grade of inflammation and stage of fibrosis as determined by liver biopsy., Results: We detected five TLR7 SNPs, three of which showed a frequency >5%. One variant, c.1-120T>G, was more common in patients with no or little inflammation than in patients with grades 2-4 (10.7% vs. 6.1%; P=0.034). The variant was also enriched in patients with no or little fibrosis compared to those with higher stages (12.6% vs. 6.6%; P=0.005). The difference was fully attributable to male patients., Conclusions: This is the first analysis of TLR7 SNPs in patients with chronic HCV-infection. Our data suggest that the c.1-120G TLR7 allele offers protection from the development of inflammation and fibrosis in male patients with chronic HCV-infection.

Background/aims: A vigorous T-cell response is essential for the resolution of HCV infection. It is modified by co-stimulatory molecules that attenuate T-lymphocyte responses by binding to CTLA4. We investigated whether CTLA4 single nucleotide polymorphisms are associated with the resolution of infection or with the course of disease., Methods: We enrolled 127 individuals with self-limited and 947 patients with chronic HCV infection, of whom 560 were treated with interferon-alpha-based therapies, and 200 healthy controls. We analyzed CTLA4 polymorphisms -318C>T and +49A>G by melting curve analysis and reconstructed haplotypes., Results: CTLA4 haplotypes were distributed differently between men but not women with self-limited and chronic infection (p=0.043) but were not predictive of the stage of fibrosis in chronic carriers. Haplotypes were distributed differently between male but not female end-of-treatment responders and non-responders (p=0.025). The influence of CTLA4 haplotypes was more pronounced in "hard-to-treat" situations, i.e., treatment with interferon-alpha monotherapy or infection with HCV genotypes 1/4. Logistic regression analysis confirmed gender-specific risk factors for a virological non-response., Conclusions: CTLA4 polymorphisms are associated with the resolution of HCV infection. This study underlines the role of an efficient T-cell response in the clearance of HCV and sheds light on a gender-dependent difference of immune regulation.

Background/aims: Interleukin-12 (IL-12) governs the Th1-type immune response, affecting the spontaneous and treatment-induced recovery from HCV-infection. We investigated whether the IL12B polymorphisms within the promoter region (4 bp insertion/deletion) and the 3'-UTR (1188-A/C), which have been reported to influence IL-12 synthesis, are associated with the outcome of HCV infection., Methods: We analyzed 186 individuals with spontaneous HCV clearance, 501 chronically HCV infected patients, and 217 healthy controls. IL12B 3'-UTR and promoter genotyping was performed by Taqman-based assays with allele-specific oligonucleotide probes and PCR-based allele-specific DNA-amplification, respectively., Results: The proportion of IL12B promoter and 3'-UTR genotypes did not differ significantly between the different cohorts. However, HCV genotype 1-infected patients with high baseline viremia carrying the IL12B 3'-UTR 1188-C-allele showed significantly higher sustained virologic response (SVR) rates (25.3% vs. 46% vs. 54.5% for A/A, A/C and C/C) due to reduced relapse rates (24.2% vs. 12% vs. zero % for A/A, A/C and C/C)., Conclusions: IL12B 3'-UTR 1188-C-allele carriers appear to be capable of responding more efficiently to antiviral combination therapy as a consequence of a reduced relapse rate. No association of IL12B polymorphisms and self-limited HCV infection could be demonstrated.

Background: Non-Wilsonian hepatic copper toxicosis includes Indian childhood cirrhosis (ICC), endemic Tyrolean infantile cirrhosis (ETIC) and the non-Indian disease known as idiopathic copper toxicosis (ICT). These entities resemble the hepatic copper overload observed in livers of Bedlington terriers with respect to their clinical presentation and biochemical and histological findings. We recently cloned the gene causing copper toxicosis in Bedlington terriers, MURR1, as well as the orthologous human gene on chromosome 2p13-p16., Aim: To study the human orthologue of the canine copper toxicosis gene as a candidate gene for ICC, ETIC, and ICT., Methods: We sequenced the exons and the intron-exon boundaries of the human MURR1 gene in 12 patients with classical ICC, one patient with ETIC, and 10 patients with ICT to see whether these patients display any mutations in the human orthologue of the canine copper toxicosis gene., Results: No mutations in the MURR1 gene, including the intron-exon boundaries, were identified in a total of 23 patients with non-Wilsonian hepatic copper toxicosis., Conclusions: Our results demonstrate that copper toxicosis in Bedlington terriers is not an animal model for the non-Wilsonian hepatic copper toxicosis described in this study.