Evaluation of the transforming growth factor beta1 codon 25 (Arg-->Pro) polymorphism in alcoholic liver disease.

INTRODUCTION: Liver cirrhosis develops only in a minority of heavy drinkers. Genetic factors may account for some variation in the progression of fibrosis in alcoholic liver disease (ALD). Transforming growth factor beta 1 (TGFbeta1) is a key profibrogenic cytokine in fibrosis and its gene contains several polymorphic sites. A single nucleotide polymorphism at codon 25 has been suggested to affect fibrosis progression in patients with chronic hepatitis C virus infection, fatty liver disease, and hereditary hemochromatosis. Its contribution to the progression of ALD has not been investigated sufficiently so far. PATIENTS AND METHODS: One-hundred-and-fifty-one heavy drinkers without apparent ALD, 149 individuals with alcoholic cirrhosis, and 220 alcoholic cirrhotics who underwent liver transplantation (LTX) were genotyped for TGFbeta1 codon 25 variants. RESULTS: Univariate analysis suggested that genotypes Arg/Pro or Pro/Pro are associated with decompensated liver cirrhosis requiring LTX. However, after adjusting for patients' age these genotypes did not confer a significant risk for cirrhosis requiring LTX. CONCLUSION: TGFbeta1 codon 25 genotypes Arg/Pro or Pro/Pro are not associated with alcoholic liver cirrhosis. Our study emphasizes the need for adequate statistical methods and accurate study design when evaluating the contribution of genetic variants to the course of chronic liver diseases.

No role of matrixmetalloproteinase-3 genetic promoter polymorphism 1171 as a risk factor for cirrhosis in alcoholic liver disease.

BACKGROUND: As only a minority of alcoholics develop cirrhosis, polymorphic genes, whose products are involved in fibrosis development were suggested to confer individual susceptibility. We tested whether a functional promoter polymorphism in the gene encoding matrix metalloproteinase-3 (MMP-3; 1171 5A/6A) was associated liver cirrhosis in alcoholics. METHODS: Independent cohorts from the UK and Germany were studied. (i) UK cohort: 320 alcoholic cirrhotics and 183 heavy drinkers without liver damage and (ii) German cohort: 149 alcoholic cirrhotics, 220 alcoholic cirrhotics who underwent liver transplantation and 151 alcoholics without liver disease. Patients were genotyped for MMP-3 variants by restriction fragment length polymorphism, single strand confirmation polymorphism, and direct sequencing. In addition, MMP-3 transcript levels were correlated with MMP-3 genotype in normal liver tissues. RESULTS: Matrix metalloproteinase-3 genotype and allele distribution in all 1023 alcoholic patients were in Hardy-Weinberg equilibrium. No significant differences in MMP-3 genotype and allele frequencies were observed either between alcoholics with or without cirrhosis. There were no differences in hepatic mRNA transcription levels according to MMP-3 genotype. CONCLUSIONS: Matrix metalloproteinase-3 1171 promoter polymorphism plays no role in the genetic predisposition for liver cirrhosis in alcoholics. Stringently designed candidate gene association studies are required to exclude chance observations.

Relevance of endotoxin receptor CD14 and TLR4 gene variants in chronic liver disease.

OBJECTIVE: The lipopolysaccharide (LPS)-triggered release of inflammatory cytokines from Kupffer cells is mediated via the CD14/TLR4 receptor complex. This inflammatory pathway can be influenced by alterations in genes encoding for LPS receptor components. Thus, a -260 C>T transition in the CD14 promoter is thought to result in enhanced CD14 expression thereby increasing the LPS responsiveness in chronic liver diseases, whereas a D299G exchange in the TLR4 gene has the opposite effect. Our objective was to analyze these two variations. MATERIAL AND METHODS: The study comprised 1712 patients with chronic liver diseases of different etiologies and 385 healthy controls. Genotyping was carried out by melting curve analysis with fluorescence resonance energy transfer (FRET) probes in the LightCycler. RESULTS: Genotype frequencies of CD14 -260C>T and TLR4 D299G did not significantly differ between patients and controls (CD14 TT 21.6% versus 21.8%; TLR4 DG or GG 9.7% versus 10.4%). We found no significant correlation of these alterations with disease course either in the groups of patients with alcoholic liver disease or hepatitis C virus (HCV) infection or among patients requiring liver transplantation. A significantly higher frequency of the CD14 -260TT genotype was observed (36.6% versus 21.8% in healthy controls, p=0.036) only in a small subgroup of patients (n=41) with mild cryptogenic chronic liver disease. CONCLUSIONS: Variants within these LPS receptor genes were equally distributed among patients with chronic liver diseases of different etiologies and obviously do not confer an increased risk for the severity of these chronic liver processes.

Association of CTLA4 single nucleotide polymorphisms with viral but not autoimmune liver disease.

BACKGROUND: CTLA4 is an inhibitory receptor expressed on a subset of T lymphocytes. Single nucleotide polymorphisms of the CTLA4 gene have been implicated in autoimmune diseases, including autoimmune hepatitis and primary biliary cirrhosis. In reverse form, CTLA4 variations are associated with chronic infections such as chronic hepatitis B. METHODS: CTLA4 variations -318C>T and +49A>G were analyzed in 2366 patients with chronic liver disease of various etiologies, including 323 patients with chronic hepatitis B virus (HBV) infection, 1181 patients with chronic hepatitis C virus infection, 180 patients with primary biliary cirrhosis, and 127 patients with autoimmune hepatitis, as well as 202 healthy control individuals. Genotyping was performed by melting curve analysis. RESULTS: The -318C>T variation was underrepresented in patients with chronic HBV infection compared with healthy controls (14.6 vs. 25.7%, P=0.002) and with patients with chronic liver disease of other origin (14.6 vs. 20.7%, P=0.011). Patients with cryptogenic cirrhosis also showed a lower frequency of the -318T allele than healthy controls (12.0 vs. 25.7%, P=0.014). No association of the +49G>A variation was found with any diagnosis, including autoimmune hepatitis and primary biliary cirrhosis. CONCLUSION: We describe the association of the CTLA4 -318C>T variation with chronic HBV infection and cryptogenic cirrhosis but find no association of the +49G>A variation with autoimmune liver disease.

Induction of interleukin-6 by hepatitis C virus core protein in hepatitis C-associated mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma.

PURPOSE: Chronic hepatitis C carries the risk to develop mixed cryoglobulinemia (MC) and B-cell non-Hodgkin's lymphoma (B-NHL), possibly because viral antigens stimulate the host's inflammatory response via extracellular pattern recognition receptors (PRR). To clarify this issue, we studied whether recognition of hepatitis C virus (HCV) proteins by PRR is involved in the pathogenesis of HCV-associated MC or B-NHL. EXPERIMENTAL DESIGN: Peripheral blood mononuclear cells of patients with HCV-associated B-NHL (n = 12), MC (n = 14), uncomplicated hepatitis C (n = 12), and healthy volunteers (n = 12) were incubated with the recombinant HCV proteins E2, core, and NS3 to study induction of cytokine production, stimulation of B-cell proliferation, and immunoglobulin secretion. In addition, serum levels of interleukin-6 (IL-6) were measured by ELISA. RESULTS: HCV core was the only studied protein, which induced production of IL-6 and IL-8 in CD14(+) cells. IL-6 induction was mediated via Toll-like receptor 2 (TLR2) and lead to increased B-cell proliferation in vitro. TLR2 expression on monocytes and IL-6 serum concentrations were increased in all groups of HCV-infected patients compared with healthy controls and were highest in MC (P < 0.05). CONCLUSIONS: Increased secretion of IL-6 via stimulation of TLR2 by HCV core protein may play a role in the pathogenesis of hepatitis C-associated MC and B-NHL.

Keratin 8 sequence variants in patients with pancreatitis and pancreatic cancer.

Keratin 8 (KRT8) is one of the major intermediate filament proteins expressed in single-layered epithelia of the gastrointestinal tract. Transgenic mice over-expressing human KRT8 display pancreatic mononuclear infiltration, interstitial fibrosis and dysplasia of acinar cells resulting in exocrine pancreatic insufficiency. These experimental data are in accordance with a recent report describing an association between KRT8 variations and chronic pancreatitis. This prompted us to investigate KRT8 polymorphisms in patients with pancreatic disorders. The KRT8 Y54H and G62C polymorphisms were assessed in a cohort of patients with acute and chronic pancreatitis of various aetiologies or pancreatic cancer originating from Austria (n=16), the Czech Republic (n=90), Germany (n=1698), Great Britain (n=36), India (n=60), Italy (n=143), the Netherlands (n=128), Romania (n=3), Spain (n=133), and Switzerland (n=129). We also studied 4,234 control subjects from these countries and 1,492 control subjects originating from Benin, Cameroon, Ethiopia, Ecuador, and Turkey. Polymorphisms were analysed by melting curve analysis with fluorescence resonance energy transfer probes. The frequency of G62C did not differ between patients with acute or chronic pancreatitis, pancreatic adenocarcinoma and control individuals. The frequency of G62C varied in European populations from 0.4 to 3.8%, showing a northwest to southeast decline. The Y54H alteration was not detected in any of the 2,436 patients. Only 3/4,580 (0.07%) European, Turkish and Indian control subjects were heterozygous for Y54H in contrast to 34/951 (3.6%) control subjects of African descent. Our data suggest that the KRT8 alterations, Y54H and G62C, do not predispose patients to the development of pancreatitis or pancreatic cancer.

Influence of alpha-1 antitrypsin heterozygosity on treatment efficacy of HCV combination therapy.

BACKGROUND: The role of heterozygosity for alpha-1 antitrypsin (A1AT) alleles in patients with chronic hepatitis C virus (HCV) is unclear. There is limited evidence to suggest that there is an increased prevalence of heterozygous A1AT carriers in HCV, but it is unclear how this affects treatment success. AIM: To investigate the (i) prevalence of A1AT heterozygosity among two HCV cohorts and (ii) its effect on treatment outcome. METHODS: We performed a retrospective cohort study using two different cohorts. Cohort 1 consisted of 678 German HCV patients, 507 of them were treated for HCV with standard therapy. Cohort 2 consisted of 370 Dutch HCV patients of which 252 were part of a clinical trial (treatment with amantadine or placebo, in combination with pegylated interferon alpha-2b and ribavirin) whereas 37 HCV patients received standard therapy. We analyzed A1AT status using direct sequencing of the A1AT gene (cohort 1) or isoelectric focusing of serum (cohort 2). In addition, we measured A1AT serum levels (cohort 2). RESULTS: In total, we included 1048 HCV patients; 986 (94%) were wildtype [protease inhibitor (Pi) MM], whereas 61 (6%) were heterozygous for a mutant A1AT allele (41 Pi MS, 20 Pi MZ). Mean A1AT serum levels (370 patients) were lower in A1AT heterozygous patients (1.68 vs. 1.36 g/l), (P<0.05) compared with wildtypes. Sustained viral response (SVR) after treatment was equal between the wildtypes and heterozygotes (54 vs. 56%). CONCLUSION: We found a heterozygosity rate of 0.06, in line with healthy controls in other studies. Serum A1AT levels from A1AT heterozygous HCV patients are significantly lower compared with wildtype patients, although they do not discriminate on an individual level. Finally, SVR in A1AT wildtypes was not different from SVR in A1AT heterozygotes.

Evaluation of angiotensinogen c.1-44G>A and p.M268T variants as risk factors for fibrosis progression in chronic hepatitis C and liver diseases of various etiologies.

BACKGROUND: Hepatic stellate cells express all components of the renin-angiotensinogen (AGT) system and secrete active angiotensin II. Animal studies provided evidence that angiotensin II stimulates the accumulation of extracellular matrix by enhancing transforming growth factor beta1 production. A functional genetic alteration in the human AGT promoter (c.1-44G>A) has been linked to accelerated progression of fibrosis in hepatitis C virus infection. METHODS: We enrolled 2154 patients with chronic liver disease of various etiologies, including 1286 individuals with chronic hepatitis C virus infection as well as 207 healthy volunteers. We performed genotyping for two AGT variants, c.1-44G>A and c.803T>C (p.M268T), by melting curve analysis using fluorescence resonance energy transfer probes. RESULTS: Allele frequencies and genotype distributions of both variants did not differ between patients and controls. Genotype frequencies of the c.1-44G>A variant were GG 31.0%, GA 45.6%, and AA 23.4% in patients and GG 30.0%, GA 47.8%, and AA 22.2% in controls. The genotype frequencies of p.M268T, which is in strong linkage disequilibrium with c.1-44G>A, were MM 30.8%, MT 45.5%, and TT 23.4% in patients and MM 29.0%, MT 48.8%, and TT 22.2% in controls. Both variants were associated with neither higher stages of fibrosis nor requirement for liver transplantation in any of the diagnosis subgroups. Particularly, these genetic alterations were not associated with progressive fibrosis in chronic HCV infection. CONCLUSION: In contrast to previous reports, both AGT variants do not predispose to the progression of fibrosis in chronic liver disease.

The role of epoxide hydrolase Y113H gene variant in pancreatic diseases.

OBJECTIVES: Chronic pancreatitis (CP) and pancreatic adenocarcinoma (pCA) are associated with risk factors such as alcohol intake and tobacco smoking. Microsomal epoxide hydrolase (EPHX1) is a phase II detoxifying enzyme capable of tobacco-borne toxicant inactivation. We studied the role of the EPHX1 c.337T>C (p.Y113H) variant, whichleads to altered enzyme activity, in pancreatic diseases. METHODS: We genotyped 2391 patients by melting curve analysis. We enrolled 367 patients with pCA, 341 patients with alcoholic CP (aCP), 431 patients with idiopathic CP or hereditary pancreatitis, 192 patients with acute pancreatitis, and 679 controls of German descent. We replicated data in 77 patients with aCP and 304 controls from The Netherlands. RESULTS: In German patients with aCP, Y113 was more common than in controls (allele frequencies, 0.73 vs 0.68; risk ratio, 1.21 [95% confidence interval, 1.05-1.39]). However, we could not confirm this association in the Dutch population (allele frequencies, 0.62 vs 0.68, P=not significant). In total, Y113 frequency was 0.71 in aCP and 0.68 in controls (P = not significant). Allele frequencies did not differ in the other disease groups (acute pancreatitis, 0.69; idiopathic CP or hereditary pancreatitis, 0.68; pCA, 0.68; and control, 0.68). CONCLUSIONS: The EPHX1 Y113H variant is not associated with pancreatic diseases indicating that EPHX1 does not play a significant role in the initiation of pancreatic inflammation or cancer.

Low-density lipoprotein receptor variants are associated with spontaneous and treatment-induced recovery from hepatitis C virus infection.

Low-density lipoprotein receptor (LDLR) is involved in the entry of hepatitis C virus (HCV) in host cells. We investigated whether three single-nucleotide alterations within LDLR might be associated with the course of hepatitis C infection and response to antiviral therapy. We enrolled 651 individuals with chronic HCV infection who had received interferon-based combination therapy, 174 individuals with self-limited HCV infection, and 516 healthy controls. LDLR c.1171G>A, c.1413G>A, and c.*52G>A genotyping was performed by real-time PCR-based assays. HCV genotype 1-infected individuals who were homozygous for 3'UTR c.*52G were at increased risk for virologic non-response to antiviral therapy compared to virologic responders (66.3% vs. 51.0%, p=0.001). Furthermore, compared to healthy controls, self-limited HCV genotype 1 infection was significantly associated with c.1171A (15.1% vs. 6.6%, p=0.006) and negatively associated with c.1413G>A heterozygosity (33.0% vs. 46.1%, p=0.023). The data indicate that LDLR alterations are correlated with response to interferon-based combination therapy and with self-limitation of HCV 1 infection.

Evaluation of complement factor 5 variants as genetic risk factors for the development of advanced fibrosis in chronic hepatitis C infection.

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.

Gender-dependent association of CTLA4 polymorphisms with resolution of hepatitis C virus 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.

A Toll-like receptor 7 single nucleotide polymorphism protects from advanced inflammation and fibrosis in male patients with chronic HCV-infection.

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.

Hepatitis C treatment in "difficult-to-treat" psychiatric patients with pegylated interferon-alpha and ribavirin: response and psychiatric side effects.

UNLABELLED: We investigated and compared the results of treating the chronic hepatitis C (HCV) infection of different groups of psychiatric-risk patients and controls with pegylated interferon alpha (pegIFN-alpha) plus ribavirin. Seventy patients were prospectively screened for psychiatric disorders. Seventeen patients without psychiatric diseases or drug addiction (controls), 22 patients with psychiatric disorders, 18 patients who had received methadone substitution treatment and 13 patients who were former drug users were treated with pegIFN-alpha plus ribavirin. Sustained virological response (SVR), adherence, and psychiatric side effects (using the Montgomery-Asberg Depression Rating Scale and the Brief Psychiatric Rating Scale) in the groups were compared. An SVR was found in 58.6% of all patients: 58.8% of the controls, 50% of psychiatric patients, 72.2% of methadone patients, and 53.8% of former drug users. Methadone-substituted patients and former drug users had significantly higher dropout rates. Scores for neither depressive nor psychotic symptoms differed significantly between groups during treatment. However, the controls had lower pretreatment scores, followed by a significant higher increase to maximum scores. A stepwise logistic regression model showed that only genotype, not group (control, psychiatric, methadone, or former drug abuse), type of psychiatric diagnosis (affective disorder, personality disorder, or schizophrenic disorder), depression scores before and during treatment, change in depression score, antidepressive treatment, sex, or liver enzymes before treatment, was associated with SVR. CONCLUSION: In an interdisciplinary treatment setting psychiatric diseases and/or drug addiction did not negatively influence psychiatric tolerability of and antiviral response rate to HCV treatment with pegIFN-alpha and ribavirin.

Influence of interleukin 12B (IL12B) polymorphisms on spontaneous and treatment-induced recovery from hepatitis C virus infection.

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.