A genetic variant in the promoter of phosphate-activated glutaminase is associated with hepatic encephalopathy.

BACKGROUND: Hepatic encephalopathy (HE) is a serious complication of liver cirrhosis. Recently, a microsatellite in the promoter region of the phosphate-activated glutaminase (GLS ) gene was associated with the risk of HE. The aim of the present study was to investigate, using the critical flicker frequency (CFF) test, whether the described GLS variant increases the risk of developing HE in patients with cirrhosis. METHODS: We recruited 158 patients (66% men; mean age 59 years, range 23-86) with liver cirrhosis. Mean model for end-stage liver disease score was 13.8 (range 5-35); 48% of patients presented with Child-Pugh score B or C. The presence and severity of HE were determined by the CFF test, with frequencies ≤39 Hz denoting cases. GLS variants were genotyped by sequencing the microsatellite in the promoter region and were classified as short, long or short-long forms (depending on the length of the macrosatellite alleles). RESULTS: In total, 53% of patients had abnormal CFF results (i.e. ≤39 Hz; range for entire cohort 26-57). The GLS microsatellite distribution amongst patients was short form (20%), long form (32%) and short-long form (48%) and was consistent with Hardy-Weinberg equilibrium. CFF values differed significantly between groups (P = 0.043). Carriers of the GLS long microsatellite had a significantly higher risk of HE according to multivariate analyses (odds ratio 3.23, 95% confidence interval 1.46-7.13, P = 0.004). CONCLUSION: CFF results were significantly lower amongst carriers of the GLS long microsatellite. Our findings support the role of the GLS long microsatellite in the development of HE; this could be important for identifying susceptible patients and for the prevention of this condition.

Graft-versus-host disease or toxic epidermal necrolysis: diagnostic dilemma after liver transplantation.

Graft-versus-host disease (GvHD) and toxic epidermal necrolysis (TEN) are rare and severe complications after liver transplantation. While mild acute GvHD is quite different from TEN and easy to distinguish, severe acute GvHD and TEN can be hard to differentiate because of similar clinical symptoms. We herein report a case with rapid progression of critical illness, after liver transplantation, caused by GvHD or TEN, although between those, diagnosis was not possible during the clinical course. Although, based on the timing/progression of the symptoms and the chimerism of >40%, the case seemed much more clinically consistent with GVHD, the combination of clinical symptoms together with skin rashes and the histologic appearance of skin lesions indicated diagnosis of a Stevens-Johnson syndrome/TEN overlap. The true diagnostic dilemma in such cases is discussed in detail, as these cases emphasize the need for more advanced diagnostic techniques.

Progression of liver fibrosis in HIV/HCV genotype 1 co-infected patients is related to the T allele of the rs12979860 polymorphism of the IL28B gene.

OBJECTIVE: HIV/HCV co-infection is characterised by accelerated progression of liver disease. Recently, the rs12979860 C/T polymorphism in the IL28B gene has been linked to progression towards cirrhosis in HCV mono-infected patients and to treatment response of HCV-infection in HIV/HCV co-infected patients. Our aim was to clarify by non-invasive techniques if this polymorphism affects fibrosis progression in HIV/HCV co-infection. METHODS: In a cross-sectional design, liver stiffness (transient elastography), surrogate markers of liver fibrosis (APRI and FIB-4 scores) and rs12979860 genotypes were analysed in 84 HCV/HIV co-infected patients. IL28B genotypes were determined by real-time PCR using a light cycler. In 56 HIV/HCV co-infected patients we also studied progression of fibrosis in relation to rs12979860 C/T genotypes over two years. RESULTS: 82% of the patients were on HAART (74% without detectable HI viremia) and 67% were haemophiliacs, respectively. HCV genotype 1 was present in 62%. Cross-sectional median liver stiffness was 7.4 kPa and correlated with APRI and FIB-4 scores (r = 0.6 each, p < 0.001). Frequencies of IL28B genotypes were: CC 50%, CT 43% and TT 7%. In the cross-sectional analysis liver stiffness values were not different between the various IL28B-genotypes. Upon follow-up under HAART carriers of a C allele did not show further progression, while liver stiffness significantly increased in HIV/HCV co-infected patients with the T allele (p = 0.047). CONCLUSION: Although progression of liver fibrosis was low under HAART in our cohort, progression was more pronounced in HIV/HCV genotype 1 co-infected patients with the T allele.

Toll-like receptor (TLR) 2 promoter and intron 2 polymorphisms are associated with increased risk for spontaneous bacterial peritonitis in liver cirrhosis.

BACKGROUND & AIMS: Toll-like receptor (TLR) 2 and nucleotide-binding oligomerisation domain (NOD) 2 recognize distinct pathogen-associated molecular patterns (PAMS) on the cell surface and in the cytoplasm, respectively. Since they may contribute to susceptibility to spontaneous bacterial peritonitis (SBP), we studied the effects of TLR2 gene variants on susceptibility for SBP in relation to the previously reported NOD2 alleles. METHODS: Overall, 150 patients with liver cirrhosis and ascites were genotyped for TLR2 gene variants -16934 (rs4696480), Arg753Gln (rs5743708), Pro631His (rs5743704) and the TLR2 GT microsatellite polymorphism in intron 2. Patients were monitored for SBP over two years. TLR2 SNPs were identified by hybridization probe assays on a LightCycler system. Numbers of GT repeats were determined with an ABI310 sequencer and Genescan Analysis 2.1 software. RESULTS: Fifty two patients (35%) had SBP. Unlike the TLR2 Arg753Gln and Pro631His mutations, SBP was significantly more frequent in patients with the TLR2 -16934 TT genotype (38.5% vs. 15.3%; p = 0.002) and in carriers with two long tandem GT repeat alleles (>20) (53.8% vs. 25.5%; p = 0.001). A multivariate analysis confirmed TLR2 GT microsatellite polymorphism (OR = 3.8, p = 0.002) and NOD2 variants (OR = 3.3, p = 0.011) as independent predictors of SBP, and the simultaneous presence of both risk factors indicated a particularly high risk for SBP (OR = 11.3, p = 0.00002). CONCLUSIONS: Analogous to NOD2 risk variants, TLR2 polymorphisms indicate increased susceptibility toward SBP in cirrhotic patients with ascites, and the combination of the TLR2 GT microsatellite polymorphism with at least one NOD2 risk variant enables improved identification of patients with a high risk for SBP.

Heterozygosity for the alpha1-antitrypsin Z allele may confer genetic risk of cholangiocarcinoma.

BACKGROUND: Alpha1-antitrypsin (α1AT) deficiency caused by Z allele homozygosity represents a well-established risk factor for hepatocellular carcinoma. Previous studies have also implicated α1AT Z heterozygosity in cholangiocarcinogenesis. AIM: To assess the 'common' Z and S alleles as well as the promoter variant rs8004738 for association with cholangiocarcinoma. METHODS: We genotyped 182 Caucasian patients and 350 controls for rs28929474 (Z), rs17580 (S) and the variant rs8004738. Exploratory analyses were performed in relation to gender and cholangiocarcinoma localisation. RESULTS: rs28929474 was significantly enriched in the cholangiocarcinoma group (4.1 vs. 1.7%; OR 2.46, 95% CI 1.14-5.32; Bonferroni corrected p(c) = 0.036), reinforced by Armitage trend testing (OR 2.53; p(c) = 0.032). The rs8004738 (promoter) minor allele tended to be overrepresented in Z heterozygotes (30.0 vs. 16.7%: P = 0.13). Exploratory data analyses suggested a high genetic risk for extrahepatic tumour localisation (OR 3.0; p(c) = 0.016) and potentially female Z allele carriers (OR 3.37; unadjusted P = 0.022, p(c) = 0.088). CONCLUSIONS: These data point to a novel role of α1AT Z heterozygosity as a potential genetic susceptibility factor for cholangiocarcinoma formation and suggest a contribution of aberrant α1AT function in biliary carcinogenesis. However, given the overall low rs28929474 minor allele frequency, larger studies are warranted to confirm and extend our findings.

Transient elastography discloses identical distribution of liver fibrosis in chronic hepatitis C between HIV-negative and HIV-positive patients on HAART.

OBJECTIVE: Progressive immunodeficiency associated with HIV-infection leads to a progressive course of liver disease in HIV/HCV-co-infected patients. Highly active antiretroviral therapy (HAART) efficiently restores and preserves immune functions and has recently been demonstrated to also result in reduced liver-related mortality in HIV/HCV-co-infected patients. METHODS: To analyse differences in current liver fibrosis as a possible effect of HAART on fibrosis progression we assessed hepatic fibrosis by transient elastography in a cross-sectional comparison between HCV-mono-infected and HIV/HCV-co-infected patients presenting at our outpatient department in 2007. RESULTS: Overall, we did not find any difference in the distribution of liver stiffness between mono- (n = 84) and double-infected (n = 57) patients (14.4 kPa (10.8-18.2) versus 12.4 kPa (9.1 - 16.1), mean (95%-CI)). However, in the 8 HIV+ patients with CD4 counts < 200/microl liver stiffness was markedly greater (18.4 kPa (0.8 - 36.0)) than in HIV+ patients with preserved immunity (11.5 kPa (8.4-15.0)). CONCLUSIONS: These findings are in line with other data that show an improved prognosis of chronic hepatitis C in HIV+ patients under effective HAART, and may be a hint that fibrosis progression in well-treated HIV+ patients will no longer be different from that in HCV-mono-infected patients.

Gallstone disease in Swedish twins: risk is associated with ABCG8 D19H genotype.

OBJECTIVE: Recently, variants of the hepatocanalicular cholesterol hemitransporters ABCG5/8 were linked to gallstone disease; ABCG8 D19H in Caucasians and ABCG5 Q604E in Chinese. We investigated these polymorphisms in Swedish twins by merging the Swedish Twin Registry with the Hospital Discharge and Causes of Death Registries for gallstone disease-related diagnoses. DESIGN: All monozygotic (MZ) twins with gallstone disease alive in the Stockholm area were invited to participate. Gallstone disease was defined by entry in all above mentioned registries, questionnaire or abdominal ultrasound. SUBJECTS: ABCG5 Q604E and ABCG8 D19H genotyping was performed in 24 unique MZ and eight dizygotic (DZ) twins from concordant pairs. Screening of the TwinGene database for gallstone disease resulted in an additional 20 concordant MZ and 54 twins from concordant DZ pairs. We included 109 concordantly stone-free MZ and 126 stone-free independent DZ twins as controls. RESULTS: Amongst the 341 twins, 20.8% carried at least one D19H allele as compared to 9.4% of stone-free controls. The association analysis showed that D19H positivity significantly increased the risk of gallstone disease [odds ratio (OR), 2.54; 95% confidence interval (CI), 1.33-4.82; P = 0.004]. We also found a trend for a positive association between gallstone disease and the Q604E variant (OR, 1.47; 95% CI, 1.00-2.16; P = 0.052). CONCLUSION: Twins carrying a heterozygous or homozygous ABCG8 D19H genotype have a significantly increased risk of gallstone disease. Our study confirms the ABCG8 D19H genotype as a major risk factor for gallstone disease.

Correlation of transient elastography with APRI and FIB-4 in a cohort of patients with congenital bleeding disorders and HCV or HIV/HCV coinfection.

SUMMARY: Patients with inherited bleeding disorders frequently suffer from chronic hepatitis C virus (HCV) mono- or human immunodeficiency virus (HIV)/HCV coinfection. Non-invasive markers for liver fibrosis are warranted for these patients. We tested a large cohort of haemophilic patients with HCV mono- or HIV/HCV coinfection for correlation of transient elastography (TE) with two simple surrogate markers of liver fibrosis and for differences in fibrosis stages according to these markers. We prospectively enrolled HCV-positive patients with congenital bleeding disorders with or without HIV coinfection. Liver function tests and platelet counts were determined and TE was performed. Aspartate aminotransferase-to-platelet ratio index (APRI) and a simple index called FIB-4 were calculated and results were correlated with TE. A total number of 174 patients were included (23% HCV, 36% HIV/HCV coinfected, 33% with cleared HCV and 8% with ongoing HIV but cleared HCV). TE correlated significantly with APRI and FIB-4 (r = 0.60; P < 0.001 and r = 0.54; P < 0.001 respectively). This correlation was pronounced in patients with ongoing HCV infection (r = 0.67; P < 0.001 and r = 0.60; P < 0.001). Prediction of advanced fibrosis resulted in concordance rates >80% with combinations of TE plus APRI and APRI plus FIB-4. HIV/HCV coinfected patients did not present with advanced fibrosis stages when compared with HCV-monoinfected patients. Combinations of two non-invasive markers may significantly reduce the number of liver biopsies in patients with bleeding disorders and advanced liver fibrosis. Furthermore, our data support previous studies that observed a favourable outcome in patients with HIV/HCV and a preserved immune function in times of highly active antiretroviral therapy.

[Genome-wide association studies in hepatology]. / Genomweite Assoziationsstudien in der Hepatologie.

Genomewide association studies (GWAS) are being reported for an increasing number of common diseases, including first reports on GWAS for hepatobiliary diseases. Most common liver diseases are multifactorial (complex) diseases that are modified by higher-order interactions between multiple genetic and environmental risk factors. The aim of GWAS is to identify the genetic risk factors contributing to disease susceptibility and/or progression. In GWAS, large patient cohorts are genotyped for genetic markers that cover the whole genome, and genotypes are associated with phenotypes by contingency tests and regression analyses. Recent GWAS have identified "risk genes" for gallstones, fatty liver, primary cholestatic liver diseases and chronic hepatitis C virus (HCV) infection as well as fibrosis progression in HCV-infected patients. For the latter patients, "gene signatures" were developed that are composed of multiple risk variants and are associated with progressive liver fibrosis. Furthermore, mouse models are an important tool to identify novel genetic determinants of complex liver diseases. In large experimental crosses of susceptible and resistant inbred mouse strains, phenotypes are correlated with genome-wide markers by genetic linkage analyses. The findings from genome-wide studies in mice and men may contribute to a better understanding of the pathogenesis of complex liver diseases and provide a framework for the development of "personalised" strategies for prediction, early prevention and therapy.

Association of the c.3972C>T variant of the multidrug resistance-associated protein 2 Gene (MRP2/ABCC2) with susceptibility to bile duct cancer.

BACKGROUND: Multidrug resistance-associated protein 2 (MRP2/ABCC2) is one of the ATP-binding cassette (ABC) transporters expressed on the apical membrane of hepatocytes and cholangiocytes. ABCC2 plays an important role in the biliary clearance of endogenous and exogenous toxic compounds. Recently, the ABCC2 variant c.3972C>T in exon 28 has been shown to be associated with hepatocellular carcinoma risk. Our aim was to assess the role of this ABCC2 variant on cholangiocarcinoma susceptibility. METHODS: Prospectively, we recruited 60 cholangiocarcinoma patients and 73 healthy controls of Caucasian origin. The c.3972C>T polymorphism was genotyped using solution-phase hybridization reactions with 5'-nuclease and fluorescence detection (TaqMan assays). RESULTS: Allele frequencies were in Hardy-Weinberg equilibrium (p > 0.05). The c.3972T allele was significantly more frequent in patients with cholangiocarcinoma (39.2%) compared to healthy controls (26.0%, p = 0.022), resulting in an odds ratio (OR) of 1.83 (95% CI = 1.09-3.08). Armitage's trend test showed a significant association between genotypes and cancer susceptibility (p = 0.026, OR = 1.95). CONCLUSIONS: We describe a novel association between the common ABCC2 variant c.3972C>T and cholangiocarcinoma risk. Further studies are warranted to replicate our findings in different populations and to elucidate the mechanisms of this observation.

[Medical therapy of complications in liver cirrhosis]. / Medikamentöse Therapie der Komplikationen der Leberzirrhose.

Patients with liver cirrhosis bear a considerable risk of a variety of complications that involve virtually all organ systems. They can be addressed with a wide spectrum of drugs for acute interventions as well as for prophylactic purposes. At the same time treatment of the underlying disease, the identification and treatment of triggering factors and the possibility of liver transplantation should be kept in mind.

[Differential diagnosis of jaundice]. / Virushepatitis oder Alkohol, Cholangitis oder Tumor? Was steckt hinter dem Symptom lkterus?

Jaundice is a symptom with a multitude of possible causes. These can be divided up into primary diseases of bilirubin metabolism, secondary hyperbilirubinemia in patients with liver disease, and diseases with bile duct occlusion. The major objective of the examination must be to exclude those causes that represent an acute danger to the patient, in particular cholangitis or cholecystitis. Symptoms that should cause alarm bells to ring include abdominal pain, fever and chills. When obtaining the patient's anamnesis, particular attention must be paid to lithiasis and previous operations. Laboratory findings of elevated alkaline phosphatase and gamma-GT indicate the presence of cholestasis. If an extrahepatic obstruction is suspected, ultrasonography of the upper abdomen is required.

Autoimmune hepatitis--sequel of a relapsing hepatitis A in a 75-year-old woman.

Acute hepatitis A virus (HAV) infection is a global cause of acute hepatitis. However, chronic HAV infection is unlikely. Nevertheless, there is some evidence that acute infection with HAV may trigger chronic active hepatitis which fulfils the criteria of autoimmune hepatitis (AIH). Whether AIH following HAV infection is virus specific remains unclear. Despite evidence that inherited factors may play a role in the development of autoimmunity after viral infection, the pathomechanism remains unclear. We describe a 75-year-old woman with a history of pulmonary sarcoidosis who developed AIH after acute HAV infection.

E-cadherin expression is homogeneously reduced in adenoma from patients with familial adenomatous polyposis: an immunohistochemical study of E-cadherin, beta-catenin and cyclooxygenase-2 expression.

BACKGROUND AND AIMS: The adenomatous polyposis coli (APC) protein plays a crucial role in the regulation of beta-catenin, which is linked to the cell adhesion molecule E-cadherin. Furthermore, beta-catenin and cyclooxygenase-2 (COX-2) are both involved in the activation of nuclear transcription factors inducing cell proliferation. Germline mutations in the APC gene are the cause of familial adenomatous polyposis (FAP). To characterise the expression pattern of these proteins in FAP in comparison with sporadic adenomas, we studied 18 FAP-associated adenomas, 16 sporadic adenomas and seven normal colonic controls. METHODS: E-cadherin, beta-catenin, COX-2 expression and the proliferative index (Ki67) were assessed by immunohistochemistry (index of expressing cells / total number of cells) in adenomatous mucosa, adjacent non-neoplastic tissue and normal colonic controls. RESULTS: E-cadherin expression was significantly and homogeneously reduced in FAP adenomas (24%; 95%CI 16-32; sporadic adenomas 61%; 38-84; normal controls 98%; 96-100). Membraneous beta-catenin expression was significantly reduced in both FAP (30%; 11-49) and sporadic (42%; 19-65) adenomas (normal controls 96%; 88-104), whereas marked nuclear staining occurred in sporadic, but not in FAP adenomas. Stromal COX-2 expression and the proliferative index were increased only in sporadic adenomas (sporadic adenomas: COX-2 12%; 7-17, Ki67 24%; 15-33, FAP adenomas: COX-2 8%; 5-11, Ki67 5%; 2-9, normal controls: COX-2 4%; 2-7, Ki67 6%; 1-11). CONCLUSION: Proteins involved in cell adhesion and cell proliferation, especially E-cadherin, are expressed differently in FAP and sporadic adenoma, pointing to possible differences in the molecular pathways to adenoma.