The impact of transmembrane 6 superfamily 2 (TM6SF2) rs58542926 on liver-related events in patients with advanced chronic liver disease.

BACKGROUND & AIMS: Genetic factors such as the transmembrane 6 superfamily 2 (TM6SF2) rs58542926 single nucleotide variant(SNV) modulate the susceptibility for (advanced) chronic liver disease ([A]CLD). However, the impact of this variant in patients who have already progressed to ACLD is unknown. METHODS: The association between TM6SF2-rs58542926 genotype and liver-related events was evaluated in 938 ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement. RESULTS: Mean HVPG was 15±7 mmHg and mean UNOS MELD (2016) 11±5 points. Viral hepatitis (n = 495, 53%) was the most common cause of ACLD, followed by alcohol-related (ARLD; n = 342, 37%) and non-alcoholic fatty liver disease (NAFLD; n = 101, 11%). While 754 (80%) patients harboured the TM6SF2 wild-type (C/C), 174 (19%) and 10 (1%) patients had one or two T-alleles. At baseline, patients with at least one TM6SF2 T-allele had more pronounced portal hypertension (HVPG: 16±7 vs. 15±7 mmHg; p = 0.031), higher gamma-glutamyl transferase levels (123 [63-229] vs. 97 [55-174] UxL-1; p = 0.002), and more commonly hepatocellular carcinoma (17% vs. 12%; p = 0.049). Harbouring the TM6SF2 T-allele was associated with the composite endpoint hepatic decompensation/liver transplantation/liver-related death (SHR: 1.44 [95%CI: 1.14-1.83]; p = 0.003). This was confirmed in multivariable competing risk regression analyses that were adjusted for severity of portal hypertension and hepatic dysfunction at baseline. CONCLUSION: The TM6SF2 variant modulates liver disease progression beyond the development of ACLD, as it modifies the risks of hepatic decompensation and liver-related death, independently of baseline liver disease severity.

Alpha-1 antitrypsin Pi∗Z allele is an independent risk factor for liver transplantation and death in patients with advanced chronic liver disease.

Background & Aims: Alpha-1 antitrypsin (AAT) deficiency causes/predisposes individuals to advanced chronic liver disease (ACLD). However, the role of the SERPINA1 Pi∗Z allele in patients who have already progressed to ACLD is unclear. Thus, we aimed to evaluate the impact of the Pi∗Z allele on the risk of liver transplantation/liver-related death in patients with ACLD, while adjusting for the severity of liver disease at inclusion. Methods: A total of 1,118 patients with ACLD who underwent hepatic venous pressure gradient (HVPG) measurement and genotyping for the Pi∗Z/Pi∗S allele at the Vienna Hepatic Hemodynamic Lab were included in this retrospective analysis. The outcome of interest was liver transplantation/liver-related death, while non-liver-related death and removal/suppression of the primary etiological factor were considered as competing risks. Results: Viral hepatitis was the most common etiology (44%), followed by alcohol-related (31%) and non-alcoholic fatty liver disease (11%). Forty-two (4%) and forty-six (4%) patients harboured the Pi∗Z and Pi∗S variants, respectively. Pi∗Z carriers had more severe portal hypertension (HVPG: 19±6 vs.15±7 mmHg; p <0.001) and hepatic dysfunction (Child-Turcotte-Pugh: 7.1±1.9 vs. 6.5±1.9 points; p = 0.050) at inclusion, compared to non-carriers. Contrarily, the Pi∗S allele was unrelated to liver disease severity. In competing risk regression analysis, harbouring the Pi∗Z allele was significantly associated with an increased probability of liver transplantation/liver-related death, even after adjusting for liver disease severity at inclusion. The detrimental impact of the common Pi∗MZ genotype (adjusted subdistribution hazard ratio: ≈1.56 vs. Pi∗MM) was confirmed in a fully adjusted subgroup analysis. In contrast, Pi∗S carriers had no increased risk of events. Conclusion: Genotyping for the Pi∗Z allele identifies patients with ACLD at increased risk of adverse liver-related outcomes, thereby improving prognostication. Therapies targeting the accumulation of abnormal AAT should be evaluated as disease-modifying treatments in Pi∗Z allele carriers with ACLD. Lay summary: Alpha-1 antitrypsin deficiency is a genetic disease that affects the lung and the liver. Carrying two dysfunctional copies of the gene causes advanced liver disease. Harbouring one dysfunctional copy increases disease severity in patients with other liver illness. However, the significance of this genetic defect in patients who already suffer from advanced liver disease is unclear. Our study found that harbouring at least one dysfunctional copy of the alpha-1 antitrypsin gene increases the risk of requiring a liver transplantation or dying from a liver disease. This indicates the need for medical therapies aimed at treating the hepatic consequences of this genetic defect.

Acute liver failure with hemolytic anemia in children with Wilson's disease: Genotype-phenotype correlations?

BACKGROUND: Wilson's disease (WD) is a rare autosomal recessive inherited disorder of copper metabolism. Acute liver failure (ALF) and hemolytic anemia represent the most severe presentation of WD in children. No clear genotype-phenotype correlations exist in WD. Protein-truncating nonsense, frame-shift, or splice-site variants may be associated with more severe disease. In contrast, missense variants may be associated with late-onset, less severe disease, and more neurological manifestations. Recently, a gene variant (HSD17B13:TA, rs72613567) with a possible hepatic protective role against toxins was associated with a less severe hepatic phenotype in WD. AIM: To analyze the possible genotype-phenotype correlations in children with WD presented with ALF and non-immune hemolytic anemia. METHODS: The medical records of children with WD diagnosed and treated in our hospital from January 2006 to December 2020 were retrospectively analyzed. The clinical manifestations (ALF with non-immune hemolytic anemia or other less severe forms), laboratory parameters, copper metabolism, ATP7B variants, and the HSD17B13:TA (rs72613567) variant were reviewed to analyze the possible genotype-phenotype correlations. RESULTS: We analyzed the data of 51 patients with WD, 26 females (50.98%), with the mean age at the diagnosis of 12.36 ± 3.74 years. ALF and Coombs-negative hemolytic anemia was present in 8 children (15.67%), all adolescent girls. The Kayser-Fleisher ring was present in 9 children (17.65%). The most frequent variants of the ATP7B gene were p.His1069Gln (c.3207A>G) in 38.24% of all alleles, p.Gly1341Asp (c.4021G>A) in 26.47%, p.Trp939Cys (c.2817G>T) in 9.80%, and p.Lys844Ter (c.2530A>T) in 4.90%. In ALF with hemolytic anemia, p.Trp939Cys (c.2817G>T) and p.Lys844Ter (c.2530A>T) variants were more frequent than in other less severe forms, in which p.His1069Gln (c.3207A>G) was more frequent. p.Gly1341Asp (c.4021G>A) has a similar frequency in all hepatic forms. For 33 of the patients, the HSD17B13 genotype was evaluated. The overall HSD17B13:TA allele frequency was 24.24%. Its frequency was higher in patients with less severe liver disease (26.92%) than those with ALF and hemolytic anemia (14.28%). CONCLUSION: It remains challenging to prove a genotype-phenotype correlation in WD patients. In children with ALF and hemolytic anemia, the missense variants other than p.His1069Gln (c.3207A>G) and frame-shift variants were the most frequently present in homozygous status or compound heterozygous status with site splice variants. As genetic analysis is usually time-consuming and the results are late, the importance at the onset of the ALF is questionable. If variants proved to be associated with severe forms are found in the pre-symptomatic phase of the disease, this could be essential to predict a possible severe evolution.

HSD17B13 truncated variant is associated with a mild hepatic phenotype in Wilson's Disease.

HSD17B13 encodes hydroxysteroid 17-ß dehydrogenase 13, a novel liver lipid-droplet associated protein that is involved in the regulation of lipid biosynthetic processes. A protein-truncating HSD17B13 variant (rs72613567) was shown to protect individuals from alcoholic and non-alcoholic liver disease. Since steatosis is a common feature in Wilson's disease (WD), we aimed to assess whether the HSD17B13 variant modulates the phenotypic presentation and progression of WD. METHODS: The HSD17B13:TA (rs72613567) variant was determined by allelic discrimination real-time PCR in 586 patients. The HSD17B13 genotype was correlated with the phenotypic presentation. The age of onset and the type of symptoms at presentation were used as markers of the WD phenotype. RESULTS: The overall HSD17B13:TA allele frequency in patients with WD was 23.3% (273/1,172), not significantly different from the reported minor allele frequency. There was a significantly lower HSD17B13:TA allele frequency in patients with fulminant WD compared to all other phenotypic WD groups (11.0% vs. 24.0%, p < 0.01). Among the patients with fulminant WD there was a trend for a gender effect; none of the male patients carried the HSD17B13:TA allele. HSD17B13:TA allele frequency was more common in patients with minimal or no fibrosis (49 [31.1%] had simple steatosis and 20 minimal changes at biopsy) than in patients with cirrhosis or advanced fibrosis (22.3%, p = 0.025). CONCLUSIONS: The HSD17B13:TA allele modulates the phenotype and outcome of WD. This allele likely ameliorates hepatic fibrosis and reduces the transition from copper induced hemolysis to fulminant disease in patients with WD. LAY SUMMARY: Wilson's disease is a hereditary disease caused by accumulation of copper in the liver and other tissues. It presents with a variety of clinical symptoms. In this study we explored the role of a recently described gene mutation (HSD17B13:TA) which apparently protects the liver against toxins like alcohol. The results indicate that this mutation plays a role in the evolution of liver disease. Patients with Wilson's disease who carry this mutation are more likely to have mild disease, while the absence of the mutation is associated with the most severe form - fulminant Wilson's disease.

Laser ablation inductively coupled plasma mass spectrometry imaging of metals in experimental and clinical Wilson's disease.

Wilson's disease is an autosomal recessive disorder in which the liver does not properly release copper into bile, resulting in prominent copper accumulation in various tissues. Affected patients suffer from hepatic disorders and severe neurological defects. Experimental studies in mutant mice in which the copper-transporting ATPase gene (Atp7b) is disrupted revealed a drastic, time-dependent accumulation of hepatic copper that is accompanied by formation of regenerative nodes resembling cirrhosis. Therefore, these mice represent an excellent exploratory model for Wilson's disease. However, the precise time course in hepatic copper accumulation and its impact on other trace metals within the liver is yet poorly understood. We have recently established novel laser ablation inductively coupled plasma mass spectrometry protocols allowing quantitative metal imaging in human and murine liver tissue with high sensitivity, spatial resolution, specificity and quantification ability. By use of these techniques, we here aimed to comparatively analyse hepatic metal content in wild-type and Atp7b deficient mice during ageing. We demonstrate that the age-dependent accumulation of hepatic copper is strictly associated with a simultaneous increase in iron and zinc, while the intrahepatic concentration and distribution of other metals or metalloids is not affected. The same findings were obtained in well-defined human liver samples that were obtained from patients suffering from Wilson's disease. We conclude that in Wilson's disease the imbalances of hepatic copper during ageing are closely correlated with alterations in intrahepatic iron and zinc content.

[ATP7B gene mutations in Hungarian patients with Wilson disease--case reports to illustrate the diverse clinical presentations]. / ATP7B génmutációk magyarországi Wilson-kóros betegekben. Esetismertetések a betegség változatos klinikai megjelenésének bemutatására.

ATP7B gene mutations were examined in 70 Wilson patients from Hungary. 11 different mutations were found. In Hungary, similarly to other Central-Eastern European countries, the H1069Q was the most the frequent mutation, detected in 51 patients (73%) by semi-nested polymerase chain reaction (PCR) based restriction fragment length polymorphism (RFLP) assay. 10 further mutations have been found by sequencing as follows: P767P-fs, R778G, K844K-fs, I857T, R969Q, T977M, E1064K, M769L, Y715H and P1273S. These latter three mutations have not been described before. Among the 11 mutations there are five, which have been published only in patients of Turkish, Italian or Albanian origin. It might be the genetic consequence of the 150 years long occupation of Hungary in the 16th and 17th century by Turks. The genotype-phenotype analysis showed that the Kayser-Fleischer ring was more frequent (10/12 = 83%), and the age at the diagnosis was higher in H1069Q homozygous patients than in compound heterozygous or negative patients. Diverse clinical presentation of the disease was demonstrated by case reports giving messages for the practitioners. The gene mutation analysis is of particular importance in siblings of the index patient, since the detection of two mutant allels confirm the diagnosis of the disease even in absence of symptoms. The clinical manifestation of the disease can be preceded by the treatment.