Link between persistent, unexplained gamma-glutamyltransferase elevation and porto-sinusoidal vascular disorder.

Background & Aims: Porto-sinusoidal vascular disorder (PSVD) is a group of vascular disorders characterized by lesions involving portal venules and sinusoids, irrespective of the presence of portal hypertension. Liver biopsy is essential for diagnosis. In a single-center study, we demonstrated high rates of PSVD in patients with persistently elevated gamma-glutamyltransferase (GGT). This multicenter study aims to establish PSVD prevalence in a larger dataset of individuals with persistent and unexplained GGT elevation, and to identify associated risk factors. Methods: The study included all patients who underwent liver biopsy for persistent and unexplained GGT elevation in five Italian hepatology units between March 2015 and December 2021. Results: A total of 144 patients met the inclusion criteria. The majority were males (76/144, 52.8%) and mean age was 51.9 years (range 19-74). Only 12 (8.3%) had liver stiffness measurements (LSM) >10 kPa, while 7 (4.8%) had ultrasound evidence of portal hypertension. Histological findings were consistent with PSVD in 96 patients (67%). Alternative diagnoses were steatohepatitis in 13 (9%), sarcoidosis in 3 (2%) and congenital hepatic fibrosis in 3 (2%) patients. Histological findings were non-specific in 29 (20%) patients. PSVD was associated with male sex (odds ratio [OR] 2.60, 95% CI 1.13-5.99), LSM <10 kPa (OR 11.05, 95% CI 2.16-56.66) and GGT <200 U/L (OR 2.69, 95% CI 1.22-5.98). Conclusions: PSVD was the main cause of persistent and unexplained elevation of GGT3. Male sex, LSM <10 kPa and GGT <200 U/L were associated with PSVD. These findings highlight the role of liver biopsy in elucidating the underlying pathology and aiding in the diagnosis of patients with persistent and unexplained GGT elevation. Impact and implications: In outpatient settings, it is common to encounter individuals with persistent and unexplained gamma-glutamyltransferase elevations. This study reveals, for the first time, a non-negligible prevalence of porto-sinusoidal vascular disorder among these individuals when they undergo liver biopsy. Male sex, liver stiffness measurement <10 kPa, and gamma-glutamyltransferase <200 IU/L predict this histological finding. These results may raise awareness of clinically relevant conditions that may be present in patients with persistent liver enzyme changes, even in the absence of signs of advanced chronic liver disease or portal hypertension. Additionally, the data may encourage further studies in the field of porto-sinusoidal vascular disorder, particularly to define its clinical evolution in patients without signs of portal hypertension at diagnosis.

Metabolic dysfunction outperforms ultrasonographic steatosis to stratify hepatocellular carcinoma risk in patients with advanced hepatitis C cured with direct-acting antivirals.

BACKGROUND AND AIMS: Metabolic dysfunction (MD)-associated fatty liver disease has been proposed to identify individuals at risk of liver events irrespectively of the contemporary presence of other liver diseases. The aim of this study was to examine the impact of MD in patients cured of chronic hepatis C (CHC). PATIENTS AND METHODS: We analysed data from a real-life cohort of 2611 Italian patients cured of CHC with direct antiviral agents and advanced liver fibrosis, without HBV/HIV, transplantation and negative for hepatocellular carcinoma (HCC) history (age 61.4 ± 11.8 years, 63.9% males, median follow-up 34, 24-40 months). Information about ultrasonographic steatosis (US) after sustained virological response was available in 1978. RESULTS: MD affected 58% of patients, diagnosed due to the presence of diabetes (MD-diabetes, 19%), overweight without diabetes (MD-overweight, 37%) or multiple metabolic abnormalities without overweight and diabetes (MD-metabolic, 2%). MD was more frequent than and not coincident with US (32% MD-only, 23% MD-US and 13% US-only). MD was associated with higher liver stiffness (p < 0.05), particularly in patients with MD-diabetes and MD-only subgroups, comprising older individuals with more advanced metabolic and liver disease (p < 0.05). At Cox proportional hazard multivariable analysis, MD was associated with increased risk of HCC (HR 1.97, 95% CI 1.27-3.04; p = 0.0023). Further classification according to diagnostic criteria improved risk stratification (p < 0.0001), with the highest risk observed in patients with MD-diabetes. Patients with MD-only appeared at highest risk since the sustained virological response achievement (p = 0.008), with a later catch-up of those with combined MD-US, whereas US-only was not associated with HCC. CONCLUSIONS: MD is more prevalent than US in patients cured of CHC with advanced fibrosis and identifies more accurately individuals at risk of developing HCC.

Programmed cell death 1 genetic variant and liver damage in nonalcoholic fatty liver disease.

BACKGROUND AND AIMS: Programmed cell death 1/programmed cell death-ligand 1 (PD-1/PDL-1) axis has been reported to modulate liver inflammation and progression to hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD). Here, we examined whether the PDCD1 variation is associated with NAFLD severity in individuals with liver biopsy. METHODS: We examined the impact of PDCD1 gene variants on HCC, as robust severe liver disease phenotype in UK Biobank participants. The strongest genetic association with the rs13023138 G>C variation was subsequently tested for association with liver damage in 2889 individuals who underwent liver biopsy for suspected nonalcoholic steatohepatitis (NASH). Hepatic transcriptome was examined by RNA-Seq in a subset of NAFLD individuals (n = 121). Transcriptomic and deconvolution analyses were performed to identify biological pathways modulated by the risk allele. RESULTS: The rs13023138 C>G showed the most robust association with HCC in UK Biobank (p = 5.28E-4, OR = 1.32, 95% CI [1.1, 1.5]). In the liver biopsy cohort, rs13023138 G allele was independently associated with severe steatosis (OR 1.17, 95% CI 1.02-1.34; p = .01), NASH (OR 1.22, 95% CI 1.09-1.37; p < .001) and advanced fibrosis (OR 1.26, 95% CI 1.06-1.50; p = .007). At deconvolution analysis, rs13023138 G>C allele was linked to higher hepatic representation of M1 macrophages, paralleled by upregulation of pathways related to inflammation and higher expression of CXCR6. CONCLUSIONS: The PDCD1 rs13023138 G allele was associated with HCC development in the general population and with liver disease severity in patients at high risk of NASH.

Development and Validation of a Score for Fibrotic Nonalcoholic Steatohepatitis.

BACKGROUND & AIMS: Noninvasive assessment of histological features of nonalcoholic fatty liver disease (NAFLD) has been an intensive research area over the last decade. Herein, we aimed to develop a simple noninvasive score using routine laboratory tests to identify, among individuals at high risk for NAFLD, those with fibrotic nonalcoholic steatohepatitis (NASH) defined as NASH, NAFLD activity score ≥4, and fibrosis stage ≥2. METHODS: The derivation cohort included 264 morbidly obese individuals undergoing intraoperative liver biopsy in Rome, Italy. The best predictive model was developed and internally validated using a bootstrapping stepwise logistic regression analysis (2000 bootstrap samples). Performance was estimated by the area under the receiver operating characteristic curve (AUROC). External validation was assessed in 3 independent European cohorts (Finland, n = 370; Italy, n = 947; England, n = 5368) of individuals at high risk for NAFLD. RESULTS: The final predictive model, designated as Fibrotic NASH Index (FNI), combined aspartate aminotransferase, high-density lipoprotein cholesterol, and hemoglobin A1c. The performance of FNI for fibrotic NASH was satisfactory in both derivation and external validation cohorts (AUROC = 0.78 and AUROC = 0.80-0.95, respectively). In the derivation cohort, rule-out and rule-in cutoffs were 0.10 for sensitivity ≥0.89 (negative predictive value, 0.93) and 0.33 for specificity ≥0.90 (positive predictive value, 0.57), respectively. In the external validation cohorts, sensitivity ranged from 0.87 to 1 (negative predictive value, 0.99-1) and specificity from 0.73 to 0.94 (positive predictive value, 0.12-0.49) for rule-out and rule-in cutoff, respectively. CONCLUSION: FNI is an accurate, simple, and affordable noninvasive score which can be used to screen for fibrotic NASH in individuals with dysmetabolism in primary health care.

The Long Non-Coding BC200 Is a Novel Circulating Biomarker of Parathyroid Carcinoma.

Long non-coding RNAs (lncRNAs) are an important class of epigenetic regulators involved in both physiological processes and cancer development. Preliminary evidence suggested that lncRNAs could act as accurate prognostic and diagnostic biomarkers. Parathyroid cancer is a rare endocrine neoplasia, whose management represents a clinical challenge due to the lack of accurate molecular biomarkers. Our previous findings showed that human parathyroid tumors are characterized by a different lncRNAs signature, suggesting heterogeneity through the different histotypes. Particularly, we found that the lncRNA BC200/BCYRN1 could represent a candidate biomarker for parathyroid carcinomas (PCas). Here we aimed to extend our preliminary data evaluating whether BC200 could be an accurate non-invasive biomarker of PCas to support the clinical management of patients affected by parathyroid tumors at diagnosis, prognosis and follow-up. To provide a non-invasive point-of-care for parathyroid carcinoma diagnosis and follow-up, we analyzed BC200 expression in patients' serum through digital PCR. Our results show that BC200 counts are higher in serum from patients harboring PCa (n=4) compared to patients with parathyroid adenoma (PAd; n=27). Further, in PAd patients circulating BC200 levels are positively correlated with serum total calcium. Then, we found that BC200 is overexpressed in metastatic PCas (n=4) compared to non-metastatic ones (n=9). Finally, the lncRNA expression in PCa patients' serum drops are reduced after parathyroidectomy, suggesting its possible use in the post-operative setting for patients follow-up. Overall, these findings extend the knowledge on BC200 in parathyroid tumors, supporting its role as a useful biomarker for management of PCa.

Rare ATG7 genetic variants predispose patients to severe fatty liver disease.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver disorders and has a strong heritable component. The aim of this study was to identify new loci that contribute to severe NAFLD by examining rare variants. METHODS: We performed whole-exome sequencing in individuals with NAFLD and advanced fibrosis or hepatocellular carcinoma (n = 301) and examined the enrichment of likely pathogenic rare variants vs. the general population. This was followed by validation at the gene level. RESULTS: In patients with severe NAFLD, we observed an enrichment of the p.P426L variant (rs143545741 C>T; odds ratio [OR] 5.26, 95% CI 2.1-12.6; p = 0.003) of autophagy-related 7 (ATG7), which we characterized as a loss-of-function, vs. the general population, and an enrichment in rare variants affecting the catalytic domain (OR 13.9; 95% CI 1.9-612; p = 0.002). In the UK Biobank cohort, loss-of-function ATG7 variants increased the risk of cirrhosis and hepatocellular carcinoma (OR 3.30; 95% CI 1.1-7.5 and OR 12.30, 95% CI 2.6-36, respectively; p <0.001 for both). The low-frequency loss-of-function p.V471A variant (rs36117895 T>C) was also associated with severe NAFLD in the clinical cohort (OR 1.7; 95% CI 1.2-2.5; p = 0.003), predisposed to hepatocellular ballooning (p = 0.007) evolving to fibrosis in the Liver biopsy cohort (n = 2,268), and was associated with liver injury in the UK Biobank (aspartate aminotransferase levels, p <0.001), with a larger effect in severely obese individuals in whom it was linked to hepatocellular carcinoma (p = 0.009). ATG7 protein localized to periportal hepatocytes, particularly in the presence of ballooning. In the Liver Transcriptomic cohort (n = 125), ATG7 expression correlated with suppression of the TNFα pathway, which was conversely upregulated in p.V471A carriers. CONCLUSIONS: We identified rare and low-frequency ATG7 loss-of-function variants that promote NAFLD progression by impairing autophagy and facilitating ballooning and inflammation. LAY SUMMARY: We found that rare mutations in a gene called autophagy-related 7 (ATG7) increase the risk of developing severe liver disease in individuals with dysmetabolism. These mutations cause an alteration in protein function and impairment of self-renewal of cellular content, leading to liver damage and inflammation.

Clinical exome sequencing for diagnosing severe cryptogenic liver disease in adults: A case series.

Liver diseases remain unexplained in up to 30% of adult patients; genetic analysis could help establish the correct diagnosis. In six adult patients with cryptogenic liver disease, we performed whole-exome sequencing (WES) and evaluated the individual predisposition to progressive fatty liver disease by polygenic risk scores (PRS). In one patient, WES was allowed to diagnose the Hermansky-Pudlak syndrome. In the other two patients, genetic variants in LDLRAP1/MSH6 and ALDOB genes were identified, contributing to explaining the clinical presentation and disease pathogenesis (50% diagnostic uptake). In the other three patients, rare variants with a high likelihood of disrupting protein function in APOB, ATP7B, ABCB4 and ATP8B1 were identified. One patient who developed hepatocellular carcinoma during the follow-up had a high PRS value. The study supports the role of WES, combined with risk stratification by PRS and accurate clinical assessment in improving the diagnosis and informed management in patients with cryptogenic liver disease, a positive family history or severe fatty liver not fully accounted for by environmental triggers.

Dysmetabolism, Diabetes and Clinical Outcomes in Patients Cured of Chronic Hepatitis C: A Real-Life Cohort Study.

The aim of this study was to examine the impact of features of dysmetabolism on liver disease severity, evolution, and clinical outcomes in a real-life cohort of patients treated with direct acting antivirals for chronic hepatitis C virus (HCV) infection. To this end, we considered 7,007 patients treated between 2014 and 2018, 65.3% with advanced fibrosis, of whom 97.7% achieved viral eradication (NAVIGATORE-Lombardia registry). In a subset (n = 748), liver stiffness measurement (LSM) was available at baseline and follow-up. Higher body mass index (BMI; odds ratio [OR] 1.06 per kg/m2 , 1.03-1.09) and diabetes (OR 2.01 [1.65-2.46]) were independently associated with advanced fibrosis at baseline, whereas statin use was protective (OR 0.46 [0.35-0.60]; P < 0.0001 for all). The impact of BMI was greater in those without diabetes (P = 0.003). Diabetes was independently associated with less pronounced LSM improvement after viral eradication (P = 0.001) and in patients with advanced fibrosis was an independent predictor of the most frequent clinical events, namely de novo hepatocellular carcinoma (HCC; hazard ratio [HR] 2.09 [1.20-3.63]; P = 0.009) and cardiovascular events (HR 2.73 [1.16-6.43]; P = 0.021). Metformin showed a protective association against HCC (HR 0.32 [0.11-0.96]; P = 0.043), which was confirmed after adjustment for propensity score (P = 0.038). Diabetes diagnosis further refined HCC prediction in patients with compensated advanced chronic liver disease at high baseline risk (P = 0.024). Conclusion: Metabolic comorbidities were associated with advanced liver fibrosis at baseline, whereas statins were protective. In patients with advanced fibrosis, diabetes increased the risk of de novo HCC and of cardiovascular events. Optimization of metabolic comorbidities treatment by a multi-disciplinary management approach may improve cardiovascular and possibly liver-related outcomes.

Genetic risk scores and personalization of care in fatty liver disease.

Nonalcoholic fatty liver disease is the leading cause of chronic liver disease. Genetic predisposition, lifestyle, and metabolic comorbidities concur to nonalcoholic fatty liver disease development and progression to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. Improvement in risk stratification and development of effective therapies for nonalcoholic steatohepatitis are key unmet clinical needs. Knowledge emerging from genomics could meet this need. A polygenic risk score (PRS) is calculated by summing the number of trait-associated alleles carried by an individual, which can be weighted by their effect size on the trait and captures the individual's genetic risk to develop a disease. In this review, we focalize on the potential use of PRSs for disease detection at an early stage and stratification of the risk of progression to severe forms. PRSs may represent robust instruments to implement targeted prevention programs, hepatocellular carcinoma surveillance in at-risk individuals, and to develop precision medicine therapeutic approaches.

Genetic predisposition similarities between NASH and ASH: Identification of new therapeutic targets.

Fatty liver disease can be triggered by a combination of excess alcohol, dysmetabolism and other environmental cues, which can lead to steatohepatitis and can evolve to acute/chronic liver failure and hepatocellular carcinoma, especially in the presence of shared inherited determinants. The recent identification of the genetic causes of steatohepatitis is revealing new avenues for more effective risk stratification. Discovery of the mechanisms underpinning the detrimental effect of causal mutations has led to some breakthroughs in the comprehension of the pathophysiology of steatohepatitis. Thanks to this approach, hepatocellular fat accumulation, altered lipid droplet remodelling and lipotoxicity have now taken centre stage, while the role of adiposity and gut-liver axis alterations have been independently validated. This process could ignite a virtuous research cycle that, starting from human genomics, through omics approaches, molecular genetics and disease models, may lead to the development of new therapeutics targeted to patients at higher risk. Herein, we also review how this knowledge has been applied to: a) the study of the main PNPLA3 I148M risk variant, up to the stage of the first in-human therapeutic trials; b) highlight a role of MBOAT7 downregulation and lysophosphatidyl-inositol in steatohepatitis; c) identify IL-32 as a candidate mediator linking lipotoxicity to inflammation and liver disease. Although this precision medicine drug discovery pipeline is mainly being applied to non-alcoholic steatohepatitis, there is hope that successful products could be repurposed to treat alcohol-related liver disease as well.

A PDCD1 Role in the Genetic Predisposition to NAFLD-HCC?

Obesity and non-alcoholic fatty liver disease (NAFLD) are contributing to the global rise in deaths from hepatocellular carcinoma (HCC). The pathogenesis of NAFLD-HCC is not well understood. The severity of hepatic steatosis, steatohepatitis and fibrosis are key pathogenic mechanisms, but animal studies suggest altered immune responses are also involved. Genetic studies have so far highlighted a major role of gene variants promoting fat deposition in the liver (PNPLA3 rs738409; TM6SF2 rs58542926). Here, we have considered single-nucleotide polymorphisms (SNPs) in candidate immunoregulatory genes (MICA rs2596542; CD44 rs187115; PDCD1 rs7421861 and rs10204525), in 594 patients with NAFLD and 391 with NAFLD-HCC, from three European centres. Associations between age, body mass index, diabetes, cirrhosis and SNPs with HCC development were explored. PNPLA3 and TM6SF2 SNPs were associated with both progression to cirrhosis and NAFLD-HCC development, while PDCD1 SNPs were specifically associated with NAFLD-HCC risk, regardless of cirrhosis. PDCD1 rs7421861 was independently associated with NAFLD-HCC development, while PDCD1 rs10204525 acquired significance after adjusting for other risks, being most notable in the smaller numbers of women with NAFLD-HCC. The study highlights the potential impact of inter individual variation in immune tolerance induction in patients with NAFLD, both in the presence and absence of cirrhosis.

Non-invasive stratification of hepatocellular carcinoma risk in non-alcoholic fatty liver using polygenic risk scores.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) risk stratification in individuals with dysmetabolism is a major unmet need. Genetic predisposition contributes to non-alcoholic fatty liver disease (NAFLD). We aimed to exploit robust polygenic risk scores (PRS) that can be evaluated in the clinic to gain insight into the causal relationship between NAFLD and HCC, and to improve HCC risk stratification. METHODS: We examined at-risk individuals (NAFLD cohort, n = 2,566; 226 with HCC; and a replication cohort of 427 German patients with NAFLD) and the general population (UK Biobank [UKBB] cohort, n = 364,048; 202 with HCC). Variants in PNPLA3-TM6SF2-GCKR-MBOAT7 were combined in a hepatic fat PRS (PRS-HFC), and then adjusted for HSD17B13 (PRS-5). RESULTS: In the NAFLD cohort, the adjusted impact of genetic risk variants on HCC was proportional to the predisposition to fatty liver (p = 0.002) with some heterogeneity in the effect. PRS predicted HCC more robustly than single variants (p <10-13). The association between PRS and HCC was mainly mediated through severe fibrosis, but was independent of fibrosis in clinically relevant subgroups, and was also observed in those without severe fibrosis (p <0.05). In the UKBB cohort, PRS predicted HCC independently of classical risk factors and cirrhosis (p <10-7). In the NAFLD cohort, we identified high PRS cut-offs (≥0.532/0.495 for PRS-HFC/PRS-5) that in the UKBB cohort detected HCC with ~90% specificity but limited sensitivity; PRS predicted HCC both in individuals with (p <10-5) and without cirrhosis (p <0.05). CONCLUSIONS: Our results are consistent with a causal relationship between hepatic fat and HCC. PRS improved the accuracy of HCC detection and may help stratify HCC risk in individuals with dysmetabolism, including those without severe liver fibrosis. Further studies are needed to validate our findings. LAY SUMMARY: By analyzing variations in genes that contribute to fatty liver disease, we developed two risk scores to help predict liver cancer in individuals with obesity-related metabolic complications. These risk scores can be easily tested in the clinic. We showed that the risk scores helped to identify the risk of liver cancer both in high-risk individuals and in the general population.