ANGPTL3 Deficiency and Risk of Hepatic Steatosis.

BACKGROUND: ANGPTL3 (angiopoietin-like 3) is a therapeutic target for reducing plasma levels of triglycerides and low-density lipoprotein cholesterol. A recent trial with vupanorsen, an antisense oligonucleotide targeting hepatic production of ANGPTL3, reported a dose-dependent increase in hepatic fat. It is unclear whether this adverse effect is due to an on-target effect of inhibiting hepatic ANGPTL3. METHODS: We recruited participants with ANGPTL3 deficiency related to ANGPTL3 loss-of-function (LoF) mutations, along with wild-type (WT) participants from 2 previously characterized cohorts located in Campodimele, Italy, and St. Louis, MO. Magnetic resonance spectroscopy and magnetic resonance proton density fat fraction were performed to measure hepatic fat fraction and the distribution of extrahepatic fat. To estimate the causal relationship between ANGPTL3 and hepatic fat, we generated a genetic instrument of plasma ANGPTL3 levels as a surrogate for hepatic protein synthesis and performed Mendelian randomization analyses with hepatic fat in the UK Biobank study. RESULTS: We recruited participants with complete (n=6) or partial (n=32) ANGPTL3 deficiency related to ANGPTL3 LoF mutations, as well as WT participants (n=92) without LoF mutations. Participants with ANGPTL3 deficiency exhibited significantly lower total cholesterol (complete deficiency, 78.5 mg/dL; partial deficiency, 172 mg/dL; WT, 188 mg/dL; P<0.05 for both deficiency groups compared with WT), along with plasma triglycerides (complete deficiency, 26 mg/dL; partial deficiency, 79 mg/dL; WT, 88 mg/dL; P<0.05 for both deficiency groups compared with WT) without any significant difference in hepatic fat (complete deficiency, 9.8%; partial deficiency, 10.1%; WT, 9.9%; P>0.05 for both deficiency groups compared with WT) or severity of hepatic steatosis as assessed by magnetic resonance imaging. In addition, ANGPTL3 deficiency did not alter the distribution of extrahepatic fat. Results from Mendelian randomization analyses in 36 703 participants from the UK Biobank demonstrated that genetically determined ANGPTL3 plasma protein levels were causally associated with low-density lipoprotein cholesterol (P=1.7×10-17) and triglycerides (P=3.2×10-18) but not with hepatic fat (P=0.22). CONCLUSIONS: ANGPTL3 deficiency related to LoF mutations in ANGPTL3, as well as genetically determined reduction of plasma ANGPTL3 levels, is not associated with hepatic steatosis. Therapeutic approaches to inhibit ANGPTL3 production in hepatocytes are not necessarily expected to result in the increased risk for hepatic steatosis that was observed with vupanorsen.

Quantitative ultrasound fatty liver evaluation in a pediatric population: comparison with magnetic resonance imaging of liver proton density fat fraction.

BACKGROUND: Biopsy remains the gold standard for the diagnosis of hepatic steatosis, the leading cause of pediatric chronic liver disease; however, its costs call for less invasive methods. OBJECTIVE: This study examined the diagnostic accuracy and reliability of quantitative ultrasound (QUS) for the assessment of liver fat content in a pediatric population, using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. MATERIALS AND METHODS: We enrolled 36 patients. MRI-PDFF involved a 3-dimensional T2*-weighted with Dixon pulse multiple-echo sequence using iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL IQ). QUS imaging relied on the ultrasound system "RS85 A" (Samsung Medison, Seoul, South Korea) and the following software: Hepato-Renal Index with automated region of interest recommendation (EzHRI), Tissue Attenuation Imaging (TAI), and Tissue Scatter Distribution Imaging (TSI). For each QUS index, receiver operating characteristic (ROC) curve analysis against MRI-PDFF was used to identify the associated cut-off value and the area under the ROC curve (AUROC). Concordance between two radiologists was assessed by intraclass correlation coefficients (ICCs) and Bland-Altman analysis. RESULTS: A total of 61.1% of the sample (n=22) displayed a MRI-PDFF ≥ 5.6%; QUS cut-off values were TAI=0.625 (AUROC 0.90, confidence interval [CI] 0.77-1.00), TSI=91.95 (AUROC 0.99, CI 0.98-1.00) and EzHRI=1.215 (AUROC 0.98, CI 0.94-1.00). Inter-rater reliability was good-to-excellent for EzHRI (ICC 0.91, 95% C.I. 0.82-0.95) and TAI (ICC 0.94, 95% C.I. 0.88-0.97) and moderate to good for TSI (ICC 0.73; 95% C.I. 0.53-0.85). CONCLUSION: Our results suggest that QUS can be used to reliably assess the presence and degree of pediatric hepatic steatosis.

Relevance of Spontaneous Portosystemic Shunts Detected with CT in Patients with Cirrhosis.

Background Cirrhosis leads to portal hypertension and to the consequent formation of spontaneous portosystemic shunts (SPSSs), leading to complications related to the diversion of portal blood into the systemic circulation, which is called portosystemic shunt syndrome. Purpose To investigate the characteristics of patients with cirrhosis and an SPSS and secondarily to assess the prognostic impact of SPSSs on portal hypertension-related complications and transplant-free survival. Materials and Methods A retrospective database review of patients with cirrhosis (observed from March 2015 to July 2019) was performed to identify patients with CT imaging and outcomes data. For each patient, clinical and biochemical data were collected, and the presence, types, and sizes of SPSSs were investigated with CT. Patients were followed for a mean of 27.5 months ± 22.8. Multivariable logistic analysis was used to identify the clinical characteristics associated with the presence of SPSSs (any size) and presence of SPSSs 1 cm or larger. Competitive risk analysis (Fine and Gray model) was used to identify the association between SPSSs and complications and mortality. Results Two hundred twenty-two patients with cirrhosis (157 male, 65 female; mean age, 62 years ± 12 [standard deviation]) were evaluated. An SPSS was found in 141 of 222 patients (63.5%), and 40 of 222 (18%) had a shunt diameter of at least 1 cm. At presentation, variables independently associated with the presence of SPSSs (any size) were portal vein thrombosis (odds ratio, 5.5; P = .008) and Child-Pugh class C (odds ratio, 3.0; P = .03). Previous hepatic encephalopathy (odds ratio, 4.4; P = .001) and portal vein thrombosis (odds ratio, 5.3; P = .001) were the only variables associated with SPSSs larger than 1 cm. Patients with SPSSs of any size had higher mortality (subdistribution hazard ratio, 1.9; P < .001) and higher frequency of hepatic encephalopathy (subdistribution hazard ratio, 2.3; P = .023), gastrointestinal bleeding (subdistribution hazard ratio, 2.9; P = .039), and portal vein thrombosis (subdistribution hazard ratio, 7.6; P = .005). Conclusion The presence of spontaneous portosystemic shunts on CT images in patients with cirrhosis was associated with higher mortality and complications, including portal vein thrombosis, hepatic encephalopathy, and gastrointestinal bleeding. © RSNA, 2021 See also the editorial by Reeder in this issue.

Sarco-Model: A score to predict the dropout risk in the perspective of organ allocation in patients awaiting liver transplantation.

BACKGROUND & AIMS: Sarcopenia in liver transplantation (LT) cirrhotic candidates has been connected with higher dropouts and graft losses after transplant. The study aims to create an 'urgency' model combining sarcopenia and Model for End-stage Liver Disease Sodium (MELDNa) to predict the risk of dropout and identify an appropriate threshold of post-LT futility. METHODS: A total of 1087 adult cirrhotic patients were listed for a first LT during January 2012 to December 2018. The study population was split into a training (n = 855) and a validation set (n = 232). RESULTS: Using a competing-risk analysis of cause-specific hazards, we created the Sarco-Model2 . According to the model, one extra point of MELDNa was added for each 0.5 cm2 /m2 reduction of total psoas area (TPA) < 6.0 cm2 /m2 . At external validation, the Sarco-Model2 showed the best diagnostic ability for predicting the risk of 3-month dropout in patients with MELDNa < 20 (area under the curve [AUC] = 0.93; P = .003). Using the net reclassification improvement, 14.3% of dropped-out patients were correctly reclassified using the Sarco-Model2 . As for the futility threshold, transplanted patients with TPA < 6.0 cm2 /m2 and MELDNa 35-40 (n = 16/833, 1.9%) had the worse results (6-month graft loss = 25.5%). CONCLUSIONS: In sarcopenic patients with MELDNa < 20, the 'urgency' Sarco-Model2 should be used to prioritize the list, while MELDNa value should be preferred in patients with MELDNa ≥ 20. The Sarco-Model2 played a role in more than 30% of the cases in the investigated allocation scenario. In sarcopenic patients with a MELDNa value of 35-40, 'futile' transplantation should be considered.

Genetic and metabolic predictors of hepatic fat content in a cohort of Italian children with obesity.

OBJECTIVES: To comprehensively explore metabolic and genetic contributors to liver fat accumulation in overweight/obese children. METHODS: Two hundred thirty Italian children with obesity were investigated for metabolic parameters and genotyped for PNPLA3, TM6SF2, GCKR, and MBOAT7 gene variants. Percentage hepatic fat content (HFF%) was measured by nuclear magnetic resonance. RESULTS: HFF% was positively related with BMI, HOMAIR, metabolic syndrome, ALT, AST, γGT, and albumin. Carriers of [G] allele in PNPLA3, [T] allele in GCKR and [T] allele in TM6SF2 genes had significantly higher hepatic fat content than wild-type carriers. HFF% was explained for 8.7% by metabolic and for 16.1% by genetic factors and, a model including age, gender, BMI, HOMAIR, PNPLA3, GCKR, and TM6SF2 variants was the best predictor of HFF%, explaining 24.8% of its variation (P < 0.001). A weighted-genetic risk score combining PNPLA3, GCKR, and TM6SF2 risk alleles was associated with almost eightfold higher risk of NAFLD. CONCLUSIONS: Our data highlighted the predominant role of genetic factors in determining the amount of liver fat content in children with obesity.

Peritoneal and pleural fluids may appear hyperintense on hepatobiliary phase using hepatobiliary MR contrast agents.

AIM: To describe the effect of hepatobiliary-specific MR imaging contrast agent (HBCA) administration on the signal intensity of peritoneal and pleural fluid effusions on T1-weighted MR images. MATERIALS AND METHODS: From October 2015 to May 2016 139 patients (mean 60±10 years old, 69 % males) with peritoneal or pleural effusions without biliary leakage who underwent HBCA-MRI (Gd-BOPTA or Gd-EOB-DTPA) at 1.5T and 3T were included from two centres. The fluid signal intensity was classified as hypo/iso/hyperintense before/after HBCA administration. The relative signal enhancement (RE) was calculated. RESULTS: On hepatobiliary phase (HBP), peritoneal fluids appeared hyper/isointense in 88-100 % and pleural effusions in 100 % of the patients following Gd-BOPTA administration. All fluids remained hypointense following Gd-EOB-DTPA. The signal intensity of fluids increased with both HBCA but RE was significantly higher following Gd-BOPTA (p=0.002 to <0.001). RE was correlated with HBP acquisition time-point (r=0.42, p<0.001 and r=0.50, p=0.033 for peritoneal and pleural fluids). CONCLUSION: The signal intensity of pleural and peritoneal fluids progressively increases following HBCA administration in the absence of biliary leakage. Due to its later hepatobiliary phase, this is more pronounced after Gd-BOPTA injection, leading to fluid hyperintensity that is not observed after Gd-EOB-DTPA injection. KEY POINTS: • Fluids appear hyper/isointense on HBP in most patients after Gd-BOPTA injection. • Fluids remain hypointense on HBP after Gd-EOB-DTPA injection. • RE of fluids increases with time after liver-specific Gd injection. • RE of fluids is higher in patients with chronic liver disease.

Volumetric Distribution of the White Matter Hyper-Intensities in Subject with Mild to Severe Carotid Artery Stenosis: Does the Side Play a Role?

PURPOSE: The purpose of this paper was to assess the difference in the distribution of white matter hyperintensities (WMHs) on left and right sides of the brain hemispheres of subjects with mild to severe carotid artery stenosis. MATERIAL AND METHODS: Eighty consecutive patients (mean age 71 ± 6 years, males 66) with carotid artery stenosis were prospectively recruited. FLAIR-WMH lesion volume was performed using a semiautomated segmentation technique (Jim, Xinapse System, Leicester, UK). The Wilcoxon test was applied to verify the differences in the volume of WMHs between the right and left hemispheres. RESULTS: A statistically significant difference was found in the middle cerebral artery (MCA) territory for the volume of the lesions (median volume of WMHs of the left side = 889.5 mm3; median volume of WMHs on the right side = 580.5 mm3; P = .0416); no statistically significant difference was found on the other territories by taking into considerations the lesions. By analyzing the degree of stenosis, we found a higher degree of stenosis of the left side (67.9%; 95% confidence interval [CI], 64.8%-70.9%) compared with the right side (65.7%; 95% CI, 62.4%-68.9%), but the Mann-Whitney test did not show a statistically significant difference (P = .3235). CONCLUSIONS: Results of our study suggest that there is a difference in the distribution of WMHs in the brain hemispheres according to the left/right side on the MCA territories and for the periventricular white matter in subjects with mild to severe carotid artery stenosis.

Radiation dose and image quality of computed tomography of the supra-aortic arteries: A comparison between single-source and dual-source CT Scanners.

PURPOSE: The purpose of this work was to compare the image quality and radiation dose delivered to patients during computed tomography (CT) angiography (CTA) of the supra-aortic arteries using two single-source (SS) and two dual-energy (DE) CT scanners. MATERIAL AND METHODS: In this retrospective study, 120 patients who underwent CTA of supra-aortic arteries were studied using four different types of CT scanners: a sixteen and forty-detector-row SS and two DE CT scanners. Seventy milliters of contrast medium were injected at a flow rate of 4mL/s using a power injector. For each patient the dose-length product (DLP), the volume computed tomography dose index (CDTIvol), the length of the scan and the effective dose (ED) were calculated. Qualitative and quantitative [image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)] image quality assessment was performed. RESULTS: A statistically significant lower value of the DE compared to the SS technology (P<0.0001) for the CDTI, DLP and ED was found, whereas we did not find any statistically significant difference between the four scanners for the measurements of the image noise, SNR and CNR. CONCLUSION: DS CT scanners allow performing CTAs with a reduced dose compared to SS CT scanner with comparable image quality.

Volumetric Analysis of Carotid Plaque Components and Cerebral Microbleeds: A Correlative Study.

PURPOSE: The purpose of this work was to explore the association between carotid plaque volume (total and the subcomponents) and cerebral microbleeds (CMBs). MATERIALS AND METHODS: Seventy-two consecutive (male 53; median age 64) patients were retrospectively analyzed. Carotid arteries were studied by using a 16-detector-row computed tomography scanner whereas brain was explored with a 1.5 Tesla system. CMBs were studied using a T2*-weighted gradient-recalled echo sequence. CMBs were classified as from absent (grade 1) to severe (grade 4). Component types of the carotid plaque were defined according to the following Hounsfield unit (HU) ranges: lipid less than 60 HU; fibrous tissue from 60 to 130 HU; calcification greater than 130 HU, and plaque volumes of each component were calculated. Each carotid artery was analyzed by 2 observers. RESULTS: The prevalence of CMBs was 35.3%. A statistically significant difference was observed between symptomatic (40%) and asymptomatic (11%) patients (P value = .001; OR = 6.07). Linear regression analysis demonstrated an association between the number of CMBs and the symptoms (P = .0018). Receiver operating characteristics curve analysis found an association between the carotid plaque subcomponents and CMBs (Az = .608, .621, and .615 for calcified, lipid, and mixed components, respectively), and Mann-Whitney test confirmed this association in particular for the lipid components (P value = .0267). CONCLUSIONS: Results of this study confirm the association between CMBs and symptoms and that there is an increased number of CMBs in symptomatic patients. Moreover, we found that an increased volume of the fatty component is associated with the presence and number of CMBs.

No effects of oral vitamin D supplementation on non-alcoholic fatty liver disease in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic disorder worldwide, reaching prevalence up to 90 % in obese patients with type 2 diabetes (T2D), and representing an independent risk factor for cardiovascular mortality. Furthermore, the coexistence of T2D and NAFLD leads to higher incidence of diabetes' complications and additive detrimental liver outcomes. The existence of a close association between NAFLD and hypovitaminosis D, along with the anti-inflammatory and insulin-sensitizing properties of vitamin D, have been largely described, but vitamin D effects on hepatic fat content have never been tested in a randomized controlled trial. We assessed the efficacy and safety of 24-week oral high-dose vitamin D supplementation in T2D patients with NAFLD. METHODS: This randomized, double-blind, placebo-controlled trial was carried out at the Diabetes Centre of Sapienza University, Rome, Italy, to assess oral treatment with cholecalciferol (2000 IU/day) or placebo in T2D patients with NAFLD. The primary endpoint was reduction of hepatic fat fraction (HFF) measured by magnetic resonance; as hepatic outcomes, we also investigated changes in serum transaminases, CK18-M30, N-terminal Procollagen III Propeptide (P3NP) levels, and Fatty Liver Index (FLI). Secondary endpoints were improvement in metabolic (fasting glycaemia, HbA1c, lipids, HOMA-IR, HOMA-ß, ADIPO-IR, body fat distribution) and cardiovascular (ankle-brachial index, intima-media thickness, flow-mediated dilatation) parameters from baseline to end of treatment. RESULTS: Sixty-five patients were randomized, 26 (cholecalciferol) and 29 (placebo) subjects completed the study. 25(OH) vitamin D significantly increased in the active treated group (48.15 ± 23.7 to 89.80 ± 23.6 nmol/L, P < 0.001); however, no group differences were found in HFF, transaminases, CK18-M30, P3NP levels or FLI after 24 weeks. Vitamin D neither changed the metabolic profile nor the cardiovascular parameters. CONCLUSIONS: Oral high-dose vitamin D supplementation over 24 weeks did not improve hepatic steatosis or metabolic/cardiovascular parameters in T2D patients with NAFLD. Studies with a longer intervention period are warranted for exploring the effect of long time exposure to vitamin D. TRIAL REGISTRATION: This trial was approved on July 2011 by the Ethics Committee of Policlinico Umberto I, Sapienza University of Rome, Italy, and registered at www.clinicaltrialsregister.eu number 2011-003010-17.