Harmonized Multisite MRI-Based Quantification of Human Liver Fat and Stiffness: A Pilot Study.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a leading cause of end-stage liver disease. NAFLD diagnosis and follow-up relies on a combination of clinical data, liver imaging, and/or liver biopsy. However, intersite imaging differences impede diagnostic consistency and reduce the repeatability of the multisite clinical trials necessary to develop effective treatments. PURPOSE/HYPOTHESIS: The goal of this pilot study was to harmonize commercially available 3 T magnetic resonance imaging (MRI) measurements of liver fat and stiffness in human participants across academic sites and MRI vendors. STUDY TYPE: Cohort. SUBJECTS: Four community-dwelling adults with obesity. FIELD STRENGTH/SEQUENCE: 1.5 and 3 T, multiecho 3D imaging, PRESS, and GRE. ASSESSMENT: Harmonized proton density fat fraction (PDFF) and magnetic resonance spectroscopy (MRS) protocols were used to quantify the FF of synthetic phantoms and human participants with obesity using standard acquisition parameters at four sites that had four different 3 T MRI instruments. In addition, a harmonized magnetic resonance elastography (MRE) protocol was used to quantify liver stiffness among participants at two different sites at 1.5 and 3 T field strengths. Data were sent to a single data coordinating site for postprocessing. STATISTICAL TESTS: Linear regression in MATLAB, ICC analyses using SAS 9.4, one-sided 95% confidence intervals for the ICC. RESULTS: PDFF and MRS FF measurements were highly repeatable among sites in both humans and phantoms. MRE measurements of liver stiffness in three individuals at two sites using one 1.5 T and one 3 T instrument showed repeatability that was high although lower than that of MRS and PDFF. CONCLUSIONS: We demonstrated harmonization of PDFF, MRS, and MRE-based quantification of liver fat and stiffness through synthetic phantoms, traveling participants, and standardization of postprocessing analysis. Multisite MRI harmonization could contribute to multisite clinical trials assessing the efficacy of interventions and therapy for NAFLD. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

Hepatic macrosteatosis in the US pediatric deceased liver donor population.

INTRODUCTION: The pediatric obesity epidemic is associated with early development of hepatic macrosteatosis, a hallmark of non-alcoholic fatty LI disease, which is thought to be more rapidly progressive in children than adults. Macrosteatosis in adult allografts is associated with allograft loss, but this has not been examined in pediatric donors. METHODS: We studied all pediatric potential whole LI donors (2005-2018) who had a LI biopsy in the SRTR (n = 862) and whose LI was transplanted (n = 862). Macrosteatosis was abstracted from biopsy reports and compared to values in the SRTR standard analytic file. Recipients of macrosteatotic pediatric allografts were matched 1:1 to recipients of non-macrosteatotic pediatric allografts by propensity score matching on donor/recipient variables. All-cause allograft loss was estimated via Kaplan-Meier analysis and Cox proportional hazards model. RESULTS: From 2005 to 2018, the proportion of pediatric donors (age ≥2 years) with obesity increased (14.8% to 21.7%; p < .001), as did the proportion of pediatric deceased whole LI-only donor allografts with macrosteatosis (n = 10 648; 1.8% to 3.9%; p < .001). The median degree of macrosteatosis among macrosteatotic donors was 10% (IQR 5-30). There were no significant differences in all-cause allograft loss between recipients of pediatric LI allografts with and without macrosteatosis at 90 days (p = .11) or 1 year (p = .14) post-transplant in Kaplan-Meier analysis or a Cox proportional hazards model (p > .05). CONCLUSION: Obese pediatric LI donors have increased over time and were more likely to have hepatic macrosteatosis; however, pediatric macrosteatosis did not appear to adversely affect recipient outcomes.

Association of Terry Nails With Liver Cirrhosis.

INTRODUCTION: We looked at the association between Terry nails and liver cirrhosis in an ambulatory population from hepatology and gastroenterology clinics. METHODS: We prospectively investigated the prevalence and determinants of Terry nails in 1,000 consecutive patients from hepatology and gastroenterology clinics at 2 institutions between May 2016 and February 2020. RESULTS: A total of 117 subjects manifested Terry nails, with a 25.6% prevalence in patients with cirrhosis. When adjusted for age, heart failure, diabetes mellitus type 2, and chronic liver disease, cirrhosis was the only significant correlate (odds ratio 5.7 [95% confidence interval 3.3-9.8]), irrespective of liver disease etiology, with a strong association with hepatic fibrosis stage (P < 0.0001). DISCUSSION: Sensitivity and specificity of Terry nails for cirrhosis (25.8%, 92.7%) was similar to palmar erythema but less than spider angioma.

Obesity is a risk factor for progression to kidney transplant waitlisting after liver transplantation.

BACKGROUND: Non-alcoholic steatohepatitis has emerged as a leading cause of cirrhosis, and obesity-associated comorbidities, including renal disease, have increased in prevalence. Obesity predisposes the kidney to hyperfiltration injury, potentially impairing acute kidney injury recovery. Identification of patients at risk for renal dysfunction is impeded by poor performance of renal function estimating equations among cirrhotics. To better understand obesity among cirrhotics and renal disease progression, we examined likelihood of kidney transplantation (KT) waitlisting after liver transplant alone (LTA) by obesity class. METHODS: 68 607 LTA recipients were identified in SRTR (2005-2018). Fine and Gray competing risks models were used to analyze likelihood of KT waitlisting. RESULTS: 27.4% of recipients were obese (BMI ≥ 30 kg/m2 ) and were 10% more likely to require KT waitlisting (aHR: 1.10, 95%CI: 1.01-1.20). Risk was highest among recipients with Classes II and III obesity (BMI: ≥35 kg/m2 ) (aHR: 1.37, 95%CI: 1.17-1.56). Moreover, recipients with Classes II and III obesity were 57% more likely to require KT waitlisting within one year post-LTA (aHR: 1.57, 95%CI: 1.18-2.10) compared to non-obese recipients. DISCUSSION: These findings suggest obesity was a risk factor for renal recovery failure and/or renal disease progression post-LTA and may confound identification of renal dysfunction and/or prediction of renal recovery among cirrhotics.

Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race.

OBJECTIVE: The objective of this study was to assess the performance of noninvasive tests (NITs) across different racial and ethnic groups in a large multiethnic cohort. METHODS: Data were derived from the National Health and Nutrition Examination Survey (NHANES) 2017 through 2020. Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study. RESULTS: Among the 6359 adults included in the study, fatty liver index and nonalcoholic fatty liver disease liver fat scores performed well for the prediction of metabolic dysfunction-associated steatotic liver disease, without significant changes across racial and ethnic groups. However, significant differences were observed across racial and ethnic groups for the prediction of advanced fibrosis and cirrhosis. The fibrosis-4 (FIB-4) index, aspartate aminotransferase to platelet ratio index (APRI), and nonalcoholic fatty liver disease fibrosis score underperformed in non-Hispanic Black patients for the detection of cirrhosis. For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI. Using a cutoff point of 12 kPa for advanced fibrosis, both APRI and the FIB-4 index performed significantly worse in non-Hispanic Black patients. CONCLUSIONS: In a large, diverse national cohort, the performance of NITs was overall poor compared with transient elastography, and NITs showed differences across racial and ethnic groups. Given the widespread use of NITs, it is imperative that the scores are equitable across racial and ethnic groups.

Metabolic dysfunction associated steatotic liver disease: Current practice, screening guidelines and management in the primary care setting.

Metabolic dysfunction associated steatotic liver disease, previously known as non-alcoholic fatty liver disease, is the most common cause of chronic liver disease in the United States with rapidly rising prevalence. There have been significant changes recently in the field with screening now recommended for patients at risk for significant liver fibrosis in primary care and endocrine settings, along with clear guidance for management of metabolic comorbidities and changes in nomenclature. This paper serves as a summary of recent guidance for the primary care physician focusing on identifying appropriate patients for screening, selecting suitable screening modalities, and determining when referral to specialty care is necessary. The hope is that providers will shift away from past practices of utilizing liver tests alone as a screening tool and shift towards fibrosis screening in patients at risk for significant fibrosis. This culture change will allow for earlier identification of patients at risk for end stage liver disease and serious liver related complications, and overall improved patient care.

Levetiracetam Liver Injury: A Benign Antiepileptic Agent?

Levetiracetam is a commonly prescribed antiepileptic agent and has rarely been linked to hepatotoxicity. This case describes a patient with drug-induced autoimmune hepatitis secondary to levetiracetam.

Gastric Xanthomatosis Secondary to Lipoprotein X in Primary Biliary Cholangitis.

Primary biliary cholangitis (PBC) is a rare autoimmune disease characterized by intralobular bile duct destruction. Patients typically present with generalized symptoms including fatigue and pruritis, and less commonly, manifestations of lipid deposition including xanthomas and xanthelasmas. We report a case of a 31-year-old female with PBC-associated cirrhosis who had cutaneous xanthelasmas and diffuse gastric xanthomas secondary to hyperlipidemia and lipoprotein X that completely resolved following liver transplantation. While gastric xanthomas have been reported in patients with PBC previously, to our knowledge, this is the first case report of diffuse gastric xanthomas secondary to PBC reported to resolve following liver transplantation, suggesting that liver transplantation is curative for gastric xanthomatosis in patients with PBC-related cirrhosis.

Assessing strategies to target screening for advanced liver fibrosis among overweight and obese patients.

Aim: The optimal screening strategy for advanced liver fibrosis in overweight and obese patients is unknown. The aim of this study is to compare the performance of different strategies to select patients at high risk of advanced liver fibrosis for screening using non-invasive tools. Methods: All patients underwent: liver 1H-MRS and percutaneous liver biopsy (in those with nonalcoholic fatty liver disease [NAFLD]). Unique selection strategies were compared to determine the best screening algorithm: (A) A "metabolic approach": selecting patients based on HOMA-IR ≥ 3; (B) A "diabetes approach": selecting only patients with type 2 diabetes; (C) An "imaging approach": selecting patients with hepatic steatosis based on 1H-MRS; (D) A "liver biochemistry approach": selecting patients with elevated ALT (i.e., ≥ 30 IU/L for males and ≥ 19 IU/L for females); and (E) Universal screening of overweight and obese patients. FIB-4 index, NAFLD fibrosis score, and APRI were applied as screening strategies. Results: A total of 275 patients were included in the study. Patients with advanced fibrosis (n = 29) were matched for age, gender, ethnicity, and BMI. Selecting patients by ALT elevation provided the most effective strategy, limiting the false positive rate while maintaining the sensitivity compared to universal screening. Selecting patients by any other strategy did not contribute to increasing the sensitivity of the approach and resulted in more false positive results. Conclusion: Universal screening of overweight/obese patients for advanced fibrosis with non-invasive tools is unwarranted, as selection strategies based on elevated ALT levels lead to the same sensitivity with a lower false positive rate (i.e., fewer patients that would require a liver biopsy or referral to hepatology).

Dietary Patterns and Prevalent NAFLD at Year 25 from the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

The prevalence of nonalcoholic fatty liver disease is rapidly rising. We aimed to investigate associations of diet quality and dietary patterns with nonalcoholic fatty liver disease (NAFLD) in Black and White adults. We included 1726 participants who attended the Year 20 Exam of the Coronary Artery Risk Development in Young Adults (CARDIA) study and had their liver attenuation (LA) measured using computed tomography at Year 25 (2010-2011). NAFLD was defined as an LA of ≤51 Hounsfield units after the exclusion of other causes of liver fat. The a priori diet-quality score (APDQS) was used to assess diet quality, and dietary patterns were derived from principal components analysis. Univariate and multivariable logistic regression models were used to evaluate the association between the APDQS, dietary patterns, and NAFLD, and were adjusted for Year 20 covariates. NAFLD prevalence at Year 25 was 23.6%. In a model adjusted for age, race, sex, education, alcohol use, physical activity, smoking, and center at Year 25, the APDQS was inversely associated (p = 0.004) and meat dietary pattern was positively associated (p < 0.0001) with NAFLD, while the fruit-vegetable dietary pattern was not significantly associated (p = 0.40). These associations remained significant when additionally adjusting for comorbidities (type 2 diabetes mellitus, dyslipidemia, hypertension), however, significant associations were diminished after additionally adjusting for body mass index (BMI). Overall, this study finds that the APDQS and meat dietary patterns are associated with prevalent NAFLD in mid-life. The associations appear to be partially mediated through higher BMI.

Spatiotemporal modulation of biodiversity in a synthetic chemical-mediated ecosystem.

Biodiversity, or the relative abundance of species, measures the persistence of an ecosystem. To better understand its modulation, we analyzed the spatial and temporal dynamics of a synthetic, chemical-mediated ecosystem that consisted of two engineered Escherichia coli populations. Depending on the specific experimental conditions implemented, the dominant interaction between the two populations could be competition for nutrients or predation due to engineered communication. While the two types of interactions resulted in different spatial patterns, they demonstrated a common trend in terms of the modulation of biodiversity. Specifically, biodiversity decreased with increasing cellular motility if the segregation distance between the two populations was comparable to the length scale of the chemical-mediated interaction. Otherwise, biodiversity was insensitive to cellular motility. Our results suggested a simple criterion for predicting the modulation of biodiversity by habitat partitioning and cellular motility in chemical-mediated ecosystems.

Acute Liver Failure Due to Toxoplasmosis After Orthotopic Liver Transplantation.

Solid organ transplant recipients are at risk for a wide range of opportunistic infections, the most common being cytomegalovirus. These infections may occur as reactivation of latent disease, donor-derived, or de novo. In this article, we present a case of acute liver failure secondary to toxoplasmosis following orthotopic liver transplantation. Our patient presented 5 weeks after orthotopic liver transplantation with altered mental status and fatigue. She was found to have disseminated cytomegalovirus infection, which resolved with intravenous ganciclovir; however, she subsequently developed acute liver failure due to toxoplasmosis, which is hypothesized to be donor-derived. Infection with Toxoplasma may be asymptomatic in the immunocompetent host; however, in immunocompromised hosts, such as solid organ transplant recipients, this infection can be life threatening. Though prophylaxis with trimethoprim-sulfamethoxazole may prevent infections with Toxoplasma, it is often held for renal dysfunction, hyperkalemia, or other side effects, placing patients at risk. With 13 cases now reported, routine screening of donor and recipient for toxoplasma exposure may be warranted.

Intact Fasting Insulin Identifies Nonalcoholic Fatty Liver Disease in Patients Without Diabetes.

CONTEXT: Patients with nonalcoholic fatty liver disease (NAFLD) are characterized by insulin resistance and hyperinsulinism. However, insulin resistance measurements have not been shown to be good diagnostic tools to predict NAFLD in prior studies. OBJECTIVE: We aimed to assess a newly validated method to measure intact molecules of insulin by mass spectrometry to predict NAFLD. METHODS: Patients underwent a 2-hour oral glucose tolerance test (OGTT), a liver magnetic resonance spectroscopy (1H-MRS), and a percutaneous liver biopsy if they had a diagnosis of NAFLD. Mass spectrometry was used to measure intact molecules of insulin and C-peptide. RESULTS: A total of 180 patients were recruited (67% male; 52 ± 11 years of age; body mass index [BMI] 33.2 ± 5.7 kg/m2; 46% with diabetes and 65% with NAFLD). Intact fasting insulin was higher in patients with NAFLD, irrespective of diabetes status. Patients with NAFLD without diabetes showed ~4-fold increase in insulin secretion during the OGTT compared with all other subgroups (P = 0.008). Fasting intact insulin measurements predicted NAFLD in patients without diabetes (area under the receiver operating characteristic curve [AUC] of 0.90 [0.84-0.96]). This was significantly better than measuring insulin by radioimmunoassay (AUC 0.80 [0.71-0.89]; P = 0.007). Intact fasting insulin was better than other clinical variables (eg, aspartate transaminase, triglycerides, high-density lipoprotein, glucose, HbA1c, and BMI) to predict NAFLD. When combined with alanine transaminase (ALT) (intact insulin × ALT), it detected NAFLD with AUC 0.94 (0.89-0.99) and positive and negative predictive values of 93% and 88%, respectively. This newly described approach was significantly better than previously validated noninvasive scores such as NAFLD-LFS (P = 0.009), HSI (P < 0.001), and TyG index (P = 0.039). CONCLUSION: In patients without diabetes, accurate measurement of fasting intact insulin levels by mass spectrometry constitutes an easy and noninvasive strategy to predict presence of NAFLD.

Evidence-based clinical advice for nutrition and dietary weight loss strategies for the management of NAFLD and NASH.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and affects approximately one third of adults in the United States. The disease is becoming a global epidemic as a result of the rising rates of obesity and metabolic disease. Emerging data suggest weight loss of ≥10% overall body weight is beneficial in resolving steatosis and reversing fibrosis. Prospective trials comparing various diets are limited by lack of sufficient power as well as pre- and post-treatment histopathology, and therefore no specific diet is recommended at this time. In this narrative review we examine the pathophysiology behind specific macronutrient components that can either promote or reverse NAFLD to help inform more specific dietary recommendations. Overall, the data supports reducing saturated fat, refined carbohydrates, and red and processed meats in the diet, and increasing the consumption of plant-based foods. Diets that incorporate these recommendations include plant-based diets such as the Dietary Approaches to Stop Hypertension, Mediterranean, vegetarian, and vegan diets.

Drug-Induced Liver Injury in the Setting of Chronic Liver Disease.

Drug-induced liver injury (DILI) is an uncommon but significant cause of liver injury and need for liver transplant. DILI in the setting of chronic liver disease (CLD) is poorly understood. Clinical features of patients presenting with DILI in the setting of CLD are similar to those without CLD with the exception of a higher incidence of diabetes among those with CLD and DILI. Diagnosis of DILI in CLD is difficult because there are no objective biomarkers and current causality assessments have not been studied in this population. Differentiating DILI from exacerbation of underlying liver disease is even more challenging.

Quantifying Sex-Based Disparities in Liver Allocation.

Importance: Differences in local organ supply and demand have introduced geographic inequities in the Model for End-stage Liver Disease (MELD) score-based liver allocation system, prompting national debate and patient-initiated lawsuits. No study to our knowledge has quantified the sex disparities in allocation associated with clinical vs geographic characteristics. Objective: To estimate the proportion of sex disparity in wait list mortality and deceased donor liver transplant (DDLT) associated with clinical and geographic characteristics. Design, Setting, and Participants: This retrospective cohort study used adult (age ≥18 years) liver-only transplant listings reported to the Organ Procurement and Transplantation Network from June 18, 2013, through March 1, 2018. Exposure: Liver transplant waiting list. Main Outcomes and Measures: Primary outcomes included wait list mortality and DDLT. Multivariate Cox proportional hazards regression models were constructed, and inverse odds ratio weighting was used to estimate the proportion of disparity across geographic location, MELD score, and candidate anthropometric and liver measurements. Results: Among 81 357 adults wait-listed for liver transplant only, 36.1% were women (mean [SD] age, 54.7 [11.3] years; interquartile range, 49.0-63.0 years) and 63.9% were men (mean [SD] age, 55.7 [10.1] years; interquartile range, 51.0-63.0 years). Compared with men, women were 8.6% more likely to die while on the waiting list (adjusted hazard ratio [aHR], 1.11; 95% CI, 1.04-1.18) and were 14.4% less likely to receive a DDLT (aHR, 0.86; 95% CI, 0.84-0.88). In the geographic domain, organ procurement organization was the only variable that was significantly associated with increased disparity between female sex and wait list mortality (22.1% increase; aHR, 1.22; 95% CI, 1.09-1.30); no measure of the geographic domain was associated with DDLT. Laboratory and allocation MELD scores were associated with increases in disparities in wait list mortality: 1.14 (95% CI, 1.09-1.19; 50.1% increase among women) and DDLT: 0.87 (95% CI, 0.86-0.88; 10.3% increase among women). Candidate anthropometric and liver measurements had the strongest association with disparities between men and women in wait list mortality (125.8% increase among women) and DDLT (49.0% increase among women). Conclusions and Relevance: Our findings suggest that addressing geographic disparities alone may not mitigate sex-based disparities, which were associated with the inability of the MELD score to accurately estimate disease severity in women and to account for candidate anthropometric and liver measurements in this study.