Distinct immunometabolic signatures in circulating immune cells define disease outcome in acute-on-chronic liver failure.

BACKGROUND AND AIMS: Acute-on-chronic liver failure (ACLF) is a complication of cirrhosis characterized by multiple organ failure and high short-term mortality. The pathophysiology of ACLF involves elevated systemic inflammation leading to organ failure, along with immune dysfunction that heightens susceptibility to bacterial infections. However, it is unclear how these aspects are associated with recovery and nonrecovery in ACLF. APPROACH AND RESULTS: Here, we mapped the single-cell transcriptome of circulating immune cells from patients with ACLF and acute decompensated (AD) cirrhosis and healthy individuals. We further interrogate how these findings, as well as immunometabolic and functional profiles, associate with ACLF-recovery (ACLF-R) or nonrecovery (ACLF-NR). Our analysis unveiled 2 distinct states of classical monocytes (cMons). Hereto, ACLF-R cMons were characterized by transcripts associated with immune and stress tolerance, including anti-inflammatory genes such as RETN and LGALS1 . Additional metabolomic and functional validation experiments implicated an elevated oxidative phosphorylation metabolic program as well as an impaired ACLF-R cMon functionality. Interestingly, we observed a common stress-induced tolerant state, oxidative phosphorylation program, and blunted activation among lymphoid populations in patients with ACLF-R. Conversely, ACLF-NR cMon featured elevated expression of inflammatory and stress response genes such as VIM , LGALS2 , and TREM1 , along with blunted metabolic activity and increased functionality. CONCLUSIONS: This study identifies distinct immunometabolic cellular states that contribute to disease outcomes in patients with ACLF. Our findings provide valuable insights into the pathogenesis of ACLF, shedding light on factors driving either recovery or nonrecovery phenotypes, which may be harnessed as potential therapeutic targets in the future.

Inhibition of SIRT7 overcomes sorafenib acquired resistance by suppressing ERK1/2 phosphorylation via the DDX3X-mediated NLRP3 inflammasome in hepatocellular carcinoma.

AIMS: Sirtuin 7 (SIRT7) plays an important role in tumor development, and has been characterized as a potent regulator of cellular stress. However, the effect of SIRT7 on sorafenib acquired resistance remains unclear and a possible anti-tumor mechanism beyond this process in HCC has not been clarified. We examined the therapeutic potential of SIRT7 and determined whether it functions synergistically with sorafenib to overcome chemoresistance. METHODS: Cancer Genome Atlas-liver HCC data and unbiased gene set enrichment analyses were used to identify SIRT7 as a potential effector molecule in sorafenib acquired resistance. Two types of SIRT7 chemical inhibitors were developed to evaluate its therapeutic properties when synergized with sorafenib. Mass spectrometry was performed to discover a direct target of SIRT7, DDX3X, and DDX3X deacetylation levels and protein stability were explored. Moreover, an in vivo xenograft model was used to confirm anti-tumor effect of SIRT7 and DDX3X chemical inhibitors combined with sorafenib. RESULTS: SIRT7 inhibition mediated DDX3X depletion can re-sensitize acquired sorafenib resistance by disrupting NLRP3 inflammasome assembly, finally suppressing hyperactive ERK1/2 signaling in response to NLRP3 inflammasome-mediated IL-1ß inhibition. CONCLUSIONS: SIRT7 is responsible for sorafenib acquired resistance, and its inhibition would be beneficial when combined with sorafenib by suppressing hyperactive pro-cell survival ERK1/2 signaling.

Adipose tissue macrophage dysfunction is associated with a breach of vascular integrity in NASH.

BACKGROUND & AIMS: In non-alcoholic fatty liver disease (NAFLD), monocytes infiltrate visceral adipose tissue promoting local and hepatic inflammation. However, it remains unclear what drives inflammation and how the immune landscape in adipose tissue differs across the NAFLD severity spectrum. We aimed to assess adipose tissue macrophage (ATM) heterogeneity in a NAFLD cohort. METHODS: Visceral adipose tissue macrophages from lean and obese patients, stratified by NAFLD phenotypes, underwent single-cell RNA sequencing. Adipose tissue vascular integrity and breaching was assessed on a protein level via immunohistochemistry and immunofluorescence to determine targets of interest. RESULTS: We discovered multiple ATM populations, including resident vasculature-associated macrophages (ResVAMs) and distinct metabolically active macrophages (MMacs). Using trajectory analysis, we show that ResVAMs and MMacs are replenished by a common transitional macrophage (TransMac) subtype and that, during NASH, MMacs are not effectively replenished by TransMac precursors. We postulate an accessory role for MMacs and ResVAMs in protecting the adipose tissue vascular barrier, since they both interact with endothelial cells and localize around the vasculature. However, across the NAFLD severity spectrum, alterations occur in these subsets that parallel an adipose tissue vasculature breach characterized by albumin extravasation into the perivascular tissue. CONCLUSIONS: NAFLD-related macrophage dysfunction coincides with a loss of adipose tissue vascular integrity, providing a plausible mechanism by which tissue inflammation is perpetuated in adipose tissue and downstream in the liver. IMPACT AND IMPLICATIONS: Our study describes for the first time the myeloid cell landscape in human visceral adipose tissue at single-cell level within a cohort of well-characterized patients with non-alcoholic fatty liver disease. We report unique non-alcoholic steatohepatitis-specific transcriptional changes within metabolically active macrophages (MMacs) and resident vasculature-associated macrophages (ResVAMs) and we demonstrate their spatial location surrounding the vasculature. These dysfunctional transcriptional macrophage states coincided with the loss of adipose tissue vascular integrity, providing a plausible mechanism by which tissue inflammation is perpetuated in adipose tissue and downstream in the liver. Our study provides a theoretical basis for new therapeutic strategies to be directed towards reinstating the endogenous metabolic, homeostatic and cytoprotective functions of ResVAMs and MMacs, including their role in protecting vascular integrity.

Alpha-1 Antitrypsin Augmentation and the Liver Phenotype of Adults With Alpha-1 Antitrypsin Deficiency (Genotype Pi∗ZZ).

BACKGROUND & AIMS: α1-Antitrypsin (AAT) is a major protease inhibitor produced by hepatocytes. The most relevant AAT mutation giving rise to AAT deficiency (AATD), the 'Pi∗Z' variant, causes harmful AAT protein accumulation in the liver, shortage of AAT in the systemic circulation, and thereby predisposes to liver and lung injury. Although intravenous AAT augmentation constitutes an established treatment of AATD-associated lung disease, its impact on the liver is unknown. METHODS: Liver-related parameters were assessed in a multinational cohort of 760 adults with severe AATD (Pi∗ZZ genotype) and available liver phenotyping, of whom 344 received augmentation therapy and 416 did not. Liver fibrosis was evaluated noninvasively via the serum test AST-to-platelet ratio index and via transient elastography-based liver stiffness measurement. Histologic parameters were compared in 15 Pi∗ZZ adults with and 35 without augmentation. RESULTS: Compared with nonaugmented subjects, augmented Pi∗ZZ individuals displayed lower serum liver enzyme levels (AST 71% vs 75% upper limit of normal, P < .001; bilirubin 49% vs 58% upper limit of normal, P = .019) and lower surrogate markers of fibrosis (AST-to-platelet ratio index 0.34 vs 0.38, P < .001; liver stiffness measurement 6.5 vs 7.2 kPa, P = .005). Among biopsied participants, augmented individuals had less pronounced liver fibrosis and less inflammatory foci but no differences in AAT accumulation were noted. CONCLUSIONS: The first evaluation of AAT augmentation on the Pi∗ZZ-related liver disease indicates liver safety of a widely used treatment for AATD-associated lung disease. Prospective studies are needed to confirm the beneficial effects and to demonstrate the potential efficacy of exogenous AAT in patients with Pi∗ZZ-associated liver disease.

Bariatric surgery post-liver transplantation: A Belgian nationwide study.

Weight gain poses a rising concern post-liver transplantation (LT), and metabolic dysfunction-associated steatotic liver disease might impair graft health. The timing is crucial when considering bariatric surgery (BS) in a population with liver disease or transplantation. BS can be considered for post-LT weight gain, although the evidence is limited and the long-term outcome still uncertain. We conducted a national retrospective analysis in 5 Belgian transplant centers and included 25 patients with an LT followed by a bariatric procedure. A total of 187 LT patients without BS were included for comparison. Clinical, biochemical, and outcome data were retrospectively retrieved. In our nationwide cohort, 25 patients had undergone BS post-LT, at a median 3.5 years after LT. Twenty-one (84.0%) patients received a sleeve gastrectomy (SG). Patients were predominantly male (72.0%), with a lower age at time of transplantation compared with the non-BS population (54.5 vs. 60.6, p <0.001). Weight loss was significant and sustained, with a decrease in body mass index from 41.0±4.5 pre-BS to 32.6±5.8 1-3 years post-BS ( p <0.001) and 31.1±5.8 3-5 years post-BS ( p <0.001). Three pre-BS (12.0%) patients presented with recurrent and one (4.0%) de novo metabolic dysfunction-associated steatotic liver disease after LT, with 100% resolution post-BS ( p =0.016). Notable reductions were observed in alanine transaminase levels (40.5±28.5 U/L to 27.1±25.1 U/L post-BS, p =0.05) and HbA1c levels (6.9±1.6 to 6.0±1.4 post-BS, p <0.001). Three patients were re-transplanted, and eight patients died, of which five (20.0%) due to a nonhepatic malignancy and one (4.0%) due to liver failure. SG is the favored BS post-LT and has proven to be safe and feasible in a post-LT setting with favorable metabolic consequences. SG post-LT is a valid treatment for de novo and recurrent metabolic dysfunction-associated steatotic liver disease post-LT. Although we report on the largest cohort to date, there is still a need for larger cohorts to examine the effect of BS on patient and graft survival.

Outcomes of liver transplantation for hepatopulmonary syndrome in patients with concomitant respiratory disease.

BACKGROUND & AIMS: Concomitant respiratory disease is a common finding in patients with hepatopulmonary syndrome (HPS). Among patients who underwent liver transplantation (LT) for HPS, we compared characteristics and outcome of patients with versus without concomitant respiratory disease. METHODS: This single center retrospective observational study included patients with HPS who underwent LT between 1999 and 2020. RESULTS: During the study period, 32 patients with HPS received a LT; nine (28%) with concomitant respiratory disease of whom one required a combined lung-liver transplantation. Patients with concomitant respiratory disease had higher PaCO2 (38 vs. 33 mm Hg, p = .031). The 30-day postoperative mortality was comparable, but the estimated cumulative probability of resolution of oxygen therapy after LT in HPS patients with versus those without concomitant respiratory disease was lower: 63% versus 91% at 12 months and 63% versus 100% at 18 months (HR 95% CI .140-.995, p = .040). In addition to the presence of concomitant respiratory disease (p = .040), history of smoking (p = .012), and high baseline 99mTcMAA shunt fraction (≥20%) (p = .050) were significantly associated with persistent need of oxygen therapy. The 5-year estimated cumulative probability of mortality in patients with concomitant respiratory disease was worse: 50% versus 23% (HR 95% CI .416-6.867, p = .463). CONCLUSIONS: The presence of a concomitant respiratory disease did not increase the short-term postoperative mortality after LT in patients with HPS. However, it resulted in a longer need for oxygen therapy.

Histological characteristics in patients admitted to the hospital with alcoholic hepatitis complicated by acute-on-chronic liver failure.

OBJECTIVES: Alcoholic hepatitis (AH) is a frequent precipitating event for the development of acute-on-chronic liver failure (ACLF), a syndrome characterised by organ failures due to immune dysfunction. The histological features of this complication are not well characterized. We investigated whether ACLF has specific histological characteristics. METHODS: Prospective cohort study in consecutive adult patients admitted between 03-2008 and 04-2021 to a tertiary referral centre with suspected AH. Diagnosis of AH was based on clinical presentation and confirmed by transjugular liver biopsy. All biopsies were assessed by a dedicated liver pathologist, blinded for clinical data and outcome. Diagnosis of ACLF was based on EASL-CLIF criteria. Histological and clinical characteristics of patients with and without ACLF at baseline were compared. RESULTS: 184 patients with biopsy-proven AH were enrolled. Median time from hospital admission to transjugular biopsy was 4.5 days (IQR 2-8). At baseline, ACLF was present in 73 patients (39.7%). Out of the 110 patients without ACLF at baseline, 30 (27.3%) developed ACLF within 28 days (median 7.5 days (IQR 2-20)). At baseline, ductular bilirubinostasis (DB) was the only histological feature significantly more frequently present in patients with ACLF compared to patients without ACLF (50.7% vs. 30.6%, p = 0.003). No clear association between histological features and the development of ACLF later on could be demonstrated. CONCLUSIONS: In this well-defined cohort of patients with biopsy-proven AH, DB was associated with the presence of ACLF. This finding fits with the pathophysiology of this syndrome, which is characterized by systemic inflammation and an increased risk of infections.

Tacrolimus Drug Exposure Level and Smoking Are Modifiable Risk Factors for Early De Novo Malignancy After Liver Transplantation for Alcohol-Related Liver Disease.

De novo malignancy (DNM) is the primary cause of mortality after liver transplantation (LT) for alcohol-related liver disease (ALD). However, data on risk factors for DNM development after LT are limited, specifically in patients with ALD. Therefore, we retrospectively analyzed all patients transplanted for ALD at our center before October 2016. Patients with a post-LT follow-up of <12 months, DNM within 12 months after LT, patients not on tacrolimus in the 1st year post-LT, and unknown smoking habits were excluded. Tacrolimus drug exposure level (TDEL) was calculated by area under the curve of trough levels in the 1st year post-LT. 174 patients received tacrolimus of which 19 (10.9%) patients developed a DNM between 12 and 60 months post-LT. Multivariate cox regression analysis identified TDEL [HR: 1.710 (1.211-2.414); p = 0.002], age [1.158 (1.076-1.246); p < 0.001], number of pack years pre-LT [HR: 1.021 (1.004-1.038); p = 0.014] and active smoking at LT [HR: 3.056 (1.072-8.715); p = 0.037] as independent risk factors for DNM. Tacrolimus dose minimization in the 1st year after LT and smoking cessation before LT might lower DNM risk in patients transplanted for ALD.

SARS-CoV-2 vaccine antibody response and breakthrough infections in transplant recipients.

Rates and modulators of SARS-CoV-2 vaccine nonresponse and breakthrough infections remain unclear in serially vaccinated transplant recipients. In a prospective, mono-centric, observational study, 1878 adult solid organ and hematopoietic cell transplant recipients, with prior SARS-CoV-2 vaccination, were included between March 2021 and February 2022. SARS-CoV-2 anti-spike IgG antibodies were measured at inclusion and details on SARS-CoV-2 vaccine doses and infection were collected. No life-threatening adverse events were reported after a total of 4039 vaccine doses. In transplant recipients without prior SARS-CoV-2 infection (n = 1636), antibody response rates ranged widely, from 47% in lung transplant to 90% in liver transplant and 91% in hematopoietic cell transplant recipients after third vaccine dose. Antibody positivity rate and levels increased after each vaccine dose in all types of transplant recipients. In multivariable analysis, older age, chronic kidney disease and daily dose of mycophenolate and corticosteroids were negatively associated with antibody response rate. Overall rate of breakthrough infections was 25.2% and mainly (90.2%) occurred after third and fourth vaccine dose. Lung transplant recipients had the highest rates of severe breakthrough infection (10.5%) and death (2.5%). In multivariable analysis, older age, daily dose of mycophenolate and corticosteroids were associated with severe breakthrough infection. Transplant recipients with infection before first vaccine dose (n = 160) had higher antibody response rates and levels after each vaccine dose, and a significantly lower overall rate of breakthrough infections compared to those without prior infection. Antibody response after SARS-CoV-2 vaccination and rate of severe breakthrough infections vary largely between different transplant types and are modulated by specific risk factors. The observed heterogeneity supports a tailored approach against COVID-19 in transplant recipients.

Utility and prognostic value of diagnosing MAFLD in patients undergoing liver transplantation for alcohol-related liver disease.

BACKGROUND: Recently, the term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed to replace non-alcoholic fatty liver disease (NAFLD). This concept enables diagnosing liver disease associated with metabolic dysfunction in patients with alcohol-related liver disease (ALD), a main indication for liver transplantation (LTx). We assessed MAFLD prevalence in ALD patients undergoing LTx and its prognostic value on post-LTx outcomes. METHODS: We retrospectively analyzed all ALD patients transplanted at our center between 1990 and August 2020. MAFLD was diagnosed based on the presence or history of hepatic steatosis and a BMI > 25 or type II diabetes or ≥ 2 metabolic risk abnormalities at LTx. Overall survival and risk factors for recurrent liver and cardiovascular events were analyzed by Cox regression. RESULTS: Of the 371 included patients transplanted for ALD, 255 (68.7%) had concomitant MAFLD at LTx. Median follow-up post-LTx was 72 months (IQR: 34.50-122). Patients with ALD-MAFLD were older at LTx (p = .001), more often male (p < .001) and more frequently had hepatocellular carcinoma (p < .001). No differences in perioperative mortality and overall survival were found. ALD-MAFLD patients had an increased risk of recurrent hepatic steatosis, irrespective of alcohol relapse, but no superimposed risk of cardiovascular events. CONCLUSIONS: The co-presence of MAFLD at LTx for ALD is associated with a distinct patient profile and is an independent risk factor for recurrent hepatic steatosis. The use of MAFLD criteria in ALD patients might increase awareness and treatment of specific hepatic and systemic metabolic abnormalities before and after LTx.

Hepatobiliary phenotypes of adults with alpha-1 antitrypsin deficiency.

OBJECTIVE: Alpha-1 antitrypsin deficiency (AATD) is a common, potentially lethal inborn disorder caused by mutations in alpha-1 antitrypsin (AAT). Homozygosity for the 'Pi*Z' variant of AAT (Pi*ZZ genotype) causes lung and liver disease, whereas heterozygous 'Pi*Z' carriage (Pi*MZ genotype) predisposes to gallstones and liver fibrosis. The clinical significance of the more common 'Pi*S' variant remains largely undefined and no robust data exist on the prevalence of liver tumours in AATD. DESIGN: Baseline phenotypes of AATD individuals and non-carriers were analysed in 482 380 participants in the UK Biobank. 1104 participants of a multinational cohort (586 Pi*ZZ, 239 Pi*SZ, 279 non-carriers) underwent a comprehensive clinical assessment. Associations were adjusted for age, sex, body mass index, diabetes and alcohol consumption. RESULTS: Among UK Biobank participants, Pi*ZZ individuals displayed the highest liver enzyme values, the highest occurrence of liver fibrosis/cirrhosis (adjusted OR (aOR)=21.7 (8.8-53.7)) and primary liver cancer (aOR=44.5 (10.8-183.6)). Subjects with Pi*MZ genotype had slightly elevated liver enzymes and moderately increased odds for liver fibrosis/cirrhosis (aOR=1.7 (1.2-2.2)) and cholelithiasis (aOR=1.3 (1.2-1.4)). Individuals with homozygous Pi*S mutation (Pi*SS genotype) harboured minimally elevated alanine aminotransferase values, but no other hepatobiliary abnormalities. Pi*SZ participants displayed higher liver enzymes, more frequent liver fibrosis/cirrhosis (aOR=3.1 (1.1-8.2)) and primary liver cancer (aOR=6.6 (1.6-26.9)). The higher fibrosis burden was confirmed in a multinational cohort. Male sex, age ≥50 years, obesity and the presence of diabetes were associated with significant liver fibrosis. CONCLUSION: Our study defines the hepatobiliary phenotype of individuals with the most relevant AATD genotypes including their predisposition to liver tumours, thereby allowing evidence-based advice and individualised hepatological surveillance.

Fibrates for Itch (FITCH) in Fibrosing Cholangiopathies: A Double-Blind, Randomized, Placebo-Controlled Trial.

BACKGROUND AND AIMS: Pruritus may seriously impair quality of life in patients with cholestatic diseases such as primary or secondary sclerosing cholangitis (PSC, SSC) and primary biliary cholangitis (PBC). Pharmacologic strategies show limited efficacy and can provoke serious side effects. We hypothesized that bezafibrate, a broad peroxisome proliferator-activated receptor (PPAR) agonist, relieves cholestasis-associated itch by alleviating hepatobiliary injury. The aim of this investigator-initiated FITCH trial (Fibrates for cholestatic ITCH) was to assess effects of bezafibrate on pruritus in patients with PSC, PBC, and SSC. METHODS: Patients with moderate to severe pruritus (≥5 of 10 on visual analog scale [VAS]) due to PSC, PBC, or SSC were recruited for this double-blind, randomized, placebo-controlled trial between 2016 and 2019. Patients received once-daily bezafibrate (400 mg) or placebo for 21 days. The primary end point was ≥50% reduction of pruritus (VAS; intention-to-treat). RESULTS: Of 74 randomized patients, 70 completed the trial (95%; 44 PSC, 24 PBC, 2 SSC). For the primary end point, bezafibrate led in 45% (41% PSC, 55% PBC) and placebo in 11% to ≥50% reduction of severe or moderate pruritus (P = .003). For secondary end points, bezafibrate reduced morning (P = .01 vs placebo) and evening (P = .007) intensity of pruritus (VAS) and improved the validated 5D-Itch questionnaire (P = .002 vs placebo). Bezafibrate also reduced serum alkaline phosphatase (-35%, P = .03 vs placebo) correlating with improved pruritus (VAS, P = .01) suggesting reduced biliary damage. Serum bile acids and autotaxin activity remained unchanged. Serum creatinine levels tended to mildly increase (3% bezafibrate, 5% placebo, P = .14). CONCLUSIONS: Bezafibrate is superior to placebo in improving moderate to severe pruritus in patients with PSC and PBC. TRIAL REGISTRATION: Netherlands Trial Register, ID: NTR5436 (August 3, 2015), ClinicalTrials.gov ID: NCT02701166 (March 2, 2016).

Telemedicine based remote monitoring after liver transplantation: Feasible in a select group and a more stringent control of immunosuppression.

Telemedicine gained interest in liver transplant patients but focused until now on the early post-operative period. This prospective cohort study assessed feasibility, safety, and clinical beneficial effects of a telemedicine based remote monitoring program (TRMP) for the chronic follow-up of adult liver transplant recipients. Between November 2017 and August 2019, a total of 87 of the 115 selected patients (76%) started the TRMP. Over the 2 years study period, none of the patients switched to standard follow-up: 39/87 (45%) continued to do this autonomously and 48/87 (55%) stopped to report their data personally but communicated their lab values to the nurse. The other 28/115 (11%) patients who did not accept the TRMP continued the standard follow-up. There was no difference in educational level between the three groups. Remote monitoring did not result in an increase in liver graft rejection and need of hospitalization. TRMP was associated with a higher number of tacrolimus level determinations and tacrolimus blood level concentrations could be kept lower. In conclusion, our results show that in patients with a stable clinical condition there is a high willingness to participate in TRMP and that this approach is safe. Remote monitoring allowed a stringent follow-up of tacrolimus levels.

Absorption of nonheme iron during gastric acid suppression in patients with hereditary hemochromatosis and healthy controls.

Phlebotomies are performed in hereditary hemochromatosis (HH) to maintain normal iron concentrations. Proton-pump inhibitors (PPIs) can reduce the number of phlebotomies in patients with HH. However, in patients without HH, the iron concentrations do not appear to be compromised when using PPIs. Therefore, we aim to explain the differences in iron absorption between patients with and without HH. In 10 p.cysteine282tyrosine (p.C282Y) homozygous HH patients with normalized iron stores and 10 healthy control subjects (HCs), the iron parameters and hepcidin concentrations were determined before ingestion of a pharmacological dose of 50 mg iron [ferric iron (Fe3+)] polymaltose and hourly for 4 h afterward. This was repeated after 7 days of treatment with pantoprazole 40 mg once daily. Serum iron concentrations and transferrin saturation percentages dropped significantly during PPI use in the patients with HH, whereas no changes were observed in the HCs. Hepcidin concentrations were lower in the patients with HH compared with the HCs both before and during PPI use. In both groups, hepcidin levels did not significantly decrease during the treatment. Seven-day PPI use significantly reduces iron absorption in patients with HH but not in HCs. Changes in hepcidin concentrations could not explain these different PPI effects on iron absorption probably due to a small sample size.NEW & NOTEWORTHY This study confirms that lowering gastric acidity by proton pump inhibitors results in a reduction in iron absorption in patients with hemochromatosis and not in healthy control subjects. The presupposition that a decrease in hepcidin concentration in healthy control subjects in response to lowering gastric acidity can explain the difference in iron absorption between these groups could not be confirmed probably because of a small sample size.

Liver Phenotypes of European Adults Heterozygous or Homozygous for Pi∗Z Variant of AAT (Pi∗MZ vs Pi∗ZZ genotype) and Noncarriers.

BACKGROUND & AIMS: Homozygosity for the Pi∗Z variant of the gene that encodes the alpha-1 antitrypsin peptide (AAT), called the Pi∗ZZ genotype, causes a liver and lung disease called alpha-1 antitrypsin deficiency. Heterozygosity (the Pi∗MZ genotype) is a risk factor for cirrhosis in individuals with liver disease. Up to 4% of Europeans have the Pi∗MZ genotype; we compared features of adults with and without Pi∗MZ genotype among persons without preexisting liver disease. METHODS: We analyzed data from the European Alpha-1 Liver Cohort, from 419 adults with the Pi∗MZ genotype, 309 adults with the Pi∗ZZ genotype, and 284 individuals without the variant (noncarriers). All underwent a comprehensive evaluation; liver stiffness measurements (LSMs) were made by transient elastography. Liver biopsies were analyzed to define histologic and biochemical features associated with the Pi∗Z variant. Levels of serum transaminases were retrieved from 444,642 participants, available in the United Kingdom biobank. RESULTS: In the UK biobank database, levels of serum transaminases were increased in subjects with the Pi∗MZ genotype compared with noncarriers. In the Alpha-1 Liver Cohort, adults with Pi∗MZ had lower levels of gamma-glutamyl transferase in serum and lower LSMs than adults with the Pi∗ZZ variant, but these were higher than in noncarriers. Ten percent of subjects with the Pi∗MZ genotype vs 4% of noncarriers had LSMs of 7.1 kPa or more (adjusted odds ratio, 4.8; 95% confidence interval, 2.0-11.8). Obesity and diabetes were the most important factors associated with LSMs ≥7.1 kPa in subjects with the Pi∗MZ genotype. AAT inclusions were detected in liver biopsies of 63% of subjects with the Pi∗MZ genotype, vs 97% of subjects with the Pi∗ZZ genotype, and increased with liver fibrosis stages. Subjects with the Pi∗MZ genotype did not have increased hepatic levels of AAT, whereas levels of insoluble AAT varied among individuals. CONCLUSIONS: Adults with the Pi∗MZ genotype have lower levels of serum transaminases, fewer AAT inclusions in liver, and lower liver stiffness than adults with the Pi∗ZZ genotype, but higher than adults without the Pi∗Z variant. These findings should help determine risk of subjects with the Pi∗MZ genotype and aid in counseling.

The effect of universal infant vaccination on the prevalence of hepatitis B immunity in adult solid organ transplant candidates.

BACKGROUND: Hepatitis B virus (HBV) immunity is recommended to optimize outcomes after solid organ transplantation (SOT). This study assessed the prevalence and predictors of HBV immunity at the time patients were placed on transplant waiting list over a period from 1997 to 2019 in a low HBV endemic region. METHODS: Data were obtained from the University Hospitals Leuven transplant database. Minors and patients with past/current HBV infection were excluded. From 1986, Belgian patients are covered by the universal infant vaccination; therefore, birth cohort was stratified in those born ≥1986 vs <1986. RESULTS: The study population consisted of 3297 SOT candidates. HBV immunity rate was superior in renal transplant candidates (55.3%), and this number was 21.5%, 15.4% and 16.8% for liver, cardiac and pulmonary transplant candidates, respectively, P < .001. Among liver transplant candidates, HBV immunity rate was 14.8% in decompensated cirrhotic patients and 27.9% in those without advanced cirrhosis (P < .001). The overall immunity rate increased from 19.3% in period 1997-2008 to 32.8% in 2009-2019, P < .001. In multivariable analyses, younger age (odds ratio (OR) 95% confidence interval (CI): 0.97-0.98, P < .001) and birth cohort ≥ 1986 (OR 95% CI: 1.18-2.66, P = .006) were associated with increased HBV immunity. CONCLUSION: An increase in HBV immunity was observed over a 20-year period related to the introduction of universal infant HBV vaccination. Nevertheless, this study highlights the low overall HBV immunity at the time of listing for organ transplantation and points out the need of an increased awareness and vaccination strategy at an early disease stage.

Diagnostic Accuracy of Biomarkers of Alcohol Use in Patients With Liver Disease: A Systematic Review.

BACKGROUND AND AIMS: Alcohol-related liver disease is the most frequent cause of cirrhosis and a major indication for liver transplantation. Several alcohol use biomarkers have been developed in recent years and are already in use in several centers. However, in patients with liver disease their diagnostic performance might be influenced by altered biomarker formation by hepatic damage, altered excretion by kidney dysfunction and diuretics use, and altered deposition in hair and nails. We systematically reviewed studies on the diagnostic accuracy of biomarkers of alcohol use in patients with liver disease and performed a detailed study quality assessment. METHODS: A structured search in PubMed/Medline/Embase databases was performed for relevant studies, published until April 28, 2019. The risk of bias and applicability concerns was assessed according to the adapted quality assessment of diagnostic accuracy studies-2 (QUADAS-2) checklist. RESULTS: Twelve out of 6,449 studies met inclusion criteria. Urinary ethyl glucuronide and urinary ethyl sulfate showed high sensitivity (70 to 89 and 73 to 82%, respectively) and specificity (93 to 99 and 86 to 89%, respectively) for assessing any amount of alcohol use in the past days. Serum carbohydrate-deficient transferrin showed low sensitivity but higher specificity (40 to 79 and 57 to 99%, respectively) to detect excessive alcohol use in the past weeks. Whole blood phosphatidylethanol showed high sensitivity and specificity (73 to 100 and 90 to 96%, respectively) to detect any amount of alcohol use in the previous weeks. Scalp hair ethyl glucuronide showed high sensitivity (85 to 100%) and specificity (97 to 100%) for detecting chronic excessive alcohol use in the past 3 to 6 months. Main limitations of the current evidence are the lack of an absolute gold standard to assess alcohol use, heterogeneous study populations, and the paucity of studies. CONCLUSIONS: Urinary and scalp hair ethyl glucuronide are currently the most validated alcohol use biomarkers in patients with liver disease with good diagnostic accuracies. Phosphatidylethanol is a highly promising alcohol use biomarker, but so far less validated in liver patients. Alcohol use biomarkers can complement each other regarding diagnostic time window. More validation studies on alcohol use biomarkers in patients with liver disease are needed.

Review and gap analysis: molecular pathways leading to fetal alcohol spectrum disorders.

Alcohol exposure during pregnancy affects the development of the fetus in various ways and may lead to Fetal Alcohol Spectrum Disorders (FASD). FASD is one of the leading preventable forms of neurodevelopmental disorders. In the light of prevention and early intervention, knowledge on how ethanol exposure induces fetal damage is urgently needed. Besides direct ethanol and acetaldehyde toxicity, alcohol increases oxidative stress, and subsequent general effects (e.g., epigenetic imprinting, gene expression, and metabolite levels). The current review provides an overview of the existing knowledge about specific downstream pathways for FASD that affects e.g., the SHH pathway, cholesterol homeostasis, neurotransmitter signaling, and effects on the cytoskeleton. Available human data vary greatly, while animal studies with controlled ethanol exposition are only to a certain limit transferable to humans. The main deficits in knowledge about FASD are the lack of pathophysiological understanding and dose-response relationships, together with the lack of reliable biomarkers for either FASD detection or estimation of susceptibility. In addition to single outcome experiments, omics data should be generated to overcome this problem. Therefore, for future studies we recommend holistic data driven analysis, which allows integrative analyses over multiple levels of genetic variation, transcriptomics and metabolomics data to investigate the whole image of FASD development and to provide insight in potential drug targets for intervention.

Intestinal permeability in human nonalcoholic fatty liver disease: A systematic review and meta-analysis.

BACKGROUND: The gut-liver axis is considered to play a critical role in the development and progression of nonalcoholic fatty liver disease (NAFLD). The integrity of the epithelial barrier is crucial to protect the liver against the invasion of microbial products from the gut, although its exact role in NAFLD onset and progression is not clear. METHODS: We performed a systematic review and meta-analysis of studies that addressed the intestinal permeability (IP) in association with NAFLD presence or severity as defined by the presence of nonalcoholic steatohepatitis (NASH) and the degree of steatosis, hepatic inflammation or fibrosis. A total of 14 studies were eligible for inclusion. RESULTS: Studies investigating IP in adult (n = 6) and paediatric (n = 8) NAFLD showed similar results. Thirteen of the included studies focussed on small IP, two studies on whole gut permeability and none on colonic permeability. In the pooled analysis, NAFLD patients showed an increased small intestinal permeability compared to healthy controls based on dual sugar tests (standardized mean difference 0.79, 95% CI 0.49-1.08) and serum zonulin levels (standardized mean difference 1.04 ng/mL, 95% CI 0.40-1.68). No clear difference in IP was observed between simple steatosis and NASH patients. Furthermore, whole gut and small intestinal permeability increased with the degree of hepatic steatosis in 4/4 studies, while no association with hepatic inflammation or fibrosis was observed. CONCLUSION: Based on the limited number of studies available, IP appears to be increased in NAFLD patients compared to healthy controls and is associated with the degree of hepatic steatosis.

The Role of Brown Adipose Tissue in the Development and Treatment of Nonalcoholic Steatohepatitis: An Exploratory Gene Expression Study in Mice.

Brown adipose tissue (BAT) might be a beneficial mediator in the development and treatment of nonalcoholic steatohepatitis (NASH). We aim to evaluate the gene expression of BAT activity-related genes during the development and the dietary and surgical treatment of NASH. BAT was collected from male C57BL/6J mice that received a high fat-high sucrose diet (HF-HSD) or a normal chow diet (NCD) for 4 and 20 weeks (n=8-9 per dietary group and timepoint) and from mice that underwent dietary intervention (return to NCD) (n=8), roux-en-y gastric bypass (RYGB) (n=6), or sham procedure (n=6) after 12 weeks HF-HSD. Expression of BAT genes involved in lipid metabolism (Cd36 and Cpt1b; p<0.05) and energy expenditure (Ucp1 and Ucp3; p<0.05) were significantly increased after 4 weeks HF-HSD compared with NCD, whereas in the occurrence of NASH after 20 weeks HF-HSD no difference was observed. We observed no differences in gene expression regarding lipid metabolism or energy expenditure at 8 weeks after dietary intervention (no NASH) compared with HF-HSD mice (NASH), nor in mice that underwent RYGB compared with SHAM. However, dietary intervention and RYGB both decreased the BAT gene expression of inflammatory cytokines (Il1b, Tnf-α and MCP-1; p<0.05). Gene expression of the batokine neuregulin 4 was significantly decreased after 20 weeks HF-HSD (p<0.05) compared with NCD, but was restored by dietary intervention and RYGB (p<0.05). In conclusion, BAT is hallmarked by dynamic alterations in the gene expression profile during the development of NASH and can be modulated by dietary intervention and bariatric surgery.