Increased Frequency of Heterozygous Alpha-1-Antitrypsin Deficiency in Liver Explants From Nonalcoholic Steatohepatitis Patients

Presence of Alpha 1 Antitrypsin Risk Variants is Not Associated With Histologic Severity of Pediatric NAFLD

BACKGROUND

Among adults with nonalcoholic fatty liver disease (NAFLD), alpha-1-antitrypsin (A1AT) heterozygosity has been linked to advanced liver disease; pediatric data remain unclear.

OBJECTIVE

The objective of this study is to determine whether A1AT PiZ or PiS variants are associated with liver disease severity in youth with NAFLD.

METHODS

Retrospective study of youth with confirmed NAFLD. Multivariable logistic regression used to determine independent associations between A1AT risk variants and histologic severity [NAFLD activity score (NAS) ≥5 and/or significant fibrosis (stage ≥2)].

RESULTS

The cohort included 269 patients, mean age 12 [±3] years with NAFLD and A1AT phenotyping (n = 260) and/or A1AT levels (n = 261). The mean NAS of the cohort was 4.2 [±1.5]; 50% had any, and 18% had significant fibrosis. Most (86%) had the MM A1AT phenotype, while 7% had the MS and 3% the MZ phenotype (the rest had other, nonpathogenic variants). Mean A1AT level was 123 mg/dL [±20]. A1AT levels did not differ by low versus high NAS (122 ± 2 vs 126 ± 19 mg/dL, P = 0.12) or by no/mild versus significant fibrosis (123 ± 20 vs 126 ± 20 mg/dL, P = 0.23, respectively). Carriers and noncarriers of the PiS or PiZ variants had similar NAS (mean NAS 3.8 ± 1.6 vs 4.2 ± 1.4; P = 0.25, respectively). Fibrosis severity did not differ by carrier vs noncarrier group: 38% versus 52% had any fibrosis ( P = 0.17) and 14% versus 18% had significant fibrosis ( P = 0.80, respectively). Multivariable modeling showed no association between A1AT risk variants and histologic severity.

CONCLUSION

While not uncommon, carriage of the A1AT PiZ or PiS risk variants was not associated with histologic severity in children with NAFLD.

NAFLD and AATD Are Two Diseases with Unbalanced Lipid Metabolism: Similarities and Differences

Non-alcoholic fatty liver disease (NAFLD) is a type of steatosis commonly associated with obesity, dyslipidemia, hypertension, and diabetes. Other diseases such as inherited alpha-1 antitrypsin deficiency (AATD) have also been related to the development of liver steatosis. The primary reasons leading to hepatic lipid deposits can be genetic and epigenetic, and the outcomes range from benign steatosis to liver failure, as well as to extrahepatic diseases. Progressive hepatocellular damage and dysregulated systemic immune responses can affect extrahepatic organs, specifically the heart and lungs. In this review, we discuss the similarities and differences between the molecular pathways of NAFLD and AATD, and the putative value of hepatic organoids as novel models to investigate the physio pathological mechanisms of liver steatosis.

Characterization of hepatic inflammatory changes in a C57BL/6J mouse model of alpha1-antitrypsin deficiency

Alpha-1 antitrypsin deficiency (AATD) is a genetic disease caused by a hepatic accumulation of mutant alpha-1 antitrypsin (ZAAT). Individuals with AATD are prone to develop a chronic liver disease that remains undiagnosed until late stage of the disease. Here, we sought to characterize the liver pathophysiology of a human transgenic mouse model for AATD with a manifestation of liver disease compared with normal transgenic mice model. Male and female transgenic mice for normal (Pi*M) and mutant variant (Pi*Z) human alpha-1 antitrypsin at 3 and 6 mo of age were subjected to this study. The progression of hepatic ZAAT accumulation, hepatocyte injury, steatosis, liver inflammation, and fibrotic features were monitored by performing an in vivo study. We have also performed a Next-Gene transcriptomic analysis of the transgenic mice liver tissue 16 h after lipopolysaccharide (LPS) administration to delineate liver inflammatory response in Pi*Z mice as compared with Pi*M. Our results show hepatic ZAAT accumulation, followed by hepatocyte ballooning and liver steatosis developed at 3 mo in Pi*Z mice compared with the mice carrying normal variant of human alpha-1 antitrypsin. We observed higher levels of hepatic immune cell infiltrations in both 3- and 6-mo-old Pi*Z mice compared with Pi*M as an indication of liver inflammation. Liver fibrosis was observed as accumulation of collagen in 6-mo-old Pi*Z liver tissues compared with Pi*M control mice. Furthermore, the transcriptomic analysis revealed a dysregulated liver immune response to LPS in Pi*Z mice compared with Pi*M. Of particular interest for translational work, this study aims to establish a mouse model of AATD with a strong manifestation of liver disease that will be a valuable in vivo tool to study the pathophysiology of AATD-mediated liver disease. Our data suggest that the human transgenic mouse model of AATD could provide a suitable model for the evaluation of therapeutic approaches and preventive reagents against AATD-mediated liver disease.NEW & NOTEWORTHY We have characterized a mouse model of human alpha-1 antitrypsin deficiency with a strong manifestation of liver disease that can be used as an in vivo tool to test preventive and therapeutic reagents. Our data explores the altered immunophenotype of alpha-1 antitrypsin-deficient liver macrophages and suggests a relationship between acute inflammation, immune response, and fibrosis.

Alpha-1 antitrypsin deficiency is under-recognized in individuals with cirrhosis undergoing liver transplantation

OBJECTIVE

Under-recognition of alpha-1 antitrypsin deficiency (AATD) is well documented in AATD-lung disease but is rarely reported in patients with liver cirrhosis requiring liver transplantation. This report examines the frequency of newly diagnosed AATD based on pathologic examination of explanted livers following liver transplantation, trends in diagnosis over time, and prognostic correlates of under-recognition outcomes following liver transplantation.

METHODS

This study retrospectively reviewed 1473 pathology reports from adult patients (>18 years) undergoing liver transplantation at Cleveland Clinic between 2004 and 2017. Pathology reports of explanted livers exhibiting periodic acid-Schiff, diastase-resistant inclusion bodies (PAS+G) suggestive of AATD were included and medical records were reviewed regarding demographics, AATD genotype, alternative etiologies for cirrhosis, presence of emphysema, and survival outcomes. Kaplan-Meier estimates of survival outcomes were compared between patients diagnosed pre-liver transplantation and that newly diagnosed post-liver transplantation.

RESULTS

Of 1473 explanted liver pathology reports examined, 117 (7.9%) showed PAS+G suggestive of AATD. The diagnosis of AATD in these 117 patients was established pre-liver transplantation in 36 (30.8%, group 1) and in 46 (39.3%) post-liver transplantation (group 2a). Testing for AATD was not undertaken in 35 (29.9%) of patients despite having PAS+G on explanted livers (group 2b). Post-liver transplantation survival analysis showed a trend (P = 0.098) towards enhanced survival in group 1 vs. group 2 at 10 years.

CONCLUSIONS

This study shows that diagnosis of AATD is overlooked and frequently delayed in patients with cirrhosis undergoing liver transplantation. The observed trend towards higher survival in patients diagnosed with AATD pre-liver transplantation suggests the opportunity to enhance outcomes by earlier recognition of AATD.

Prevalence and clinical characteristics of alpha-1 antitrypsin deficiency in liver explants in a Mexican cohort

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is a risk factor for liver disease. PASD-positive inclusions have been found unexpectedly in approximately 10% of liver explants in patients with no previous diagnosis of AATD, particularly, in patients with non-alcoholic steatohepatitis (NASH), supporting a synergistic mechanism of liver injury between AATD and environmental factors. We aimed to determine the clinical characteristics of mestizo patients in which AATD was diagnosed before or after liver transplantation.

METHODS

Liver explants of patients with cryptogenic, alcoholic, and NAFLD/NASH cirrhosis undergoing orthotopic liver transplantation (OLT) were included. Liver histopathology was assessed by two expert pathologists. Hematoxylin and eosin staining, PASD staining, and confirmatory AAT immunohistochemistry were performed. In explants with positive histopathology, genotyping for SERPINA1 was performed.

RESULTS

A total of 180 liver transplants were performed during the study period. Of these, 44 patients with cryptogenic cirrhosis, NASH, and alcoholic cirrhosis were included. Of these patients, two liver explants (4.5%) had PASD-positive inclusions stain and confirmatory immunochemistry. During the period evaluated, another two patients with a diagnosis of AATD before the OLT were also included. The four patients had overweight or obesity, three had type 2 diabetes mellitus, and two developed liver steatosis after the OLT.

CONCLUSION

AATD was found to be an infrequent finding in patients with cryptogenic, NASH/NAFLD, and alcoholic cirrhosis in our population. However, it is important to consider this entity as it may represent an additional factor in the appearance and progression of liver fibrosis in patients with metabolic syndrome.

Identification of Protein Expression Changes in Hepatocellular Carcinoma through iTRAQ

Background

Hepatocellular carcinoma (HCC) is a malignant tumor associated with a poor prognosis. Serum biomarkers of HCC have the potential to improve the diagnosis, provide a means to monitor the tumors, and predict their malignancy. Proteins that are expressed differentially between HCC patients and normal controls have the potential to be biomarkers.

Method

Serum samples from 10 confirmed HCC patients and 10 controls were collected. The differentially expressed proteins in the serum were identified using an isobaric tags for relative and absolute quantitation- (iTRAQ-) based method. Potential serum biomarkers were validated by ELISA in another 20 HCC patients and 20 controls. Their expression data in HCC were extracted from The Cancer Genome Atlas (TCGA) dataset.

Results

A total of 260 proteins were measured in the serum of HCC patients and compared to those in sex- and age-matched normal controls. Forty-one proteins displayed significant changes, with 26 being downregulated and 15 being upregulated. Upregulated proteins included alpha-1-antitrypsin (A1AT) and peroxiredoxin 2 (PRDX2), and downregulated proteins included paraoxonase 1 (PON1) and C-reactive protein (CRP). We then used ELISA to measure serum levels of A1AT, PRDX2, PON1, and CRP in another 20 patients with HCC and found that only PON1 levels were consistent with the iTRAQ result. In TCGA dataset, PON1 expression was downregulated in HCC tissues (P < 0.001) and low expression of PON1 was associated with poor survival in HCC patients (P < 0.001) and low expression of PON1 was associated with poor survival in HCC patients (

Conclusions

PON1 could act as a biomarker for HCC to assist in the diagnosis of HCC.