Alpha-1 antitrypsin Pi∗Z allele is an independent risk factor for liver transplantation and death in patients with advanced chronic liver disease

Early detection of hepatobiliary involvement in cystic fibrosis: Biomarkers, radiologic methods, and genetic influences

Cystic fibrosis-related hepatobiliary involvement (CFHBI) is a term used to describe a spectrum of hepatobiliary involvement ranging from a transient elevation of transaminase levels to advanced cystic fibrosis-associated liver disease (aCFLD). While CFHBI is common among people with cystic fibrosis (PwCF), aCFLD is rare impacting only approximately 5%-10% of the CF population. After respiratory/cardiorespiratory issues and transplant-related complications, aCFLD is now the 4th leading cause of mortality among PwCF. Additionally, aCFLD is an independent predictor of all-cause mortality and is associated with significant morbidity. Despite this recognition, our ability to predict those patients at greatest risk for aCFLD, identify early aCFLD, and monitor the incremental progression of CFHBI is lacking. Here, we review the strengths and weaknesses of the common biomarkers and imaging modalities used in the evaluation and monitoring of CFHBI, as well as the current understanding of genetic modifiers related to aCFLD.

MetALD: Does it require a different therapeutic option?

New guidelines for the definitions of steatotic liver disease have named the entity of metabolic dysfunction and alcohol-associated liver disease (MetALD) as an overlap condition of metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-associated liver disease. There is a broad range of therapeutics in all stages of development for MASLD, but these therapeutics, in general, have not been studied in patients with significant ongoing alcohol use. In this review, we discuss the current understanding of the endogenous and exogenous risks for MASLD and MetALD. Rational strategies for therapeutic intervention in MetALD include biopsychosocial interventions, alcohol use cessation strategies, including the use of medications for alcohol use disorder, and judicious use of therapeutics for steatotic liver disease. Therapeutics with promise for MetALD include incretin-based therapies, FGF21 agonists, thyroid hormone receptor beta agonists, sodium-glucose co-transporter 2 inhibitors, and agents to modify de novo lipogenesis. Currently, glucagon-like peptide 1 receptor agonists and peroxisome proliferator-activated receptor γ agonists have the largest body of literature supporting their use in MASLD, and there is a paucity of agents in trials for alcohol-associated liver disease. From existing studies, it is not clear if unique therapeutics or a combinatorial approach are needed for MetALD. Further elucidation of the safety and benefits of MASLD-related therapies is of paramount importance for advancing therapeutics for MetALD in carefully designed inclusive clinical trials.

Review article: New developments in biomarkers and clinical drug development in alpha-1 antitrypsin deficiency-related liver disease

BACKGROUND

Alpha-1 antitrypsin liver disease (AATLD) occurs in a subset of patients with alpha-1 antitrypsin deficiency. Risk factors for disease progression and specific pathophysiologic features are not well known and validated non-invasive assessments for disease severity are lacking. Currently, there are no approved treatments for AATLD.

AIMS

To outline existing understanding of AATLD and to identify knowledge gaps critical to improving clinical trial design and development of new treatments.

METHODS

This report was developed following a multi-stakeholder forum organised by the Alpha-1 Antitrypsin Deficiency Related Liver Disease Expert Panel in which experts presented an overview of the available literature on this topic.

RESULTS

AATLD results from a 'gain of toxic function' and primarily manifests in those with the homozygous Pi*ZZ genotype. Accumulation of misfolded 'Z' AAT protein in liver cells triggers intracellular hepatocyte injury which may ultimately lead to hepatic fibrosis. Male gender, age over 50 years, persistently elevated liver tests, concomitant hepatitis B or C virus infection, and metabolic syndrome, including obesity and type 2 diabetes mellitus, are known risk factors for adult AATLD. While the gold standard for assessing AATLD disease activity is liver histology, less invasive measures with low intra- and inter-observer variability are needed. Measurement of liver stiffness shows promise; validated thresholds for staging AATLD are in development. Such advances will help patients by enabling risk stratification and personalised surveillance, along with streamlining the development process for novel therapies.

CONCLUSIONS

This inaugural forum generated a list of recommendations to address unmet needs in the field of AATLD.

The polymorphic variant of SerpinB3 (SerpinB3-PD) is associated with faster cirrhosis decompensation

BACKGROUND

SerpinB3 is a cysteine protease inhibitor involved in liver disease progression due to its proinflammatory and profibrogenic properties. The polymorphic variant SerpinB3-PD (SB3-PD), presents a substitution in its reactive centre loop, determining the gain of function.

AIMS

To disclose the clinical characteristics of a cohort of patients with cirrhosis in relation to the presence of SB3-PD and to assess the effect of this genetic variant on fibrogenic and inflammatory cytokines in vitro.

METHODS

We assessed SB3 polymorphism in 90 patients with cirrhosis, prospectively followed up in our referral centre. We used HepG2 and HuH-7 cells transfected to overexpress either wild-type SB3 (SB3-WT) or SB3-PD to assess their endogenous effect, while LX2 and THP-1 cells were treated with exogenous SB3-WT or SB3-PD proteins.

RESULTS

Patients carrying SB3-PD had more severe portal hypertension and higher MELD scores, than patients carrying SB3-WT. In multivariate analysis, SB3-PD was an independent predictor of cirrhosis complications. Patients with SB3-PD polymorphism presented with more severe liver fibrosis and inflammatory features. Hepatoma cells overexpressing SB3-PD showed higher TGF-β1 expression than controls. The addition of recombinant SB3-PD induced an up-regulation of TGF-β1 in LX2 cells and a more prominent inflammatory profile in THP-1 cells, compared to the effect of SB3-WT protein.

CONCLUSIONS

The polymorphic variant SB3-PD is highly effective in determining activation of TGF-β1 and inflammation in vitro. Patients with cirrhosis who carry SB3-PD polymorphism may be more prone to develop severe liver disease progression. However, further validation studies are warranted to support the in vivo relevance of this polymorphism.

Future Perspectives in the Diagnosis and Treatment of Liver Disease Associated with Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is one of the most common genetic diseases and is caused by mutations in the SERPINA1 gene. The homozygous Pi*Z variant is responsible for the majority of the classic severe form of alpha-1 antitrypsin deficiency, which is characterized by markedly decreased levels of serum alpha-1 antitrypsin (AAT) with a strong predisposition to lung and liver disease. The diagnosis and early treatment of AATD-associated liver disease are challenges in clinical practice. In this review, the authors aim to summarize the current evidence of the non-invasive methods in the assessment of liver fibrosis, as well as to elucidate the main therapeutic strategies under investigation that may emerge in the near future.