Case report of a novel alpha1-antitrypsin null variant in Türkiye: Q0RİZE

BACKGROUND

Alpha1-antitrypsin (AAT) is a serine protease inhibitor that serves as a counterbalance to the activity of elastases, e.g., neutrophil elastase in lung tissue. AAT deficiency (AATD) is a rare disorder usually arising from mutations to the SERPINA1 gene that codes for AAT. The most common AATD alleles are S and Z which produce ~ 40% and ~ 90% reductions in serum AAT, respectively. Rare genetic variants (> 500 identified) can also be associated with mild to severe AATD.

RESULTS

This report describes a novel mutation of SERPINA1 producing AATD, which we have designated, Q0RİZE. This mutation was identified in a 44-year-old woman admitted with massive hemoptysis and treated with bronchial artery embolization. Computed tomography revealed centriacinar and panacinar emphysema with prominent air entrapment, atelectasis, and localized bronchiectasis. Serum AAT was < 0.27 g/L (below detection limit). Genetic analysis showed homozygous deletion of exons I to III.

CONCLUSIONS

Although many SERPINA1 variants have been identified, variants with large deletions and identified in a homozygous individual, as seen in this case with Q0RIZE, are uncommon. AATD is an underdiagnosed and undertreated disease. Wider screening of COPD patients could result in earlier diagnosis and treatment that could preserve lung function.

Alpha-1-Antitrypsin Pi*MZ variant increases risk of developing hepatic events in nonalcoholic fatty liver disease patients. Clin Res Hepatol Gastroenterol 2023;47:102066. [PMID: 36509354 DOI: 10.1016/j.clinre.2022.102066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

AIMS

Heterozygous alpha-1-antitrypsin (A1AT) Pi*MZ variant has been shown to increase the risk of developing liver cirrhosis in patients with non-alcoholic fatty liver disease (NAFLD). We aimed to determine the association between heterozygous Pi*MZ and Pi*MS variants and development of hepatic decompensation events in NAFLD patients.

METHODS

We included patients with NAFLD who also had A1AT genotyping performed from 2005 to 2020. We recorded demographic and clinical variables, and data on hepatic events (ascites, hepatic encephalopathy, esophageal variceal bleed, or hepatocellular carcinoma), if any. We performed binary logistic regression analysis to assess the association between A1AT variants and hepatic events, and calculated Odds ratio (OR) with their 95% confidence intervals (Cl).

RESULTS

We included 1532 patients with NAFLD, of which 1249 patients had Pi*MM, 121 had Pi*MS, and 162 had Pi*MZ. Of the 1532 patients, hepatic events developed in 521 (34%) patients. The percentage of patients with Pi*MZ variant was significantly higher in patients with hepatic events as compared to patients without hepatic events (18.7 % vs 8.1%, p<0.0001). Pi*MZ variant was noted to significantly increase the odds of developing hepatic events in NAFLD patients, unadjusted OR: 1.82 (1.3-2.5, p<0.001), adjusted OR (for age, sex, body mass index, and diabetes mellitus) 1.76 (1.2-2.5, p = 0.002). Pi*MS variant did not increase the odds of hepatic events in NAFLD patients, OR: 0.92 (0.6-1.4, p = 0.70).

CONCLUSION

Patients with NAFLD and A1AT Pi*MZ variant are at increased risk for developing hepatic decompensation. NAFLD patients should be offered A1AT genotyping for risk stratification, counseling, and multidisciplinary intervention for NAFLD.

Hereditary hemochromatosis: Temporal trends, sociodemographic characteristics, and independent risk factor of hepatocellular cancer – nationwide population-based study

BACKGROUND

Hereditary hemochromatosis (HH) has an increased risk of hepatocellular cancer (HCC) both due to genetic risks and iron overload as iron overload can be carcinogenic; HH impacts the increasing risk of HCC, not only through the development of cirrhosis but concerning hepatic iron deposition, which has been studied further recently.

AIM

To evaluate HH yearly trends, patient demographics, symptoms, comorbidities, and hospital outcomes. The secondary aim sheds light on the risk of iron overload for developing HCC in HH patients, independent of liver cirrhosis complications. The study investigated HH (without cirrhosis) as an independent risk factor for HCC.

METHODS

We analyzed data from National Inpatient Sample (NIS) Database, the largest national inpatient data collection in the United States, and selected HH and HCC cohorts. HH was first defined in 2011 International Classification of Disease - 9^th edition (ICD-9) as a separate diagnosis; the HH cohort is extracted from January 2011 to December 2019 using 275.01 (ICD-9) and E83.110 (ICD-10) diagnosis codes of HH. Patients were excluded from the HH cohort if they had a primary or secondary diagnostic code of cirrhosis (alcoholic, non-alcoholic, and biliary), viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease (NAFLD), and non-alcoholic steatohepatitis (NASH). We removed these patients from the HH cohort to rule out bias or ICD-10 diagnostic errors. The HCC cohort is selected from January 2011 to December 2019 using the ICD-9 and ICD-10 codes of HCC. We selected a non-HCC cohort with the 1:1 fixed ratio nearest neighbor (greedy) propensity score method using the patients' age, gender, and race. We performed multivariate analysis for the risk factors of HCC in the HCC and non-HCC matched cohort. We further analyzed HH without cirrhosis (removing HH patients with a diagnosis of cirrhosis) as an independent risk factor of HCC after adjusting all known risk factors of HCC in the multivariate model.

RESULTS

During the 2011-2019 period, a total of 18031 hospitalizations with a primary or secondary diagnosis of HH (excluding liver diseases) were recorded in the NIS database. We analyzed different patients’ characteristics, and we found increments in inpatient population trend with a Ptrend < 0.001 and total hospital cost of care trend from $42957 in 2011 to $66152 in 2019 with a Ptrend < 0.001 despite no change in Length of Stay over the last decade. The multivariate analyses showed that HH without cirrhosis (aOR, 28.8; 95%CI, 10.4–80.1; P < 0.0001), biliary cirrhosis (aOR, 19.3; 95%CI, 13.4–27.6; P < 0.0001), non-alcoholic cirrhosis (aOR, 17.4; 95%CI, 16.5–18.4; P < 0.0001), alcoholic cirrhosis (aOR, 16.9; 95%CI, 15.9–17.9; P < 0.0001), hepatitis B (aOR, 12.1; 95%CI, 10.85–13.60; P < 0.0001), hepatitis C (aOR, 8.58; 95%CI, 8.20–8.98; P < 0.0001), Wilson disease (aOR, 4.27; 95%CI, 1.18–15.41; P < 0.0001), NAFLD or NASH (aOR, 2.96; 95%CI, 2.73–3.20; P < 0.0001), alpha1-antitrypsin deficiency (aOR, 2.10; 95%CI, 1.21–3.64; P < 0.0001), diabetes mellitus without chronic complications (aOR, 1.17; 95%CI, 1.13–1.21; P < 0.0001), and blood transfusion (aOR, 1.80; 95%CI, 1.69–1.92; P < 0.0001) are independent risk factor for liver cancer.

CONCLUSION

Our study showed an increasing trend of in-hospital admissions of HH patients in the last decade. These trends were likely related to advances in diagnostic approach, which can lead to increased hospital utilization and cost increments. Still, the length of stay remained the same, likely due to a big part of management being done in outpatient settings. Another vital part of our study is the significant result that HH without cirrhosis is an independent risk factor for HCC with adjusting all known risk factors. More prospective and retrospective large studies are needed to re-evaluate the HH independent risk in developing HCC.

Clinical characterization of a novel alpha1-antitrypsin null variant: PiQ0Heidelberg

The clinical characterization of a null variant of SERPINA1 - PiQ0_Heidelberg - resulting in alpha1-antitrypsin (AAT) deficiency is described. This rare mutation (c.-5+5 G > A) has been previously identified but not clinically described. The 77 year-old female patient had GOLD-3, Group B COPD, severe destructive panlobular emphysema and newly observed respiratory failure on exertion at the time the genetic analysis was performed. Serum AAT level was 0.1 g/L (reference 0.9-2.0 g/L). Isoelectric focusing showed only the Z-protein indicating that this was a null mutation. The patient has started AAT replacement. Early screening and identification of AAT deficiency would allow for earlier intervention.

Pulmonary Manifestations of Gastrointestinal, Pancreatic, and Liver Diseases in Children

Pulmonary manifestations of gastrointestinal (GI) diseases are often subtle, and underlying disease may precede overt symptoms. A high index of suspicion and a low threshold for consultation with a pediatric pulmonologist is warranted in common GI conditions. This article outlines the pulmonary manifestations of different GI, pancreatic, and liver diseases in children, including gastroesophageal reflux disease, inflammatory bowel disease, pancreatitis, alpha1-antitrypsin deficiency, nonalcoholic fatty liver disease, and complications of chronic liver disease (hepatopulmonary syndrome and portopulmonary hypertension).

A rare mutation on alpha-1 antitrypsin deficit and lung fibrosis: case report

Alpha1-antitrypsin deficiency (AATD) is an autosomal codominant disease, and different genetic variants are known, some of which very rare. Usual pulmonary manifestations include emphysema, bronchiectasis and asthma. Pulmonary fibrosis is uncommon. We describe a case of a 64 year old man with an inaugural diagnosis of cirrhosis and lung fibrosis, without emphysema or bronchiectasis, associated with AATD. Further investigation identified a rare variant in heterozigosity (MM_Palermo), usually associated with liver disease. Concomitantly, he had a secondary iron overload, and in the course of the investigation, a type 2 diabetes mellitus installed. The association between AATD and pulmonary fibrosis is rare, however it has been identified in a few studies and case reports, questioning the role of AAT in pulmonary fibrosis. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (4): e2020019)

Regulation of reticulophagy by the N-degron pathway

Cellular homeostasis requires selective autophagic degradation of damaged or defective organelles, including the endoplasmic reticulum (ER). Previous studies have shown that specific ER transmembrane receptors recruit LC3 on autophagic membranes by using LC3-interacting domains. In this study, we showed that the N-degron pathway mediates ubiquitin (Ub)-dependent reticulophagy. During this 2-step process, the ER transmembrane E3 ligase TRIM13 undergoes auto-ubiquitination via lysine 63 (K63) linkage chains and acts as a ligand for the autophagic receptor SQSTM1/p62 (sequestosome 1). In parallel, ER-residing molecular chaperones, such as HSPA5/GRP78/BiP, are relocated to the cytosol and conjugated with the amino acid L-arginine (Arg) at the N-termini by ATE1 (arginyltransferase 1). The resulting N-terminal Arg (Nt-Arg) binds the ZZ domain of SQSTM1, inducing oligomerization of SQSTM1-TRIM13 complexes and facilitating recruitment of LC3 on phagophores to the sites of reticulophagy. We developed small molecule ligands to the SQSTM1 ZZ domain and demonstrate that these chemical mimics of Nt-Arg facilitate reticulophagy and autophagic protein quality control of misfolded aggregates in the ER.

Lessons from the Past: Some Histories of Alpha-1 Antitrypsin Deficiency Before Its Discovery

A1AT deficiency- a genetically inherited autosomal codominant disease with more than 120 identified alleles- was first identified by Laurell and Eriksson in 1963. The most common hereditary disorder in adults, A1AT causes an increased risk of developing pulmonary emphysema and liver disease. In A1AT patients, lung disease generally presents at a younger age than "usual" chronic obstructive pulmonary disease (COPD) and it may be misdiagnosed as asthma. Because A1AT deficiency patients can show the same clinical features as non-deficient COPD (including increased evidence of bronchiectasis, frequent exacerbations, impaired health status and a degree of reversibility of airflow obstruction), the World Health Organization recommend to test every patient with a diagnosis of COPD or adult-onset asthma for A1AT deficiency. Despite these recommendations, the epidemiology of A1AT deficiency remains uncertain. Although recently discovered A1AT deficiency has affected human populations since antiquity. By using scientific data and recently studied skeletons and historical cases, we show that it is now possible to reconstruct the natural history of pathological processes, whether due to genetic, infectious or environmental factors. We believe that the evolution of disease in patients and research to elucidate the relationship between social science and environmental are pertinent contemporaneous subjects.

Alpha1-Antitrypsin Deficiency: Transition of Care for the Child With AAT Deficiency into Adulthood

IMPORTANCE

Alpha1-antitrypsin (AAT) deficiency is a common, but an underdiagnosed genetic condition, affecting 1 in 1500 individuals. It can present insidiously with liver disease in children. Although clinical practice guidelines exist for the management of AAT deficiency, especially with regards to pulmonary involvement, there are no published recommendations that specifically relate to the management of the liver disease and monitoring for lung disease associated with this condition, particularly in children.

OBJECTIVE

To review the literature on the management of AAT deficiency-associated liver disease in adults and children.

EVIDENCE REVIEW

A systematic search for articles indexed in PubMed and published was undertaken. Some earlier selected landmark references were included in the review. Search terms included: "alpha1-antitrypsin deficiency"; "liver disease"; "end-stage liver disease"; "liver transplantation" and "preventative management". Recommendations for the management of children with suspected or confirmed AAT deficiency were made according to the Strength of Recommendation Taxonomy scale.

FINDINGS

Liver complications arising from AAT deficiency result from the accumulation of mutated AAT protein within hepatocytes. Liver disease occurs in 10% of children, manifested by cholestasis, pruritus, poor feeding, hepatomegaly, and splenomegaly, but the presentation is highly variable. A diagnostic test for AAT deficiency is recommended for these children. Baseline liver function tests should be obtained to assess for liver involvement; however, the only curative treatment for AAT deficiency-associated liver disease is organ transplantation. Conclusion and Relevance: There should be a greater vigilance for AAT deficiency testing among pediatricians. Diagnosis should prompt assessment of liver involvement. Children with AATdeficiency- associated liver disease should be referred to a liver specialist and monitored throughout their lifetimes for the symptoms of AAT-deficiency-related pulmonary involvement.

Liver - master and servant of serum proteome

Hepatocytes synthesise the majority of serum proteins. This production occurs in the endoplasmic reticulum (ER) and is adjusted by complex local and systemic regulatory mechanisms. Accordingly, serum levels of hepatocyte-made proteins constitute important biomarkers that reflect both systemic processes and the status of the liver. For example, C-reactive protein is an established marker of inflammatory reaction, whereas transferrin emerges as a liver stress marker and an attractive mortality predictor. The high protein flow through the ER poses a continuous challenge that is handled by a complex proteostatic network consisting of ER folding machinery, ER stress response, ER-associated degradation and autophagy. Various disorders disrupt this delicate balance and result in protein accumulation in the ER. These include chronic hepatitis B infection with overproduction of hepatitis B surface antigen or inherited alpha1-antitrypsin deficiency that give rise to ground glass hepatocytes and alpha1-antitrypsin aggregates, respectively. We review these ER storage disorders and their downstream consequences. The interaction between proteotoxic stress and other ER challenges such as lipotoxicity is also discussed. Collectively, this article aims to sharpen our view of liver hepatocytes as the central hubs of protein metabolism.

Diagnosis of alpha1-antitrypsin deficiency not just in severe COPD

Alpha1-antitrypsin deficiency (AATD) is a well known genetic risk factor for pulmonary disease and is the most frequent hereditary disease diagnosed in adults. Despite being one of the most common hereditary diseases, AATD remains under-diagnosed because of its variable clinical presentation and the poor knowledge of this disease by physicians. With the aim of identifying clinical differences that could influence early diagnosis, we compared two groups of six AATD Pi*ZZ patients with different lung function severity and clinical expression at diagnosis. On comparing the two groups, we observed a younger mean age at diagnosis and more exacerbations in the severe group, but the percentage of smokers did not statistically differ between the two groups. Our results suggest that AATD continues being a disease suspected on younger patients with a worse lung function. In addition these findings confirm the clinical variability of the disease and that there are still unknown factors that contribute to its development. Therefore, early diagnosis may modify the prognosis of this disease.

A novel alpha1-antitrypsin null variant (PiQ0Milano)

Alpha1-antitrypsin deficiency is an autosomal recessive disease characterized by reduced serum levels of alpha1-antitrypsin (AAT) due to mutations in the SERPINA1 gene causing early onset pulmonary emphysema and, occasionally, chronic liver disease. We report an incidental finding of a novel null AAT allele, Q0_Milano, consisting of a 17 nucleotides deletion in exon 3 of SERPINA1 gene, in an Italian child with persistently increased liver enzymes, a mild decrease in circulating AAT levels and without any pulmonary disease. Q0_Milano variant results in an unfunctional protein lacking of AAT active site, as the resultant protein is truncated near PiS locus involved in AAT protein stability.