Liver carcinoma in PiZ alpha-1-antitrypsin deficiency

Beneficial effects of alpha-1 antitrypsin therapy in a mouse model of colitis-associated colon cancer

BACKGROUND

It is widely accepted that chronic inflammatory bowel diseases significantly higher a risk for colorectal cancer development. Among different types of treatments for patients with colon cancer, novel protein-based therapeutic strategies are considered.

AIM

To explore the effect of human plasma alpha-1 antitrypsin (AAT) protein in the chemically induced mouse model of colorectal cancer.

METHODS

BALB/c mice with azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colitis-associated colorectal cancer (CAC), we intraperitoneally treated with commercial preparation of human plasma AAT (4 mg per mouse). Effects of this therapy were evaluated histologically, and by immunohistochemical and gene expression assays.

RESULTS

When compared with non-treated controls, AOM/DSS mice receiving AAT therapy exhibited significantly longer colons, and less anal bleeding. Concurrently, AAT-treated mice had significantly fewer polyps, and lower numbers of large colon tumors. Immunohistochemical examinations of colon tissues showed significantly lower neutrophil counts, more granzyme B-positive but fewer MMP9 (gelatinase B)-positive cancer cells and lower numbers of apoptotic cells in mice receiving AAT therapy. The expression levels of IL4 were significantly higher while TNFA was slightly reduced in tumor tissues of AOM/DSS mice treated with AAT than in AOM/DSS mice.

CONCLUSION

Human AAT is an acute phase protein with a broad-protease inhibitory and immunomodulatory activities used as a therapeutic for emphysema patients with inherited AAT deficiency. Our results are consistent with previous findings and support an idea that AAT alone and/or in combination with available anti-cancer therapies may represent a new personalized approach for patients with colitis-induced colon cancer.

Alpha-1 antitrypsin (AAT) augmentation therapy in individuals with the PI*MZ genotype: a pro/con debate on a working hypothesis

Alpha-1 antitrypsin deficiency (AATD) is a significantly under-diagnosed genetic condition caused by reduced levels and/or functionality of alpha-1 antitrypsin (AAT), predisposing individuals to lung, liver or other systemic diseases. The management of individuals with the PI*MZ genotype, characterized by mild or moderate AAT deficiency, is less clear than of those with the most common severe deficiency genotype (PI*ZZ). Recent genetic data suggest that the PI*MZ genotype may be significantly more prevalent than currently thought. The only specific treatment for lung disease associated with severe AATD is the intravenous infusion of AAT augmentation therapy, which has been shown to slow disease progression in PI*ZZ individuals. There is no specific evidence for the clinical benefit of AAT therapy in PI*MZ individuals, and the risk of emphysema development in this group remains controversial. As such, current guidelines do not support the use of AAT augmentation in PI*MZ individuals. Here, we discuss the limited data on the PI*MZ genotype and offer pro and con perspectives on pursuing an AAT-specific therapeutic strategy in PI*MZ individuals with lung disease. Ultimately, further research to demonstrate the safety, risk/benefit balance and efficacy of AAT therapy in PI*MZ individuals is needed.

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

Cirrhotic explanted livers occasionally have unexpected periodic acid-Schiff-diastase (PASD)-positive globules within the hepatocyte cytoplasm. It is often unclear whether this finding is a nonspecific consequence of cirrhosis or is indicative of an underlying alpha-1-antitrypsin deficiency (A1ATD) contributing to the cirrhosis. In this study, explanted livers were retrospectively evaluated for histopathology (including PASD status with confirmatory alpha-1-antitrypsin [A1AT] immunohistochemistry [IHC]), and chart review provided etiology of liver failure and general clinical parameters. Real-time polymerase chain reaction was used to detect A1AT genotype (SERPINA1 S and Z alleles) by melting curve analysis on liver explant tissue from selected cases. Of 196 explanted livers, 21 (11%) had PASD+ globules, which were significantly enriched in patients with a clinical diagnosis of nonalcoholic steatohepatitis (NASH; 47%) compared with other causes (P < 0.001). IHC confirmed all PASD+ globules were A1AT+, with 20 of 21 cases demonstrating diffuse A1AT staining. In an expanded NASH cohort, 42% (14/33) of explants had PASD+ globules, 92% of which were homozygous (n = 1) or heterozygous (n = 11) for the SERPINA1 Z allele, corresponding to nearly 40% of all NASH patients. Overall, the Z allele was present in 10% of all tested liver explants, with 85% of PASD+ cases genotyping homozygous (n = 2) or heterozygous (n = 20), which is far in excess of the estimated 2% in the general population. These results indicate PASD+ A1AT globules (with confirmatory genotyping showing at least 1 Z allele) are commonly observed in NASH, suggesting a synergistic relationship toward liver fibrosis. In addition, the high frequency of SERPINA1 Z alleles in liver transplantation patients supports the utility of pretransplant genotyping.

Systematic review: the natural history of alpha-1 antitrypsin deficiency, and associated liver disease

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is estimated to affect three million people worldwide. It causes liver disease in a proportion of carriers of the PiS and PiZ allele due to the formation and retention of polymers within the endoplasmic reticulum of hepatocytes. The reason for this selective penetrance is not known. Although clinical trials are underway, liver transplantation is the only effective treatment for liver disease due to AATD.

AIMS

To report the prevalence and natural history of liver disease among individuals with AATD, and assess the outcomes of liver transplantation through systematic review.

METHODS

A comprehensive search was conducted across multiple databases. Two independent authors selected the articles and assessed bias using the Newcastle-Ottawa Scale. Data were pooled for analysis, where comparable outcomes were reported.

RESULTS

Thirty-five studies were identified related to disease progression and 12 for the treatment of AATD. Seven per cent of children were reported to develop liver cirrhosis, with 16.5% of individuals presenting in childhood requiring liver transplantation. Of those surviving to adulthood, 10.5% had liver cirrhosis and 14.7% required transplantation. Liver transplantation was the only effective treatment reported and outcomes compare favourably to other indications, with 5-year survival reported as over 90% in children and over 80% in adults.

DISCUSSION

The clinical course of liver disease in individuals with AATD remains poorly understood, but affects about 10% of those with AATD. More research is required to identify those patients at risk of developing liver disease at an early stage, and to provide alternative treatments to liver transplantation.

Liver tumors in children with metabolic disorders

Hepatic neoplasia is a rare but serious complication of metabolic diseases in children. The risk of developing neoplasia, the age at onset, and the measures to prevent it differ in the various diseases. We review the most common metabolic disorders that are associated with a heightened risk of developing hepatocellular neoplasms, with a special emphasis on reviewing recent advances in the molecular pathogenesis of the disorders and pre-clinical therapeutic options. The cellular and genetic pathways driving carcinogenesis are poorly understood, but best understood in tyrosinemia.

Alpha-1 antitrypsin deficiency and the risk of hepatocellular carcinoma in end-stage liver disease

AIM: To evaluate the association between alpha-1 antitrypsin deficiency (A1ATD) and hepatocellular carcinoma (HCC) in patients with end-stage liver disease (ESLD).

METHODS: Patients with cirrhosis and ESLD referred to the Cleveland Clinic Foundation for liver transplantation between 2003 and 2014 were included in the study (N = 675). ESLD was defined as having histological features of cirrhosis and/or radiological evidence of cirrhosis in the context of portal hypertension (ascites, variceal bleeding, thrombocytopenia, or hepatic encephalopathy). A1ATD was diagnosed using phenotype characterization (MZ or ZZ), liver biopsy detection of PAS-positive diastase-resistant (PAS+) globules, or both. Patients with other causes of liver diseases such as hepatitis C virus (HCV), alcoholic liver disease and non-alcoholic steatohepatitis (NASH) or NASH were also included in the study. HCC was diagnosed by using imaging modalities, biopsy findings, or explanted liver inspection. Follow-up time was defined as the number of years from the diagnosis of cirrhosis to the diagnosis of hepatocellular carcinoma, or from the diagnosis of cirrhosis to the last follow up visit. The rate of HCC was assessed using time-to-interval analysis for interval censored data.

RESULTS: This study included 675 patients. 7% of subjects had A1ATD (n = 47). Out of all subjects who did not have A1ATD, 46% had HCV, 17% had alcoholic liver disease, 19% had NASH and 18% had another primary diagnosis. Of the 47 subjects with A1ATD, 15 had a primary diagnosis of A1ATD (PI*ZZ phenotype and PAS+ globules), 8 had a PI*MZ phenotype alone, 14 had PAS+ alone, and 10 had both the PI*MZ phenotype and PAS+. Median follow-up time was 3.4 (25^th, 75^th percentiles: 1, 5.2) years. The overall rate of hepatocellular carcinoma in all subjects was 29% (n = 199). In the A1ATD group, the incidence rate of HCC was 8.5% compared to 31% in the group of patients with other causes of cirrhosis (P = 0.001). Patients with ESLD due to A1ATD had the lowest yearly cumulative rate of hepatocellular carcinoma at 0.88% per year compared to 2.7% for those with HCV cirrhosis, 1.5% in patients with NASH and 0.9% in alcohol-induced liver disease (P < 0.001).

CONCLUSION: Within this group of patients with ESLD, there was no significant association between A1ATD and increased risk of HCC.

Serum concentration of alpha-1 antitrypsin is significantly higher in colorectal cancer patients than in healthy controls

Background

The association between alpha-1 antitrypsin (AAT) deficiency and colorectal cancer (CRC) is currently controversial. The present study compares AAT serum concentrations and gene frequencies between a group of CRC patients and a control group of healthy unrelated people (HUP).

Methods

267 CRC subjects (63% males, 72 ± 10 years old) were enlisted from a Hospital Clinic setting in Asturias, Spain. The HUP group comprised 327 subjects (67% males, mean age 70 ± 7.5 years old) from the same geographical region. Outcome measures were AAT serum concentrations measured by nephelometry, and AAT phenotyping characterization by isoelectric focusing.

Results

Significantly higher serum concentrations were found among CRC (208 ± 60) than in HUP individuals (144 ± 20.5) (p = 0.0001). No differences were found in the phenotypic distribution of the Pi*S and Pi*Z allelic frequencies (p = 0.639), although the frequency of Pi*Z was higher in CRC (21%) than in HUP subjects (15%).

Conclusions

The only statistically significant finding in this study was the markedly higher AAT serum concentrations found in CRC subjects compared with HUP controls, irrespective of whether their Pi* phenotype was normal (Pi*MM) or deficient (Pi*MS, Pi*MZ and Pi*SZ). Although there was a trend towards the more deficient Pi* phenotype the more advanced the tumor, the results were inconclusive due to the small sample size. Consequently, more powerful studies are needed to reach firmer conclusions on this matter.

Mysteries of α1-antitrypsin deficiency: emerging therapeutic strategies for a challenging disease

The classical form of α1-antitrypsin deficiency (ATD) is an autosomal co-dominant disorder that affects ~1 in 3000 live births and is an important genetic cause of lung and liver disease. The protein affected, α1-antitrypsin (AT), is predominantly derived from the liver and has the function of inhibiting neutrophil elastase and several other destructive neutrophil proteinases. The genetic defect is a point mutation that leads to misfolding of the mutant protein, which is referred to as α1-antitrypsin Z (ATZ). Because of its misfolding, ATZ is unable to efficiently traverse the secretory pathway. Accumulation of ATZ in the endoplasmic reticulum of liver cells has a gain-of-function proteotoxic effect on the liver, resulting in fibrosis, cirrhosis and/or hepatocellular carcinoma in some individuals. Moreover, because of reduced secretion, there is a lack of anti-proteinase activity in the lung, which allows neutrophil proteases to destroy the connective tissue matrix and cause chronic obstructive pulmonary disease (COPD) by loss of function. Wide variation in the incidence and severity of liver and lung disease among individuals with ATD has made this disease one of the most challenging of the rare genetic disorders to diagnose and treat. Other than cigarette smoking, which worsens COPD in ATD, genetic and environmental modifiers that determine this phenotypic variability are unknown. A limited number of therapeutic strategies are currently available, and liver transplantation is the only treatment for severe liver disease. Although replacement therapy with purified AT corrects the loss of anti-proteinase function, COPD progresses in a substantial number of individuals with ATD and some undergo lung transplantation. Nevertheless, advances in understanding the variability in clinical phenotype and in developing novel therapeutic concepts is beginning to address the major clinical challenges of this mysterious disorder.

[Hepatic involvement in hereditary alpha-1-antitrypsin deficiency]

Apha-1-antitrypsin deficiency is an autosomal recessive genetic disorder seen in all races. The molecular defect is a specific mutation of the SERPINA1 gene leading to synthesis of an abnormal protein (alpha-1-antitrypsin Z) that cannot be secreted and polymerizes in the endoplasmic reticulum of hepatocytes. The inter-individual variability in the responses to intracellular stress induced by the accumulation of abnormal polymers and the mechanisms allowing their degradation is, without doubt, responsible for the different clinical manifestations of the disease. The disease affects the liver where the abnormal protein is synthesized and the lung, which is its place of action. Liver involvement is well recognized in homozygous infants of the phenotype ZZ. In this situation the disease may present a varying picture from neonatal cholestasis (about 15% of neonatal defects) to cirrhosis. However, evolution towards cirrhosis affects less than 3% of infants with the ZZ phenotype and it is preceded in 80% of cases by neonatal cholestasis. In adolescents or adults the manifestations associated with alpha-1-antitrypsin deficiency are usually limited to biochemical abnormalities but may lead to cirrhosis or hepatocellular carcinoma. The hepatic disorder and its complications are treated symptomatically though the pulmonary involvement may benefit from substitution treatment. More specific treatments targeting the molecular and cellular abnormalities are the subject of research.

Heterozygous α1-antitrypsin Z allele mutation in presumed healthy donor livers used for transplantation

OBJECTIVES

The Z allele (Glu342Lys) in α1-antitrypsin (AAT) deficiency is a combined deficiency and dysfunctional allele. Carrying one Z allele induces a risk of a more aggressive evolution in patients with a chronic liver disease. As most of the carriers of Z allele do not have overt liver disease, it is likely that Z allele-containing livers have been used previously for liver transplantation. We analyzed the incidence, epidemiology, and clinical features of AAT accumulation in the hepatocytes after liver transplantation.

METHODS

Follow-up biopsies of liver transplant recipients were analyzed with periodic acid Schiff staining until 2006 (n=486); from 2006 on (n=303), all biopsies were stained with a specific monoclonal antibody against mutated AATZ protein. Genotyping of both recipient and donor was performed in the case of positive staining.

RESULTS

Of 789 liver transplantation patients, six patients (0.8%) showed mutated AATZ accumulation in the transplanted liver. Mutation analysis confirmed the presence of the Z allele in all donor organs including one transplanted organ with the SZ phenotype. There was a clear concordance between the isoelectrical focusing of the recipient AAT after transplantation and the genotype of the donor.

CONCLUSION

Presumed healthy donor organs containing the Z allele were used for transplantation in 0.8% of cases in our series. As the presence of a Z allele is an independent risk factor of aggravation of chronic liver disease, AATZ accumulation in biopsies after liver transplantation should be actively looked for.

Pediatric Cholestatic Disorders: Approach to Pathologic Diagnosis

This article addresses select liver diseases that are commonly seen in the pediatric group and pose diagnostic challenges in practice. The key genetic/molecular abnormalities, clinical features, histopathologic findings, diagnostic modalities, differential diagnoses, and possible pitfalls in diagnosis are discussed in detail. Although recent advances in understanding the pathophysiology of bile synthesis and transport along with advances in molecular genetics have allowed a better characterization of many of these liver diseases, significant overlap in the histopathologic features of many of these disorders still leads to diagnostic challenges for the pathologist.

Pulmonary diseases and the liver

Chronic liver disease is associated with many pulmonary complications. Several, including hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax have been extensively reviewed. However, hepatobiliary manifestations of primary pulmonary diseases have received less attention. This review focuses on hepatobiliary complications of respiratory failure, cystic fibrosis, α-1 antitrypsin deficiency, sarcoidosis, and tuberculosis.

Heterozygosity for the alpha1-antitrypsin Z allele may confer genetic risk of cholangiocarcinoma

BACKGROUND

Alpha1-antitrypsin (α1AT) deficiency caused by Z allele homozygosity represents a well-established risk factor for hepatocellular carcinoma. Previous studies have also implicated α1AT Z heterozygosity in cholangiocarcinogenesis.

AIM

To assess the 'common' Z and S alleles as well as the promoter variant rs8004738 for association with cholangiocarcinoma.

METHODS

We genotyped 182 Caucasian patients and 350 controls for rs28929474 (Z), rs17580 (S) and the variant rs8004738. Exploratory analyses were performed in relation to gender and cholangiocarcinoma localisation.

RESULTS

rs28929474 was significantly enriched in the cholangiocarcinoma group (4.1 vs. 1.7%; OR 2.46, 95% CI 1.14-5.32; Bonferroni corrected p(c) = 0.036), reinforced by Armitage trend testing (OR 2.53; p(c) = 0.032). The rs8004738 (promoter) minor allele tended to be overrepresented in Z heterozygotes (30.0 vs. 16.7%: P = 0.13). Exploratory data analyses suggested a high genetic risk for extrahepatic tumour localisation (OR 3.0; p(c) = 0.016) and potentially female Z allele carriers (OR 3.37; unadjusted P = 0.022, p(c) = 0.088).

CONCLUSIONS

These data point to a novel role of α1AT Z heterozygosity as a potential genetic susceptibility factor for cholangiocarcinoma formation and suggest a contribution of aberrant α1AT function in biliary carcinogenesis. However, given the overall low rs28929474 minor allele frequency, larger studies are warranted to confirm and extend our findings.

Hepatic neoplasia and metabolic diseases in children

Hepatic neoplasia is a rare but serious complication of metabolic diseases in children. The risk of developing neoplasia, the age at onset, and the measures to prevent it differ in various diseases. This article reviews the most common metabolic disorders in humans that are associated with neoplasms, with a special emphasis on the molecular etiopathogenesis of this process. The cellular pathways driving carcinogenesis are poorly understood, but best known in tyrosinemia.

Biopsy Diagnosis of Inherited Liver Disease

Hepatic dysfunction during childhood can be due to acquired or inherited etiologies or a combination. The distinction can be difficult to make on liver biopsy, because the inherited disorders are rare and often lack pathognomonic light microscopic features. Recent progress in understanding the pathogenesis of these disorders has led to advances in molecular genetic screening and confirmatory tests. For a majority of these disorders, the liver biopsy continues to play a crucial role in primary diagnosis or confirmation. This article discusses algorithms that may aid pathologists in differential diagnosis of common inherited disorders of the liver, with emphasis on ancillary diagnostic tools and reference assays that are critical in establishing the diagnosis.

Hepatocellular carcinoma in non-cirrhotic liver: a reappraisal

Although not frequently, hepatocellular carcinoma (HCC) can ensue in a non-cirrhotic liver. As compared to cirrhotic HCC, this kind of tumour has some peculiarities, such as: (a) a lower male preponderance and a bimodal age distribution; (b) a lower prevalence of the three main risk factors (hepatitis B and C virus infections and alcohol abuse), with an increased prevalence of other etiologic factors, such as exposure to genotoxic substances and sex hormones, inherited diseases, genetic mutations; (c) a more advanced tumour stage at the time of diagnosis, as it is usually detected due to the occurrence of cancer-related symptoms, outside any scheduled surveillance program; (d) a much higher amenability to hepatic resection, due to the low risk of liver failure even after extended parenchymal mutilation; (e) overall and disease-free survivals after resection of non-advanced tumours (meeting the Milano criteria) comparable to that obtained with liver transplantation in cirrhotic patients carrying an early tumour; (f) overall survival strictly dependent on tumour burden (and its recurrence) and barely influenced by liver function.

Liver disease in alpha 1-antitrypsin deficiency: a review

Alpha 1-antitrypsin deficiency is an inherited metabolic disorder that predisposes the affected individual to chronic pulmonary disease, in addition to chronic liver disease, cirrhosis, and hepatocellular carcinoma. Just over one-third of genetically susceptible adult patients with the most severe phenotype, PiZZ, develop clinically significant liver injury. The clinical presentation of liver disease is variable, and the genetic and environmental factors that predispose some individuals to liver disease while sparing others are unknown. The mechanisms of liver and lung disease are distinct and unique. This article reviews the liver disease associated with alpha 1-antitrypsin deficiency, emphasizing the genetic defect, molecular pathogenesis, natural history, and promising therapies.

Alpha-1-Antitrypsin-Positive “Signet-Ring” Bile Duct Adenoma in a Patient With MMALTON Mutation

A 65-year-old man with a colonic adenocarcinoma and a single small liver nodule underwent surgery. The nodule showed the histological features of a bile duct adenoma. Large eosinophilic, periodic acid-Schiff—positive diastase-resistant intracytoplasmic globules conferred a signet-ring appearance to the cells. Similar globules were found in the biliary epithelium in perinodular portal tracts, whereas smaller globules were detected in periportal hepatocytes. All globules showed strong immunoreactivity for alpha-1-antitrypsin, and the sequence of the alpha-1-antitrypsin gene showed a heterozygous Mmalton genotype. The selective recurrence of large alpha-1-antitrypsin globules within the bile ducts may indicate a neoplastic rather than a reactive or hamartomatous nature of the nodule.

Hepatocarcinoma in viral and metabolic liver disease

It is becoming increasingly evident that children, like adults, with chronic viral or metabolic liver diseases are at risk for the development of hepatocarcinoma. The aims of this article are to review the risk factors for hepatocarcinoma in chronic viral or metabolic liver disease, outline potential pathogenic mechanisms of hepatocarcinoma, and describe surveillance strategies, clinical evaluation, and management of hepatocarcinoma in children.

Alpha-1-antitrypsin deficiency: a new paradigm for hepatocellular carcinoma in genetic liver disease

Liver disease in alpha-1-antitrypsin (alpha1AT) deficiency is caused by a gain-of-toxic function mechanism engendered by the accumulation of a mutant glycoprotein in the endoplasmic reticulum (ER). The extraordinary degree of variation in phenotypical expression of this liver disease is believed to be determined by genetic modifiers and/or environmental factors that influence the intracellular disposal of the mutant glycoprotein or the signal transduction pathways that are activated. Recent investigations suggest that a specific repertoire of signaling pathways are involved, including the autophagic response, mitochondrial- and ER-caspase activation, and nuclear factor kappaB (NFkappaB) activation. Whether activation of these signaling pathways, presumably to protect the cell, inadvertently contributes to liver injury or perhaps protects the cell from one injury and, in so doing, predisposes it to another type of injury, such as hepatocarcinogenesis, is not yet known. Recent studies also suggest that hepatocytes with marked accumulation of alpha1ATZ, globule-containing hepatocytes, engender a cancer-prone state by surviving with intrinsic damage and by chronically stimulating in 'trans' adjacent relatively undamaged hepatocytes that have a selective proliferative advantage. Further, this paradigm may apply to other genetic and infectious liver diseases that are predisposed to hepatocellular carcinoma.

Screening and treatment for hepatocellular carcinoma

Surveillance for hepatocellular carcinoma (HCC) has become routine despite a lack of evidence of efficacy. Suitable candidates for surveillance include patients with cirrhosis and some subsets of noncirrhotic chronic hepatitis B carriers. The best surveillance testis ultrasonography at 6- to 12-month intervals. Serological tests are less effective. Defining an abnormal result is difficult in the cirrhotic liver. Diagnosis requires radiological investigations and may require a biopsy if the lesion is between 1 and 2 cm in diameter. In the face of an abnormal surveillance test and failure to confirm the diagnosis initially, enhanced follow-up is required. HCC can be treated for cure by liver transplantation, resection, or local ablation. For patients with suitable lesions, liver transplantation offers the best form of therapy. Chemoembolization offers increased survival over no therapy. Several experimental therapies are being investigated.

Alpha 1-antitrypsin deficiency. 3: Clinical manifestations and natural history

A review of the clinical manifestations of alpha(1)-antitrypsin (AAT) deficiency, including lung disease and liver disease, and risk factors affecting the rate of decline in lung function in AAT deficient patients.

Pathogenesis and screening for hepatocellular carcinoma

Hepatocellular carcinoma is an increasingly common clinical problem. Investigators have begun to understand aspects of the pathogenesis of the tumor, mainly from a morphologic point of view. Preneoplastic lesions and early cancer may be difficult to distinguish radiologically. Nonetheless, programs for surveillance of liver cancer have been developed. Little uniformity exists in methods of surveillance, and even less in methods of investigation and follow-up after an abnormal result is obtained. This article attempts to bring some rigor to the understanding of hepatocellular carcinoma.

[Liver alterations due to alpha-1-antitrypsin deficiency in adults. Study of 5 patients and analysis of the cases reported in the Spanish literature]

BACKGROUND

To determine the epidemiological characteristics of liver disease secondary to alpha-1-antitrypsin deficiency and associated processes in the Spanish population.

PATIENTS AND METHOD

We reviewed the medical records of adults with liver abnormalities due to alpha-1-antitrypsin deficiency diagnosed between 1981 and 2001 in the Hospital Donosti in San Sebastian (Spain) as well as the cases published in the literature before 1999. Diagnosis was based on clinical and biochemical data, imaging tests and/or liver biopsy and/or necroscopy together with serum values of alpha-1-antitrypsin and phenotyping.

RESULTS

Fifty cases of liver disease secondary to alpha-1-antitrypsin deficiency (45 from the literature and 5 from our hospital) were included. There were 34 men and 16 women aged between 18 and 77 years. Fifteen (30%) had relatives with alpha-1-antitrypsin deficiency. Hepatitis and/or neonatal cholestasis were confirmed in 4 and alcoholism was confirmed in 17. Of the series, 8 (16%) had portal fibrosis and 29 (58%) had cirrhosis. Cirrhosis was mainly macro-micronodular and was decompensated in 48% of the cases. Of the patients with cirrhosis, 12 were ZZ homozygotes and 12 were heterozygotes, mainly MZ and SZ. The most frequent associated process was respiratory disease (emphysema and/or chronic bronchitis) in 25 of the 50 cases (50%).

CONCLUSIONS

The presence of cirrhosis in alpha-1-antitrypsin deficiency is low, approximately 2.2/100,000 for ZZ homozygotes. Age at diagnosis of cirrhosis or fibrosis was more than 50 years. The male-to-female ratio was 2 to 1. In one-third of the patients alcohol could have been a coadjuvant or aggravating factor in the liver disease. No differences were found between homo- and heterozygote phenotypes in patients with cirrhosis. The most frequently associated processes were respiratory diseases due to alpha-1-antitrypsin deficiency.

Metabolic liver disease in the young adult

This chapter describes the gene mutations, phenotypes, diagnosis and therapy of the common metabolic liver diseases in young adulthood: haemochromatosis, Wilson disease, alpha(1)-anti-trypsin deficiency and cystic fibrosis. The remarkable variability of the phenotypical expression of the mutated genotypes makes screening recommendations and the establishment of prognosis for these liver disorders in young adults problematical. The diagnosis and therapy of the young adult with metabolic liver disease is discussed, with an emphasis on maintaining quality-of-life and balancing the importance of early intervention with the stigmatization of the diagnosis of potentially life-threatening liver disease. There is a critical need for the development of biochemical markers that would predict the risk of expression of clinical phenotypes and prognosis.

Hepatocellular carcinoma: predisposing conditions and precursor lesions

The global incidence of HCC is rising; in the United States, its rise is in parallel to that of cirrhosis due to the HCV and obesity epidemics. The lack of adequate treatment for advanced HCC mandates both prevention and early detection of these lesions. The limitations of currently available histopathologic evaluations, serologic markers, and radiographic imaging modalities in detecting HCC and its precursors have been outlined in this review. Refinements of all of these may lead to better HCC detection, earlier intervention, and successful treatment. Randomized controlled trials are necessary to evaluate the most efficacious and cost-effective approach to screening.

Coexpression and accumulation of ubiquitin +1 and ZZ proteins in livers of children with alpha(1)-antitrypsin deficiency

The ZZ variant of alpha(1)-antitrypsin deficiency (AATD) is well known to cause liver damage and cirrhosis in some affected children. Ubiquitin abnormality was recently shown to be significant in AATD in childhood cirrhosis. Molecular misreading (MM), defined as faulty transcription of genomic information from DNA into mRNA, as well as its translation into mutant proteins, has been documented in many pathologic processes where aggregation of abnormal proteins occurs. The misread protein, ubiquitin-B(+1) (UBB(+1)), was recently identified in the hallmarks of various neurological disorders. The objective of this study was to determine whether MM of ubiquitin occurs in AATD. Twelve explanted liver specimens from AATD-affected children with cirrhosis were retrieved from archival sources, along with 10 control liver specimens obtained from autopsies of age-matched children with no clinical, gross anatomic, or histologic evidence of liver disease. Double immunofluorescence studies using rabbit polyclonal antibodies against UBB(+1) and AAT were performed on consecutively sectioned tissue. UBB(+1) immunoreactivity was colocalized with AAT in all cirrhotic AATD livers. The control livers were consistently negative. Ubiquitin MM is prominent in AATD-affected cirrhotic livers. This indicates that for children with AATD and cirrhosis, ubiquitin MM is a necessary cofactor to the aggregation of mutant ZZ isoform of AATD.

Primary liver carcinoma in genetic hemochromatosis reveals a broad histologic spectrum

Hepatocellular carcinoma (HCC) is a well-known complication of genetic hemochromatosis (GH). However, the frequency of primary liver carcinoma (PLC) with biliary differentiation, such as cholangiocarcinoma (CC) and combined hepatocholangiocarcinoma (CHCC), in GH remains unclear We analyzed the histologic type of 20 PLCs occurring in the background of GH; all patients were homozygotic for the C282Y mutation. Ten were depleted of iron by successive phlebotomies, while the remaining 10 were untreated. Histologically, 13 cases were classified as HCC, 3 as CC, and 4 as CHCC. Immunohistochemical detection of Hep Par 1, cytokeratin 19 (CK19), and MUC1 supported this classification; PLC with biliary differentiation was immunoreactive for MUC1 in 86% (6/7) of cases and for CK19 in 100% (7/7) of cases. The nontumoral liver exhibited no cirrhosis or extensive fibrosis in 6 cases. Von Meyenburg complexes were present in 11 cases and intraparenchymal bile duct adenomas in 3. These data suggest that PLCs in patients with GH present a wide histologic spectrum, with tumors showing frequent biliary differentiation; may arise on a nonfibrotic or a cirrhotic liver; and often are associated with Von Meyenburg complexes and to a lesser extent with bile duct adenomas.

Chronic liver disease in heterozygous alpha1-antitrypsin deficiency PiZ

BACKGROUND/AIMS

The contribution of the heterozygous state PiZ of alpha1-antitrypsin deficiency (AATD) to the pathogenesis of chronic liver disease is debated. We analyzed whether patients with this genetic defect carrying a single PiZ gene are at increased risk for developing chronic liver disease.

METHODS

1847 consecutive biopsy cases and 1030 autopsy cases of Caucasian adults were screened immunohistochemically for PiZ deposits. The zygosity status was analyzed by single-strand conformational polymorphism (SSCP) and by sequencing DNA extracted from paraffin-embedded tissue.

RESULTS

All analyzed biopsy cases were heterozygous for the PiZ mutation. The biopsy group revealed a significantly higher rate of PiZ-positive cases (3.4%) than the autopsy group (1.8%) (p=0.019). PiZ deposits ranged from scarce granules to extensive globular inclusions as in homozygous AATD of PiZ type. The extent of PiZ deposits correlated well with the inflammatory activity and stage of fibrosis. Cirrhotic livers contained globular PiZ deposits significantly more often than the biopsies with minor fibrosis. PiZ-positive biopsies from patients without concurrent liver disease (n= 26) revealed only minor fibrosis in the age group between 20 and 39 years, but significantly more severe fibrosis and significantly more PiZ deposits in the older age groups. Biopsies with concurrent liver disease (n=28) presented with significantly more severe inflammation and fibrosis, and more PiZ deposits than the cases without concurrent liver disease.

CONCLUSIONS

Patients with heterozygous AATD of PiZ type bear an increased risk for chronic liver disease. If at all, this genetic defect will become clinically relevant only in middle-aged or old adults. It rarely causes liver cirrhosis even without concurrent liver disease. It can aggravate or can be aggravated by advanced coexistent chronic liver diseases. PiZ immunohistochemistry is an easy, highly specific method to detect this metabolic defect on liver biopsies.

Is heterozygous alpha-1-antitrypsin deficiency type PIZ a risk factor for primary liver carcinoma?

BACKGROUND

It is well known that homozygotes with alpha-1-antitrypsin deficiency type PiZ are associated with an increased risk of chronic liver disease and liver carcinoma. The aim of this study was to determine whether heterozygous PiZ status is a risk factor for liver carcinoma development.

METHODS

Three hundred seventeen consecutive primary liver carcinomas and the tumor-bearing liver tissue (tumor series) from adult patients were screened immunohistochemically for hepatocellular PiZ deposits. Liver specimens from 1663 consecutive adult patients (biopsy series) and liver tissue from 1030 consecutive adult autopsies (autopsy series) served as controls. The zygosity status of alpha-1-antitrypsin was verified by analysis of single strand conformational polymorphism and by sequencing DNA extracted from paraffin embedded tissue.

RESULTS

The PiZ frequency in the tumor series (5.99%) was significantly higher than in the biopsy series (3.43%) or the autopsy series (1.84%). Cholangiocarcinomas and/or combined hepatocholangiocarcinomas were seen significantly more frequently in PiZ-associated liver carcinomas (57.9%) than in non-PiZ-associated carcinomas (27.2%). Cirrhosis was found in only 3 of the 19 PiZ-associated carcinomas. The remaining 16 livers showed varying stages of fibrosis or normal tissue. All nine cases with PiZ-associated liver carcinoma suitable for genetic analysis showed heterozygous PiZ mutations.

CONCLUSIONS

Heterozygotes of type PiZ are associated with an increased risk of primary liver carcinoma. PiZ-associated carcinoma may develop in noncirrhotic liver tissue and without concurrent liver disease, and is frequently characterized by cholangiocellular differentiation. The site specific antibody ATZ11 is a reliable morphologic tool for detecting PiZ individuals.

Detection of alpha-1-antitrypsin PiZ individuals by SSCP and DNA sequencing in formalin-fixed and paraffin-embedded tissue: a comparison with immunohistochemical analysis

BACKGROUND/AIM

The role of alpha-1-antitrypsin (AAT) deficiency in the development of cirrhosis and carcinoma of the liver can be investigated from the analysis of archival biopsy specimens. Immunohistochemistry can visualize the storage of defective protease inhibitor (Pi) variant Z, but does not allow differentation between homozygous and heterozygous patients. The aim of the study was to establish a method for the detection of the PiZ mutation on the gene level.

METHODS

Liver biopsy and autopsy samples in which AAT deficiency was detected immunohistochemically by a monoclonal PiZ-antibody were analyzed by single-strand conformational polymorphism (SSCP) to reliably determine hetero- and homozygote carrier state in the absence of blood samples and to confirm the histological diagnosis. The accuracy of SSCP was verified by direct DNA sequencing.

RESULTS

Tissue slices (>0.8 cm2) from 29 consecutive cases with immunohistochemically detected PiZ depositions and from ten PiZ-negative control cases were provided for extraction and amplification of DNA. In comparison to wild-type sequence of AAT exon V, all 29 cases showed band shifts on SSCP analysis, with a heterozygous pattern in 28 patients and a homozygous pattern in one patient. DNA sequence analysis revealed the same single-base mutation at position 342 of AAT exon V.

CONCLUSIONS

SSCP analysis proved a sensitive and specific technique for the detection of the PiZ mutation at the gene level, which allowed unequivocal differentiation between heterozygous and homozygous PiZ status from paraffin-embedded archival tissue specimens. Besides a use in diagnostic pathology, this technique could be valuable for prenatal diagnosis and population screening purposes.