Saudi Journal of Gastroenterology
Home About us Instructions Submission Subscribe Advertise Contact Login    Print this page  Email this page Small font sizeDefault font sizeIncrease font size 
Users Online: 359 


 
SPECIAL ARTICLE Table of Contents   
Year : 1999  |  Volume : 5  |  Issue : 1  |  Page : 1-8
Alpha 1-antitrypsin deficiency and related liver disease


Department of Medicine, Malmo University Hospital, Malmo, Sweden

Click here for correspondence address and email

Date of Submission25-May-1998
Date of Acceptance01-Jul-1998
 

   Abstract 

α1 ,-antitrypsin (α1 AT) deficiency is a relatively common genetic cause of liver disease among Caucasians. It is an autosomal recessive disorder characterized by reduced serum levels of α1 AT, a 52-kD glycoprotein that functions as an antiprotease. The deficiency state is caused by mutations in the α1 AT gene on chromosome 14. α1 AT shows considerable genetic variability, having more than 75 genetic variants (Pi types). The PiZ allele is the most common deficiency variant. PiZZ homozygotes have 15-20% of the normal plasma levels of α1 AT. The deficiency is due to lack of secretion of Z α1 AT from the hepatocyte, where inclusions are formed in the endoplasmic reticulum. Homozygous α1 AT deficiency (PiZZ) is known to predispose to emphysema and chronic liver disease. This review outlines the clinical manifestations and treatment of α1 AT deficiency associated liver disease, focusing on recent advances in the pathogenic mechanism of liver disease in this genetic disorder.

How to cite this article:
Elzouki AN. Alpha 1-antitrypsin deficiency and related liver disease. Saudi J Gastroenterol 1999;5:1-8

How to cite this URL:
Elzouki AN. Alpha 1-antitrypsin deficiency and related liver disease. Saudi J Gastroenterol [serial online] 1999 [cited 2021 Sep 28];5:1-8. Available from: https://www.saudijgastro.com/text.asp?1999/5/1/1/33518


α1 -antitrypsin (α1 AT), the archetype of the serpin superfamily, is the most abundant circulating protese inhibitor (Pi). It is an acute phase glycoprotein synthesized mainly in the liver, and inhibits a broad variety of serine proteases released by activated neutrophils, including neutrophil elastase (NE) and proteinase 3 (PR3) [1] . The Pi locus for α1 AT is on chromosome 14 at 14g32.1 [1] . α1 AT is characterized by considerable genetic variation, more than 75 genetic variants (Pi types) having been recognized [3] . The PiZ allele is the most common deficiency variant. PiZZ homozygotes have 15-20% of the normal plasma levels of α1 AT. The deficiency is due to lack of secretion of Z α1 AT from the hepatocyte, where inclusions are formed in the endoplasmic reticulum (ER). There are several rare deficiency types, including some that show lack of secretion, and some that have no product (null or QO).

α1 AT deficiency is a relatively common genetic cause of liver disease among Caucasians. Studies of this error of metabolism have not only provided new insights into the pathogenesis of emphysema, the major clinical sequela of the deficiency state, but have also provided a model for a new type of liver disease. Abnormal α1 AT is accumulated in the ER and consequently one may speak of an ER storage disease, quite distinct from the better known lysosomal storage diseases. Furthermore, several recent studies have shown that α1 AT deficiency is overrepresented in patients with systemic vasculitis [4],[5],[6],[7] . Moreover, a subnormal response of plasma α1 AT seen in vasculitic patients enhances the risk of dissemination of the vasculitic proces and the risk of a fatal outcome [8],[9] . This article outlines the clinical manifestations and treatment of a,AT deficiency associated liver disease, focusing on recent advances in the pathogenic mechanism of liver disease in this inborn error.


   Childhood onset liver disease Top


α1 AT deficiency is the most common genetic cause of liver disease in infants and children and is the most common metabolic error for which liver transplantation is indicated [10] . Clinically important liver disease occurs in about 10-20% of all neonates with homozygous (PiZZ) α1AT deficiency, but the majority (70%) have abnolnlal liver function tests [11] . The most predominant sign of liver abnormality associated with α1AT deficiency is the neonatal hepatitis syndrome characterized by pruritus, conjugated hyperbilirubinemia, increased serum aminotransferase levels, frequently with hepatomegaly and paucity of intrahepatic bile ducts on histopathological examination [12],[13] . Signs of cholestasis begin between 4 days and 2 months after birth and can persist from weeks up to 8 months. Cholestasis can be severe enough to cause acholic stool and the disease can be confused with hepatic biliary atresia. Spontaneous clinical regression is common and usually occurs before 6 months of age, although mild biochemical abnormalities can persist. In minority of the homozygous (PiZZ) neonates who develop liver disease, the disease does not subside but goes on to cirhosis and liver failure [14] . Before age of 20, cirrhosis and/or fibrosis occurs in approximately 3% of individuals born with α1 AT deficiency, representing about 30% of all neonates who develop cholestasis. In most of these children, there is progressive liver failure, resulting in death unless corrected by liver transplantation [15] . Liver disease associated with α1AT deficiency may also be first discovered in late childhood when the affected individual presents with abdominal distention due to hepatomegaly and signs of portal hypertension [16],[17] .

The only available prospective data on the natural history of PiZZ α1AT deficiency-associated liver injury were elicited in the Swedish nationwide screening study by Sveger [14] . In this study, 200,000 newborns were screened and 127 PiZZ infants identified, of them 22 manifested clinical signs of liver disease in infancy. Of these 22, two died early in life of cirrhosis. Another two children died of other causes, though autopsy showed the presence of histological signs of cirrhosis in one of them and fibrosis in the other. Approximately 50% of the remainder of the 127 children had abnormal liver function test results. Followup studies of the original cohort of 127 PiZZ children at 12 years of age [18] and at 18 years of age [11] showed that 13% of these subjects still had marginally abnormal liver function test results, but none have manifested clinical signs of liver dysfunction [Figure - 1]. Contrary to the initial indications of a poor prognosis in children with α1AT deficiency and early liver symptoms (19) , this prospective cohort has shown more than two-thirds of the children to recover from their liver damage up to age 20.


   Adult onset liver disease Top


Cirrhosis and fibrosis of the liver were noted early on in Swedish adults with α1AT deficiency [20] . Larsson found 12% of 246 Swedish adults with α1AT deficiency, identified through hospital admissions, to have liver cirrhosis [21] ; of PiZZ individuals over 50 years of age, 19% had cirrhosis. Of a series of 115 Canadian adults with α1AT deficiency, four had biopsy or autopsy-verified cirrhosis, and two manifested definite biochemical evidence of liver disease, i.e. a total prevalence of liver disease of 5.2% [22] . When these patients were subgrouped by sex and age, the risk of liver disease was higher for the male than the female subgrouped by sex and age, the risk of liver disease was higher for the male than the female subgroup and reached a peak of 15.4% at age 51-60 years. No corresponding figures for the general population were reported for these studies. In an epidemiologic study based on representative autopsy cases, α1AT deficiency (PiZZ) was found to manifest strong relationship both with cirrhosis and with hepatocellular carcinoma, though the relationships were statistically significant only for male patients [23] . In a more recent autopsy-based case-control study we have substantiated a high risk of cirrhosis also to be inceased in female PiZZ-deficients [24] . Approximately 40% and 15% of α1AT-deficient adults had cirrhosis and hepatocellular carcinoma, respectively [24] . Cirrhosis in adults with α1AT deficiency can occur without preceding history of childhood liver disease. The liver disease in adults appears to be characterized by rapid progression and, in most patients, death occur within two years of the diagnosis of cirrhosis, partially due to concomitant emphysema. The estimated prevalence and estimated age at death due to liver disease in PiZZ-individuals are shown in [Figure - 2].


   Pathogenic mechanism of liver disease in α1AT deficiency Top


Individuals who synthesize the PiZ variant almost always manifest an aggregation of PAS-positive inclusion bodies in the ER of hepatocytes. Biochemical studies and immunoelectron microscopy has shown this material to consist of human α1AT that has accumulated within distended regions of the hepatocyte ER [12] . Individuals manifesting this intrahepatic aggregation of mutant α1AT are at increased risk of developing cirrhosis, because it is directly related to liver cell injury [25] . There is no evidence that the liver injury in α1AT deficiency is due to a deficiency of elastase inhibitory capacity (i.e. the protease-antiprotease imbalance). The strongest clinical argument against this hypothesis is the fact that Pi null (QO) individuals, i.e. patients with no detectable α1AT in their plasma, do not develop liver disease [26] . More importantly, individuals with Pi null (QO) lack the PAS-positive inclusion bodies. Furthermore, those with the PiS variant, who also lack the PAS-positive inclusion bodies, do not develop liver disease despite low plasma α1AT levels.

A conceptual model for the fate of the PiZ α1AT in the ER has recently been proposed by Qu et al [27] . Normally, α1AT molecules are synthesized in the hepatic cells begining with the transcription of mRNA from the α1AT gene. The rnRNA is then translocated out of the nucleus and translated on the ER to form a protein in the lumen of the ER. It may transiently associate with a polypeptide chain­binding protein (PCBP) until it has folded into a conformation that allows it to translocate to the Golgi apparatus. In α1AT-deficient individuals, the abnormal molecule is translocated into the lumen of the ER and associates with PCBP but is much less efficient at folding into the translocation-component, because of a single amino acid substitution (Glu 342→Lys) in a peptide fragment of the α1AT molecule. Only 15% of the newly synthesized molecules traverse the secretory pathway to the Golgi apparatus. Most newly synthesized α1AT molecules remain bound and ultimately undergo degradation in the ER. Therefore, any factor that inceases the net balance of abnormally folded α1AT in the ER would predispose the α1AT-deficient individual to hepatic disease. Experimental results in transgenic mice, with normal plasma α1AT levels, are consistent with this theory and exclude the possibility that liver damage is caused by a 'proteolytic attack' as a consequence of diminished serum α1AT concentrations [28],[29] .


   Mechanism of Z α1AT aggregation in the ER Top


One possible mechanism of Z α1AT aggregation in the ER has recently been suggested [30],[31] . These studies have shown that the α1AT can polymerize when the reactive center loop of an α1AT molecule is inserted into a gap in the β-pleated sheet of an adjacent native α1AT molecule. Lomas and coworkers [30] , noted that the site of the amino acid substitution in the PiZ α1AT variant was at the base of the mobile reactive center loop, adjacent to the gap in the A sheet. These authors predicted that the mutation would act to open the A sheet, thereby favoring spontaneous loop into β-sheet polymerization [Figure - 3], a process that is both concentration and temperature dependent. Presumably, an increase in body temperature during systemic inflammation may thus accelerate the polymerization process and increase the intracellular aggregation thus exacerbating subsequent liver cell damage. Using electron microscopy, these authors showed the presence of such polymers in the ER of hepatocytes in a liver biopsy specimen from a PiZZ individual [30] . They also showed the presence of similar polymers in the plasma of patients with other mutants of α1AT than PiZ: α1AT iivama (Ser 53Phe) and α1AT M malton (52Phe deletion ) [32],[33] . As a AT is an acute-phase protein, its level will increase during episodes of inflammation. At these times, the formation of polymers is likely to overwhelm the degradative pathway, thereby promoting an increase of hepatic inclusions and exacerbating the associated hepatocellular damage [34] .


   Factors that may modulate liver disease in α1AT deficiency Top


Although the structural defect resulting in aggregation of Z α1AT is known, less is known about why the aggregation of this deficient variant (PiZ) should cause liver injury. Any pathogenesis proposed for permanent liver injury must take into consideration the fact that the majority of homozygotes (PiZZ) do not develop liver disease. Because the polymerization defect is universal in such individuals, the presence of hepatocyte inclusion bodies does not provide a full explanation. This suggests that additional environmental agents or the presence of auxiliary genetic determinants may be required to produce hepatocyte injury in such individuals. Findings in a recent investigation, using mutant protein insertion into fibroblasts from α1AT-deficient patients who develop liver disease, suggest the possibility that a second inherited defect (i.e. a lag in ER degradation) exists in the ER, which does not allow adequate degradation of the Z α1AT [35] . Alcohol consumption has not proved to be an important additional factor in the development of liver disease in homozygous (PiZZ) adults with α1AT deficiency [23],[24] but may be important as an additional factor in the development of liver disease in heterozygous (PiZ) individuals with α1AT deficiency [36] . An Austrian study has suggested chronic liver disease in patient with α1AT deficiency to be associated with a high prevalence of viral hepatitis, particularly hepatitis C infection [37] . This infection, rather than α1AT deficiency alone, was suggested to be the cause of the liver disease in such patients. But PiZ homozygosity does not seem to be associated with an increased prevalence of virus infection [24],[28] . Moreover, Eigenbrodt and coworkers have shown an association to exist between heterozygous α1AT deficiency (PiZ) and end stage liver disease of several etiologies, but not of HCV infection alone [36] . These authors concluded that the association with some types of chronic liver disease (i.e. hepatitis C infection and alcoholic liver disease) but no others (i.e. autoimmune hepatitis) supports the concept that exaggeration of the retention of α1AT may be the pathogenetic mechanism involved. It has been shown that at least two products of hepatitis C virus bind with calnexin and are retained in the ER [39] ; therefore, it has been suggested that hepatitis C infection could exaggerate the hepatotoxic effect of α1AT in the heterozygote by competing with α1AT for binding to calnexin, in effect preventing the abnormal α1AT from accessing the degradative compartment [25] .

Isolated case reports have suggested relationship to exist between severe α1AT deficiency and genetic hemochromatosis (GH) [40],[41] and more recently correlation was reported to exist between heterozygous (PiZ) α1AT deficiency and GH in a series of 15 patients referred to a liver transplantation center in the USA [42] . In a recent study [42] , no relationship was found to exist between GH and heterozygous α1AT deficiency, but unexpectedly 4.5% of the GH patients were found to be homozygous for the PiZ gene, a proportion more than 80-fold greater than that expected in the general population. The presence of the PiZ gene in these patients contributed to an earlier onset of cirrhosis. The hemochromatosis gene, HLA-H, has recently been cloned and two mutations have been described (Cys 282→Tyr and His 63→Asp) [44],[45] . Further studies are needed to evaluate that frequency of these mutations of the HLA-H, gene in patients with homozygous and heterozygous α1AT deficiency.


   Heterozygous a,AT deficiency and chronic liver disease Top


Heterozygous carriers of a single dose of the mutan PiZ-gene are frequent in the general population, close to 5% in the Scandinavian countries. Most heterozygous deficients are PiMZ and have 50-60% of nonnal plasma a,AT level and a minority, approximately 1/750, are PiSZ and have 30-40% of the normal plasma α1AT level [1] . Two screening programmes have provided information about the propensity of PiZ-heterozygotes to develop liver disease early in life. In the first [46] close to 25.000 Italian new boors were subjected to Pi-phenotyping of α1AT by isoelectric focusing. Liver function tests were performed in 833 PiMZ children. The results were noteworthy, and clearly demonstrated a partly self-limiting, predominantly subclinical liver involvement in 19% of the children with intermediate α1AT deficiency. The results of a long-term follow-up is awaited with great interest. Sveger's prospective study [11] , discussed above, includes not only PiZ homozygotes but also a number of PiSZ heterozygotes. In adolescence age 16 and 18 years, 8 and 12% of the PiSZ subjects had subtle serum enzyme abnormalities respectively. PAS-positive inclusion bodies are less abundant in heterozygotes than in homozygotes, and the presence of some additional factor such as chronic virus infection may be necessary to provoke serious liver disease. We have recently studied 706 consecutive patients with clinical and/or biochemical evidence of chronic liver disease, 44 were found to have the PiZ variant of a,AT deficiency, of whom one was a homozygote (PiZZ) and the remaining 43 were heterozygotes (PiZ) [47] . Although there was no overrepresentation of chronic viral infection (B or C) or alcohol abuse in heterozygous α1AT deficiency as compared to the non-PiZ carriers, the possibility that viral infection or alcohol abuse is associated with greater severity of liver disease in PiZ-heterozygotes could not be excluded. These findings are noteworthy, if confirmed in a larger population of PiZ-carriers, because they bear out the long-held notion of many clinicians that heterozygosity for the α1AT gene should not be accepted as a diagnostic cause of severe liver disease. One possible explanation is that exogenous factors (i.e. the presence of viral hepatitis and/or alcohol abuse) cause liver injury, which in turn brings the patient to the attention of the hepatologist, it being this attention alone that results in the detection of the PiZ heterozygous state. Were this true, then the prevalence of the heterozygosity would be the same among patients with hepatitis C infection or among alcohol abusers as it is in the general population. To the best of knowledge such data are not available. Another possible explanation is that the presence of theα1AT PiZ gene product predisposes to viral infection. Were this true, however, then the viral infection rate should be even higher among homozygotes, which we did not find to be the case [24] . Clearly, further studies of large series of heterozygotes for α1AT deficiency with chronic liver disease are needed to investigate the presence of such risk factors that might predispose to chronic liver disease, and to test these factors for correlation to the severity of liver disease.


   Treatment Top


The diagnosis ofα1AT deficiency in a patient, irrespective of the mode of presentation (lung, liver or other symptoms, i.e. vasculitis), should lead to family investigations, at least of first degree relatives. It is important to identify homozygotes (25% of siblings are homozygotes) in an early and asymptomatic stage. Emphysema is the basic defect in α1AT deficiency-related lung disease. It is, however, desirable to perform lung function studies occasionally even in asymptomatic non-smoking individuals with homozygous α1AT deficiency (PiZZ). Emphysema development may occur in such individuals, particularly after age 50 [50] . Avoidance of smoking is an important preventative therapy.

A regular assessment of liver function is appropriate for all patients with α1AT deficiency particularly the homozygotes (PiZZ). Considering the indolent nature of the liver disease test reflecting total hepatocellular function should be the most useful in monitoring. Amino transferases and bilinibin may be normal at any given time. In elderly patients with severe α1AT deficiency the significant risk of malignant transformation in a cirrhotic liver should be recognized [24] . Physicians should also be alert to the possible of renal disease [48],[49] and vasculitic complications in both heterozygous [4],[5],[6],[7] and homozygous deficiency [9] .In adults rapidly progressive decompensation of liver disease is frequent. In the absence of serious pulmonary manifestations, indication for liver transplantation are essentially those for decompensation due to chronic liver disease of any type. Careful preoperative evaluation of lung function and for the presence of hepatocellular carcinoma is mandatory. In children, a ,AT deficiency (PiZZ) constitutes the largest indication subgroup of metabolic errors for liver transplantation. But, as demonstrated in the large Swedish prospective series [11] only a minority of all children with α1AT deficiency will develop cirrrhosis before age 20. Many of them have a slow disease progression and favourable prognosis despite biochemical (transferase) or even clinical signs (hepatomegaly) of chronic liver disease. When liver transplantation is performed survival rates in children are excellent, close to 90% at one year and 80% at five years. Survival rate in adults is lower partly due to concomitant disease manifestations such as emphysema.

At present somatic gene therapy is not a realistic therapeutic alternative for α1AT deficiency related liver disease. To have significant effect, hepatic gene therapy must ideally result in correction of the genetic defect in a majority of cells. So far, levels of transferred gene products have been too low and been maintained only transiently. Both retro- and adenoviral vectors have been disappointing and even if the gene products had reached significant levels residual PiZ genes may possibly have hepatotoxic effects via feed-back induction of the aberrant PiZ protein. Attractive alternatives for treatment of liver disease are novel types of gene therapy permitting inhibition of PiZ protein synthesis and thereby accumulation of the aberrant protein in the ER (reviewed by Qu et al, reference 27).

 
   References Top

1.Eriksson S, Elzouki AN. α1,-Antitrypsin deficiency. Bailliere's Clin Gastroenterol. In press.  Back to cited text no. 1    
2.Rabin M, Watson M, Kidd V, Woo SLC, Breg WR, Rudde FH. Regional location of α1,-antichymotrypsin and α1,­antitrypsin genes on human chromosome 14. Somatic Cell Mol Genet 1986;12:209-14.  Back to cited text no. 2    
3.Crystal RG. α1,-Antiitrypsin deficiency, emphysema, and liver disease: genetic basis and strategies for therapy. J Clin Invest 1990;85:1343-52.  Back to cited text no. 3    
4.Esnault VL, Testa A, Audrain M. Alpha 1-antitrypsin genetic polymorphism in ANCA-positive systemic vasculitis. Kidney Int 1993;43:1329-32.  Back to cited text no. 4    
5.Elzouki AN, Segelmark M, Wieslander J, Eriksson S. Strong link between the alpha 1-antitrypsin PiZ allele and Wegener's granulomatosis. J Int Med 1994;236:543-8.  Back to cited text no. 5    
6.Savige JA, Chang L, Cook L, Burden J, Daskalakis M, Doery J. a,-antitrypsin deficiency and anti-proteinase 3 antibodies in anti­neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis. Clin Exp Immunol 1995:100:194-7.  Back to cited text no. 6    
7.Griffith ME, Lovegrove JU, Gaskin G, Whitehouse DB, Pusey CD. C-antineutrophil cytoplasmic antibody positivity in vasculitis patients is associated with the Z allele of alpha 1­antitrypsin, and p-antineutrophil cytoplasnc antibody positivity with the S allele. Nephrol Dial Transplant 1996;11:438-43.  Back to cited text no. 7    
8.Segelmark M, Elzouki AN, Wieslander J, Eriksson S. The PiZ gene of α1-antitrypsin as a determinant of outcome in PR3-ANCA-positive vasculitis. Kidney Int 1995;48:844-50.  Back to cited text no. 8    
9.Mazodier P, Elzouki AN, Segelmark M, Eriksson S. Systemic necrotizing vasculitides in severe α1-antitrypsin deficiency. Q J Med 1996;89:599-511.  Back to cited text no. 9    
10.Gartner JC, Zitelli BJ, Malatack JJ, Shaw BW, Iwatsuki S, Starzl TE. Orthotopic liver transplantation in children: Two­year experience with 47 patients. Pediatrics 1984;74:140-5.  Back to cited text no. 10    
11.Sveger T, Eriksson S. The liver in adolescents with α1,­antitrypsin deficiency. Hepatology 1995;22:514-7.  Back to cited text no. 11    
12.Sharp HL, Bridges RA, Krivit W, Freier EF. Cirrhosis associated with alpha 1-antitrypsin deficiency: A previsouly unrecognized inherited disorder. J Lab Clin Med 1969;73:934-9.  Back to cited text no. 12    
13.Cottrall K, Cook PJG, Mowat AP. Neonatal hepatitis syndrome and alkpha I -antitrypsin deficiency: An epidemiological study in south-east England. Postgrad Med J 1974;50:376-80.  Back to cited text no. 13    
14.Sveger T. Liver disease in alpha 1-antitrypsin deficiency detacted by screening of 200.000 infants. N Engl J Med 1976;299:1316-21.  Back to cited text no. 14    
15.Birrer P, Me El vaney NG, Chang-Stroman LM, Crystal RG. Alpha I-antitrypsin deficiency and liver disease. JInherit Metab Dis 1991;14:512-25.  Back to cited text no. 15    
16.Nebbia G, Hadchouel M, Odievre M, Alagille D. Early assessment of evolution of liver disease associated with α1AT deficiency in childhood. J Pediatr 1983;102:661-5.  Back to cited text no. 16    
17.Ibarguen E, Gross CR, Savik SK, Sharp HL. Liver disease in α1AT deficiency: prognostic indicators. J Pediatr 1990;117:864-70.  Back to cited text no. 17    
18.Sveger T. The natural history of liver disease in α1r­antitrypsin deficient children. Acta Paediatr Scand 1988;77:847-51.  Back to cited text no. 18    
19.Psacharopoulos HT, Mowat AP, Cook PJL, Carlille PA, Portmann B, Rodeck CH. Outcome of liver disease associated with alpha ,-antitrypsin deficiency (PiZ). Arch Dis Child 1983;58:882-7.  Back to cited text no. 19    
20.Berg NO. Eriksson S. Liver disease in adults with alpha,­ antitrypsin deficiency. N Engl J Med 19972;287:1264-7.  Back to cited text no. 20    
21.Larsson C. Natural history and life expectancy in severe alpha 1-antitrypsin deficiency, PiZ. Acta Med Scand 1978;204:345-51.  Back to cited text no. 21    
22.Cox DW, Smyth S. Risk for liver disease in adults with α1,­ antitrypsin deficiency. Am J Med 1983:74:221-7.  Back to cited text no. 22    
23.Eriksson S, Carlson J, Velez R. Risk of cirrhosis and hepatocellular carcinoma in alpha ,-anti trypsin deficiency. N Engl J Med 1986;314:736-9.  Back to cited text no. 23    
24.Elzouki AN, Eriksson S. Risk of hepatobiliary diseases in adults with severe alpha ,-antitrypsin deficiency (PiZZ): Is chronic viral hepatitis B or C an additional risk factor for cirrhosis and hepatocellular carcinoma? Eur J Gastroenterol Hepatol 1996;8:989-94.  Back to cited text no. 24    
25.Teckman JH, QU D, Perlmutter DH. Molecular pathogenesis of liver disease in α1,-antitrypsin deficiency. Hepatology 1996;24:15.4-16.  Back to cited text no. 25    
26.Curiel D, Brantly M, Curiel E, Stier L, Crystal RG. aantitrypsin nullMattawa gene. J Clin Invest 1989;83:1144-52.   Back to cited text no. 26    
27.Qu D, Teckman JH, Perlmutter DH. α1-Antitrypsin deficiency associated liver disease J Gastroenterol Hepatol 1997;12:404-16.  Back to cited text no. 27    
28.Dycaico JM, Pollard AJ, Kohler SW, Short HP, Jink FR, Hanathan D, Sorge JA. Neonatal hepatitis induced by α1-­antitrypsin: a transgenic mouse model. Science 1988;242:1409-12.  Back to cited text no. 28    
29.Carlson JA, Rogers BB, Sifers RN, et al. Accumulation of PiZ α1,-antitrypsin causes liver damage in transgenic mice. J Clin Invest 1988;83:1183-90.  Back to cited text no. 29    
30.Lomas DA, Evans DLI, Finch JT, Carrell RW. The mechanism of Z α1-antitrypsin accumulation in the liver. Nature 1992;357:605-7.  Back to cited text no. 30    
31.Mast AE, Enghild JJ, Salvesen G. Conformation of the reactive site loop of α1-proteinase inhibitor probed by limited proteolysis. Biochemistry 1992;31:2720-8.  Back to cited text no. 31    
32.Lomas DA, Finch JT, Seyama K, Nukiwa T, Carrell RW. α1-­antitrypsin Siiyama (ser53→Phe); further evidence for intracellular loop-sheet polymerization. J Biol Chem 1993;268:15333-35.  Back to cited text no. 32    
33.Lomas DA, Elliott PR, Sidhar SK, et al. Alpha, -antitrypsin Mmalton ( 52 Phe deleted) forms loop sheet polymers in vivo. Evidence for the C sheet mechanism of polymerisation. J Biol Chem 1995;270:16864-70.  Back to cited text no. 33    
34.Lomas DA. New insights into the structural basis of α1-­antitrypsin deficiency. Q J Med 1996;89:807-12.  Back to cited text no. 34    
35.Wu Y, Whitman F, Mobments E, Moore K, Hippenmeyer P, Perlmutter DH. A lag in intracellular degradation of mutan α1-antitrypsin correlated with the liver disease phenotype in homozygous PiZZ a,-antitrypsin deficiency. Proc Natl Acad Sci USA 1995;91:9014-8.  Back to cited text no. 35    
36.Eigenbrodt ML, Me Cashland TM, Dy RM, Clark JC, Galati J. Heterozygous a,-antitrypsin phenotypes in patients with end stage liver disease. Am J Gastroenterol 1997;92:602-6.  Back to cited text no. 36    
37.Propst T, Props A, Dietze O, Judmaier G, Braunsteiner H, Vogel W. High prevalence of viral infection in adults with homozygous and heterozygous alpha 1-antitrypsin deficiency and chroni liver disease. Ann Int Med 1992;1 17:641-5.  Back to cited text no. 37    
38.Teckman J, Perlmutter DH. Conceptual advances in the pathogenesis and treatment of childhood metabolic liver disease. Gastroenterology 1995;108:1263-79.  Back to cited text no. 38    
39.Dubuisson J, Rice CM. Hepatitis C virus glycoprotein folding: Disulfide bond formation and association with calnexin. J Virol 1996;70:778-86.  Back to cited text no. 39    
40.Anand S, Schade RR, Bendetti C, et al. Idiopathic hemochromatosis and alpha I-antitrypsin deficiency: Coexistence in a family with progressive liver disease in the proband. Hepatology 1983;3:714-8.  Back to cited text no. 40    
41.Eriksson S, Lindmark B, Hanik L. A swedish family with alpha I-antitrypsin deficiency, haemochromatosis, haernoglobinopathy D and early death in liver cirrhosis. J Hepatol 1986;2:65-72.  Back to cited text no. 41    
42.Rabinovitz M, Gavaler JS, Kelly RH, van Thiel DH. Association between heterozygous alpha I-antitrypsin deficiency and henetic hemochromatosis. Hepatology 1992;16:145-8.  Back to cited text no. 42    
43.Elzouki AN, Hultcrantz R, St$l P, Befrits R, Eriksson S. Increased PiZ gene frequency for a,-antitrypsin in patients with genetic haemochromatosis. Gut 1995;36:922-6.  Back to cited text no. 43    
44.Fader JN, Gnirke A, Thomas W, et al. A novel MHC class (­like gene is mutated in patients with herediatry haemochromatosis. Nat Genet 1996;13:399-408.  Back to cited text no. 44    
45.Beutler E, Gelbart T, West C, et al. Mutation analysis in hereditary hemochromatosis. Blood Cells Mol Dis 1996;22:187-94.  Back to cited text no. 45    
46.Pittschieler K. Heterozygotes and liver involvement. Acta Paediatrica I994;83(suppl 393):21-3.  Back to cited text no. 46    
47.Elzouki AN, Verbaan H, Lindgren S, Widell A, Carlson J, Eriksson S. Serpins in patients with chronic viral hepatitis. J Hepatol 1997:27:42-8.  Back to cited text no. 47    
48.Elzouki AN, Lindgren S, Nilsson S, Bela Veress, Eriksson S. Severe α-antitrypsin deficiency (PiZ homozygosity) with membranoproliferative glomerulonephritis and nephrotic syndrome, reversible after orthotopic liver transplantation. J 1-lepatol 1997;26:1403-7.  Back to cited text no. 48    
49.Elzouki AN, Sterner G, Eriksson S. Henoch-Schonlein purpura and α1-antitrypsin deficiency. Nephrol Dial Transpi 1995:10:1454-7.  Back to cited text no. 49    
50.Piitulainen E, Tomling G, Eriksson S. Effect of age and occupational exposure to airway irritants on lung function in non-smoking individuals with α1-antitrypsin deficiency (PiZZ). Thorax 1997;52:244-8.  Back to cited text no. 50    

Top
Correspondence Address:
Abdul-Nasser Elzouki
Department of Medicine, Malmo University Hospital, 205 02 Malmo
Sweden
Login to access the Email id

Source of Support: None, Conflict of Interest: None


PMID: 19864752

Rights and PermissionsRights and Permissions


    Figures

  [Figure - 1], [Figure - 2], [Figure - 3]



 

Top
 
  Search
 
  
  
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Email Alert *
    Add to My List *
* Registration required (free)  


    Abstract
    Childhood onset ...
    Adult onset live...
    Pathogenic mecha...
    Mechanism of Z &...
    Factors that may...
    Heterozygous a,A...
    Treatment
    References
    Article Figures

 Article Access Statistics
    Viewed5294    
    Printed180    
    Emailed3    
    PDF Downloaded0    
    Comments [Add]    

Recommend this journal