Portacaval shunt in three children with alpha-1-antitrypsin deficiency and cirrhosis: 9 to 12 1/3 years later

Liver Transplantation in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin (AAT) deficiency is a common inherited metabolic disorder caused by a point mutation in the SERPIN1A gene. A small portion of homozygous PI*ZZ individuals develop severe liver disease that requires liver transplantation. Posttransplant survival is excellent. The largest burden of advanced liver disease lies within the adult population rather than children. Evaluation of lung function in adults before transplant is essential because of the underlying risk for chronic obstructive pulmonary disease. Post-liver transplantation lung function should also be monitored for decline. Although uncommon, cases of simultaneous lung and liver transplant for AAT deficiency have been reported.

Alpha-1-Antitrypsin Deficiency: Current Concepts

Since the condition was first described four decades ago, alpha-1-antitrypsin (A1AT) deficiency has served as a model for other disease processes. A1AT is the archetypal serpin designed to ensnare proteases, a process that involves significant conformational change within the molecule. Mutations in the A1AT gene lead to misfolding of the protein and accumulation within the endoplasmic reticulum of hepatocytes resulting in two different pathologic processes. First, the accumulation of mutant A1AT protein has a directly toxic effect on the liver, resulting in hepatitis and cirrhosis. Second, the resultant decrease in circulating A1AT results in protease-antiprotease imbalance at the lung surface and emphysema ensues. A1AT deficiency therefore can be seen as two distinct disease processes: a conformational disease of the liver and a protease-antiprotease imbalance of the lung. This two-stage model of disease in A1AT deficiency is elegant in its simplicity and goes a long way to explaining the clinical manifestations that occur in patients with the condition. However, some aspects of the disease are not readily explained. Recent findings suggest that there is more to the lung damage in A1AT deficiency than simple proteolytic insult and that the presence of the mutant protein itself is proinflammatory and may indeed cause chronic injury to the cells that produce it. This review discusses some of the emerging concepts in alpha-1-antitrypsin research and outlines the implications these new ideas may have for treatment of this condition.

Alpha1-antitrypsin deficiency: biological answers to clinical questions

Alpha1-antitrypsin (alpha1AT) deficiency is a common lethal hereditary disorder of white persons of European descent. The condition is characterized by reduced serum levels of alpha1AT, a 52-kDa glycoprotein synthesized chiefly in the liver and, to a lesser extent, by macrophages and neutrophils. Alpha1AT acts as an antiprotease and is the physiological inhibitor of neutrophil serine proteases such as neutrophil elastase cathepsin G and proteinase 3. The clinical manifestations of alpha1AT deficiency occur chiefly in the lung, with a high risk of emphysema occurring by the third or fourth decade of life. Cigarette smoking accelerates the development of emphysema in persons with alpha1AT deficiency. There is also an increased risk of liver disease in alpha1AT deficiency, which occurs mostly in childhood. In this review, we will define further the diagnosis of alpha1AT deficiency and its clinical manifestations and describe the therapeutic strategies that are currently being developed to treat the hepatic and pulmonary disease associated with this condition.

Prognosis of alpha-1-antitrypsin deficiency-related liver disease in the era of paediatric liver transplantation

BACKGROUND/AIM

Alpha-1-antitrypsin deficiency (alpha1ATD) is the commonest metabolic disease leading to liver transplantation (LT) in children. Approximately 10-15% of the PiZZ population develops liver disease. Five percent of them will require LT within the first 4 years of life. This study aimed to investigate the prognosis of the liver disease associated with PiZZ alpha1ATD in the era of liver transplantation and to determine predictors of outcome.

METHODS

We reviewed retrospectively the clinical notes of 97 consecutive patients referred from January 1989, when LT became routinely available in our Unit, to July 1998.

RESULTS

Of 26 (27%) patients who developed end-stage liver disease, 24 have been transplanted and two are waiting for LT. Twenty-one (81%) of these patients presented with neonatal hepatitis at a median age of 2.1 months. Of 71 (73%) children who have not required LT, 61 (86%) presented with neonatal hepatitis at a median age of 1.6 months. Among infants with neonatal hepatitis who required LT, 18 out of 21 (86%) had jaundice for more than 6 weeks compared with 34 of 61 (56%) who survived without LT (p<0.01). Children requiring LT had higher aspartate aminotransferase (AST) at presentation (p<0.0001) and both higher AST and gamma-glutamyl transferase (GGT) at 6 months (p<0.001), 1-year (p<0.0003) and 5-year (p<0.01) follow up when compared to those who are well without LT. Furthermore, children who developed end-stage liver disease more frequently had severe bile duct reduplication (p<0.01), severe fibrosis (p<0.03) with bridging septa (p<0.02) and established cirrhosis (p<0.04) in the initial liver biopsy. Ninety-five of the 97 children (98%) are currently alive; two died after LT.

CONCLUSIONS

The advent of liver transplantation has significantly improved the prognosis of liver disease associated with PiZZ alpha1ATD. Duration of jaundice, severity of histological features and biochemical abnormalities predict outcome at an early stage of the disease.

Transplantation for end stage liver disease related to alpha 1 antitrypsin

Alpha 1 antitrypsin deficiency (AT) is an autosomal recessive disease associated with chronic liver disease in adults and children and emphysema in adults. The disease is one of the most common inherited disorders of the Caucasian population of North Europe and North America and is the most common genetic reason for pediatric orthotopic liver transplantation (OLTx), although it is a rare indication in adults. The natural history of the disease is unpredictable and the pathogenesis of the liver injury unclear. Thirty-five patients with histologically apparent alpha 1 AT accumulation in the liver (22 adults, 13 children) have been transplanted in this center. Clinical features were correlated with the pretransplant phenotype, serum alpha 1 antitrypsin levels and potential precipitating factors. All children were PiZZ homozygotes, most of whom had presented with neonatal hepatitis. The majority of adult patients were heterozygotes presenting with portal hypertension and liver cirrhosis. Current one-year posttransplant survival figures are 73% for adults and 87.5% for children. Replacement of the cirrhotic liver results in acquisition of the donor phenotype, a rise in serum levels of alpha 1 antitrypsin, and apparent prevention of associated disease.

Liver transplantation for end-stage liver disease associated with alpha-1-antitrypsin deficiency in children: pretransplant natural history, timing and results of transplantation

Alpha-1-antitrypsin deficiency is an inborn metabolism error which can cause emphysema and liver disease. As regards the pathophysiology of liver disease, this deficiency is poorly understood, and it is also not known why only a small proportion of Pi ZZ individuals progress towards cirrhosis and liver failure. Since there is no specific therapy for end-stage liver disease associated with alpha-1-antitrypsin deficiency, patients are considered candidates for liver transplantation. In this paper, the natural history of 16 children who underwent liver transplantation is reviewed. Fourteen patients had neonatal cholestasis as a first symptom of the disease and hepatosplenomegaly was present in all children by the age of 12 months. In 11 children, jaundice recurred, always with liver function deterioration. Two patients had a histological paucity of interlobular bile ducts and required early transplantation due to rapid progression of liver failure. At the time of pretransplant assessment, all the patients in this study had portal hypertension and seven of them had experienced at least one episode of gastrointestinal bleeding. One child had moderate intrapulmonary shunts with hypoxemia, but the others had normal spirometry and blood gases. There was no other extrahepatic complication of alpha-1-antitrypsin deficiency. Eighteen orthotopic liver transplantations were performed in 16 patients. One patient died 8 days after retransplantation due to graft necrosis. Fifteen patients (94%) were alive after a median follow-up of 22 months with an excellent quality of life, normal serum alpha-1-antitrypsin levels and without evidence of liver disease recurrence or pulmonary complications.(ABSTRACT TRUNCATED AT 250 WORDS)