Alpha1-antichymotrypsin globules within hepatocytes in patients with chronic hepatitis C and cirrhosis

Protease inhibitors: a panacea?

With the increasing evidence of protease involvement in several diseases, novel strategies for drug development involve the use of protease inhibitors (PIs). The local balance between protease inhibitors and proteases is an important determinant of the occurrence and progression of a particular disease. Hence, enzymes and their cognate inhibitors are finding their applications as diagnostic and prognostic markers. PIs are widely implicated for their use in host defense against infection, tissue repair and matrix production, blood coagulation, cancer, and they are, therefore, the current focus as therapeutic alternatives for major diseases such as AIDS and Alzheimer's diseases. This review is a brief summary of the varied role of protein protease inhibitors in controlling the activity of aberrant enzymes in several diseases afflicting mankind today.

[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.

Inherited metabolic diseases of the liver

Many inherited metabolic diseases affect the liver in neonates, children, or adults. The histopathologic changes are diverse and may be acute or chronic. They can be considered primary (when the injury is from the cytopathic effect of an accumulated metabolite) or secondary (e.g., an infection caused by an immune deficiency). All forms of liver disease are described: for example, intrahepatic cholestasis, neonatal hepatitis with giant-cell transformation, paucity of bile ducts, steatosis, steatohepatitis, necroinflammatory diseases (acute or chronic), fibrosis, cirrhosis, and neoplasms (benign or malignant). Familiarity with the morphologic changes is important in clinicopathologic correlation, diagnosis, and understanding of pathogenetic mechanisms.

Role of alpha-1-antichymotrypsin deficiency in promoting cirrhosis in two siblings with heterozygous alpha-1-antitrypsin deficiency phenotype SZ

BACKGROUND

Alpha-1-antitrypsin (A1AT) deficiency is the most common inherited metabolic disorder with the potential to cause injury in the lung and liver. Recent reports suggested that alpha-1-antichymotrypsin (A1AC) deficiency may also be a possible cause of chronic liver disease. However, it has received little attention and is rarely investigated in the clinical setting.

AIMS

To assess the role of A1AC deficiency in the pathogenesis of chronic liver disease in two siblings with heterozygous A1AT phenotype Pi SZ.

PATIENTS

Two adult siblings with an A1AT Pi SZ phenotype and reduced levels of A1AC consistent with heterozygosity who developed cirrhosis and underwent liver transplantation.

METHODS AND RESULTS

A1AT and A1AC levels in plasma measured by electroimmunoassay were 74 mg/dl and 90 mg/dl (140-470) and 0.12 mg/ml and 0.14 mg/ml (0.173-0.46), respectively. Immunohistochemistry revealed an apparent accumulation of both A1AT and A1AC in hepatocytes. A previously reported point mutation in exon III (Pro(229) to Ala substitution) of the A1AC gene was not detected by polymerase chain reaction amplification and a single strand conformation polymorphism analysis.

CONCLUSIONS

Our report represents the first case of two siblings with A1CA phenotype Pi SZ who developed cirrhosis and underwent liver transplantation. Both siblings were heterozygous for A1AT and A1AC deficiency suggesting that combined deficiency of these two major serine protease inhibitors may enhance the risk of developing liver disease.