Pathogenesis of liver disease in alpha 1-antitrypsin deficiency

Alpha-1-antitrypsin deficiency (A1ATD) is one of the most common lethal hereditary disorders. Approximately 5 to 10% of the general population carry an "at risk" gene for the development of liver disease or emphysema of the lung. Patients with A1ATD associated liver disease constitute a histologically and clinically heterogeneous group. The pathogenesis of the disease still remains to be elucidated. Recent experimental evidence produced in the transgenic mouse model is in favour of the engorgement hypothesis considering the deposition of amorphous A1AT in the hepatocytes the prime event causing liver disease. This theory, however, fails to explain the clinical observation of the presence of a number of other factors known to cause chronic liver disease in A1ATD patients. The latter observation is in support of the deficiency theory, which explains the pathogenesis of emphysema of the lung, and would point to A1ATD as a predisposition to acquire chronic disease. The meaning of the increased synthesis of stress proteins in patients with liver disease is still speculative.