Pathogenesis and pathology of liver disease associated with alpha 1-antitrypsin deficiency.

alpha 1-Antitrypsin (alpha 1-AT) accumulates in the rough endoplasmic reticulum through a mechanism of polymerization. Polymerization is favored by the incorrect tertiary structure of the alpha 1-AT caused by a point mutation at position 342 of the protein. Accumulation of alpha 1-AT in the liver cells (and in hepatocytes and colangiocytes) is not sufficient per se to explain the liver disease that is manifested in a minority of PiZ subjects and thus, a trigger factor must be hypothesized. A virus (hepatitis C virus or some other kind of virus not identified as yet) is among the most probable trigger factors. In Z subjects (among the general population), relevant liver disease is probably a more rare event than thought in the past and most of these subjects escape major liver disease. Usually, liver disease is not a significant problem in patients with COPD.