Figure 2.

Z α₁-antitrypsin is retained within hepatocytes as intracellular inclusions. These inclusions are PAS-positive and diastase resistant (A) and are associated with neonatal hepatitis and hepatocellular carcinoma. (B) Electron microscopy of a hepatocyte from the liver of a patient with Z α₁-antitrypsin deficiency shows the accumulation of α₁-antitrypsin within the rough ER (arrow). These inclusions are composed of chains of α₁-antitrypsin polymers shown here from the plasma of a Siiyama α₁-antitrypsin homozygote (C). More recently, polymers have been identified within PAS-positive inclusions with a monoclonal anti-polymer α₁-antitrypsin antibody. (D and E) Immunochemistry of the liver from an individual with Z α₁-antitrypsin deficiency, showing staining with an anti-α₁-antitrypsin polyclonal antibody (D, arrow) and a monoclonal anti-polymer α₁-antitrypsin antibody (E, arrow). It is these intracellular inclusions of polymers that are associated with neonatal hepatitis and hepatocellular carcinoma. Figure reproduced with permission from Lomas et al.⁹⁷