Alpha-1-antitrypsin deficiency and juvenile liver disease Ultrastructural observations compared with light microscopy and routine liver tests

Abstract

Sixteen children (aged between 1 month and 20 years) with α-1-antitrypsin deficiency (PiZ) were investigated by liver biopsy on one or more occasions. Eight patients had suffered from neonatal cholestasis, and two of them were investigated during the cholestatic period as well. The clinical status and liver function tests were compared with the light and electron microscopical findings. According to the light microscopical analyses at the latest investigation, the cholestatic and noncholestatic patients were classified as healthy, fibrotic or cirrhotic cases. All livers displayed periodic acid-Schiff positive, diastase-resistant globules in some but not all periportally located hepatocytes. By electron microscopy accumulation of retained secretory material was found in all PiZ patients. This accumulation was most conspicuous in the smooth endoplasmic reticulum of hepatocytes. α-1-antitrypsin deficiency seems to affect some, but not all hepatocytes. In the affected cells disappearance or hypotrophy of the Golgi complex could be observed. The intracellular transport of very low density lipoproteins (VLDL) was apparently not affected. The migration block in α-1-antitrypsin deficiency seems to occur before transportation to the Golgi complex. The extent of the involvement was not strictly age-dependent. There was no ultrastructural evidence of subclinical cholestasis as a possible triggering factor in the development of cirrhosis.