Orcein positive hepatocellular material in long-standing biliary diseases. II. Ultrastructural studies.

An ultrastructural study of liver cells was performed on 4 patients with primary biliary cirrhosis (PBC) and on 3 patients with chronic active hepatitis (CAH). In liver cells of PBC patients large (ad 2-3 mu in diameter) particles were seen, which morphologically resembed autophagic vacuoles or large secondary lysosymes. The morphology, size, location, and quantity of these particles corresponded to the orcein positive material seen in light microscopy of adjacent sections in specimens from PBC patients. These large particles were not seen in liver cells of CAH patients, which also lacked the orcein positive material in light microscopy. The author suggests that the observed particles indicate the activation of lysosomal compartment in liver cells in PBC, and that the orcein positive material (copper-protein complex accumulating in liver cells in chronic cholestasis) is taken into the phagolysosomal metabolism and processing in liver cells, and possibly resembles in this respect the intracellular metabolism of iron-compounds.