BILE-DUCT DESTRUCTION AND COLLAGEN DEPOSITION - A PROMINENT ULTRASTRUCTURAL FEATURE OF THE LIVER IN CYSTIC-FIBROSIS

To study the liver disease of patients with cystic fibrosis, percutaneous liver biopsies were performed in 10 patients with cystic fibrosis aged 6 to 22 yr. Nine of 10 patients had high Shwachman scores, eight had normal serum levels of transaminases. Light-microscopical examination showed steatosis in seven cases and in five slight or moderate inflammatory infiltration. Eight patients showed varying degrees of fibrosis and even cirrhosis. Six patients had bile-duct proliferation and, in one case a bile plug was found. Other signs of cholestasis were not seen. Electron-microscopical investigation showed no specific signs of cholestasis such as ductal plugs or intracellular bile pigments. The canaliculi were not dilated, except in one case. Most patients had bile-duct cells with irregular shapes, protruding into the lumen, and some cases even had necrotic cells. Around the bile ducts and ductules, collagen was deposited and fat-storing cells were a common finding. Our findings do not support the view that cholestasis is the pathogenetic factor in liver disease in cystic fibrosis. A cytotoxic influence on the biliary cells, stimulating collagen deposition, seems more likely.