Liver ultrastructure in psoriatics related to methotrexate therapy. 2. Findings in bile ducts from 11 methotrexate treated psoriatics and 2 controls.

To determinate what damage occurred in the bile ducts of psoriatics receiving Methotrexate (MTX) therapy liver biopsies from 11 patients were studied with the light and electron microscope and compared with normal material. Thick sections (1 micrometer) showed light and dark cells in biliary epithelium and lipofuscin granules. At the ultrastructural level these were confirmed. The lumen of the bile ducts contained debris. The microvilli were decreased in number and damaged forms appeared. Damage to the biliary epithelial mitochondria was widespread and there were foci of intracellular oedema. The Golgi apparatus was hypertrophied and dilated. Atrophic cells were seen. The lateral intercellular spaces were dilated and contained debris and the basement membrane showed zones of duplication. Similar changes were found in the ducts of Hering.