Hepatic stellate cells (Ito cells) in veno-occlusive disease of the liver after allogeneic bone marrow transplantation

Aims: To evaluate the role of activated hepatic stellate cells (HSCs) in hepatic veno-occlusive disease (VOD) after bone marrow transcription (BMT), we studied the distribution and area of activated HSCs by immunohistochemistry for a-smooth muscle actin (SMA). Methods and results: We examined the liver of seven autopsy cases with hepatic VOD or without VOD after allogeneic BMT and ave autopsy cases without liver disease as a control both microscopically and immunohistochemically. In normal liver tissues, SMA-positive cells were observed around the central veins, while they were more frequently noted along the sinusoidal walls as well as around the central veins in liver tissues with or without VOD after BMT. The area of activated HSCs increased significantly in zones 1 and 2, and more prominently in zone 3 of the liver tissues after BMT than normal liver tissues, and was much larger in zone 3 of liver tissues with VOD, The activated HSCs were immunohistochemically negative for the regulatory contractile proteins (heavy caldesmon and calponin). Conclusions: These results indicated that the activated HSCs may play an important role in sinusoidal fibrosis and luminal narrowing or occlusion of the central veins in VOD after BMT.