Biliary casts after liver transplantation: morphology and biochemical analysis.

Aim: To investigate the pathogenesis of biliary casts after liver transplantation relative to their morphology and biochemical markers.

Methods: The microstructure of biliary casts was assessed using scanning electron microscopy and Hematoxylin and eosin staining assessed their histology. The expression levels of CD3, CD5, CD34, CD68 and CD79a in these biliary casts were evaluated immunohistochemically.

Results: Biliary casts differed widely in their microstructure, with some containing blood vessels positive for CD34 and collagen fibers with positive Masson staining. Large numbers of neutrophils and other inflammatory cells were present, but only on the edge of the biliary casts; although the boundaries were clear without crossover. None of the biliary casts contained T-lymphocytes, B-lymphocytes, macrophages and other inflammatory cells.

Conclusion: The microcostructure of biliary casts differed. Bacteria and acute rejection are not clearly related to their formation.