Published online Nov 21, 2013. doi: 10.3748/wjg.v19.i43.7772
Revised: September 24, 2013
Accepted: September 29, 2013
Published online: November 21, 2013
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.
Core tip: This experimental study employed scanning electron microscopy, Hematoxylin and eosin staining and immunohistochemistry to investigate biliary casts following liver transplantation. The results indicated that blood vessels and collagen fibers are present in biliary casts; however, bacteria and acute rejection are not clearly related to their formation, as evidenced by blood vessels positive for CD34 and collagen fibers with positive Masson staining, and no T-lymphocytes, B-lymphocytes, macrophages and other inflammatory cells. Thus, although bile duct injury after liver transplantation is significantly associated with biliary cast formation, their role in acute rejection is unclear.