A morphological and immunohistochemical study of the effects of prednisolone or ursodeoxycholic acid on liver histology in feline lymphocytic cholangitis.

Feline lymphocytic cholangitis (LC) has been commonly treated with prednisolone, and more recently with ursodeoxycholic acid (UDCA). Previously, we found that prednisolone treatment resulted in a statistically longer survival time than treatment with UDCA. In order to explain this difference, we compared the effects of prednisolone and UDCA treatment on hepatic tissue by evaluating consecutive liver biopsies. Archival serial biopsy materials from cats with LC treated with prednisolone (n = 5) or UDCA (n = 4) were evaluated. We employed haematoxylin and eosin staining to evaluate inflammation, and reticulin staining for fibrosis. Immunohistochemical stainings for Ki-67, K19 (Cytokeratin 19) and α-smooth muscle actin were used to evaluate cell type-specific proliferation and activation of hepatic stellate cells. Inflammation decreased more in the group treated with prednisolone, while the number of cholangiocytes, progenitor cells and fibroblasts did not differ between the treatment groups. Additionally, no difference was found for the amount of fibrosis in both treatment groups.