New insights from recurrent primary biliary cirrhosis in liver transplantation: the paradox of BEComing a fibroblast?

Keratin 19 epithelial patterns in cirrhotic stroma parallel hepatocarcinogenesis

Cirrhotic septa harbor vessels and inflammatory, fibrogenic, and ductular epithelial cells, collectively referred to as the ductular reaction (DR). Lack of the DR in the stromal compartment around hepatocellular carcinoma (HCC) has been documented; however, the relationship of epithelial keratin 19 (K19) structures to progression of intralesional carcinogenesis has not been explored. K19 immunoreactivity in the stromal compartment around 176 nodules in cirrhotic explants was examined. Quantitative differences (P < 0.0001) were manifested in three distinct histologically identifiable patterns: "complex" around cirrhotic nodules (CN), "attenuated" around dysplastic nodules (DN), and "absent" around HCC. Markers of necrosis or apoptosis could not explain the perinodular K19 epithelial loss; however, multicolor immunolabeling for K19, vimentin, E-Cadherin, SNAIL, and fibroblast-specific protein 1 (FSP-1) demonstrated discrepancies in immunophenotype and cytomorphologic features. Variability of cellular features was accompanied by an overall decrease in epithelial markers and significantly increased fractions of SNAIL- and FSP-1-positive cells in the DR around DN when compared with CN (P < 0.0001). Immunolabeling of transforming growth factor-β signaling components (TGFβR1, SMAD3, and pSMAD2/3) demonstrated increased percentages of pSMAD2/3 around DN when compared with CN (P < 0.0001). These findings collectively suggest marked alterations in cellular identity as an underlying mechanism for the reproducible extralesional K19 pattern that parallels progressive stages of intranodular hepatocarcinogenesis. Paracrine signaling is proposed as a link that emphasizes the importance of the epithelial-stromal compartment in malignant progression of HCC in cirrhosis.

Cyclosporine A protects against primary biliary cirrhosis recurrence after liver transplantation

Primary biliary cirrhosis (PBC) reoccurs in a proportion of patients following liver transplantation (LT). The aims of our study were to evaluate the risk factors associated with PBC recurrence and determine whether recurrent disease constitutes a negative predictor for survival. One hundred and eight patients receiving LT for end-stage PBC were studied. Recurrent disease was diagnosed in 28 patients (26%). Probability of recurrent PBC at 5 years was 13% and 29% at 10 years with an overall incidence of 3.97 cases per 100 patient years. By univariate Cox analysis use of tacrolimus (HR 6.28, 95% CI, 2.44-16.11, p < 0.001) and mycophenolate mofetil (HR 5.21, 95% CI, 1.89-14.33, p = 0.001) were associated with higher risk of recurrence; whereas use of cyclosporine A (CsA) and azathioprine were associated with reduced risk of recurrence (HR 0.13, 95% CI 0.05-0.35, p < 0.001 and HR 0.27, 95% CI 0.11-0.64, p = 0.003, respectively). In the multivariate Cox analysis, only CsA was independently associated with protection against recurrence (HR 0.17, 95% CI 0.06-0.71, p = 0.02). Five-year probability of survival was 83% and 96%, in patients without and with recurrence (log-rank test, p = 0.3). Although PBC transplant recipients receiving CsA have a lower risk of disease recurrence, the development of recurrent PBC did not impact on long-term patient survival.

Pathogenesis of primary biliary cirrhosis

Autoimmune phenomena have been recognized in primary biliary cirrhosis (PBC) for more than 50 years and the specificity of the characteristic responses directed at highly conserved mitochondrial antigens determined in detail over the past 20. Effecter autoreactive immune responses are characterized and potential mechanisms of breakdown of tolerance to self proposed. Elements of the clinical pattern of PBC, including the recurrence of the disease across HLA boundaries after liver transplantation, remain difficult to reconcile with a simple autoimmune model. Alternative (but not necessary mutually exclusive) pathogenetic models have been outlined, including a potential role for retroviral pathogens and directly cytopathic effects.