CONCLUSION: BSIA in H69 cholangiocytes is calcium-dependent. Inhibition of sAC prevents BSIA. Cyto-solic sAC but not mitochondrial sAC is responsible for BSIA. Our results suggest that cAMP from cytosolic sAC promotes BSIA, whereas cAMP from tmAC protects against BSIA. These results provide an important link between the observed down-regulation of AE2 and increased apoptosis of cholangiocytes in PBC. (1)Hohenester et al. 2012 HEPATOLOGY 55:173 (2) Mardones et al. 2008 JBC 283:12146 Disclosures: Ulrich Beuers – Consulting: Intercept, PD-332991 Novartis; Grant/Research Support: Zam-bon; Speaking and Teaching: Falk Foundation, Gilead, Roche, Scheringh, Zam-bon The following
people have nothing to disclose: Jung-Chin Chang, Simei Go, Coen C. Paulusma, Ronald Oude Elferink Background Several biochemical criteria have been proposed to assess the therapeutic JQ1 response and long-term prognosis in ursodeoxycholic acid (UDCA)-treated PBC. These criteria were shown to have independent and additive predictive ability. This study aimed to define a single, unifying criterion identifying those patients at greatest need for second-line treatment. Methods Long-term follow-up data collected in 15 North American and European centers were analysed using Cox proportional hazard
regression models to construct prediction models based on numerous combinations of biochemical and clinical parameters that were obtained after one year of treatment with UDCA. The ability of these models to predict both liver transplantation-free Carnitine palmitoyltransferase II survival and liver-related death or liver transplantation (LTx), was tested using c-statistic and Akaike Information Criterion (AIC) and was compared with previously reported response criteria. A predictive index (PI) was calculated based on the beta coefficient of the final Cox regression model. Results 4119 UDCA-treated PBC patients were included. During a mean follow-up time of 8.4 years 320 patients underwent liver transplantation and 566 patients (269 liver
related) died. In the final multivariate model the following variables had the best predictive performance: Age at entry (p=8.7*10-39), bili-rubin (p=1.0*10-56), albumin (p=7.0*10-14) and AST/platelets ratio (APRI) (p=1.8*10-20). Survival for patients with a PI <50th percentile was comparable to that of an age-, sex- and calendar time-matched Dutch population (5-yr: 98% vs 98% and 10-yr: 94% vs 95% respectively, p=0.07). For patients with a PI ≥50th percentile survival was worse compared to a matched population (5-yr: 90% vs 94%, 10-yr: 75% vs 86% respectively, p<8.0*10-16). The prognostic utility of this model was superior to that of previously reported response criteria and was satisfactory in specific subgroups (Table). Conclusion This new composite model, based on age, bilirubin, albumin and APRI, represents an improved clinical tool for identifying patients with an insufficient therapeutic response after one year of UDCA treatment.