Natural history and prognostic models in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the intra- and extra-hepatic bile ducts. Despite the recognition of immunological and genetic alteratio ns cited as factors in its pathogenesis, the exact cause for PSC remains un known. Observational cohort studies, however, have demonstrated that PSC is a progressive disease culminating in liver failure or death. Natural histo ry assessment in PSC, however, has been complicated by variable rates of di sease progression and the impact of clinical symptoms upon initial presenta tion. The development of mathematical models by multivariable regression te chniques (most notably Cox proportional hazards regression) has allowed for an improved description of overall survival on an individual basis among p atients with PSC. Additionally, these models have also been employed for de termining the optimal selection and timing for liver transplantation when a dvanced disease is imminent.