Patients with acute or subacute onset of liver disease Patients who have received a liver transplant Age < 18 MELD score >12 Patients whose MELD scores are currently less than or equal to 12 but with history of prior deterioration with MELD score >12 Unable to provide informed consent Patients with HIV or HBsAg seropositivity Pregnant or lactating females Enrolled in another research protocol Any condition that precludes serial follow up Patients with history of malignancy within the last 5 years, except for non-melanoma skin cancer or cervical carcinoma in situ Any lesions suspicious for liver cancer on CT and/or MRI within prior 4 months Patients with palpable splenomegaly on physical examination ANy condition that in the investigators opinion would likely increase the risk of particpation or would likely confound interpretation of the data