This study is to investigate the clinical efficacy of artificial liver support system using combination of plasma exchange and continuous hemodiafiltration in treatment of Wilson's Disease - related liver failure. 30 patients will receive treatment of plasma exchange and continuous hemodiafiltration and internal medicine. 30 patients will receive treatment of internal medicine.

Wilson's disease (WD) is an inherited disorder in which defective biliary excretion of copper leads to its accumulation, particularly in liver and brain. Presenting symptoms of liver disease can be highly variable, ranging from asymptomatic, with only biochemical abnormalities, to overt cirrhosis with all its complications. Acute liver failure (ALF) presentation is the most dramatic and may arise with catastrophic suddenness. It is considered rare, constituting only 3% of ALF cases in the pediatric ALF series in USA and associated with a high mortality reaching 95%. Patients with acute liver failure due to WD require liver transplantation, which is lifesaving. Kido J et al reported clinical outcomes of patients with liver failure were improved by artificial liver support system using combination of plasma exchange and continuous hemodiafiltration. So the investigators design this protocol: 30 patients will receive treatment of plasma exchange and continuous hemodiafiltration and internal medicine, 30 patients will receive treatment of internal medicine.

Inclusion Criteria:

1. Clinical diagnosis of Wilson Disease: serum ceruloplasmin < 0.2g/L, 24 hours urinary copper > 40μg, Kayser-Fleischer ring present;
2. Do not receive drugs to promote the excretion of copper ever before;
3. Serum total bilirubin > 10 times upper limit of normal, prothrombin time activity < 40% or prothrombin time international ratio > 1.5.

Exclusion Criteria:

1. Other active liver diseases;
2. Hepatocellular carcinoma or other malignancy;
3. Pregnancy or lactation;
4. Human immunodeficiency virus infection or congenital immune deficiency diseases;
5. Severe diabetes, autoimmune diseases;
6. Other important organ dysfunctions.