Mycophenolate Mofetil Versus Cyclosporin A in the Treatment of Primary Biliary Cholangitis-autoimmune Hepatitis Overlap Syndrome Due to Nonresponse to Standard Therapy

Inclusion Criteria: 1. Patients aged 18-70 years; 2. Diagnosed with PBC-AIH overlap syndrome according to Paris criteria; 3. Patients have a nonresponse to azathioprine; 4. The WBC count ≥2.5x10\^9/L and platelet count ≥50x10\^9/L. 5. Agreed to participate in the trial, and assigned informed consent; Exclusion Criteria: 1. The presence of hepatitis A, B, C, D, or E virus infection; 2. Patients with presence of serious decompensated cirrhosis; 3. Patients have a history of glucocorticoid or immunosuppressant medication before enrollment; 4. Liver damage caused by other reasons: such as primary sclerosing cholangitis, non-alcoholic steatohepatitis, drug induced liver disease or Wilson's disease. 5. Pregnant and breeding women and women of childbearing age in need of reproduction 6. Severe disorders of other vital organs, such as severe heart failure, cancer; 7. Patients with presence of renal insufficiency; 8. Parenteral administration of blood or blood products within 6 months before screening; 9. Recent treatment with drugs having known liver toxicity; 10. Taken part in other clinic trials within 6 months before enrollment. 11. Patients who are allergic to these drugs; 12. Uncontrolled infection and hypertension ;