Hepatitis C in a Cohort of Patients With Maintenance Therapy for Opiate Dependence - Prevalence, Severity and Outcome of Antiviral Therapy

Inclusion Criteria: * Patients that meet all of the following inclusion criteria are eligible for part I of the study: 1. Registered in a clinic providing maintenance therapy for opiate dependence at the date of study initiation. 2. Written informed consent for part I of the study. * Patients that meet all of the following inclusion criteria are eligible for part II of the study: 1. Fulfilled part I 2. Registered in a clinic providing maintenance therapy for opiate dependence at the date of study initiation. 3. HCV-PCR positive. 4. Written informed consent for part II of the study. * Patients that meet all of the following inclusion criteria are eligible for part III of the study: 1. Fulfilled part II 2. Registered in a clinic providing maintenance therapy for opiate dependence at the date of study initiation. 3. HCV-PCR positive. 4. Written informed consent for part III of the study and able to adhere to dosing and visiting schedules. 5. At least 6 months of uninterrupted maintenance therapy for opiate dependence. 6. Treatment indication with at least one of the following: * Fibrosis/cirrhosis * Other HCV related disease/symptoms * Psychological indication 7. For patients with cirrhosis, an ultrasound investigation should be performed within six months before study initiation, part III, (not showing signs of HCC). 8. Use of adequate contraception during the treatment period and for six months after the completion of therapy (for all participants regardless of gender). Exclusion Criteria: * The presence of any of the following criteria will exclude the patient from participating in part III of the study: 1. Pregnant women, women who plan to become pregnant, male patients whose partner wants to become pregnant, and breastfeeding women. 2. Previous treatment for chronic hepatitis C with an antiviral or immunomodulating agent or with an interferon or ribavirin product, whether alone or in combination. 3. Participation in another clinical drug trial. 4. Coinfection with HBV or HIV 5. Hemoglobin \<120 g/L for females and \<130 g/L for males. 6. LPK \<3,0 x 109/L 7. Platelets \<80 x 109/L 8. Creatinin clearance \<50mL/min 9. Any of the following diseases considered to be a dominant cause of the patients chronic liver disease: * Hemochromatosis * Alpha-1 antitrypsin deficiency * Wilson's disease * Autoimmune hepatitis * Alcoholic liver disease * Non-alcoholic steatohepatitis (NASH) * Drug-related liver disease 10. Active malignant disease or suspicion or history of malignant disease within five previous years (except for adequately treated basal cell carcinoma). 11. Patients with organ transplants, except for corneal or hair transplant. 12. Poorly controlled diabetes mellitus. 13. Evidence of severe retinopathy or clinically relevant ophthalmological disorder in patients with diabetes mellitus or hypertension. 14. Poorly controlled epilepsy. 15. Thyroid dysfunction not adequately controlled 16. Decompensated cirrhosis (Child-Pugh B-C). 17. Treatment with immunomodulatory drugs (chronic systemic corticosteroids (equivalent to \>10 mg prednisone/day), immunosuppressive drugs, chemotherapy) and/or treatment with herbal drugs for chronic hepatitis. 18. Any other condition which in the opinion of the investigator would make the patient unsuitable for enrollment, or could interfere with the patient participating in and completing the study.