PRO-HEP study.

1. HIV-infected with an undetectable HIV-RNA for the preceding 6 months and on a stable anti-retroviral regimen during this period; the only anti-retroviral drugs allowed are either efavirenz of ritonavir boosted atazanavir in combination with tenofovir/emtricitabin;

2. Male sex since acute HCV is prevalent among MSM;

3. Diagnosed with an acute HCV defined as a positive HCV serology and/ or detectable HCV-RNA with negative serology and/ or HCV-RNA in the preceding 6 months;

4. HCV genotype 1a or 1b;

5. ALAT elevation > 2 times the upper limit of normal (ULN in the UMC Utrecht is 35);

6. Low baseline HCV-RNA viral load (i.e. below 800.000 IU/ml);

7. Start of therapy within 4 weeks after the diagnosis of acute HCV;

8. Age 18 to 65 years.

1. Age under 18 years or above 65 years;

2. Co-infections with acute or chronic hepatitis A, B, D and E;

3. Patients who are unable to give informed consent due to other circumstances, like delirium at admission, severe psychiatric disease, without a legal representative;

4. Subjects who have changed their anti-retroviral regimen within the last 3 months prior to Day 1 (other than zidovudine (AZT), didanosine (ddI), stavudine (d4T), efavirenz, etravirine, nevirapine, and HIV protease inhibitors without the coadministration of ritonavir which may be substituted at least one month prior to Day 1) or had first initiated anti-retroviral therapy within the last 6 months of Day 1;

5. Subjects who received prior treatment for hepatitis C (including any investigational medication) other than herbal remedies, except those with known hepatotoxicity (which are exclusionary). All herbal remedies used for hepatitis C treatment must be discontinued before Day 1. Only silymarin (milk thistle) is allowed during the trial;

6. Fibroscan indicating severe fibrosis (F3) or cirrhosis (F4) or any other clinical sign of decompensated liver disease including, but not limited to, a history or presence of clinical ascites, bleeding varices, or hepatic encephalopathy;

7. Any current evidence of substance abuse of alcohol, intravenous drugs, inhalational (not including marijuana), psychotropics, narcotics, cocaine use, prescription or over-the-counter drugs or a clinical diagnosis of polysubstance abuse (≥3 of the above substances) within 1 years of the Screening Visit;

8. Patients included in an opiate substitution program;

9. Laboratory Exclusion Criteria (more than 10% of the listed laboratory exclusion criterion value):

A. Hemoglobin <7 mmol/L for females and <8 mmol/L for males;

B. Neutrophils <1500/mm3 (blacks/African-Americans: <1200/mm3);

C. Platelets <100,000/mm3.

10. Any known pre-existing medical condition that could interfere with the subject’s participation in and completion of the trial, including but not limited to Central nervous system (CNS) trauma, Immunologically-mediated diseases, Chronic pulmonary diseases, Current or history of any clinically significant cardiac abnormalities, Active clinical gout within the last year, hematologic abnormalities, Organ transplants and Evidence of active or suspected malignancy;

11. Subjects who are pregnant or nursing. Subjects who intend to become pregnant during the trial period. Male subjects with partners who are, or intend to become, pregnant during the trial period;

12. Any other condition which, in the opinion of the Principal Investigator, would make the subject unsuitable for enrollment or could interfere with the subject participating in and completing the trial.