Efficacy of PegIntron and Rebetol in Previously Untreated Patients With Chronic Hepatitis C Infected With HCV Genotype 1/4/5/6 (Study P04243)

Inclusion Criteria: * Previously untreated ('treatment naïve') adults (18 year or more) for whom the treating physician has decided to start treatment with PegIntron and Rebetol * Detectable Hepatitis C Virus - Ribonucleic Acid (HCV-RNA) in serum by Polymerase Chain Reaction (PCR) * Repeated (with at least a 1 month interval) serum transaminase (alanine aminotransferase \[ALT\]) levels above the upper normal limit for gender * Documented chronic hepatitis C (CHC) of genotype 1/4/5/6 * A representative liver biopsy within 1 year prior to inclusion, allowing fibrosis grading into METAVIR score F0, F1, F2, F3 or F4 Exclusion Criteria: * Known hypersensitivity for any active ingredient or constituent * Pregnancy or lactation * Medically documented history of severe psychiatric disturbance, including severe depression, suicidal ideation or suicide attempt * Medically documented history of severe heart disease, including unstable or uncontrolled cardiac disease, within the last 6 months * Severely weakening medical condition, including chronic renal insufficiency or creatinine clearance \<50 mL/minute * Hepatitis of immunologic origin or medically documented history of auto-immune disease * Severe hepatic disorder or decompensated cirrhosis * Pre-existing thyroid disorder, except if under control with classical treatment * Epilepsy or central nervous system disorder * Hemoglobin pathology, eg, thalassaemia, sickle cell anemia