This is a prospective, interventional, case-control study at King Faisal Specialist Hospital & Research Centre in post-renal transplant patients who are receiving Grazoprevir/Elbasvir combination. Data will be compared with matched historical controls, which will be selected according to the following matching criteria: age, time from transplant to initiation of therapy. Only patients who completed at least 48 weeks of pegylated Interferon + Ribavirin therapy in the control group and 12 weeks of therapy on the case group will be enrolled. Any patient who received at least one dose of Grazoprevir/Elbasvir combination will be included in the safety analysis.

Inclusion Criteria:

In order to be eligible for participation in this trial, the subject must be:

• Male or female > 18 years on the day of consent signature.
• Post renal transplant with stable graft function divided into 2 groups according to Creatinine Clearance (CrCl <30 mL/min Or CrCl ≥30 mL/min).
• Positive HCV infection post renal transplant defined as: Positive HCV RNA with documented HCV Genotype 4 (including those with mixed infections with Genotype 4 & Genotype 1 or Genotype 4 & Genotype 6).
• Fibro scan (Liver Elastography) performed prior to the baseline with evidence of chronic HCV infection.
• Liver Cirrhosis subjects may be included but will be limited to those with compensated liver disease (Child Pugh-A)
• Patient understands the study procedures, alternative treatments available, risks involved with the study and voluntarily agree to participate by giving written informed consent.
• Reproductive potential patient agrees to avoid becoming pregnant or impregnating a partner until at least 6 months after the last dose of medication. Acceptable methods of contraception (IUD or contraceptive rod implanted into the skin may, or combination of two: diaphragm with spermicide (cannot be used in conjunction with cervical cap/spermicide); cervical cap with spermicide (women only), male condom or female condom (cannot be used together), oral contraceptive pills: estrogen/progestine or progestin-only pill, contraceptive skin patch, vaginal contraceptive ring, or subcutaneous contraceptive injection. Abstinence can be used as a sole method of contraception if it is consistently employed and considered acceptable by the patient and Institutional Review Board.

Exclusion Criteria:

The subject must be excluded from participating in the trial if the subject:

• Is under the age of legal consent, is mentally or legally incapacitated, has significant emotional problems at the time of pre-study screening visit or expected during the conduct of the study or has a history of a clinically significant psychiatric disorder which, in the opinion of the investigator, would interfere with the study procedures.
• Is infected with HCV Genotypes 1,2,3,5 or 6 except those with Genotype 1 or 6 with mixed infection with Genotype 4.
• Is co-infected with Hepatitis B Virus or HIV.
• Has evidence of decompensated liver disease manifested by the presence of or history of ascites, esophageal or gastric variceal bleeding, hepatic encephalopathy or other signs or symptoms of advanced liver disease (Child Pugh-B or Child Pugh-C based on a platelet count below 75000 or an albumin below 3 g/dL)
• Pregnant or nursing female or male patient with pregnant female partner.
• Contraindications for Grazoprevir/Elbasvir.
• Is currently participating or has participated in a study with an investigational compound within 30 days of signing informed consent and is not willing to refrain from participating in another such study during the course of this study.
• Has any condition or pre-study laboratory abnormality, ECG abnormality, or history of any illness, which, according to the opinion of the investigator, might confound the results of the study or pose additional risk in administering the study drugs to the subject.
• Patient has not signed informed consent form