Eligibility Criteria- The inclusion criteria for this case-control study was that the patients had to be participating in both the open-label phase and the randomization phase of any of ENABLE 1 or ENABLE 2 clinical trials.
Inclusion criteria for the ENABLE clinical trials included
- age>18 years
- evidence of chronic HCV infection
- candidates for peg-interferon and ribavirin combination antiviral therapy
- baseline platelet count of <75,000/µl
- no significant anemia or neutropenia.
Exclusion criteria for the ENABLE clinical trial included:
- non-responders to previous treatment with peg-interferon and ribavirin unless due to thrombocytopenia
- decompensated liver disease, e.g. Child-Pugh score >6 or history of ascites or hepatic encephalopathy or current evidence of ascites
- serious cardiac, cerebrovascular, or pulmonary disease
- documented history of clinically significant bleeding from oesophageal or gastric varices, haemoglobinopathies, e.g. sickle cell anemia, thalassemia major, history of arterial or venous thrombosis, hepatocellular carcinoma, Human Immunodeficiency Virus (HIV) or Hepatitis B infection
- any disease condition associated with active bleeding or requiring anticoagulation
- history of malignancy, history of alcohol/drug abuse or dependence within 6 months of the study start
- history of platelet clumping that prevents reliable measurement of platelet counts
- history of major organ transplantation with an existing functional graft
- evidence of portal vein thrombosis on abdominal imaging within 3 months of the baseline visit.
No additional exclusion criteria were applied to the case-control study.