Funded by the Centers for
Disease Control and Prevention
- Very Rapid Virologic Response (vRVR): "Undetectable" HCV RNA at week 2 of treatment. The definition of undetectable varies based on the sensitivity of the assay used (which can range from 10 to 50 IU/ml in lower limit of detection) and stringency required for a particular treatment regimen.
- Viral Rebound, HBV: Increase in serum HBV DNA to >20,000 IU/mL or above pre-treatment HBV DNA level after achieving virologic response on continued treatment.
- Virologic Breakthrough, HBV: Increase in serum HBV DNA of greater than 1 log10 IU/mL above nadir after achieving virologic response, occurring during continued treatment.
- Virologic Breakthrough, HCV: Reappearance of HCV RNA during treatment, occurring after patient has achieved complete virologic suppression (undetectable HCV RNA level).
- Virologic Relapse, HBV: Increase in serum HBV DNA of ≥1 log10 IU/mL after cessation of treatment in at least two measurements more than 4 weeks apart.
- Virologic Response, HBV: A decrease in serum HBV DNA to undetectable levels by PCR assays, and loss of HBeAg in patients who were initially HBeAg-positive.