Hepatitis viral load testing: what does it all mean?

Abstract

The availability of assays for quantification of HBV DNA and HBsAg has resulted in a surge of research redefining the natural history of chronic hepatitis B (CHB) and the effects of specific antiviral therapy on levels of these viral markers. Assessment of on-treatment changes in HBsAg titre has provided new management algorithms to achieve the endpoint of HBsAg seroconversion. As with chronic hepatitis C management, response guided therapy (RGT) has arrived for hepatitis B. specific antiviral therapy has been available for hepatitis B for over a decade, and is now becoming available for hepatitis C. There are a number of direct acting antivirals (DAA) for hepatitis C and these should quickly replace the current standard of care of pegylated IFN and ribavirin, and the need for complex testing algorithms using HCV RNA and RGT (including stopping rules). Not only has molecular diagnostics emerged as an important tool for measuring viral load and burden, response to therapy as well as staging of disease, but is also useful for defining emergence of antiviral drug resistance. These viral load and molecular assays actually simplify patient management and monitoring for all concerned.