It is important to assess the degree of liver damage at baseline and its progression over time in people with HIV-HCV co-infection. The gold standard for assessing liver damage remains liver biopsy, which was required to access HCV therapy under the Australian Government’s Highly Specialised Drugs Program Section 100 reimbursement guidelines until 2006. Liver biopsy is limited by cost, availability, sampling error and the risk of complications associated with an invasive procedure.
Over recent years transient elastography (FibroScan) has become a widely used non-invasive way of estimating the degree of liver fibrosis, and usually obviates the need for a biopsy.38 Transient elastography uses modified ultrasound technology to measure the speed of a vibration wave transmitted through the liver. A healthy elastic liver transmits the wave more slowly giving a lower liver stiffness measurement (LSM), whereas a cirrhotic liver transmits the wave more quickly, producing a higher LSM (Figure 1). Transient elastography is widely used in Europe and has been used in Australia since 2008.39 Its use may be limited in obese people, those with narrow rib spaces and in the presence of ascites. Transient elastography is available in most tertiary referral hospitals, with some rural outreach services now also available. Other non-invasive methods for assessing liver damage are being explored, such as acoustic radiation force impulse elastography (ARFI), shear wave elastography (Aixplorer) and magnetic resonance (MR) elastography. In addition, biomarker algorithms such as aspartate aminotransferase (AST) to platelet ratio index (APRI), Hepascore and Fibrotest have been used, either alone, or in combination with transient elastography.38