HIV-positive people who have low blood levels of alpha-fetoprotein (AFP) before starting hepatitis C virus (HCV) treatment are more likely to have a highly favorable response to therapy, say the authors of a study published in the July 31 issue of AIDS.

AFP is a protein that is present during fetal development and decreases throughout a person’s life. Doctors often test for high levels of AFP as a method for diagnosing liver cancer. In a small study in HIV-negative people, researchers found that lower AFP levels at the beginning of treatment were associated with higher rates of sustained virologic responses (SVRs), specifically, undetectable HCV viral loads six months after completing therapy.

To validate these results in a group of people coinfected with both HIV and HCV, Fabrice Carrat, MD, from the Saint-Antoine Hospital in Paris, and his colleagues conducted an analysis of medical records and blood samples from the ANRS HC02 RIBAVIC study. This study compared two different brands of pegylated interferon and ribavirin as treatment for HCV. The study had 383 patients, the majority of whom were male and white. Therapeutic success was defined as having an SVR after completing 48 weeks of HCV treatment.

Dr. Carrat’s team found that people who began treatment with a low AFP level were more likely to achieve an SVR than people with higher AFP levels; the lower the level of AFP before starting HCV treatment, the better the outcome. The authors recommend AFP testing for coinfected patients before commencing HCV treatment.