I'm at the American Association for the Study of Liver Diseases' annual Liver Meeting, the major U.S. conference on hepatitis C and other liver diseases. Here's some quick notes from the research presented so far:
- Daily marijuana (cannabis) smoking appears to accelerate and worsen fibrosis progression, according to French researchers. They found that long-term daily marijuana smokers were more likely to experience rapid fibrosis progression, and more likely to have serious fibrosis, than non-smokers or occasional smokers. Other research to be presented today will suggest a biological mechanism to explain these findings. While this data should be confirmed through other studies, it suggests that people with chronic hepatitis C should avoid daily marijuana smoking.
- A growing body of data implicates insulin resistance (associated with obesity and diabetes) in poorer responses to hepatitis C treatment. Poorer response to treatment has been seen in people with greater weights and body mass indices, and insulin resistance may explain why this group is less likely to experience sustained virologic responses. In test tube studies, high insulin levels appear to mitigate the antiviral effects of interferon.
- New research suggests that in people who achieve sustained virologic responses, very low levels of hepatitis C can persist for several years, despite undetectable viral loads using conventional tests. The implications of these findings is unclear -- rates of relapse to detectable viral loads remain low in long-term follow-up studies, and growing evidence shows that people who achieve sustained virologic responses have good long-term outcomes overall, low rates of liver cancer, and improvements in fibrosis and liver inflammation. But this research suggests that it would be premature to classify a sustained virologic response as having "cured" hepatitis C infection.
- New (acute) hepatitis C infection can be successfully treated with only 3 months of pegylated interferon monotherapy (e.g., no ribavirin), according to two new studies from Europe. One of these studies, conducted in Italy, included a large proportion of acutely infected injection drug users. Sustained virologic response rates were very high (in the range of 70-90%), and tolerability and adherence were very good. These results suggest the value of very early diagnosis and treatment, particularly in groups with high rates of new infections -- injection drug users. Currently, very few hepatitis C infections are diagnosed during the acute phase.
More later -- several presentations today will provide results on clinical trials of new drugs to treat hepatitis C.