Effective combination antiretroviral therapy (cART) has resulted in a dramatic reduction in AIDS mortality. Over the last decade, the proportion of deaths caused by liver-related etiologies, including co-infection with hepatitis C (HCV) and hepatitis B (HBV) viruses, alcohol abuse, and fatty liver, has increased between 8 to 10 fold in the post-cART era while AIDS-related mortality has fallen more than 90-fold. HIV infection without viral hepatitis is also at risk for liver disease. Indeed, HIV mono-infected persons experience common conditions, such as obesity, diabetes and dyslipidemia, which are risk factors for non-alcoholic fatty liver disease (NAFLD). NAFLD is the most common liver disease in Canada. It is a fatty infiltration of the liver that is not evolutive per se, but it is the first histopathological step for non-alcoholic steatohepatitis (NASH), a progressive disease characterized by much inflammation leading to liver fibrosis and cirrhosis. NASH may be frequent in the setting of HIV mono-infection due to excess of metabolic risk factors, long-term cART, HIV itself and lipodystrophy. An early diagnosis of NASH is essential to establish a prognosis and initiate interventions to reduce progression of liver disease towards cirrhosis. Early diagnosis of NASH is critical for targeting metabolic and hepatologic interventions, which can impact on progression to cirrhosis and end-stage complications. Non-invasive tools for liver fibrosis and NASH, including Fibroscan/CAP and CK-18, are accurate and ideal for screening and serial monitoring. No study has specifically targeted the non-invasive diagnosis of NASH in HIV mono-infected patients. There has been no study about the use of CK-18 as a biomarker for NASH in the setting of HIV mono-infection. Furthermore, CAP has never been applied to this specific population. Finally, there is no data about the potential beneficial therapeutic effect of vitamin E on NASH associated to HIV infection. The investigators hypothesize that CK-18 and Fibroscan/CAP can be used as non-invasive tests to diagnose NASH in HIV mono-infected persons. Likewise, the investigators hypothesize that there will be a significant prevalence of NASH diagnosed by non-invasive tools among patients with HIV mono-infection. The investigators further hypothesize that a 6 months treatment trial with vitamin E supplementation will improve non-invasive diagnostic tests, and/or the metabolic and hepatic profile in HIV mono-infected patients with a non-invasive diagnosis of NASH.