The risk of death from each specific cause was higher in IDUs than non-IDUs, with particularly marked increases in risk for liver-related deaths, and those from violence and non-AIDS infection. While liver-related deaths and deaths from direct effects of substance abuse appear to explain much of the excess mortality in IDUs, they are at increased risk for many other causes of death, which may relate to suboptimal management of HIV disease in these
individuals. Injecting drug use (IDU) is one of the most frequent routes of HIV transmission in FG-4592 clinical trial many industrialized countries  and is responsible for up to one-third of HIV transmission globally, outside of sub-Saharan Africa . Since the introduction of combination antiretroviral therapy (cART) in 1996, mortality rates related to HIV infection have significantly decreased [3–9]. Rates of morbidity and mortality subsequent to initiation of cART are higher in HIV-positive IDUs than in other HIV-positive persons [10–13], although some studies found only
limited evidence for this effect [6,14,15]. Several factors may contribute to the relatively poor response to treatment observed in HIV-positive patients who have a history of IDU. They have been shown to have decreased access to HIV care and treatment [16,17], more comorbid conditions associated with drug use and addiction [such as hepatitis C virus (HCV) coinfection], poorer adherence to treatment , and more adverse drug interactions [19,20]. They are also more likely to come from MEK inhibitor particular ethnic or racial groups that have historically been disadvantaged with respect
to health outcomes . In some studies, immunological or virological responses to cART appeared to be lower in HIV-positive IDUs than in other patients [11,22]. However, it is important to distinguish between those who are and are not actively injecting G protein-coupled receptor kinase drugs, as the former will have additional risks from overdose, accidents and violence. Given the high prevalence of IDU among HIV-positive individuals receiving cART, it is important to understand what factors affect disease progression and death in this group: for example, in order to design programmes to reduce disparities in health outcomes between IDUs and non-IDUs receiving cART. We examined determinants of disease progression and death among IDUs and non-IDUs initiating cART in participants in a large multinational collaboration of HIV treatment programmes, and compared causes of death in IDU and non-IDU populations. The Antiretroviral Therapy Cohort Collaboration (ART-CC) is a multinational collaboration of HIV cohort studies. The collaboration has been described in detail elsewhere [12,23,24]. In brief, it was established in 2001, updated in 2004, 2006 and 2008, and includes cohort studies from Canada, Europe and the USA.