Hepatitis C virus/human T lymphotropic virus 1/2 co-infection: Regional burden and virological outcomes in people who inject drugs

Abstract

This review analyses current data concerning co-infection with hepatitis C virus (HCV) and human T lymphotropic virus (HTLV)-1/2 in people who inject drugs (PWID), with a particular focus on disease burden and global implications for virological outcome. In addition, the available treatment options for HTLV-1/2 are summarized and the ongoing and likely future research challenges are discussed. The data in this review was obtained from 34 articles on HCV/HTLV-1/2 co-infection in PWID retrieved from the PubMed literature database and published between 1997 and 2015. Despite unavailable estimates of the burden of HCV/HTLV-1/2 co-infection in general, the epidemiologic constellation of HTLV-1/2 shows high incidence in PWID with history of migration, incarceration, and other blood-borne infectious diseases such as HCV or human immunodeficiency virus. The most recent research data strongly suggest that HTLV-1 co-infection can influence HCV viral load, HCV sustained virological response to α-interferon treatment, and HCV-related liver disease progression. In short, outcome of HCV infection is worse in the context of HTLV-1 co-infection, yet more studies are needed to gain accurate estimations of the burden of HCV/HTLV-1/2 co-infections. Moreover, in the current era of new direct-acting antiviral treatments for HCV and proven HTLV-1/2 treatment options, prospective clinical and treatment studies should be carried out, with particular focus on the PWID patient population, with the aim of improving virological outcomes.

Family Aggregation of Human T-Lymphotropic Virus 1-Associated Diseases: A Systematic Review

“…It is noticeable that co-infections were not mentioned in this context, because co-infections may also run in families and because specific co-infections have been linked to HTLV-1-associated diseases before, particularly infective dermatitis with HAM/TSP (Bittencourt and de Oliveira, 2010), and strongyloidiasis with ATLL (Plumelle et al, 1997). Furthermore, there is evidence that HTLV-1 can influence the outcome and severity of other infections such as tuberculosis (Verdonck et al, 2007a), HIV (Brites et al, 2001; Silva et al, 2009), and hepatitis C (Castro and Roger, 2016). Although none of the records suggested the role of co-infections in explaining family aggregation, they did report families in which co-infections (i.e., strongyloidiasis and infective dermatitis) were present (Blank et al, 1993; Wilks et al, 1993; LaGrenade et al, 1996; Gonçalves et al, 1999; Araújo et al, 2002; Mahé et al, 2004; Primo et al, 2005; Nobre et al, 2006; Suite et al, 2009; Alvarez et al, 2011; da Silva et al, 2013).…”

Making the invisible visible: searching for human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2) in Brazilian patients with viral hepatitis B and C

“…However, as the benefit of HTLV-1 co-infection had not been confirmed in patients with hepatitis C from other parts of the world, except in Brazil ( Castro & Roger 2016 ), further studies were needed to confirm and clarify these issues.…”

Neurological Aspects of HIV-1/HTLV-1 and HIV-1/HTLV-2 Coinfection

“…The risk of OIs will be greater, the higher the degree of immunosuppression of patients [13]. CD8+ T-cell encephalitis is another neurological disease associated with HIV-1.…”

“…PWID are at higher risk of infection with blood-borne viruses and even coinfection. This occurs not only in HIV-1/HTLV-1/2 but also in HIV-1/HCV coinfection [13].…”