Hepatitis C Virus (HCV)–Specific T Cell Responses in Injection Drug Users with Apparent Resistance to HCV Infection

Thurairajah, Prem Harichander; Hegazy, Doha; Chokshi, Shilpa; Shaw, Steve; Demaine, Andrew G.; Kaminski, É.; Naoumov, Nikolai V.; Cramp, Matthew

doi:10.1086/593337

Cited by 46 publications

(70 citation statements)

References 37 publications

(26 reference statements)

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“…Thus, the final testing for HCV RNA and HCV antibodies should occur more than 7 months after exposure, which is a longer follow-up than currently recommended by the Centers for Disease Control and Prevention (CDC) (17). The presence of T cell responses in the absence of viremia and seroconversion in the 3 experimental chimpanzees is reminiscent of the immune status of subgroups of injection drug users, health care workers, and family members of chronic HCV patients who are frequently exposed to low-level HCV but test negative for HCV RNA and antibodies (24)(25)(26)(27)(28)(29)(30). Of note, however, there was no substantial increase in the breadth or strength of the immune response after each exposure, which is consistent with attrition of memory T cell subpopulations after heterologous exposures (31,32) and with the observation that the T cell responses of the lowdose HCV-exposed chimpanzees did not protect against highdose HCV challenge (33).…”

Section: Discussionmentioning

confidence: 99%

Trace amounts of sporadically reappearing HCV RNA can cause infection

Veerapu¹,

Park²,

Tully³

et al. 2014

J. Clin. Invest.

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Section: Discussionmentioning

confidence: 99%

Trace amounts of sporadically reappearing HCV RNA can cause infection

Veerapu¹,

Park²,

Tully³

et al. 2014

J. Clin. Invest.

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“…HCV-specific T cell responses are detected in some subjects without history of acute HCV infection despite frequent exposure (Mizukoshi et al, 2008; Thurairajah et al, 2008). Such T cells can indeed be induced in the absence of systemic viremia and seroconversion by repeated exposure to trace amounts of HCV as demonstrated in health care workers after accidental needlestick injury (Heller et al, 2013) and in the chimpanzee model (Park et al, 2013).…”

Section: Conditions For Induction and Maintenance Of Protective Immunitymentioning

confidence: 99%

Immune Responses to HCV and Other Hepatitis Viruses

2014

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Summary Five human hepatitis viruses cause most acute and chronic liver disease worldwide. Over the past 25 years hepatitis C virus (HCV) in particular has received much interest because of its ability to persist in most immunocompetent adults and the lack of a protective vaccine. Here we examine innate and adaptive immune responses to HCV infection. Although HCV activates an innate immune response, it employs an elaborate set of mechanisms to evade interferon (IFN)-based antiviral immunity. By comparing innate and adaptive immune responses to HCV with those to hepatitis A and B viruses, we suggest that prolonged innate immune activation impairs the development of successful adaptive immune responses. Comparative immunology furthermore provides insights into the maintenance of immune protection. We conclude by discussing prospects for an HCV vaccine and future research needs for the hepatitis viruses.

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“…With respect to those who consistently engaged in risky practices, yet were found to be HCV negative, the possibility of cell-mediated immunity or of spontaneous seroreversion could not be ruled out. [37], [38].…”

Section: Discussionmentioning

confidence: 99%

Hepatitis C Avoidance in Injection Drug Users: A Typology of Possible Protective Practices

2013

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IntroductionHepatitis C virus (HCV) represents a serious public health concern. People who inject drugs (PWID) are at particular risk and nearly half (45%) of PWID in England may be infected. HCV prevention interventions have only had moderate impact on the prevalence of HCV in this population. Using qualitative methods, we sought to detail the protective practices potentially linked to HCV avoidance among PWID, and explore the motivations for these.MethodsThe study used a life history approach allowing participants to detail their lived experience both before and during the course of their injecting careers. Thirty-seven participants were recruited from drug services in London, and from referrals within local injecting networks. A baseline and follow-up in-depth qualitative interview was carried out with each participant, and for half, a third interview was also undertaken. All underwent testing for HCV antibody. Analyses focused on developing a descriptive typology of protective practices potentially linked to HCV avoidance.ResultsPractices were deemed to be protective against HCV if they could be expected a priori to reduce the number of overall injections and/or the number of injections using shared injecting equipment. Participants reported engaging in various protective practices which fell into three categories identified through thematic analysis: principles about injecting, preparedness, and flexibility.ConclusionsAll participants engaged in protective practices irrespective of serostatus. It is important to consider the relative importance of different motivations framing protective practices in order to formulate harm reduction interventions which appeal to the situated concerns of PWID, especially given that these protective practices may also help protect against HIV and other blood borne infections.

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Hepatitis C Virus (HCV)–Specific T Cell Responses in Injection Drug Users with Apparent Resistance to HCV Infection

Cited by 46 publications

References 37 publications

Trace amounts of sporadically reappearing HCV RNA can cause infection

Trace amounts of sporadically reappearing HCV RNA can cause infection

Immune Responses to HCV and Other Hepatitis Viruses

Hepatitis C Avoidance in Injection Drug Users: A Typology of Possible Protective Practices

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