Premium
Enhanced natural killer cell activity is found in exposed uninfected recipients of hepatitis C‐contaminated blood
Author(s) -
Ow M. M.,
Hegazy D.,
Warshow U. M.,
Cramp M. E.
Publication year - 2018
Publication title -
journal of viral hepatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 100
eISSN - 1365-2893
pISSN - 1352-0504
DOI - 10.1111/jvh.12810
Subject(s) - immunology , hepatitis c , immune system , medicine , cell , cohort , natural killer cell , cytotoxicity , biology , in vitro , biochemistry , genetics
Summary A minority of injecting drug users, termed exposed uninfected, are resistant to hepatitis C ( HCV ) infection despite repeated low‐dose exposures. We identify for the first time a cohort of blood recipients who remained uninfected despite large‐dose exposure to HCV ‐contaminated blood and characterize immune factors that may confer protection. Of 1340 blood recipients from the English Look Back database who were transfused HCV ‐contaminated blood, we identified 8 who remained uninfected. In these 8 exposed uninfecteds, we characterized their natural killer ( NK ) cell populations and HCV ‐specific T‐cell responses. Findings were compared with 10 spontaneous resolvers of HCV infection, 10 patients with chronic HCV infection and 10 healthy controls. Exposed uninfecteds had significantly greater numbers of NK cells with the activating receptor NK p30+ on CD 56 bright and CD 56 dim subsets compared with other groups ( P < .05). Following interleukin‐2 activation, NK cells of exposed uninfecteds had enhanced cytotoxicity that positively correlated with NK p30 expression ( P = .02). Differences in NK p80 and KIR 2 DL 3 expression were also observed. HCV ‐specific T‐cell responses were observed in some exposed uninfecteds but of low amplitude. Exposure without infection following transfusion of HCV ‐contaminated blood is a very rare phenomenon and suggests a high level of resistance to infection. Enhanced NK cell activation and killing, with weak HCV ‐specific T‐cell responses, were observed many years after exposure in uninfected recipients and may contribute to protection from HCV acquisition, although additional protective factors are being sought in this important cohort.