Evidence of hepatitis C virus–specific interferon gamma–positive T cells in health care workers in an infectious disease department

Abstract

Few studies are available on possible hepatitis C virus (HCV)-specific T-cell immune response in health care workers (HCWs) involved in the care of patients with HCV infection. We aimed to investigate whether a HCV-specific interferon (IFN)-gamma T-cell response, known to be involved in infection resolution, was present in those HCWs involved in the management of patients with persistent HCV infection. Our study involved 30 subjects, classified as group A (20 consecutive patients, 16 males and 4 females, with histologically proven chronic hepatitis), or group B (10 HCWs, 7 males and 3 females, with at least 7 years of health care experience and HCV-RNA and anti-HCV negative). As a control group, we used 10 blood samples from healthy donors at a blood donor center (group C). HCV-RNA was measured by real-time polymerase chain reaction. Blood samples (at least 35 mL) were collected from all group A and group B subjects in our hospital. Specific IFN-gamma was stimulated with HCV pool peptides (core, 2 microg/mL), with influenza Mp peptides used as a positive control. Levels of HCV-specific IFN-gamma-positive cells were higher in the HCWs (group B) compared with the infected patients (group A) and healthy blood donors (group C) (Mann-Whitney U test, P < .001). A clinically silent persistent exposure to HCV, through some as-yet undetermined mechanism, may induce a virus-specific IFN-gamma-producing CD8(+) T-cell response in healthy aviremic HCWs. This finding suggests that possible unapparent parenteral routes may stimulate host defenses with no evidence of hepatitis.