Virus-specific T-cell responses associated with hepatitis C virus (HCV) persistence in the liver after apparent recovery from HCV infection

• Published in: Journal of medical virology Vol. 78; no. 9; pp. 1190 - 1197
• Main Authors: Quiroga, Juan A., Llorente, Silvia, Castillo, Inmaculada, Rodríguez-Iñigo, Elena, López-Alcorocho, Juan Manuel, Pardo, Margarita, Carreño, Vicente
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.09.2006; Wiley-Liss
• Subjects: Adult; Aged; asymptomatic aviremic anti-HCV carrier; Biological and medical sciences; Biomarkers; Biopsy; Carrier State; CD4+ and CD8+ T-cell responses; CD4-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - immunology; Cells, Cultured; Female; Fundamental and applied biological sciences. Psychology; HCV persistence; Hepacivirus - genetics; Hepacivirus - immunology; Hepacivirus - isolation & purification; Hepatitis C - drug therapy; Hepatitis C - immunology; Hepatitis C - pathology; Hepatitis C virus; hepatitis C virus (HCV); HLA-A2 Antigen; Human viral diseases; Humans; Infectious diseases; Interferon-gamma - analysis; Leukocytes, Mononuclear; Liver - pathology; Liver - virology; Lymphocyte Activation; Male; Medical sciences; Microbiology; Middle Aged; Miscellaneous; RNA, Viral - genetics; sustained virological response to antiviral therapy; T-Cell Antigen Receptor Specificity; T-Lymphocyte Subsets - immunology; Viral Core Proteins - immunology; Viral diseases; Viral hepatitis; Viral Nonstructural Proteins - immunology; Virology; Virus Replication - immunology; hepatitis C virus (HCV); sustained virological response to; Digestive system; Hepatic disease; Cellular immunity; Infection; Virus; Associated virus; Viral disease; Digestive diseases; Flaviviridae; Hepatitis C virus; Hepacivirus; Viral hepatitis C
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.20680

Hepatitis C virus (HCV) RNA persistence in the liver has been described even after apparent resolution of HCV infection. Because T‐cell reactivity plays a role in recovery from HCV infection, virus‐specific T‐cell responses were investigated in apparently recovered individuals in whom hepatic HCV RNA persistence was documented: 15 sustained virological responders to interferon (IFN)‐treatment and 9 asymptomatic aviremic anti‐HCV carriers. HCV‐specific CD4+ T‐cell proliferative responses were detected significantly more often in apparently recovered individuals (sustained virological responders: 60%; asymptomatic anti‐HCV carriers: 66%) compared with 50 chronic hepatitis C patients (28%; P < 0.05). However, T‐cell frequencies and numbers tended to decline over time and the number of HCV proteins targeted by CD4+ T‐cell proliferative responses was limited. Interestingly, liver viral load correlated inversely with virus‐specific immune responses. Thus, CD4+ T‐cell responders showed significantly lower hepatic HCV RNA levels (P < 0.05). HCV‐specific IFN‐γ‐secreting CD4+ T‐cells were not detected in all the apparently recovered patients although they were found significantly more often compared with chronic hepatitis C patients (P < 0.05). Also, HCV NS3‐specific CD8+ T‐cells were detected in 11 HLA‐A2‐positive apparently recovered individuals (8 sustained virological responders and 3 asymptomatic anti‐HCV carriers); T‐cell frequencies tended to be greater in those patients who had lower hepatic viral levels. In conclusion, HCV‐specific T‐cells are detectable in apparently recovered individuals in whom HCV RNA can persist in the liver indicating that HCV replication may be prolonged in the face of an insufficient or inadequate virus‐specific CD4+ and CD8+ T‐cell response. J. Med. Virol. 78:1190–1197, 2006. © 2006 Wiley‐Liss, Inc.