1236. HCV-specific post-partum T cell function in women chronically infected with hepatitis C virus
Session: Poster Abstract Session: Viral Infections: Pathogenesis and Immunity
Friday, October 9, 2015
Room: Poster Hall
Posters
  • POSTER with logos %28ID Week%29-2.pdf (554.3 kB)
  • Background: Chronic hepatitis C virus (HCV) infection is typically characterized by stable high-level viremia and exhaustion of virus-specific CD8+ and CD4+ T-cell responses.   Nevertheless, some chronically infected women experience substantial transient decreases in viral load after childbirth.  We hypothesized that resurgent HCV-specific Th1 and Tc1 activity may contribute to improved viral control following pregnancy.

    Methods:  Cryopreserved peripheral blood mononuclear cells collected from HCV-infected women during and after pregnancy were thawed, stimulated with peptides corresponding to HCV NS3 and NS4 proteins, and analyzed for production of IFNγ, IL2, IL10, IL17a, and IL21 by intracellular cytokine staining and flow cytometry.  Longitudinal HCV-specific T cell responses were compared between 6 women with ≥ 1 log10 declines in viral load between the 3rd trimester of pregnancy and 3 months postpartum and 12 women with < 1 log10 decline in viral load.

    Results: Although the two groups of women exhibited similar T-cell responses in late pregnancy, at 3 months postpartum those women with significant postpartum viral declines had higher frequencies of HCV-specific IFNγ+ (p=0.047) and IFNγ+IL2+ co-producing CD4+ T-cells (p=0.041) than women with stable viremia.  Postpartum viral control was also associated with greater increases in IFNγ+ CD4+ T-cell frequencies between late pregnancy and 3 months postpartum (median absolute increase: 0.04% versus 0.00%, p=0.018).  For CD8+ T-cells, a trend toward greater HCV-specific IFNγ production at 3 months postpartum was detected among women with postpartum viral control (p=0.072).  Virus-specific T cell production of IL10, IL17a, and IL21 was rare for both groups.

    Conclusion: Women with postpartum viral load declines of at least 1 log10 demonstrated increased HCV-specific Th1 T cell responses at 3 months postpartum as compared to the 3rd trimester, and these increases were larger than those seen in women with stable viremia.  These functional improvements correspond temporally with declines in viral load, suggesting that restoration of virus-specific Th1 function may contribute to the spontaneous control of HCV viral load in the postpartum period.

    Samantha Ohmer, BA, Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH and Jonathan Honegger, MD, The Research Institute at Nationwide Children's Hospital, Columbus, OH

    Disclosures:

    S. Ohmer, None

    J. Honegger, None

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