1312. Cellular immune responses in non-HIV immunodeficiency patients infected with unusual intracellular microorganisms
Session: Poster Abstract Session: Biomarkers and Correlates of Protection
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • ID week poster_1312.pdf (255.1 kB)
  • Background: Cell mediated immunity plays a crucial role in resistance to intracellular infection through the activation of macrophages, the stimulation of major histocompatibility complex molecules on antigen presenting cells, and through the activation of cytokine production by CD4 and CD8 effector T cells. We have previously reported the presence of antibody against interferon-gamma (IFN-γ) in non-HIV patients presenting with repeated episodes of disseminated infection caused by unusual intracellular pathogens. The study presented here aimed to investigate cellular immune responses in these patients compare to HIV-infected controls, and healthy controls.

    Methods: Twenty HIV negative patients presented with at least 2 episodes of culture or histopathology proven opportunistic infections were enrolled at Chiang Mai University Hospital. Controls comprised 20 HIV-infected patients and 20 healthy adults who were age- and sex-matched with cases. Classical markers on macrophage (CD68, HLA-DR and Fc receptor-1) and intracellular cytokine production in response to mitogen (phytohemagglutinin; PHA) by CD4 and CD8 T cells were determined by staining with specific antibodies and analyzed by flow cytometry.

    Results: There were no differences in the percentages of macrophages, CD68 and HLA-DR expression on the surface of macrophages among cases, HIV-infected, and healthy controls. The expression of FcR1 on macrophages were statistically significantly higher in cases than in HIV-infected (p < 0.05) and healthy controls (p < 0.01), suggesting the presence of activated macrophages in the circulation. Interleukin (IL)-2 and tumor necrosis factor (TNF)-a production in response to PHA among CD4 T cells of cases were significantly lower than that of healthy control group (p < 0.01 and P < 0.001, respectively). CD8 T cells from cases also produced TNF-a significantly less than that of healthy controls (p < 0.05).

    Conclusion: Immunodeficiency in non-HIV individuals who had repeated episodes of infections caused by intracellular pathogens may be associated with the reduced production of IL-2 by CD4 T cells and of TNF-a by both CD4 T cells and CD8 T cells observed in cases or with antibody to IFN-g as  previously reported, or with all of these abnormal immune responses.

    Jiraprapa Wipasa, PhD, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand, Panuwat Wongkulab, MD, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, Romanee Chaiwarith, MD, MHS, Internal Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand and Khuanchai Supparatpinyo, MD, Internal Medicine, Chiang Mai University, Maung, Chiang Mai, Thailand

    Disclosures:

    J. Wipasa, None

    P. Wongkulab, None

    R. Chaiwarith, None

    K. Supparatpinyo, None

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