Interferon-γ Marks Activated T Lymphocytes in AIDS Patients

Lymphocytes expressing interferon-γ (IFN-γ) on their surface were evaluated in 61 patients, all IV drug abusers, infected with human immunodeficiency virus type 1 (HIV-1), and in 85 healthy subjects (61 of whom were blood donors and 24 HIV-1 seronegative IV drug abusers). Data obtained demonstrated that IFN-γ-expressing T lymphocytes, mostly CD8+ cells, were present in HIV-1-infected patients, and that their percentage, always higher in HIV-1-infected patients than in healthy subjects (p ≤ 0.001), increased with progressive stages of HIV-1 infection. At the same time other markers of T-cell activation, namely interleukin-2 receptor (rIL-2), transferrin receptor, and HLA-DR were also found to be positive in some of the HIV-1-infected subjects. The presence in the HIV-1-infected patients of activated CD8+ T cells, which are resistant to HIV-1 infection, may suggest that these cells are able to respond to continuous and progressive viral expression (HIV or/and other viruses) and may be a component of the spe...