Do CD4+ T Cell Functional Responses to Epstein–Barr Virus Provide Protective Immunity Against CNS Lymphoma in AIDS?

March 2007 | Volume 4 | Issue 3 | e110 Since highly active antiretroviral treatment (HAART) regimens became widely available in North America and Europe in 1996, the incidence of AIDS-defi ning opportunistic infections and malignancies has declined dramatically. This decline has been attributed to restoration of protective immunity by HAART since HAART improves many of the defi cits in T and B cell function that are caused by uncontrolled HIV infection. Some of these defi cits include diminished antigen-specifi c T cell proliferation and cytokine expression, decreased production of new naïve T cells by the thymus, and abnormally high levels of CD4+ and CD8+ T cell and B cell activation [1–3]. However, the causal link between the reversal or prevention of these T and B cell functional abnormalities and immune protection against AIDSdefi ning opportunistic infections and malignancies remains largely hypothetical at present.