IL-23 and IFN- gamma deficiency in immunodeficient HIV patients who achieved a long-term increase in CD4 T-cell counts on highly active antiretroviral therapy

The pathogenesis of HIV infection and the susceptibility to opportunistic infections has been associated with poor type 1 cytokine production. In severely immunodeficient HIV patients who achieved increased CD4 T-cell counts on longterm highly active antiretroviral therapy, we observed reduced expression of IL-23p19 and IFN- gamma messenger RNA. Impaired IL-23-induced IFN- gamma production by memory T cells might thus contribute to opportunistic infections in a minority of patients with substantial CD4 T-cell recovery.