Immunity to placental malaria. II. Placental antigen-specific cytokine responses are impaired in human immunodeficiency virus-infected women

An association was demonstrated recently between elevated in vitro production of interferon (IFN)-γ by intervillous blood mononuclear cells (IVBMCs) and protection against placental malaria (PM). Because human immunodeficiency virus (HIV)-infected pregnant women have increased susceptibility to PM, loss of the IFN-γ response in these women may impair their ability to control PM. Measurement of cytokines in culture supernatants by ELISA revealed that IFN-γ responses by HIV-positive IVBMCs were impaired, especially after malarial antigen stimulation. Interleukin (IL)-4 and IL-10 responses also were reduced in HIV-positive persons, the latter more so in HIV-positive, PM-positive persons. In contrast, tumor necrosis factor-α production generally was enhanced in PM-positive and HIV-positive persons. Over-all, cytokine production was reduced in HIV-positive persons with CD4 T cell counts <500/μL, particularly in response to malarial antigen. Thus, HIV-mediated cytokine dysregulation and impairment of the protective IFN-γ response may contribute to the increased susceptibility of HIV-positive pregnant women to malaria.