Selected P. falciparum specific immune responses are maintained in AIDS adults in Burkina Faso.

Abstract

In tropical areas where Plasmodium falciparum malaria is endemic, co-infection with HIV-1 does not lead to a worsening of malaria, raising questions about the immunological interactions between both infections. Alterations of immune response to malaria during HIV-1 infection was investigated in the town of Bobo Dioulasso, Burkina Faso. Sixty-six adults were enrolled, including 37 HIV-1 positive subjects with < 250 CD4+ cells/microliter and clinical AIDS, and 29 HIV-1, negative healthy subjects. In vitro lymphocyte proliferation and cytokine (IFN-gamma, IL-2 and IL-4) production were assessed in isolated mononuclear cells (PBMC) in presence of PHA, PPD or three malarial antigens: the baculovirus-expressed protein from P. falciparum Merozoite Surface Protein-I, a P. falciparum in vitro culture and a crude schizont extract. Compared with healthy subjects. AIDS patients presented with decreased levels of cell proliferation and of IFN-gamma and IL-2 production, in response to all antigens except the schizont extract. Similar levels of IL-4 production were obtained in both groups. Mitogenic stimulation of whole blood cultures was also performed, and revealed similar trends in cytokine production as in PBMC cultures. These results show that some components of the specific human immune responses to falciparum parasites may not be modified during AIDS, in spite of the strong cellular alterations induced by HIV, namely the decrease of the CD4+ lymphocyte subset.