Cellular immune responses to Plasmodium falciparum antigens in Gambian children during and after an acute attack of falciparum malaria.

Peripheral blood mononuclear cells from 63 Gambian children with acute Plasmodium falciparum malaria were examined for lymphoproliferation and interferon-gamma (IFN) production in response to stimulation by mitogens, malaria antigens and other soluble antigens. Mitogen or Candida-induced proliferation was not depressed during acute infection but was enhanced 2 to 4 weeks after treatment. Responses to partially purified soluble P. falciparum antigens were minimal or absent in all children in the acute phase but approximately 50% of the children responded by proliferation or IFN-gamma production during the 2 to 8 week convalescent period. These proliferative responses were severely depressed in the presence of the patient's own serum. Nine children with significant convalescent phase proliferative responses were re-examined several months after acute infection. Of these, four remained responsive for at least 8 months in the probable absence of reinfection.