Fifty subjects living in a
malaria endemic area were studied at diagnosis of a Plasmodium falciparum attack and 3 weeks later. Absolute numbers of CD3(+), CD4(+) and CD8(+) lymphocytes as well as plasma
cytokines and secreted
cytokines after in vitro mitogenic stimulation were measured. At enrollment,
lymphopenia was observed, lending support to the reallocation hypothesis during the acute phase. A significant elevation of the number of CD8(+) cells was present in the peripheral blood during the recovery phase. During the acute phase, plasma
IL-6 levels peaked while in vitro production capacity was high at both phases. Plasma
IL-6 concentrations were positively related to blood parasite density at D0, as
IL-4 and IFN-gamma, suggesting an early intervention of these
cytokines. Plasma
IL-2 levels were low at diagnosis although cells retained their ability to produce
IL-2, which was found more frequently in plasma after cure. Acquisition of immunity with age was in relation with greater secretion abilities of cells for type 1 and type 2
cytokines during the parasite clearance phase. We conclude to an early implication of type 2
cytokines and IFN-gamma, with particularly high levels of
IL-6.