Serum levels of interleukin-18 in patients with uncomplicated Plasmodium falciparum malaria.
Interleukin (IL)-18, a newly discovered cytokine produced primarily by macrophages, has been shown to induce gamma interferon (IFN-gamma) production by natural killer cells, to induce the T helper type 1 response. To further elucidate the role of this cytokine in uncomplicated malaria caused by Plasmodium falciparum, serum levels of IL-18, and gamma interferon (IFN-gamma), determined by an immunoenzymatic assay, were analyzed in 40 adult patients, and in 15 healthy control subjects. A significant increase in serum levels of IL-18 was observed in patients with uncomplicated P. falciparum malaria on admission, whereas serum levels of IFN-gamma tended to increase although not significantly. Serum levels of IL-18 decreased three days later, but still remained significantly high, whereas IFN-gamma levels returned to normal levels compared to the controls. No significant correlation was found between parasitemia and serum levels of IL-18 and IFN-gamma. The increase of IL-18 levels during acute and recovery phases of uncomplicated P. falciparum malaria may reflect a proinflammatory role of IL-18 in these patients. An early and effective immune response regulated by proinflammatory Th1 cytokines, including tumor necrosis factor (TNF), interleukin (IL)-12, and possibly IFN-gamma may limit the progression from uncomplicated malaria to severe and life-threatening complications.
Torre
D
D
Division of Infectious Diseases, Regional Hospital, Viale Borri 57, 21100 Varese, Italy. eiwle@tin.it
Giola
M
M
Speranza
F
F
Matteelli
A
A
Basilico
C
C
Biondi
G
G
D000328:Adult; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007371:Interferon-gamma / Q000097:blood; D020382:Interleukin-18 / Q000097:blood*; D016778:Malaria, Falciparum / Q000097:blood*; D008297:Male
D020382:Interleukin-18; D007371:Interferon-gamma