Plasma levels of interleukin 27 in falciparum malaria is increased independently of co-infection with HIV: Potential immune-regulatory role during malaria

Abstract

<i>Background</i> - The immune response during falciparum malaria mediates both harmful and protective effects on the host; however the participating molecules have not been fully defined. Interleukin (IL)-27 is a pleiotropic cytokine exerting both inflammatory and anti-inflammatory effects, but data on IL-27 in malaria patients are scarce.<p><p>

<i>Methods</i> - Clinical data and blood samples were collected from adults in Mozambique with <i>P. falciparum</i> infection, with (<i>n</i> = 70) and without (<i>n</i> = 61) HIV-1 co-infection, from HIV-infected patients with similar symptoms without malaria (<i>n</i> = 58) and from healthy controls (<i>n</i> = 52). In vitro studies were performed in endothelial cells and PBMC using hemozoin crystals. Samples were analyzed using enzyme immunoassays and quantitative PCR.<p><p>

<i>Results</i> - (i) IL-27 was markedly up-regulated in malaria patients compared with controls and HIV-infected patients without malaria, showing no relation to HIV co-infection. (ii) IL-27 was correlated with <i>P. falciparum</i> parasitemia and von Willebrand factor as a marker of endothelial activation, but not with disease severity. (iii) In vitro, IL-27 modulated the hemozoin-mediated cytokine response in endothelial cells and PBMC with enhancing effects on IL-6 and attenuating effects on IL-8.<p><p>

<i>Conclusion</i> - Our findings show that IL-27 is regulated during falciparum malaria, mediating both inflammatory and anti-inflammatory effects, potentially playing an immune-regulatory role during falciparum malaria.