VWF and Plasmodium falciparum malaria: Interestingly, plasma levels of IL-27 were positively correlated with vWF in patients with malaria alone and in HIV-infected patients without malaria (r = 0.54, p < 0.001), but not in those that were co-infected with HIV and malaria (Fig. 2b), potentially indicating some interactions between HIV and falciparum malaria that affects the pattern of endothelial cell activation.