Figure 4.

Characterization of biologically active factor(s) in Plasmodium vivax paroxysm plasma. Paroxysm plasmas from P. vivax patients (n = 6) were tested in the white blood cell aggregation assay before and after treatment of the plasmas by heating, filtration or centrifugation and with or without supplementation with recombinant human cytokines or freeze-thawed parasite schizont extracts. The bars indicate the median values of the data series together with the interquartile range (25%–75%). PP: Paroxysm plasma (untreated); NHP: normal human plasma (untreated); hPP: paroxysm plasma pre-heated at the indicated temperature; bPP: paroxysm plasma pre-treated at 100°C; PP-A: top layer of centrifuged paroxysm plasma; PP-B: bottom layer of centrifuged paroxysm plasma; Cyto: cytokines (TNF-∝, GM-CSF, IL-6 and IL-10); ScE: freeze-thawed P. vivax schizont extract.