['Galectin-9 (Gal-9) is a β-galactoside-binding lectin that interacts with sugar moieties on glycoproteins and glycolipids of cells and pathogens. Gal-9 is known as an immune modulator that induces cell death via interaction with T cell immunoglobulin and mucin domain-3 (Tim3), a co-inhibitory receptor, and it inhibits production of several pro-inflammatory cytokines (TNF, IL-6 and IL-1α) and enhances production of IL-10. To understand the immune pathology of malaria, the Gal-9 in plasma was measured.', 'Plasma samples and clinical parameters were obtained from 50 acute malaria cases (nine severe and 41 uncomplicated cases) from Thailand at three time points: day 0, day 7 and day 28. Gal-9 levels were determined by ELISA. A total of 38 species of cytokines and chemokines were measured using a BioPlex assay.', 'Gal-9 levels were higher at day 0 compared to day 7 and day 28 (P\xa0<\xa00.0001). Gal-9 levels were also higher in severe malaria (SM) cases compared to uncomplicated (UM) cases at day 0 and day 7 (923 vs 617\xa0pg/mL; P\xa0=\xa00.03, and 659 vs 348\xa0pg/mL; P\xa0=\xa00.02 respectively). Median Gal-9 levels were higher in patients with blood urea nitrogen to creatinine ratio (BUN/creatinine)\xa0≥20 (mg/dL) than in patients with BUN/creatinine\xa0<20 (mg/dL) at day 0 (817.3 vs 576.2\xa0pg/mL, P\xa0=\xa00.007). Gal-9 was inversely significantly correlated with chloride levels in both SM and UM cases (r s\xa0=\xa0-0.73 and r s\xa0=\xa0-0.46, respectively). In both UM and SM cases, Gal-9 was significantly associated with pro- and anti-inflammatory cytokines and chemokines such as TNF, IL-6, IFN-α2, IFN-γ, IL-1Ra and IL-10. These correlations were observed at day 0 but disappeared at day 28.'] Do plasma levels of Galectin-9 reflect disease severity in malaria infection?