Remarkably, plasmatic cystatin C levels were positively correlated with CIC containing IgG (Fig. 4a), IgG1 (Fig. 4b) and IgG3 (Fig. 4c) (Spearman correlation—IgG: r = 0.54, p < 0.001; IgG1: r = 0.48, p < 0.001; IgG3: r = 0.61, p < 0.001), as well as with anti-Leishmania IgG (Fig. 4d), IgG1 (Fig. 4e) or IgG3 (Fig. 4f) levels (Spearman correlations—IgG: r = 0.55, p < 0.001; IgG1: r = 0.36, p = 0.01; IgG3: r = 0.50, p < 0.001), suggesting that high levels of CIC or specific Igs may be involved in the AKI observed in patients with VL. This evidence concerns the gene CST3 and acute kidney injury.