Fig 2: On the left: comparison of discrimination performance of cystatin C, KIM-1, NGAL, FGF23 and SCr regarding the incidence of AKI after sepsis. Cystatin Cis blue, SCr is yellow, KIM-1 is green, NGAL is orange, and FGF-23 is red. The respective AUROC are 0.830 (P < 0.001), 0.819 (P < 0.001), 0.765 (P < 0.001), 0.620 (P = 0.021) and 0.596 (P = 0.042); On the right: comparison of discrimination performance of cystatin C combined with SCr, which AUROC was 0.847 (P < 0.001)

Fig 3: Mean level NGAL (ng/ml) in all studied groups.

Fig 4: Increased LTB4 and LCN2 systemic levels in COVID-19 and long-COVID patients. (A,B) Plasma levels of LTB4 and LCN2 in COVID-19 patients (n = 30), long-COVID-19 patients (n = 10), and healthy donors (n = 25) were analyzed using ELISA. Data reported in this figure are the mean ± SE of two independent experiments (** p < 0.01).

Fig 5: Western blot analysis for iron-related proteins in PBMCs isolated from COVID-19, long-COVID patients, and healthy controls. (A) Panels report the proteins levels for CP, Tf, HPX, LCN2, SOD1 and ACTIN in PBMCs isolated from COVID-19 patients (n = 7), long-COVID (n = 7) patients, and healthy volunteer donors (n = 7). (B) Band intensities were quantified using Image J and are reported in the figure as arbitrary units (AU). Data reported in this figure are the mean ± SE of two independent experiments (* p < 0.1, ** p < 0.01, *** p < 0.001).