LCN2 and infection: Because these NGAL characteristics have been shown to be early markers of renal structural damage [19,20], our findings are indicative of HIIRT-associated kidney injury, possibly at the thick ascending Henle loop, proximal tubule or both since the average baseline levels of the studied population were normal, and there are no other factors such as infection or increased extra-renal production of NGAL to confound the results.