2.3.11. Urinary Interleukins

Urinary interleukins, Il-1, Il-6, IL-8 and Il-18, were proposed as markers of AKI. Interleukins are important mediators of the immune reaction in the innate immune system response and adaptive immunity [8]. All these cytokines are freely filtered and then reabsorbed and metabolized in the proximal tubule; therefore, tubular injury leads to an elevation in their levels in urine [5,6,8,9,48].

Manosur et al. studied changes in urinary interleukins after a marathon and found a 19.2-fold increase in uIL-6, a 9.13-fold increase in uIL-8 and a 7.13-fold increase in uIL-18 [46]. Similarly, Semen et al. observed significant increases of urinary interleukins after a half marathon and the use of 400 mg ibuprofen. There was a 10-fold increase in uIL-6, a 2.87-fold increase in uIL-8 and a non-significant increase in IL-18. The elevations of uIL-6 and uIL-8 were smaller in runners supplemented with MOF-VVPP (5.8- and 1.49-fold, respectively) [50]. Elevation of uIL-6 and uIL-8 was also found by Sugama et al. after a duathlon [59]. Spada et al. found an increase in uIL-18 after a HIIT session [48]. Dutheil et al. found an increase in uIL-8 after a 24 h work shift and, according to the author, this elevation was related to stress [60].
