Is urinary kidney injury molecule-1 a noninvasive marker for renal injury in patients with ureteral stones?

Abstract

Lokman Irkilata, Hasan Riza Aydin, Huseyin Cihan Demirel, Mustafa Aydin, Mansur Daggullu, Mehmet Hakan Taskin, Senol Adanur, Ebubekir Akgunes, Ahmet Ali Sancaktutar, Mustafa Kemal Atilla

Objective: The objective of this study is to evaluate whether levels of urinary kidney injury molecule-1 (KIM-1) are increased in patients in different stages of hydronephrosis and to follow the course of the KIM-1 levels after ureterorenoscopy (URS). Methods: The study included 39 ureteral stone patients who had planned to undergo URS and had various degrees of hydronephrosis, as well as 40 healthy control patients. The levels of urinary KIM-1 molecule were detected before URS (U1) and on the 30th day following the procedure (U2) in the study group and compared with the urinary KIM-1 levels of the control group. Results: The levels of urinary KIM-1 were significantly higher in the study group as compared with the control group. Preoperative levels of KIM-1 were not found to depend on hydronephrosis level. Postoperative levels of KIM-1 were significantly higher, with higher degrees of hydronephrosis, as detected by ultrasonography, on postoperative day 30 as compared with lower degrees of hydronephrosis detected at the same time. The localization and the size of the ureteral stone showed no differences with respect to the levels of KIM-1 among patients in the study group. Conclusions: Elevated urinary KIM-1 levels at the end of the first month after URS indicate continued renal injury due to ureteral stone. The degree of hydronephrosis was proportional to the level of urinary KIM-1. The degree of hydronephrosis at postoperative day 30 is the most important factor determining KIM-1 levels. Neither the localization of the ureteral stone nor the size of the stone are important in determining KIM-1 levels