Evaluating ESWL-induced renal injury based on urinary TNF-α, IL-1α, and IL-6 levels

Extracorporeal shockwave lithotripsy (ESWL) has dramatically changed the treatment of urinary lithiasis and has been the first treatment option for the majority of patients for more than two decades. Despite its significant benefits, it induces acute renal injury that extends from the papilla to the outer cortex. We evaluated the severity of the inflammatory response to ESWL by measuring the urinary excretion of the cytokines TNF-alpha, IL-1 alpha, and IL-6. The study included 21 selected patients and 14 control subjects. All patients underwent the same ESWL procedure (2,500 shockwaves at 100 shockwaves/min and 0.039 J from the lithotripter). Urine TNF-alpha, IL-1 alpha, and IL-6 levels were measured using standard ELISA kits. In the study population (patients and controls), we did not detect TNF-alpha in the urine samples. The levels of both IL-1 alpha (2.5 pg/ml) and IL-6 (3.8 pg/ml) measured before ESWL were not significantly different from the control group (2.5 and 5.2 pg/ml, respectively; p > 0.05). Twenty-four hours after ESWL, in contrast to IL-1 alpha (4 pg/ml), urine IL-6 (19.7 pg/ml) increased significantly (p < 0.05). Fourteen days after ESWL, IL-1 alpha increased to 5 pg/ml, while IL-6 (7 pg/ml) decreased to the control level. Urine cytokine levels may be used to evaluate the inflammatory response to ESWL. After ESWL, IL-6 levels increased in the early phase, while IL-1 alpha levels increased later. These two markers may be used to measure the severity of inflammation. In contrast to IL-1 alpha and IL-6, urine TNF-alpha excretion was not increased by ESWL. We believe that the inflammatory response to ESWL can be detected by the urinary excretion of IL-1 alpha for up to 14 days.