Evaluation of Neutrophil Gelatinase-associated Lipocalin, Interleukin-18, and Cystatin C as Molecular Markers Before and After Unilateral Shock Wave Lithotripsy

Abstract

OBJECTIVE To investigate the impact of shock wave lithotripsy (SWL) on renal tissues using neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, and interleukin 18 (IL-18) levels in serum and urine and to examine the relationship of these biomarkers with patient and calculus characteristics as well as SWL treatment parameters. MATERIALS AND METHODS Thirty-seven patients with renal calculi were included in this study. Blood and urine samples were attained from each patient at 4 time points; immediately before SWL, 6 hours after, 3 days after, and 10 days after the SWL. A new generation lithotripter was used for all cases. Serum and urine NGAL concentrations were measured using commercially available enzyme-linked immunosor-bent assay kits according to manufacture's protocol. The concentration of cystatin C was measured in serum, whereas IL-18 concentration was assessed in urine. RESULTS There were no statistically significantly differences in the levels of NGAL in serum and urine before and after SWL. The mean levels of cystatin C in serum appeared significantly higher 3 and 10 days after SWL. No statistically significant differences were identified between levels of IL-18 before and after SWL. Patients with diabetes mellitus demonstrated significantly higher baseline cystatin C levels. There was no correlation between calculus characteristics or treatment parameters and the levels of all 3 biomarkers after SWL. CONCLUSION The results of this study indicate that SWL is associated with minimal acute injury to renal tissues. Our findings support the safety profile of new generation lithotripters, provided orthodox indications and treatment principles are followed. (C) 2014 Elsevier Inc.