Interleukin-18 and NGAL in assessment of ESWL treatment safety in children with urolithiasis

Urolithiasis is recurrent chronic disease and a complex nephro-urological problem. Currently it is diagnosed in very young children, even infants in the first quarter of life. Until recently the main method of treatment for stones, which for various reasons did not pass spontaneously, was open surgery. At present, the main method replacing open surgery is extracorporeal shock wave lithotripsy (ESWL). Usefulness of common known indicators of the renal function to assess the safety of ESWL procedure is evaluated and verified. The basic markers are serum creatinine, cystatin C, urea, glomerular filtration rate and albuminuria assessment. Unfortunately all these methods show little sensitivity in the case of acute injury processes. There are efforts to use new biomarkers of renal tubular activity, which include among others interleukin 18 (IL-18) and neutrophil gelatinase-associated lipocalin (NGAL). The aim of the study was to assess the safety of ESWL by means of albumin to creatinine ratio, serum cystatin C levels and concentration of two new markers: IL -18 and NGAL. Albumin to creatinine ratio (p = 0.28) and serum cystatin C (p = 0.63) collected before and 48 hours after ESWL did not show statistically significant differences. Similarly, both new markers (IL -18 and NGAL) showed no significant differences (urine IL -18 p = 0.31; serum NGAL p = 0.11; urine NGAL p = 0.29). In conclusion, serum cystatin C tests, urine albumin to creatinine ratio and new early markers of renal tubular injury confirmed the safety of the extracorporeal shock wave lithotripsy (ESWL) and show that the procedure does not cause any episode of acute renal injury.