Effects of extracorporeal shockwave lithotripsy on urinary concentration of epidermal growth factor

In a prospective study, we tried to determine whether extracorporeal shockwave lithotripsy (SWL) has any effect on urinary epidermal growth factor (EGF) concentrations and to investigate whether EGF can be used as a marker for detecting shockwave-induced impairment of distal tubular cells. A total of 12 patients with renal pelvic or caliceal stones < or = 2 cm undergoing anesthesia-free SWL without ancillary measures and a control group of 10 patients without any urologic symptoms were included in this study. The urinary concentrations of EGF were measured by radioimmunoassay before and 4 hours, 24 hours, and 7 days after SWL. Relative urinary EGF concentrations were expressed as the ratio of EGF to creatinine (ng/mL creatinine). The mean urinary EGF concentration (mean +/- standard error) in control subjects and patients with renal pelvic or caliceal stones before SWL was 23.90 +/- 3.15 ng/mL creatinine and 22.18 +/- 6.85 ng/mL creatinine, respectively (p > 0.05). In patients with stones, we found a decrease in urinary EGF concentration 4 hours, 24 hours, and 7 days after SWL. Indeed, 7 days after SWL, the EGF concentration was on average half of the original value, a biologically significant, although not statistically significant, decrease.