Urinary endothellin-1 level in children with pyelonephritis and hydronephrosis.

Hydronephrosis is a common finding in patients with urinary tract infection (UTI). Endothellin-1 (ET-1) is a potent vasoactive peptide that has vasoconstrictive effects. It has been shown that urinary ET-1 increases in urinary obstructions. In this study, we measured the urinary ET-1 level in patients with UTI and hydronephrosis of various causes. In this case-control study, we evaluated the urinary ET-1 level in 45 patients who had UTI and hydronephrosis, serving as a case group, and 45 patients who had UTI without hydronephrosis, serving as a control group. Urinary ET-1 was quantified using enzyme-linked immunosorbent assay and urinary creatinine (Cr) by Jaffe method. To rule out the effect of urinary flow rate, the urinary ET-1 to Cr correlation was considered for analysis of the results. The mean age of the patients in the case and control groups was 36.5 ± 27.2 and 26.2 ± 15.5 months, respectively (P >0.01). The mean urinary ET-1 was 89.6 ± 41.7 pg/dL in the case group and 29.3 ± 26 pg/dL in the control group, P <0.001. The mean urinary ET-1 was 121 ± 55.4 pg/dL in patients who had grade 4 hydronephrosis. We conclude that urinary ET-1 was significantly higher in the obstructed than in non-obstructed cases. Urinary ET-1 could be a useful marker that can be utilized in young children for diagnosis of hydronephrosis, especially obstructive cases.