Clinical Significance of Urinary Epidermal Growth Factor Levels in Patients with Acute Renal Failure

Takayasu T. Taira, MD, Department of Internal Medicine, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Midoriku, Yokohama 227 (Japan) Dear Sir, The origin and the significance of urinary human epidermal growth factor (hEGF) remain in hypothesis. We investigated urinary hEGF levels in 16 patients with acute renal failure (12 men and 4 women aged 18-77 years, mean 46.2 ± 4.6 SEM) and compared these with healthy controls (7 men and 5 women aged 24-73 years, mean 42.9 ± 6.0 SEM). Changes in urinary hEGF levels over the course of time were also studied in 9 patients who recovered from the acute phase. Urinary hEGF levels were determined by radioimmunoassay with a specific anti-hEGF antibody and 125I-hEGF, and were corrected for creatinine (Cre) concentration. Plasma Cre concentration ranged from 3.3 to 13.7 mg/dl (5.09 ± 0.68; n = 16) in the acute phase and 0.6 to 1.9 mg/dl (1.09 ± 0.7; n = 9) in the recovery phase. The urinary hEGF levels in the acute phase were 0.98 ± 0.20 ng/mg Cre (n = 16) – a level significantly (p < O.01) lower than the normal control (13.74 ± 1.18; n = 12) – and this subsequently increased significantly (6.10 ± 0.73 ng/mg Cre) during recovery (n = 9, p < 0.01; fig. 1). There was a significant correlation (r = 0.712, p < 0.001) between urinary hEGF and Cre clearance (ml/min) and an inverse correlation (r =-0.406, p < 0.05) between urinary hEGF levels and fractional excretion of sodium. There was no significant correlation between hEGF concentrations in serum and urine (r=0.230, p < 0.43). The remarkable decreased level of urinary hEGF was already observed before urinary ß2-microglobulin and N-acetyl-ß glucosamin-idase increased. Thus, urinary hEGF levels .1 ιo