Abstract
The urinary Tamm Horsfall glycoprotein (T-HGP) excretion was estimated by the electroim-munoassay method in 79 patients with various renal diseases and was compared with that in normal subjects. In the patient group, the urinary T-HGP concentration was 12.9±12.5 mg/l (mean±S.D.) and the daily T-HGP excretion was 16.9±14.1 mg/day, respectively. Good correlations were found between the urinary T-HGP concentration and the urine osmolarity (r=0.696, P<0.001), sodium (r=0.509, P<0.001) and creatinine (r= 0.343, P<0.01). A significant correlation between the daily T-HGP excretion and creatinine clearance (Ccr) was also noted (r=0.650, P<0.001). These results suggest that the urinary T-HGP concentration reflects the urine osmolarity and urinary solute excretion. Furthermore, the daily T-HGP excretion may reflect the functioning nephron mass. The urinary T-HGP excretion was influenced by the glomerular filtration rate. The T-HGP concentration was 19.2±13.8 mg/l and the daily T-HGP excretion was 24.3±14.5 mg/day in subjects with a Ccr greater than 70 ml/min, while the corresponding values were 5.9±13.9 mg/l and 6.1±8.5 mg/day, respectively, in subjects with a Ccr less than 30 ml/min. The values in the former group were significantly higher. On the other hand, T-HGP/Ccr (μg/ml) was significantly higher in the renal failure patients (Ccr less than 30 ml/min). There was no significant difference in T-HGP excretion between patients with primary glomerular diseases and those with renal involvement associated with systemic diseases. The urinary T-HGP concentration and the daily T-HGP excretion were 15.5±12.0 mg/l and 21.9±13.4 mg/day in the patients with primary glomerular diseases, while the corresponding values were 17.3±8.8 mg/l and 24.7±16.7 mg/day, respectively, in the patients with systemic diseases. Eighteen patients with normal renal function (Ccr greater than 70 ml/min) were compared with age and Ccr-matched control subjects. The urinary T-HGP concentration and the daily T-HGP excretion of the patient group were significantly lower than those of the control group. These results suggest that the urinary T-HGP excretion decreases in patients with renal diseases in spite of a well-preserved renal function.
