[Urine sediment combined with urine protein as a biomarker for renal injury]

To investigate whether combination of urine sediment and urine protein can predict the renal pathological changes.

We prepared 146 specimens of routine fresh fasting morning urine. Sediment analysis was performed with phase-contrast microscopy and 24-hour urine protein was measured. Both urine protein and sediment data were integrated to form three urine analysis groups. Urine group I: proteinuria, hematuira, urine white blood cells, red/white cell casts. Urine group II: proteinuria, few cell hyaline/fine granular casts. Urine group III: minor proteinuira, epithelial cells of tubule, granular/cell casts. The renal pathological lesions were predicted before and then confirmed by renal biopsy. Statistical analyses were performed using kappa test, chi-square test, and significance was accepted at P<0.05.

After renal biopsy, we identified 95 cases of glomerular lesion with proliferation, 46 cases of glomerular disease without obvious proliferation and 5 cases of tubular interstitial lesion. According to the sediment analysis, only 67 cases (46%) could be attributed to urine group I. When combined with urine protein, we could pick out another 75 cases from urine groups I and II, and 8 cases from urine group III. The combined urine analysis could predict glomerular disease (77.7%).

Clinically we can take advantage of the combined urine analysis to predict the pathological lesion of kidney disease, which is especially suitable for primary care doctor, who can not perform renal biopsy.