Last update:
10-Dec-2008

Urinalysis is one of the basic laboratory tests for the evaluation of renal disease. The appropriate interpretation of urinary sediment findings can lead to the accurate localization of renal lesions (glomerulus, interstitial tissue, renal tubules or a combination). The main patterns of urinary sediment that reflect different clinical conditions are (a) the nephrotic, characterized by lipiduria (oval fat bodies, fatty casts, free fat droplets), (b) the nephritic (dysmorphic erythrocytes and/or red blood cell casts), (c) mixed, with nephrotic and nephritic features, (d) the sediment of acute tubular necrosis (renal tubular cells, renal epithelial fragments, renal tubular epithelial cell casts, waxy and acute renal necrosis casts or dirty brown granular casts), and (e) the sediment of acute interstitial nephritis (polymorphonuclear leukocytes, white cell casts). In this review the urinary findings in acute and chronic renal disease are interpreted according to the causative agents, and the importance of measurement of the ratio of protein or albumin to creatinine in a spot urine sample is explained.

Key words: Αcute renal failure, Chronic renal failure, Urinary sediment.