[Clinical significance of urinary sediment dysmorphic red blood cells and casts in renal disease].

We investigated the utility of measuring dysmorphic red blood cells (d-RBC) and urinary casts in the diagnosis and assessment of prognosis of renal diseases by evaluating these parameters in a total of 278 urine specimens from 78 patients with various renal diseases at our hospital. Urinary sediments obtained by the conventional method with in 4 hours after voiding were subjected to Sternheimer and Malbin's staining and examined under a conventional light microscope. We used the criteria we previously devised for classification of RBC as d-RBC and for classification of casts hyaline, granular, epithelial, red blood cell, white blood cell, fatty, or waxy. When there were 5 or more urinary sediment red blood cells per high-power field, d-RBC was found in 94% of samples from patients with chronic glomerulonephritis. The finding of d-RBC was not related to glomerulonephritis pathologically diagnosed according to the WHO classification system for biopsy specimens. Even when there were fewer than 5 red blood cells per high-power field, d-RBC was sometimes found. Casts of all types were found in samples from patients with chronic glomerulonephritis or chronic renal failure. In samples from patients with chronic pyelonephritis, however, white blood cell, fatty, and waxy casts were not found, and less than 1 granular or epithelial cast per low-power field was found. The findings for the presence and the extent of both d-RBC and casts were in good accord with and changed with the clinical course, indicating that d-RBC and casts of urinary sediment can be used to predict the prognosis of patients with renal disease.