Evaluation of glomerular and nonglomerular hematuria by phase-contrast microscopy.

Glomerular and nonglomerular origins of hematuria may be identified by assessment of the shape and size of the excreted red blood cells. We examined 380 urine specimens from 179 children with hematuria (greater than or equal to 3500 RBC/minute) with phase-contrast microscopy. In 106 cases, the cause was known; the results agreed with the clinical, histologic, and laboratory diagnosis in 63 of 65 subjects (97%) with glomerulopathies and in 39 of 41 (95%) with nonglomerular hematuria. Casts were found in 54% of the specimens from the children with definite glomerular hematuria. Phase-contrast microscopic examination of red blood cells in the urine is a simple, inexpensive, and noninvasive technique that permits an accurate distinction between glomerular and nonglomerular bleeding in pediatric patients.