All issues > Volume 37(8); 1994

Original Article

J Korean Pediatr Soc. 1994;37(8):1097-1103. Published online August 15, 1994.

Identification of the Source of hematuria by the Ratio of the Urinary Erythrocyte MCV to That in Blood

Young Guk YG Kim¹, Gi Chan GC Lee¹, Keun Haeng KH Cho¹, Kee Hwan KH Yoo¹, Soon Kyum SK Kim¹

¹Department of Pediatrics, College of Medicine, Korea University, Seoul, Korea

Abstract

The frequent occurrence of hematuria in children necessitates diagnostic evaluation. Hematuria may occur with either renal or lower urinary tract disease. Clarification of the etiology of hematuria, whether microscopic or gross, is facilited by localizing the site of bleeding to the kidney(glomerular) or the lower urinary tract (non-glomerular). The mean cellular volume (MCV) of urinary red blood cells (RBCs) of pediatric patients with glomerular (group I; n=77) and non-glomerular (group II; n=34) hematuria was determined using coulter Counter Model S plus IV. We found that red blood cells of glomerular origin had a smaller volume than non-glomerular cells (73.79¡¾9.75um3 vs 83.55¡¾3.77 um3, p<0.001). If an urinary MCV equal to 80.56um3 was taken as the cut-off value between glomerular and non-glomerular hematuria, a correct assessment of the site of bleeding was made in 89 (80%) of the 111 patients studied (sensitivity 76%, specificity 88%). The ratio of the urinary erythrocyte MCV to that in blood (Umcv/Bmcv) was compared with the diagnosis. If an Umcv/Bmcv ratio equal to 0.95 was taken as the cut-off value between glomerular and non-glomerular hematuria, a correct assessment of the site of bleeding was made in 93 (83%) of the 111 patients studied (sensitivity 79.6%, specificity 94%). Coulter counter analysis of urine provides a simple nonivasive and objective aid to the diagnosis of hematuria. This test, when used early in the management of pediatric patients with hematuria, may help to avoid invasive investigations.

Keywords :Hematuria, Urinary red blood cell volume