DIFFERENTIATION OF GLOMERULAR AND NONGLOMERULAR HEMATURIA IN CHILDRENBY MEASUREMENT OF MEAN CORPUSCULAR VOLUME OF URINARY RED-CELLS USING A SEMIAUTOMATED CELL COUNTER

Urine samples from 110 children and adolescents with micro- or macrohe maturia were compared using phase-contrast microscopy and a semi-autom ated cell counter to differentiate glomerular from non-glomerular hema turia. Glomerular hematuria, defined by clinical criteria from biopsy and standard chemical evaluation, was observed in 73 patients (group 1 ): non-glomerular hematuria was found in 37 patients (group 2). The la tter group underwent urological operation and had normal urine before operation. Mean corpuscular erythrocyte volume (MCVU) and percent of d ysmorphic erythrocytes were determinated. To exclude the influence of mean erythrocyte volume of blood erythrocytes (MCVB), MCVB was determi ned and additionally the quotient of MCVU/MCVB was calculated (MCVUB). The percentage of dysmorphic erythrocytes differed significantly betw een the two groups ((75 +/- 13% in group 1 versus 38 +/- 27% in group 2 (mean +/- SD); p < 0.01), MCVU (34.0 +/- 11.1 fl in group 1 versus 5 5.5 +/- 16.3 fl in group 2; p < 0.01) and MCVUB (0.41 +/- 0.14 in grou p 1 versus 0.67 +/- 0.20 in group 2; p < 0.01). When glomerular hematu ria was defined on the basis of more than 80% dysmorphic erythrocytes, the sensitivity of phase-contrast microscopy was 0.52, specificity ve rsus 0.96 and efficiency 0.64. When glomerular hematuria was defined a s <5011 MCVU, sensitivity was 0.92, specificity 0.57 and efficiency 0. 80 and as <0.06 MCVUB, sensitivity was 0.89, specificity 0.62 and effi ciency 0.80. The correlation coefficient between MCVU and dysmorphic e rythrocytes was -0.71 (p < 0.01). The differentiation of glomerular an d non-glomerular hematuria in children by determination of MCVU appear s to be equivalent to and easier to perform than phase-contrast micros copy.