Differentiation of glomerular and non‐glomerular hematuria in children by measurement of mean corpuscular volume of urinary red cells using a semi‐automated cell counter

Abstract

Urine samples from 110 children and adolescents with micro- or macrohematuria were compared using phase-contrast microscopy and a semi-automated cell counter to differentiate glomerular from non-glomerular hematuria. 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 latter group underwent urological operation and had normal urine before operation. Mean corpuscular erythrocyte volume (MCVU) and percent of dysmorphic erythrocytes were determinated. To exclude the influence of mean erythrocyte volume of blood erythrocytes (MCVB), MCVB was determined and additionally the quotient of MCVU/MCVB was calculated (MCVUB). The percentage of dysmorphic erythrocytes differed significantly between 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 55.5 +/- 16.3 fl in group 2; p < 0.01) and MCVUB (0.41 +/- 0.14 in group 1 versus 0.67 +/- 0.20 in group 2; p < 0.01). When glomerular hematuria was defined on the basis of more than 80% dysmorphic erythrocytes, the sensitivity of phase-contrast microscopy was 0.52, specificity versus 0.96 and efficiency 0.64. When glomerular hematuria was defined as < 50 fl 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 efficiency 0.80. The correlation coefficient between MCVU and dysmorphic erythrocytes was -0.71 (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Dysmorphic erythrocytes and G1 cells as markers of glomerular hematuria

“…Our specificities for different cut-off levels of G1 cells agree well with those of others [22,23,24]. However, since 36% of the urine samples from our patients with biopsy-proven glomerulonephritis contained no G1 cells, our diagnostic sensitivities for percentage G1 cells were lower than those reported by Kohler et al [3], Lettgen and Wohlmuth [8], and Tomita et al [4] for the corresponding cut-off levels.…”

“…However, the clinical usefulness of this technique remains controversial, since there is no agreement over the criteria for the interpretation of the urinary dysmorphic erythrocytes [3,4] or the minimum number of dysmorphic erythrocytes deemed to indicate glomerular hematuria. The diagnostic cut-off for the percentage of dysmorphic erythrocytes giving a definitive diagnosis of glomerular hematuria has varied between 10% and 80% [5,6,7,8,9,10,11,22,23,24]. In these studies the sensitivities have ranged from 21% to 95% and the specificities from 75% to 100%.…”

“…In these studies there was either no diagnostic limit for dysmorphic erythrocytes [25,27] or the diagnostic levels ranged from 20% to 80% [8,10,22]. The sensitivities varied between 52% and 94% and specificities ranged from 81% to 100%.…”

“…In the literature there are a few studies on exclusively pediatric patients [8,10,21,22,27]. In these studies there was either no diagnostic limit for dysmorphic erythrocytes [25,27] or the diagnostic levels ranged from 20% to 80% [8,10,22].…”

Hämaturie

“…Wesentliche Hinweise auf den Ursprung der Hämaturie liefert die Morphologie der Erythrozyten aus dem frisch gewonnenen Urin (10,14).…”