Differentiation of Glomerular from Non-Glomerular Hematuria by Three Different Methods of Microscopic Examinations of Erythrocytes in Urine

Background: morphological examinations of urinary erythrocytescan be of diagnostic value in initial evaluation of hematuria.dysmorphic urinary red blood cells are known to indicatea glomerular origin of bleeding. we examined the clinicalusefulness of this test in a population complained of hematuriaby use of three different methods: light microscopy,phase contrast microscopy, and wright staining and comparedtheir sensitivity and specificity.methods: the study included 169 patients with hematuria (89glomerular and 80 non-glomerular). the urine specimens werecollected before invasive procedures such as biopsy and cystoscopy.in each urine sample, 100 urinary erythrocytes wereexamined. statistical analysis was performed using student's ttest, correlation coefficient, and x2. reliability parameters includingsensitivity, specificity and predictive values of negativeand positive tests were also evaluated.results: dysmorphic red cells were recorded as acanthocytes,doughnut-like cells, yeast like cells with more than one blebsand ghost forms. isomorphic erythrocytes had uniform sizeand shape. significant difference was found in the number ofurinary dysmorphic red cells between the two groups of patients.statistical analysis showed that by using percentage ofglomerular type erythrocytes and setting the cut.off at 20-25%, the specificity for three procedures was almost the same(. 97.5%). but sensitivity for light microscopy, phase contrastmicroscopy, and wright staining was in different ranges as70.7%, 89.8%, and 86.5% respectively.conclusion: it was concluded that with some limitations, thesesimple, non-invasive techniques were useful in identifying thesource of bleeding in the work up of hematuria by consideringthat sensitivity of the methods were in the order of phase contrastmicroscopy, wright staining, and light microscopy