Comparison between optical microscopic examination and phase contrast microscopic examination for diagnosing the origin of urinary bleeding

Purpose: Phase contrast microscopy method is useful in the examination of urine sediment to differentiate glomerular(G1) hematuria from non-glomerular(nonG1) hematuria. In this study, we compared the diagnostic value of optical microscopy with that of phase contrast microscopy. Method: One hundred and sixty fresh urine samples of microscopic hematuria (5/HPF or more) from 118 patients with renal disease and 42 patients with urologic disease were analyzed. The erythrocytes referred to as G1, are defined to have acanthocytes, target configuration, or finger ring shape, and a G1 cell/total erythrocyte ratio greater than 3% is defined as reliable marker for G1 bleeding. Result: Sensitivity and specificity of this criteria for G1 bleeding were 50.9% and 94.9% in acanthocytes, 69.6% and 89.1% in the target configuration, and 88.4% and 89.1% in the finger ring, respectively. As for the microscopic observation methods, the sensitivity and specificity of this criteria for G1 bleeding were 88.1 % and 81.0% with phase contrast microscopy, 74.6% and 90.9% with optical microscopy with no dyeing, and 74.6% and 88.6% with optical microscopy with dyeing, respectively. Conclusion: G1 and nonG1 hematuria were correctly diagnosed by counting the urinary G1 cells not only by phase contrast microscopy, but also by optical microscopy. This method seems to have important clinical usefulness by offering information on urinary bleeding.