ABSTRACT
BACKGROUND: Recently, G1 cells, characterized by distinctive doughnut-like shape with blebs have been reported as a reliable marker for glomerular hematuria. We investigated the validity of the urinary G1 cells in distingushing glomerular from non-glomerular hematuria. In addition, we evaluate the influence of urine osmolality, pH and proteinuria on dysmorphic erythrocytes and G1 cells. METHODS: One hundred and twenty patients with hematuria including 60 glomerular (GH) and 60 non- glomerular hematuria (NGH) were examined. The percentage of urinary dysmorphic erythrocytes and G1 cells using phase-contrast microscopy was determined. Urine osmolality, pH, and spot urine protein/ creatinine ratio were examined. RESULTS: The proportion of G1 cells differed significantly between the two group (7.8+/-16.0% in GH vs. 0% in NGH, p<0.05). At the cut-off value of 50 % dysmorphic erythrocytes, the sensitivity and specificity for the detection of GH was 88.3% and 93.3%, respectively. At the cut-off value of 1% G1 cells, sensitivity and specificity were 60.0% and 100%, respectively. When both of 50% dysmorphic erythrocytes and 1% G1 cells were considered as the cut-off value, the sensitivity and specificity were 91.0% and 100%, respectively. There was a significant difference in the percentage of dysmorphic erythrocytes and G1 cells at different urine pH. There was a significant correlation between urine osmolality and dysmorphic erythrocytes (r=0.41, p< 0.05), but not for G1 cells. No significant correlations were observed between G1 cells and proteinuria or pH. CONCLUSION: Evaluation of both urinary G1 cell and dysmorphic erythrocytes at the same time could improve the diagnostic value for differentiating glomerular hematuria.