Urinary WT1‐positive cells as a non‐invasive biomarker of crescent formation

Objective The purpose of this study was to assess the relationship between urinary WT1‐positive cells (podocytes and active parietal epithelial cells) and WT1‐positive cells in renal biopsy to investigate whether urinary WT1‐positive cells are useful for detection of crescent formation. Methods Fifty‐two patients with kidney disease were investigated (15 cases with crescentic lesions and 37 cases with non‐crescentic lesions) for immunoenzyme staining using anti‐WT1 antibody for urine cytology and renal biopsy. Numbers of WT1‐positive cells in urine and renal biopsy were counted. Results There was no correlation between urinary WT1‐positive cells and WT1‐positive cells in renal biopsy. However, the number of urinary WT1‐positive cells in patients with crescentic lesions was significantly higher than in patients with non‐crescentic lesions. In addition, the best cut‐off value to detect patients with crescentic lesions using urinary was 5 cells/10‐mL (area under the concentration‐time curve=0.735). Conclusions The results of our study suggest urinary WT1‐positive cells can be used to detect patients with crescent formation using 5 cells/10‐mL cutoff value. WT1‐positive glomerular podocytes and parietal epithelial cells may be shed into urine in active glomerular disease. This study, investigating the relationship between WT1‐positive cells in urine and in the renal biopsy found no correlation; however, the results do suggest that, using a cutoff value of 5 cells/10 mL, WT1 positive urinary cells can be used to detect patients with crescent formation. WT1 positive glomerular podocytes and parietal epithelial cells may be shed into urine in active glomerular disease. This study, investigating the relationship between WT1 positive cells in urine and in the renal biopsy found no correlation; however, the results do suggest that, using a cutoff value of 5 cells/10 mL, WT1 positive urinary cells can be used to detect patients with crescentic formation.