Quantitation of urinary red blood cells by phase-contrast microscopy: its relationship to severity of glomerular damage
Osmani, M.H.; Wu, A.Y.; Lim, C.H.
Singapore Medical Journal 28(5): 406-409
1987
ISSN/ISBN: 0037-5675 PMID: 3324354 Document Number: 291339
The present study utililised phase-contrast microscopy (P-CM) to quantitate and characterise the morphology of the urinary red blood cells (RBCs) excreted in microscopic range by 50 consecutive patients admitted for renal biopsy and correlated the urinary findings with various clinicopathologic parameters. All proliferative glomerulonephritis (GN) patients (41/50) excreted abnormal numbers of dysmorphic urinary RBCs and the only patient with normal renal histology had numerous isomorphic RBCs. Nephrotic patients (8/50) excreted dysmorphic RBCs in normal range. GN patients excreting 80,000 RBCs/ml were more likely to have underlying glomerular crescents (X2 = 9.95, p 0.005) or global sclerosis (X2 = 5.56, p 0.02). The number os urinary RBCs excreted did not correlate with segmental sclerosis, serum creatinine or proteinuira. 17/20(85%) who excreted mixed pattern of dysmorphic ( 8000/ml) and isomorphic (5-30%) RBCs had underlying IgA GN. Oral Frusemide 40 mg given to 12 patients increased the % of isomorphic RBCs from 11.8 .+-. 9.9 (mean .+-. SD) to 83.1 .+-. 9.4 (t = 17.25, p 0.001) 1.5 hours later. In conclusion, P-MC of urinary sediment is useful in confirming haematuria and localising its source. Increased excretion of dysmorphic RBCs ( 80,000/ml) is more likely to indicate underlying glomerular crescents or global sclerosis. Oral Frusemide should not be served before urinary P-CM because of its significant effect on morphologic transformation of urinary RBCs.