Correlation of Urine Red Cell Morphology and Renal Biopsy Findings
David Hull, David G Bostwick. Bostwick Laboratories, Inc., Glen Allen, VA
Background: Hematuria may indicate serious disease such as infection, renal disease, and malignancy. Examination of the urine sediment, including detailed analysis of red blood cell morphology, may be useful in discriminating the source of hematuria. Specifically, dysmorphic red blood cells are associated with glomerulopathy; various sensitivities and specificities have been reported depending upon the end point of the study. We report the association of urinary dysmorphic red blood cells with biopsy-confirmed glomerulopathy.
Design: Between 2008 and 2012, 162 patients with renal biopsies had prior RenalVysion™ analysis, which included cytologic examination of the cellular elements of urine using Papanicolau and acid hematoxylin-stained concentrated urine specimens with cellular enhancement. A total of 16 patients were excluded owing to lack of glomeruli on renal biopsy or lack of red blood cells observed during urine cytologic examination, with a final study group of 146 patients. We evaluated the correlation of dysmorphic red blood cells in the urine with subsequent diagnosis of glomerulopathy by renal biopsy.
Results: We found that 76 of 108 patients with biopsy-confirmed glomerulopathy had dysmorphic red blood cells in the urine; in addition, one of 38 patients without glomerulopathy had dysmorphic red blood cells. Using biopsy-confirmed glomerulopathy as the end point for this analysis of dysmorphic red blood cells, sensitivity was 70.3%, specificity was 97.4%, positive predictive value was 98.7%, and negative predictive value was 53.6%.
Conclusions: Detection of dysmorphic red blood cells in urine is a sensitive and specific marker of glomerulopathy. This finding is best utilized in conjunction with the patient's clinical history, urine cytology findings (including casts, tubular cells, and inflammatory cells), urine chemistry, and serum chemistry.
Category: Kidney (does not include tumors)
Monday, March 4, 2013 1:00 PM
Poster Session II # 235, Monday Afternoon