What are dysmorphic red cells?
Phase-contrast morphology can be used to characterize urinary erythrocyte morphology.
Glomerular bleeding, a characteristic of glomerulonephritis, causes red cells in the urine to have a non-uniform morphology with irregular outlines and small blebs projecting from their surfaces (i.e., the red cells are “dysmorphic”).
Red cells in the urine from non-glomerular bleeding in the urinary tract are uniform in shape and similar in appearance to red cells in the circulation.
Urine can be analyzed by the clinical laboratory for the presence of dysmorphic red cells.
The sensitivity, specificity, and predicative values for this test are limited, and results need to be interpreted in the context of other clinical and diagnostic data.
Clinical labs most often quantify numbers of dysmorphic red cells as a percentage of total red cells, and define the upper limit of normal to aid in the interpretation of the test.