Characteristics of leukocytes in the urine sediment in pyelonephritis: Correlation with renal biopsies

Abstract

In a study of patients with infected urine who were shown by needle biopsy of the kidney to represent all stages of pyelonephritis, the gentian violet and safranine stain described by Sternheimer and Malbin [2] was employed routinely to study the urine sediment. A correlation was found between renal parenchymal inflammation and the presence in the urine sediment of leukocytes with pale-staining characteristics. Granular motility was found to be dependent upon the composition and osmolarity of the urine and occurred irregularly in pale-staining granulocytes. It was most striking in urines of low specific gravity. Various solutes added in increasing concentrations to the suspension medium differed in their capacity to inhibit granular motility. The observations appear consistent with the hypothesis that pale cells in the urine usually come from the kidney and reflect the presence and, to some extent, the degree of acute inflammation present at the time of the examination. If this interpretation is correct vital granulocytes from the inflamed kidney rapidly appear in the urine, exhibiting only minor alteration of their staining characteristics. Granular motility is of incidental importance. Application of this concept was found to improve the validity of the clinical diagnosis of pyelonephritis as established by biopsy specimens from the kidney. In the early stages of pyelonephritis, when the concentrating power of the kidney has not yet been jeopardized, the staining properties of the white blood cells in the urine sediment arc of particular significance in diagnosis whereas the criterion of granular motility seems less important.