A comparative analysis of the Iris iQ200 with manual microscopy as a diagnostic tool for dysmorphic erythrocytes in urine

摘要

Microscopic analysis of erythrocytes in urine is a valuable diagnostic tool for identifying glomerular hematuria. Indicative of glomerular hematuria is the presence of eryth-rocyte casts and poly- and dysmorphic erythrocytes. In contrast, in non-glomerular hematuria, urine sediment erythrocytes are mono- and isomorphic, and erythrocyte casts are absent (1, 2). To date, various variant forms of dysmorphic erythrocyte morphology have been defined and classified. They are categorized as: D1, D2, and D3 cells (2). D1 and D2 cells are also referred to as acanthocytes or G1 cells which are mickey mouse-like cells with membrane protrusions and severe (D1) to mild (D2) loss of cytoplasmic color (2). D3 cells are doughnut-like or other poly- and dysmorphic forms that include discocytes, knizocytes, anulocytes, stomatocytes, codocytes, and schizocytes (2, 3). The cellular morphology of these cells is observed to have mild cytoplasmic loss, and symmetrical shaped membranes free of protrusions. Echinocytes and pseudo-acanthocytes (bite-cells) are not considered to be dysmorphic erythrocytes. Glomerular hematuria is likely if more than 40% of erythrocytes are dysmorphic or 5% are D1-D2 cells and nephrologic work-up should be considered (2).