Microscopic hematuria: advances in identification of glomerular dysmorphic erythrocytes.

The high diagnostic sensitivity and specificity of microscopically visible, typically glomerular dysmorphic erythrocytes for identification of the cause of glomerular bleeding have been recognized worldwide. Although glomerular dysmorphic erythrocytes are simple to detect on phase contrast microscopy, immediate microscopic diagnosis still is indispensable, since a change in the morphology of the erythrocytes with restriction of the diagnostic relevance is anticipated because of the high autolytic potency of the urine. It may be postulated that this need for immediate diagnosis has led to the method being neglected owing to the high work load at hospitals and physician offices. Moreover, a physician who does not perform microscopic investigations or who lacks experience with the method will not be able to use this diagnostic technique, since it appeared to be impossible to transport urine samples by mail. In the context of a study comprising 30 patients, of whom 10 had histologically confirmed glomerulonephritis, we have shown that glomerular dysmorphic erythrocytes have a manifest form stability for at least 3 days. The preservative used was thimerosal. Also, the urine can be investigated independent of time even after alcoholic Papanicolaou staining without an alteration of erythrocyte morphology. The practicality of the form stability of glomerular erythrocytes can be exploited in everyday medical routine. There are well founded prospects that the rate of early diagnosis of glomerulonephritis will increase.