[Diagnosis of glomerular microhematuria. Study of general practice-relevant form stability and stainability of dysmorphic glomerular erythrocytes].

The high diagnostic sensitivity and specificity of microscopically visible, typically glomerular dysmorphic erythrocytes for identification of the cause of glomerular bleeding is now recognized all over the world. Although glomerular dysmorphic erythrocytes are simple to detect in phase-contrast microscopy, immediate microscopic diagnosis is still indispensable, since a change in the morphology of the erythrocytes with reduced accuracy of the diagnosis must be anticipated because of the high autolytic potency of urine. It may be postulated that this need for immediate diagnosis has led to neglect of the method, owing to the high workload in hospitals and doctor's surgeries. Moreover, a physician who does not carry out microscopic investigations him/herself or who lacks experience with the method has not been able to use this diagnostic technique, since it appeared impossible to send urine samples by post. In the context of a pilot study comprising 30 patients, 10 of whom had developed histologically confirmed glomerulonephritis, we have shown that glomerular dysmorphic erythrocytes have manifest form stability for at least 3 days. The preservative used was thiomersal. Also, the urine can be investigated regardless of the time lapse since sampling, even after Papanicolaou alcohol staining, with no alteration of erythrocyte morphology by alcoholic dehydration, which would limit the value of the diagnosis. The practicability of the form stability of glomerular erythrocytes can be exploited in everyday medical routine. This would increase the rate of early diagnosis of glomerulonephritis and make it more likely that patients will receive adequate nephrological therapy in good time.