Clinical prevalence of glomerular hematuria: a nine-year retrospective study.

The authors evaluated red blood cell (RBC) morphology by phase contrast microscopy and identified casts and lipidic material in 4,448 urine sediments (US). Microhematuria was discovered on systematic examination in 1,186 apparently healthy patients (group I). Another 4,362 patients (group II) with microscopic or gross hematuria were being treated or evaluated for various renal or extrarenal diseases (renal transplantation excepted). Glomerular hematuria (GH) was observed in 93.1% of group I patients and in 58.0% of group II patients. GH and non-GH were observed together in 0.6% of cases. The origin of hematuria remained uncertain in 11.6% of cases. In GH, the other cytological findings were as follows: RBC casts were seen in 5.3% of group I and 20.5% of group II; granular and/or cellular casts were seen in 12.8% of group I and 39.6% of group II; and lipidic material was seen in 0.6% of group I and 8.8% of group II. Both groups showed a higher frequency of RBC casts, granular and/or cellular casts, and lipidic material in patients under 20. This method of investigation of urine, which is simple, rapid, inexpensive, and noninvasive, provides useful information for the clinician and avoids unnecessary investigations.