Urinary doubly refractile lipid bodies in nonglomerular renal diseases

Urinary doubly refractile lipid bodies (DRLB) are a characteristic finding in patients with glomerular renal diseases causing heavy proteinuria. DRLB are felt to be an uncommon finding in glomerular diseases without heavy proteinuria, and a rare finding in nonglomerular renal diseases. In order to determine whether DRLB are found in nonglomerular renal diseases, we reviewed the medical records of all patients who had urinalyses performed in our laboratory from February 1975 to June 1983. Three hundred sixty one patients demonstrated less than or equal to +2 proteinuria, and at least two DRLB. Of these, 290 were identified as having a single renal diagnosis. One hundred forty eight patients (51%) had a variety of acute and chronic glomerular diseases, and 125 patients (43.2%) had nonglomerular renal diseases, including acute tubular necrosis (ATN), prerenal azotemia, chronic interstitial nephritis, polycystic kidney disease, acute interstitial nephritis, renal neoplasia, and acute myeloma kidney. Ten patients had transient proteinuria associated with acute illness, and seven patients had no renal disease at all. Only two patients with nonglomerular renal disease had more than five DRLB per 20 high power microscopic fields. The frequency of DRLB in patients with nonglomerular renal diseases was: chronic interstitial nephritis, 26%; polycystic kidney disease, 38%; prerenal azotemia, 20%; ATN, 15%; and acute interstitial nephritis, 33%. These data suggest that at lower levels of proteinuria, DRLB are found frequently in nonglomerular renal diseases, and that DRLB do not differentiate glomerular from nonglomerular renal diseases unless more than five DRLB are found on urinary sediment examination.