title: Detection of indinavir crystals in urine: dependence on method of analysis.
abstract: OBJECTIVE
  To determine the frequency of crystalluria in patients treated with the human immunodeficiency virus protease inhibitor indinavir and to compare methods of detecting crystalluria.
  
  
  METHODS
  A total of 308 freshly voided urine specimens from 168 patients treated with indinavir were evaluated by manual microscopy of sediment and microscopy with an automated workstation and by dipstick analysis.
  
  
  RESULTS
  Crystals were detected in 22%, 31%, or 32% of specimens using, respectively, an automated workstation, manual microscopy, or both methods. Proteinuria or hemoglobinuria occurred significantly more often in specimens with (28%) than without (18%) crystals. Frequency of crystalluria was unrelated to specific gravity, but it increased at higher pH. Crystals were detected in 21% of specimens with pH less than 6 and 42% of specimens with pH of 6 or higher.
  
  
  CONCLUSIONS
  Crystalluria occurs in more than 30% of urine specimens from patients treated with indinavir, but detection rates vary substantially with method of analysis. Manual microscopy detected crystalluria 41% more often than did an automated workstation.
authors.affiliation: Clinical Pathology Department, Warren Grant Magnusson Clinical Center, National Institute of Diabetes and Digestive Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
authors.forename: G L
authors.initials: GL
authors.lastname: Hortin
authors.forename: C
authors.initials: C
authors.lastname: King
authors.forename: K D
authors.initials: KD
authors.lastname: Miller
authors.forename: J B
authors.initials: JB
authors.lastname: Kopp
mesh_terms: D003460:Crystallization; D015658:HIV Infections / Q000188:drug therapy / Q000652:urine*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use / Q000652:urine*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019469:Indinavir / Q000627:therapeutic use / Q000652:urine*; D008859:Microscopy, Polarization / Q000379:methods; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000379:methods*
chemical_list: D017320:HIV Protease Inhibitors; D019469:Indinavir