Detection of indinavir crystals in urine - Dependence on method of analysis

Objectives.-To determine the frequency of crystalluria in patients treated with the human immunodeficiency virus protease inhibitor indinavir and to c ompare methods of detecting crystalluria. Methods.-A total of 308 freshly voided urine specimens from 168 patients tr eated with indinavir were evaluated by manual microscopy of sediment and mi croscopy with an automated workstation and by dipstick analysis. Results.-Crystals were detected in 22%, 31%, or 32% of specimens using, res pectively, an automated workstation, manual microscopy, or both methods. Pr oteinuria or hemoglobinuria occurred significantly more often in specimens with (28%) than without (18%) crystals. Frequency of crystalluria was unrel ated to specific gravity, but it increased at higher pH. Crystals were dete cted in 21% of specimens with pH less than 6 and 42% of specimens with pH o f 6 or higher. Conclusions.-Crystalluria occurs in more than 30% of urine specimens from p atients treated with indinavir, but detection rates vary substantially with method of analysis. Manual microscopy detected crystalluria 41% more often than did an automated workstation.