TY - JOUR
T1 - Crystalluria
T2 - Prevalence, different types of crystals and the role of infrared spectroscopy
AU - Verdesca, Simona
AU - Fogazzi, Giovanni B.
AU - Garigali, Giuseppe
AU - Messa, Piergiorgio
AU - Daudon, Michel
PY - 2011/3/1
Y1 - 2011/3/1
N2 - Background: Studies on the frequency of the different types of urinary crystals and the role of Fourier transform infrared microspectroscopy (FTIRM) for identification are few. We describe the results of a retrospective study on the prevalence and typology of crystalluria and on the role of FTIRM. Methods: Urinary crystals were identified using the combined knowledge of crystal morphology, birefringence features and urine pH (combined approach). When this was inconclusive, FTIRM was performed. Results: Crystalluria was found in 807 out of 9834 samples (8.2%). In 793, the combined approach identified "typical" crystals, while in 14 FTIRM was needed to identify "atypical" crystals. Among "typical crystals", calcium oxalate (75.9%), uric acid (25.9%) and amorphous urates (7.9%), alone or in combination, were the most frequent. Brushite, ammonium biurate and cystine were the most rare (0.1%-0.7%). FTIRM identified 12 of 14 atypical crystals: three crystals were due to a drug (amoxicillin, indinavir, doubtful phenytoloxamine); four were due to calcium oxalate mono- or bihydrate, uric acid bihydrate or struvite; five were due to calcium carbonate, Tamm-Horsfall glycoprotein, or rare salt combinations. Conclusions: Crystalluria is not rare and most crystals can be identified by the combined approach. Occasionally, identification of crystals will require FTIRM.
AB - Background: Studies on the frequency of the different types of urinary crystals and the role of Fourier transform infrared microspectroscopy (FTIRM) for identification are few. We describe the results of a retrospective study on the prevalence and typology of crystalluria and on the role of FTIRM. Methods: Urinary crystals were identified using the combined knowledge of crystal morphology, birefringence features and urine pH (combined approach). When this was inconclusive, FTIRM was performed. Results: Crystalluria was found in 807 out of 9834 samples (8.2%). In 793, the combined approach identified "typical" crystals, while in 14 FTIRM was needed to identify "atypical" crystals. Among "typical crystals", calcium oxalate (75.9%), uric acid (25.9%) and amorphous urates (7.9%), alone or in combination, were the most frequent. Brushite, ammonium biurate and cystine were the most rare (0.1%-0.7%). FTIRM identified 12 of 14 atypical crystals: three crystals were due to a drug (amoxicillin, indinavir, doubtful phenytoloxamine); four were due to calcium oxalate mono- or bihydrate, uric acid bihydrate or struvite; five were due to calcium carbonate, Tamm-Horsfall glycoprotein, or rare salt combinations. Conclusions: Crystalluria is not rare and most crystals can be identified by the combined approach. Occasionally, identification of crystals will require FTIRM.
KW - crystalluria
KW - Fourier transform infrared micro-spectroscopy
KW - urinalysis
KW - urinary microscopy
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U2 - 10.1515/CCLM.2011.078
DO - 10.1515/CCLM.2011.078
M3 - Article
C2 - 21143023
AN - SCOPUS:79952784623
VL - 49
SP - 515
EP - 520
JO - Clinical Chemistry and Laboratory Medicine
JF - Clinical Chemistry and Laboratory Medicine
SN - 1434-6621
IS - 3
ER -