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.
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.
Authors: Raed M Almannie; Abdullah K Alsufyani; Abdullah U Alturki; Mana Almuhaideb; Saleh Binsaleh; Abdulaziz M Althunayan; Mohammed A Alomar; Khalid M Albarraq; Fahad A Alyami Journal: Res Rep Urol Date: 2021-12-29
Authors: James C Williams; Giovanni Gambaro; Allen Rodgers; John Asplin; Olivier Bonny; Antonia Costa-Bauzá; Pietro Manuel Ferraro; Giovanni Fogazzi; Daniel G Fuster; David S Goldfarb; Félix Grases; Ita P Heilberg; Dik Kok; Emmanuel Letavernier; Giuseppe Lippi; Martino Marangella; Antonio Nouvenne; Michele Petrarulo; Roswitha Siener; Hans-Göran Tiselius; Olivier Traxer; Alberto Trinchieri; Emanuele Croppi; William G Robertson Journal: Urolithiasis Date: 2020-10-13 Impact factor: 3.436