Research Laboratory on Urine, Unità Operativa di Nefrologia, Dialisi, Trapianto, Fondazione IRCCS Ca' Granda, Ospedale Maggiore-Policlinico, Milano, Italy.
Clin Chem Lab Med. 2011 Mar;49(3):515-20. doi: 10.1515/CCLM.2011.078. Epub 2010 Dec 14.
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.
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.
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.
Crystalluria is not rare and most crystals can be identified by the combined approach. Occasionally, identification of crystals will require FTIRM.
关于不同类型尿结晶的频率以及傅里叶变换红外微光谱（FTIRM）在鉴定中的作用的研究较少。我们描述了一项关于结晶尿的患病率和类型学以及 FTIRM 作用的回顾性研究结果。
使用晶体形态、双折射特征和尿液 pH 值的综合知识（综合方法）鉴定尿结晶。当结果不确定时，进行 FTIRM。
在 9834 个样本中的 807 个样本中发现结晶尿（8.2%）。在 793 个样本中，综合方法确定了“典型”晶体，而在 14 个样本中需要 FTIRM 来鉴定“非典型”晶体。在“典型晶体”中，草酸钙（75.9%）、尿酸（25.9%）和无定形尿酸盐（7.9%）单独或组合是最常见的。鸟粪石、氨尿酸和胱氨酸是最罕见的（0.1%-0.7%）。FTIRM 鉴定出 14 个非典型晶体中的 12 个：三个晶体是由于药物（阿莫西林、茚地那韦、可疑苯乙醇胺）；四个晶体是由于草酸钙单水合物或二水合物、尿酸二水合物或鸟粪石；五个晶体是由于碳酸钙、Tamm-Horsfall 糖蛋白或罕见盐的组合。
结晶尿并不罕见，大多数晶体可以通过综合方法来鉴定。偶尔，需要 FTIRM 来鉴定晶体。
