Martinez Marila Gaste, dos S Silva Vanessa, do Valle Adriana P, Amaro Carmen R P R, Corrente José E, Martin Luis Cuadrado
Division of Nephrology, Department of Internal Medicine, Botucatu Medical School, Universidade Estadual Paulista, Botucatu, Brazil.
Nephron Clin Pract. 2014;128(1-2):88-94. doi: 10.1159/000367848. Epub 2014 Nov 8.
BACKGROUND/AIMS: There is disagreement regarding the performance of conventional optical microscopy to assess the origin of hematuria. The aim of this study was to determine the optimal cutoff point for dysmorphic cells in order to detect glomerular hematuria by optical and phase-contrast microscopy.
In total, 131 urine samples (66 from patients with glomerulopathies and 65 from nephrolithiasis patients) were evaluated in a blinded fashion. The percentages of doughnut cells and acanthocytes were verified by optical and phase-contrast microscopy. A total of 131 patients were randomly allocated to the derivation (n = 73) and validation (n = 58) groups. Receiver-operating characteristic (ROC) curves were plotted to check the discriminatory power of each group and the best cutoff points were determined by the Youden index in the derivation group and subsequently tested in the validation group.
All areas under the ROC curve (AUCs) were statistically significant using both methods (conventional optical and phase-contrast microscopy) and both groups (derivation and validation). AUCs did not differ between different glomerulopathies. The best cutoff point to determine the glomerular origin of hematuria by total dysmorphic cells was 22% using an optical conventional microscope and 40% by phase-contrast microscopy.
We determined the best cutoff points to interpret erythrocyte dysmorphism and demonstrated that it is possible to discriminate the origin of hematuria by evaluating erythrocyte dysmorphism in urinalysis using either an optical or a phase-contrast microscope.
背景/目的：关于传统光学显微镜评估血尿来源的表现存在分歧。本研究的目的是确定异型细胞的最佳截断点，以便通过光学显微镜和相差显微镜检测肾小球性血尿。
总共对131份尿液样本（66份来自肾小球疾病患者，65份来自肾结石患者）进行了盲法评估。通过光学显微镜和相差显微镜验证甜甜圈样细胞和棘形红细胞的百分比。总共131名患者被随机分配到推导组（n = 73）和验证组（n = 58）。绘制受试者操作特征（ROC）曲线以检查每组的鉴别能力，并通过约登指数在推导组中确定最佳截断点，随后在验证组中进行测试。
使用两种方法（传统光学显微镜和相差显微镜）以及两组（推导组和验证组），ROC曲线下的所有面积（AUC）均具有统计学意义。不同肾小球疾病之间的AUC没有差异。使用光学传统显微镜通过总异型细胞确定血尿肾小球来源的最佳截断点为22%，相差显微镜为40%。
我们确定了解释红细胞异型性的最佳截断点，并证明通过使用光学显微镜或相差显微镜评估尿液分析中的红细胞异型性，可以区分血尿的来源。
