Sikora Przemysław, Zajaczkowska Małgorzata, Hoppe Bernd
Department of Pediatric Nephrology, Lublin Medical University, 20-093 Lublin, Poland.
Pediatr Nephrol. 2009 Oct;24(10):1997-2003. doi: 10.1007/s00467-009-1167-0. Epub 2009 Mar 31.
The pathogenesis of calcium urolithiasis involves complex interactions of urinary promoters and inhibitors of crystallization. A variety of risk formulas have been established to approximate these interactions for clinical evaluation, and the aim of our study was to determine their usefulness as predictors of stone formation. The study cohort comprised 126 patients (63 boys and 63 girls) aged 6.7-18 years (mean age 14.1 +/- 2.9 years) with calcium urolithiasis (61 with chemically confirmed calcium oxalate stones and 65 children with a strong clinical suspicion of this type of urolithiasis). Of these, 36 children were classified as recurrent stone-formers, whereas the remaining 90 had experienced only one stone episode. The values obtained were compared to those of a control group of 60 age- and gender- matched healthy children. A number of crystallization risk indices were calculated from analytes obtained in 24-h urine: calcium/magnesium ratio (Ca/Mg), calcium/citrate ratio (Ca/Cit), (calcium x oxalate)/(magnesium x citrate) ratio (CaOx/MgCit), relative urinary CaOx supersaturation (RS(CaOx)), CaOx activity product index (AP(CaOx)), and standardized CaOx activity product index (AP(CaOx stand)). All indices, except for the AP(CaOx) index, were significantly higher in stone-formers than in the controls. The Ca/Mg, Ca/Cit, CaOx/MgCit, AP(CaOx), and AP(CaOx stand) indices were significantly higher in recurrent stone-formers than in first-episode ones. However, the determination of precise cutoffs between pathological and non-pathological values was problematic due to a considerable overlap of individual values. Based on our results, we conclude that calculation of the majority of risk indices may play a rather supplementary role in the evaluation of children with calcium urolithiasis.
草酸钙结石的发病机制涉及尿液中结晶促进剂和抑制剂的复杂相互作用。已经建立了多种风险公式来估算这些相互作用以用于临床评估，而我们研究的目的是确定它们作为结石形成预测指标的实用性。研究队列包括126例年龄在6.7至18岁（平均年龄14.1±2.9岁）的草酸钙结石患者（63名男孩和63名女孩）（61例经化学确认的草酸钙结石患者以及65例临床高度怀疑为此类结石的儿童）。其中，36名儿童被归类为复发性结石形成者，而其余90名仅经历过一次结石发作。将获得的值与60名年龄和性别匹配的健康儿童对照组的值进行比较。根据24小时尿液中获得的分析物计算了多个结晶风险指数：钙/镁比值（Ca/Mg））、钙/柠檬酸盐比值（Ca/Cit）、（钙×草酸盐）/（镁×柠檬酸盐）比值（CaOx/MgCit）、相对尿CaOx过饱和度（RS(CaOx)）、CaOx活性产物指数（AP(CaOx)）和标准化CaOx活性产物指数（AP(CaOx stand)）。除AP(CaOx)指数外，所有指数在结石形成者中均显著高于对照组。Ca/Mg、Ca/Cit、CaOx/MgCit、AP(CaOx)和AP(CaOx stand)指数在复发性结石形成者中显著高于首次发作的患者。然而，由于个体值有相当大的重叠，确定病理值和非病理值之间的精确临界值存在问题。根据我们的结果，我们得出结论，大多数风险指数的计算在草酸钙结石患儿的评估中可能起相当辅助的作用。
