BACKGROUND Serum cystatin C (CysC) is a promising biomarker of kidney function, which has higher accuracy and sensitivity when compared with creatinine. To better utilize serum CysC in clinical practice, this study aimed to establish continuous paediatric reference intervals (RIs) for serum CysC. METHODS The study subjects consisted of healthy term neonates and children aged 30 days to 18 years. Venous blood samples were collected and serum CysC levels were measured using the immunoturbidimetric measurement principle. Fractional polynomial regression model and quantile regression was applied in the statistical analysis to generate continuous RIs. RESULTS A total of 378 samples with equal numbers of males and females were analysed for serum CysC. No outliers were found in this analysis. The continuous RIs are presented as equations and graphical scatterplots. CONCLUSIONS This study established continuous paediatric reference intervals (RIs) for serum CysC in healthy term neonates and children. The continuous RIs generated from this study show age-based dynamic changes as well as blood group and gender-specific differences for serum CysC. Graphical abstract.

中文翻译：

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新生儿和 30 天至 18 岁儿童血清胱抑素 C 的参考区间。

背景血清胱抑素C（CysC）是一种很有前景的肾功能生物标志物，与肌酐相比具有更高的准确性和敏感性。为了在临床实践中更好地利用血清 CysC，本研究旨在建立血清 CysC 的连续儿科参考区间 (RI)。方法 研究对象包括健康足月新生儿和 30 天至 18 岁的儿童。收集静脉血样并使用免疫比浊测量原理测量血清 CysC 水平。在统计分析中应用分数多项式回归模型和分位数回归以生成连续的RI。结果 共分析了 378 个具有相同数量的男性和女性样本的血清 CysC。本次分析未发现异常值。连续 RI 表示为方程和图形散点图。结论 本研究建立了健康足月新生儿和儿童血清 CysC 的连续儿科参考区间 (RI)。本研究产生的连续 RI 显示了血清 CysC 基于年龄的动态变化以及血型和性别特异性差异。图形概要。