[Consistency evaluation of 2 methods in detecting serum insulin-like growth factorⅠ in children].

Objective: To evaluate the consistency of mass spectrometry (MS) and chemiluminescence immunoassay (CLIA) in detecting serum insulin-like growth factor-1 (IGF-1) and IGF-1 standard deviation score (SDS). Methods: This cross-sectional parallel control study prospectively collected the serum samples of 115 children with short stature disorders who were admitted in the Department of Endocrinology, Beijing Children's Hospital, Capital Medical University from February 2020 to December 2021. The serum IGF-1 level was detected by CLIA and MS, and converted to SDS for consistency analysis. Pearson analysis was used to analyze the correlation between the 2 methods, and Deming regression equation was established. Bland-Altman diagram and weighted Kappa coefficient were used to evaluate the consistency of the 2 methods. Results: There were 46 boys (40.0%) and 69 girls (60.0%), aged (8±3) years. Among the 115 cases, 37 were Turner syndrome, 59 were small for gestational age (SGA) at term, 1 was growth hormone deficiency (GHD) and 18 were other diseases. Pearson correlation analysis showed a preferable correlation between IGF-1 measured by the 2 detection methods (r=0.94, P<0.01), and IGF-1 SDS was also significantly correlated (r=0.92, P<0.01). Bland-Altman analysis showed that the consistency of serum IGF-1 levels detected by the 2 methods was poor, and the mean difference between CLIA and MS was 33.38 μg/L. The result detected by CLIA was significantly higher than that by MS, with SDS of 43.51 μg/L (95%CI -51.89-118.7 μg/L). After converting the results to SDS and removing 3 outliers (including 1 GHD patient), the weighted Kappa showed acceptable consistency (κ=0.68). Conclusion: In clinical application, after converting to IGF-1 SDS, IGF-1 detected by MS and CLIA can be used for cross-reference, but too high or too low levels should be cautious about.目的： 比较并评价儿童身材矮小症诊疗过程中应用质谱分析法（MS）与化学发光免疫分析法（CLIA）检测血清胰岛素样生长因子Ⅰ（IGF-1）水平以及转化为标准差积分（SDS）的一致性。 方法： 横断面研究，收集2020年2月至2021年12月首都医科大学附属北京儿童医院内分泌科收治的115例不同病因身材矮小症患儿血清样本。用CLIA与MS分别检测患者血清IGF-1水平，并转化为SDS。使用Pearson相关分析法进行两种检测方法的相关性分析，并建立Deming回归方程。用Bland-Altman图和加权Kappa系数分析两种检测法所得IGF-1和计算所测IGF-1 SDS的一致性。 结果： 115例身材矮小症患儿中男46例（40.0%），女69例（60.0%），年龄（8±3）岁，包括特纳综合征37例、足月小于胎龄儿（SGA）59例、生长激素缺乏症（GHD）1例及其他病因18例。Pearson相关分析提示两种检测方法IGF-1有良好的相关性（r=0.94，P<0.01），换算成IGF-1 SDS仍然有良好的相关性（r=0.92，P<0.01）。Bland-Altman分析两种方法检测的血清IGF-1实测值一致性差，所测差值的均值为33.38 μg/L，CLIA测定值显著高于MS检测结果，差值为43.51 μg/L（95%CI -51.89~118.70 μg/L）。转换为IGF-1 SDS，去除3个离群值后（其中包括1例GHD患儿），加权Kappa提示一致性好（κ=0.68）。 结论： 临床应用中MS与CLIA检测的IGF-1转换为IGF-1 SDS后一致性好，可互相参考使用，但是对过高或者过低极值需依赖临床判断。.