Department of Pathology, Virginia Commonwealth University, Richmond, VA, United States.
Jeff Budd Consulting, St. Paul, MN, United States.
Clin Chem. 2024 Nov 4;70(11):1375-1382. doi: 10.1093/clinchem/hvae122.
Urine albumin (UA) is an important biomarker of chronic kidney disease. Current in vitro diagnostic medical devices (IVD-MDs) for measuring UA are not standardized, and median results among IVD-MDs differ by approximately 45%. Since fixed decision values are used to interpret UA, higher-order reference measurement procedures (RMPs) are needed for metrological traceability. Three candidate liquid chromatography-tandem mass spectrometry RMPs have been developed for UA.
Eight single-donation human urine samples were measured by 3 candidate RMPs. Results were compared using t-test and variance component analysis.
The mean results for each urine sample from each RMP laboratory were not statistically different from the overall mean value by t-test. The median total CV including contributions from bias and imprecision among the 3 RMP laboratories was 6.23% using variance component analysis for each sample. The allowable bias to the RMP for an end-user IVD-MD was ≦9.0% or ≦3.0% based on the desirable or optimal total allowable error of 30% or 24%, respectively. A maximum allowable standard uncertainty for an RMP result was determined to be 4.3% or 3.3% for desirable or optimal performance, respectively. The standard uncertainties for all of the RMP laboratories meet the desirable and optimal standard uncertainty specifications.
The candidate RMPs for UA in these 3 laboratories have suitable agreement of results and uncertainties for use as higher-order RMPs in the metrological traceability of end-user IVD-MDs for measuring UA.
尿白蛋白 (UA) 是慢性肾脏病的重要生物标志物。目前用于测量 UA 的体外诊断医疗器械 (IVD-MD) 尚没有标准化，不同 IVD-MD 的中位数结果差异约为 45%。由于 UA 的解释采用固定的决策值，因此需要更高阶的参考测量程序 (RMP) 来实现计量溯源性。已经为 UA 开发了三个候选液相色谱-串联质谱 RMP。
对 8 个单份人尿样本，用 3 个候选 RMP 进行了测量。通过 t 检验和方差分量分析对结果进行了比较。
每个 RMP 实验室的每个尿液样本的平均值结果通过 t 检验与总体平均值无统计学差异。使用方差分量分析，3 个 RMP 实验室的每个样本的总 CV 中位数（包括偏差和不精密度的贡献）为 6.23%。根据理想或最佳总允许误差分别为 30%或 24%，对最终用户 IVD-MD 的 RMP 允许偏差≦9.0%或≦3.0%。RMP 结果的最大允许标准不确定度分别为理想或最佳性能的 4.3%或 3.3%。所有 RMP 实验室的标准不确定度均符合理想和最佳标准不确定度规范。
这三个实验室的 UA 候选 RMP 在结果的一致性和不确定性方面具有适宜性，可作为测量 UA 的最终用户 IVD-MD 计量溯源性的更高阶 RMP 使用。
