高血压妊娠中白蛋白尿和蛋白尿的实验室间偏倚。

Interlaboratory bias of albuminuria and proteinuria in hypertensive pregnancy.

机构信息

Département de médecine, Université de Sherbrooke, Sherbrooke, QC, Canada.

Department of Pathology and Laboratory Medicine, University of British Columbia, BC, Canada.

出版信息

Clin Biochem. 2021 Jan;87:13-18. doi: 10.1016/j.clinbiochem.2020.10.002. Epub 2020 Oct 6.

DOI:10.1016/j.clinbiochem.2020.10.002

PMID:33031818

Abstract

BACKGROUND

Measurement of proteinuria in women with hypertensive disorders of pregnancy is of major importance in the diagnosis and management of preeclampsia. Urinary protein/creatinine ratio, which is commonly used to detect kidney damage in preeclampsia, suffers from important analytical limitations, including poor harmonization of results between laboratories. Adoption of albuminuria could help reduce interlaboratory bias, since methods used to quantify it are better harmonized.

METHODS

A total of 27 urinary samples collected from hypertensive women evaluated for preeclampsia were sent to four different clinical laboratories in Canada. Urinary proteins and albumin as well as urinary creatinine were measured in duplicates in one batch to calculate protein/creatinine (PCR) and albumin/creatinine (ACR) ratio. Statistical analyses were done to evaluate interlaboratory variability of urinary proteins and urinary albumin.

RESULTS

Interlaboratory bias for urinary proteins ranged from 64.7% at low concentration to 3.9% at higher concentrations. In contrast, urinary albumin interlaboratory bias ranged from 29.2% to 4% from low to high concentrations. Coefficient of variation for urinary proteins reached a maximum of 91.5% in lower concentration while urinary albumin highest value was 42.7%. When looking at PCR and ACR ratio, eight samples had PCR measurement range that contained the diagnostic threshold used to detect kidney damage in HDP (30 mg/mmol), while only four samples had ACR ratio measurement range that contained the diagnostic threshold used outside of pregnancy in Canada (2 mg/mmol).

CONCLUSION

Interlaboratory bias was lower for urinary albumin measurement compared to urinary proteins in hypertensive women evaluated for preeclampsia. Better harmonization with the use of albumin instead of protein measurement would reduce instances where results of different laboratories lead to opposite diagnosis of kidney damage in pregnancy.

摘要

背景

在妊娠高血压疾病的女性中，蛋白尿的测量对于子痫前期的诊断和管理非常重要。尿蛋白/肌酐比值常用于检测子痫前期的肾损伤，但存在重要的分析局限性，包括实验室间结果的协调性差。采用白蛋白尿可以帮助减少实验室间的偏倚，因为用于定量白蛋白尿的方法具有更好的协调性。

方法

从评估子痫前期的高血压女性中收集了 27 份尿液样本，分发给加拿大的四个不同临床实验室。在一批中重复测量尿液中的蛋白质和白蛋白以及尿肌酐，以计算蛋白/肌酐（PCR）和白蛋白/肌酐（ACR）比值。进行统计分析以评估尿液蛋白和白蛋白的实验室间变异性。

结果

尿液蛋白的实验室间偏倚范围从低浓度的 64.7%到高浓度的 3.9%。相比之下，尿液白蛋白的实验室间偏倚范围从低浓度的 29.2%到高浓度的 4%。尿液蛋白的变异系数在低浓度时达到最高的 91.5%，而尿液白蛋白的最高值为 42.7%。当观察 PCR 和 ACR 比值时，有 8 个样本的 PCR 测量范围包含用于检测 HDP 肾损伤的诊断阈值（30mg/mmol），而只有 4 个样本的 ACR 比值测量范围包含在加拿大妊娠以外使用的诊断阈值（2mg/mmol）。