MSACL 2024 Abstract

Impact of Measurement Science on the Standardization of Urine Albumin Ashley Beasley Green National Institute of Standards and Technology (NIST) Ashley Beasley-Green, PhD (Presenter) NIST

Presenter Bio: Ashley Beasley-Green, PhD, received her BS in Biochemistry from Spelman College and obtained her PhD from the Department of Pharmacology and Molecular Sciences at The Johns Hopkins University School of Medicine. Dr. Green received a National Research Council Postdoctoral Fellowship at the National Institute of Standards and Technology (NIST) and is currently a Staff Scientist in the Biomolecular Measurement Division of the Materials Measurement Laboratory (MML) at NIST. Dr. Green’s research primarily focuses on the standardization of protein measurement science and the development of protein-based NIST Reference Materials and Standard Reference Materials to support basic research and clinical applications.

INTRODUCTION: Urine albumin is a major clinical biomarker of acute and chronic renal failure. Due to the severity of the conditions that stem from kidney dysfunction, accurate measurement of urine albumin is vital to the clinical diagnosis of renal failure and the evaluation of treatment efficacy.

OBJECTIVE: The primary objective of this study was to establish a traceability framework that links fundamental units of measure to clinical urine albumin results.

METHODS: To address urine albumin measurement accuracy and precision, we have developed the following foundational components: a multiplexed measurement procedure that utilizes isotope dilution-mass spectrometry (ID-MS) and multiple reaction monitoring (MRM) to quantify urine albumin; a primary reference material to be used as a calibrator for higher-order urine albumin methods; and a matrix-based reference material.

RESULTS: The multiplexed measurement procedure for urine albumin incorporates isotopically labeled full-length recombinant human serum albumin (HSA) internal standard, which enables the absolute quantitation of albumin in human urine, and a highly characterized unlabeled recombinant HSA material (NIST SRM 2925) as the method calibrator. A statistical approach was used to define and characterize the measurement uncertainty to support the use of the measurement procedure for value-assignment of albumin in human urine samples and the matrix-based reference material, SRM 3666 Albumin and Creatinine in Frozen Human Urine.

CONCLUSION: To enhance the quality and accuracy of routine clinical measurements of urine albumin, we have developed the foundational components of the urine albumin reference measurement system and utilized a statistical approach to establish measurement uncertainty of a MS-based quantitative proteomics method.