The study of interferences for diagnosing albuminuria by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry.

Abstract

BACKGROUND:

Matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) mass spectrometric analysis of albumin (ALB) biomarkers is an alternative approach toward the rapid diagnosis of proteinuria for screening a large number of samples. The aim of this study is to reveal if interfering factors in urinary dipstick approach would affect the results of diagnosing albuminuria by MALDI-TOF MS.

METHODS:

The effects of various interfering chemicals on the diagnosis of albumin in urine were examined using both MALDI-TOF mass spectrometric and dipstick approaches. Semi-quantification of albumin was performed by using MALDI-TOF MS.

RESULTS:

Interferences from various drugs, detergents, vitamins and their metabolites, alkaline, and blood, which often cause false-positive and false-negative results in conventional urinary dipstick analysis, are avoided when using this MALDI-TOF MS approach. It was found that the intensity of +1 and +2 albumin ions varies with the albumin concentration. A log/log plot of the intensity ratio vs. albumin concentration is then used as a calibration curve for semi-quantifying the albumin in urines.

CONCLUSIONS:

MALDI-TOF MS is an effective approach toward avoiding interferences caused by various chemical compounds during the rapid diagnosis of albumin in urine. Semi-quantification of albuminuria is also achieved by this MALDI-TOF MS approach.

• Authors: Yi-Tzu Cho, Yu-Syuan Chen, Jia-Lun Hu, Jentaie Shiea, Shih Meng Yeh, Hung-Chun Chen, Yi-Chern Lee, Deng-Chyang Wu
• Journal: Clinica chimica acta; international journal of clinical chemistry (Clin Chim Acta) Vol. 413 Issue 9-10 Pg. 875-82 (May 18 2012) ISSN: 1873-3492 [Electronic] Netherlands
• PMID: 22327002 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Elsevier B.V. All rights reserved.

Topics

• Adult
• Aged
• Albuminuria (diagnosis, urine)
• False Positive Reactions
• Female
• Humans
• Male
• Middle Aged
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization (methods, standards)
• Young Adult