Simultaneous Detection of Six Urinary Pteridines and Creatinine by High-Performance Liquid Chromatography-Tandem Mass Spectrometry for Clinical Breast Cancer Detection
Recent preliminary studies have implicated urinary pteridines as candidate biomarkers in a growing number of malignancies including breast cancer. While the developments of capillary electrophoresis-laser induced fluorescence (CE-LIF), high performance liquid chromatography (HPLC), and liquid chromatography-mass spectroscopy (LC-MS) pteridine urinalyses among others have helped to enable these findings, limitations including poor pteridine specificity, asynchronous or nonexistent renal dilution normalization, and a lack of information regarding adduct formation in mass spectrometry techniques utilizing electrospray ionization (ESI) have prevented application of these techniques to a larger clinical setting. In this study, a simple, rapid, specific, and sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been developed and optimized for simultaneous detection of six pteridines previously implicated in breast cancer and creatinine as a renal dilution factor in urine. In addition, this study reports cationic adduct formation of urinary pteridines under ESI-positive ionization for the first time. This newly developed technique separates and detects the following six urinary pteridines: 6-biopterin, 6- hydroxymethylpterin, d-neopterin, pterin, isoxanthopterin, and xanthopterin, as well as creatinine. The method detection limit for the pteridines is between 0.025 and 0.5 µg/L, and for creatinine, it is 0.15 µg/L. The method was also validated by spiked recoveries (81-105%), reproducibility (RSD: 1-6%), and application to 25 real urine samples from breast cancer positive and negative samples through a double-blind study. The proposed technique was finally compared directly with a previously reported CE-LIF technique, concluding that additional or alternative renal dilution factors are needed for proper investigation of urinary pteridines as breast cancer biomarkers.
C. Burton et al., "Simultaneous Detection of Six Urinary Pteridines and Creatinine by High-Performance Liquid Chromatography-Tandem Mass Spectrometry for Clinical Breast Cancer Detection," Analytical Chemistry, vol. 85, no. 22, pp. 11137 - 11145, American Chemical Society (ACS), Nov 2013.
The definitive version is available at https://doi.org/10.1021/ac403124a
Keywords and Phrases
80 And Over; Adult; Aged; Biological; Breast Cancer Detection; Breast Neoplasms; Breast Tumor; Capillary Electrophoresis; Chromatography; Clinical Settings; Comparative Study; Creatinine; Diseases; Electrospray Ionization (ESI); Electrospray Mass Spectrometry; Equipment; Female; High Performance Liquid Chromatography; High Pressure Liquid; Human; Mass; Mass Spectrometry; Method Detection Limits; Methodology; Middle Aged; Pteridine Derivative; Pteridines; Reproducibilities; Simultaneous Detection; Spectrometry; Spectrometry Technique; Tandem Mass Spectrometry; Tumor Marker; Urinalysis; Urine; Very Elderly
International Standard Serial Number (ISSN)
Article - Journal
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01 Nov 2013