Multiplexed LC鈥揗S/MS Assay for Urine Albumin
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- 作者：Ashley Beasley-Green ; Nijah M. Burris ; David M. Bunk ; Karen W. Phinney
- 刊名：Journal of Proteome Research
- 出版年：2014
- 出版时间：September 5, 2014
- 年：2014
- 卷：13
- 期：9
- 页码：3930-3939
- 全文大小：476K
- ISSN：1535-3907
文摘
Urinary excretion of albumin is a major diagnostic and prognostic marker of renal dysfunction and cardiovascular disease; therefore, accurate measurement of urine albumin is vital to clinical diagnosis. Although intermethod differences and analyte heterogeneity have been reported for urine albumin measurements, accuracy assessments of the available methods have been hindered by the lack of a reference system, including reference measurement procedures and reference materials, for this clinical analyte. To address the need for a reference measurement system for urine albumin, we have developed a candidate reference measurement procedure that utilizes isotope dilution鈥搈ass spectrometry (ID鈥揗S) and multiple reaction monitoring (MRM) to quantify full-length urine albumin in a targeted mass spectrometric-based approach. The reference measurement procedure incorporates an isotopically labeled (15N) full-length recombinant human serum albumin (15N-rHSA) material as the internal standard, which permits the absolute quantitation of albumin in urine. A total of 11 peptides with two transitions per peptide were selected from the tryptic digestion of human serum albumin on the basis of retention time reproducibility, peak intensity, and the degree of HSA sequence coverage. In addition to method validation, the generated calibration curves were used to determine the albumin content in pooled human urine samples to access the accuracy of the MS-based urine albumin quantitation method.