High-Sensitivity NanoLC−MS/MS Analysis of Urinary Desmosine and Isodesmosine

• Published in: Analytical chemistry (Washington) Vol. 81; no. 5; pp. 1881 - 1887
• Main Authors: Boutin, Michel, Berthelette, Carl, Gervais, François G, Scholand, Mary-Beth, Hoidal, John, Leppert, Mark F, Bateman, Kevin P, Thibault, Pierre
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-03-2009
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Liquid - methods; Chronic obstructive pulmonary disease; Desmosine - urine; Elastin - analysis; Exact sciences and technology; Humans; Ion chromatography; Isodesmosine - urine; Limit of Detection; Lungs; Mass spectrometry; Mass Spectrometry - methods; Other chromatographic methods; Proteins; Smoking; Spectrometric and optical methods; Tandem Mass Spectrometry - methods; Urine; Urine; Tissue; Sensitivity; Sensitivity analysis; Internal standard; Detection limit; Mass spectrometry MS/MS; Liquid chromatography; By product; Monitoring; Protein; Quantitative analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac801745d

Chronic obstructive pulmonary disease (COPD) is characterized by the degradation of elastin, the major insoluble protein of lung tissues. The degradation of elastin gives rise to desmosine (DES) and isodesmosine (IDES), two major urinary products typified by a hydrophilic pyridinium-based cross-linker structure. A high sensitivity method based on nanoflow liquid chromatography tandem mass spectrometry with multiple reaction monitoring was developed for the analysis of urinary DES and IDES. The analytes were derivatized with propionic anhydride and deuterated DES (D4-DES) was used as an internal standard. This method enables the quantification of DES and IDES in as little as 50 μL of urine and provides a detection limit of 0.10 ng/mL (0.95 fmol on-column). We report the analysis of DES and IDES in a cohort of 40 urine specimens from four groups of individuals: (a) COPD rapid decliners (11.8 ± 3.7 ng/mg creatine (crea)), (b) COPD slow decliners (16.0 ± 3.1 ng/mg crea), (c) healthy smokers (13.2 ± 1.9 ng/mg crea), and (d) healthy nonsmokers (14.9 ± 2.9 ng/mg crea). Our analysis reveals a statistically significant decrease in the level of urinary DES and IDES in COPD rapid decliner patients compared to healthy nonsmoker controls and COPD slow decliner patients. This methodology may be useful for monitoring DES and IDES levels in well controlled animal models for COPD or for longitudinal studies in COPD patients.