title: Measurement of urinary total desmosine and isodesmosine using isotope-dilution liquid chromatography-tandem mass spectrometry.
abstract: The current LC-MS based desmosine/isodesmosine (DES/IDS) assays may be unsatisfactory for clinical use due to lack of an appropriate internal standard or low throughput. A fast and reliable LC-MS method using a D(5)-DES as an internal standard for measuring urinary total DES/IDS was developed and validated in this study. The reportable range of this assay was 1.0 and 480.0 ng/mL. The intra- and interassay imprecision, accuracy, and recovery for quality control samples were within acceptable range (<25%). Urinary total DES/IDS level was stable at room temperature or 4 degrees C for 20 h, and for three freeze/thaw cycles. The assay was employed to measure urine samples from COPD patients and demographically matched healthy volunteers. The total urinary DES/IDS levels were approximately 3-fold higher in COPD patients compared to healthy volunteers. The suitability of using urinary free DES to estimate elastin degradation was also evaluated in a second cohort. Despite urinary free and total DES/IDS levels being highly correlated, our data suggest that urinary total DES/IDS level is a preferred biomarker for elastin degradation. These results demonstrate that the LC-MS/MS method provides sensitive, reproducible and accurate quantification of urinary total DES/IDS as a biomarker for monitoring elastin degradation in diseases such as COPD.
authors.affiliation: Translational Medicine Research Collaboration, TMRC Laboratory, James Arrott Drive, Dundee, DD1 9SY, Pfizer Inc., United Kingdom.
authors.forename: Osama
authors.initials: O
authors.lastname: Albarbarawi
authors.forename: Alun
authors.initials: A
authors.lastname: Barton
authors.forename: Zhaosheng
authors.initials: Z
authors.lastname: Lin
authors.forename: Eddie
authors.initials: E
authors.lastname: Takahashi
authors.forename: Ajay
authors.initials: A
authors.lastname: Buddharaju
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Brady
authors.forename: Douglas
authors.initials: D
authors.lastname: Miller
authors.forename: Colin N A
authors.initials: CN
authors.lastname: Palmer
authors.forename: Jeffrey T-J
authors.initials: JT
authors.lastname: Huang
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D003895:Desmosine / Q000652:urine*; D006801:Humans; D007524:Isodesmosine / Q000652:urine*; D057230:Limit of Detection; D011865:Radioisotope Dilution Technique; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D003895:Desmosine; D007524:Isodesmosine