About the Authors

Anne C. Bay-Jensen

acbj@nordicbioscience.com

Affiliation Rheumatology, Nordic Bioscience, Herlev, Denmark

Stephanie Wichuk

Affiliation Division of Rheumatology, University of Alberta, Edmonton, Alberta, Canada

Inger Byrjalsen

Affiliation Rheumatology, Nordic Bioscience, Herlev, Denmark

Diana J. Leeming

Affiliation Rheumatology, Nordic Bioscience, Herlev, Denmark

Nathalie Morency

Affiliation Division of Rheumatology, University of Alberta, Edmonton, Alberta, Canada

Claus Christiansen

Affiliation Rheumatology, Nordic Bioscience, Herlev, Denmark

Morten A. Karsdal

Affiliation Rheumatology, Nordic Bioscience, Herlev, Denmark

Walter P. Maksymowych

Affiliation Division of Rheumatology, University of Alberta, Edmonton, Alberta, Canada

Competing Interests

ACBJ, IB, DJL and MK are full time employees at, and CC and MK hold stocks in, Nordic Bioscience. This study was partly funded by Nordic Bioscience. Nordic Bioscience is a privately-owned; small-medium size enterprise partly focused the development of biomarkers for rheumatic and fibrotic diseases. The two biomarkers described in the manuscript are patented by Nordic Bioscience (C2M, "ASSAY FOR A TYPE II COLLAGEN BIOMARKER" Patent Application WO/2012/038331; C3M, "FIBROSIS BIOMARKER ASSAY" Patent Application WO/2010/115749 & United States Patent Application 20100209940). Further research on the markers will be conducted which may lead to commercialization. There are no further patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials. None of the authors received fees, bonuses or other benefits for the work described in the manuscript. WP, SW and NM have no financial or competing interest to declare. WP is a Medical Scientist of the Alberta Heritage Foundation for Medical Research.

Author Contributions

Conceived and designed the experiments: ACBJ SW MK WPM CC. Performed the experiments: ACBJ DJL SW NM. Analyzed the data: ACBJ SW MK WPM CC. Contributed reagents/materials/analysis tools: ACBJ SW IB DJL NM CC MK WPM. Wrote the paper: ACBJ SW MK WPM CC.