(2017) Pain prediction by serum biomarkers of bone turnover in people with knee osteoarthritis: an observational study of TRAcP5b and cathepsin K in OA. Osteoarthritis and Cartilage, 25 (6). pp. 858-865. ISSN 1522-9653 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/40543/1/1-s2.0-S1063458417300092-main_accepted %20manuscript%20copy.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the Creative Commons Attribution Non-commercial No Derivatives licence and may be reused according to the conditions of the licence. For more details see: http://creativecommons.org/licenses/by-nc-nd/2.5/ A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Two putative osteoclast biomarkers were measured in sera: TRAcP5b and cathepsin K. 30Medial tibia plateaux were donated at knee arthroplasty for symptomatic OA (n=84) or from Results 35Serum TRAcP5b activity, but not cathepsin K-immunoreactivity, was associated with density 36 of TRAcP-positive osteoclasts in the subchondral bone of medial tibia plateaux. TRAcP-37 positive osteoclasts were more abundant in people with symptomatic OA compared to 38 controls. Serum TRAcP5b activity was associated with baseline pain and pain change.

Presence and severity of synovitis helps define distinct histopathological OA subgroups. The absence of a discrete 'normal' subgroup indicates a pathological continuum between normality and OA status. Identifying specific pathological processes and their clinical correlates in OA subgroups has potential to accelerate the development of more effective therapies.