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Serum-based soluble markers differentiate psoriatic arthritis from osteoarthritis
  1. Vinod Chandran1,
  2. Fatima Abji2,
  3. Anthony V Perruccio3,4,
  4. Rajiv Gandhi5,
  5. Suzanne Li6,
  6. Richard J Cook7,
  7. Dafna D Gladman1
  1. 1 Division of Rheumatology, Department of Medicine, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
  2. 2 Rheumatology Research, University of Toronto, University Health Network, Toronto, Ontario, Canada
  3. 3 Arthritis Program, University Health Network, Toronto, Ontario, Canada
  4. 4 Surgery, University of Toronto, Toronto, Ontario, Canada
  5. 5 Division of Orthopaedic Surgery, Department of Surgery, Toronto Western Hospital, Toronto, Ontario, Canada
  6. 6 Centre for Prognosis Studies in the Rheumatic Diseases, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
  7. 7 Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada
  1. Correspondence to Professor Dafna D Gladman, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada; dafna.gladman{at}


Objectives We aimed to identify soluble biomarkers that differentiate psoriatic arthritis (PsA) from osteoarthritis (OA).

Methods Markers of cartilage metabolism (cartilage oligomeric matrix protein [COMP], hyaluronan), metabolic syndrome (adiponectin, adipsin, resistin, hepatocyte growth factor [HGF], insulin, leptin) and inflammation (C-reactive protein [CRP], interleukin-1β [IL-1β], IL-6, IL-8, tumour necrosis factor alpha [TNFα], monocyte chemoattractant protein-1 [MCP-1], nerve growth factor [NGF]) were compared in serum samples from 201 patients with OA, 77 patients with PsA and 76 controls. Levels across the groups were compared using the Kruskal-Wallis test. Pairwise comparisons were made with Wilcoxon rank-sum test. Multivariate logistic regression analyses were performed to identify markers that differentiate PsA from OA. Receiver operating characteristic (ROC) curves were constructed based on multivariate models. The final model was further validated in an independent set of 73 PsA and 75 OA samples using predicted probabilities calculated with coefficients of age, sex and biomarkers.

Results Levels of the following markers were significantly different across the three groups (p<0.001)—COMP, hyaluronan, resistin, HGF, insulin, leptin, CRP, IL-6, IL-8, TNFα, MCP-1, NGF. In multivariate analysis, COMP (OR 1.24, 95% CI 1.06 to 1.46), resistin (OR 1.26, 95% CI 1.07 to 1.48), MCP-1 (OR 1.10, 95% CI 0.07 to 1.48) and NGF (OR<0.001, 95% CI <0.001 to 0.25) were found to be independently associated with PsA versus OA. The area under the ROC curve (AUROC) for this model was 0.99 compared with model with only age and sex (AUROC 0.87, p<0.001). Similar results were obtained using the validation sample.

Conclusion A panel of four biomarkers may distinguish PsA from OA. These results need further validation in prospective studies.

  • biomarkers
  • psoriatic arthritis
  • osteoarthritis

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  • Handling editor Josef S Smolen

  • Presented at The abstract for this manuscript (Abstract 1657) has been presented at the American College of Rheumatology (ACR)/AHRP Annual Meeting Poster Session B held on 14 November 2016 (

  • Contributors All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published. All authors were likewise involved in the study conception and design, acquisition of data as well as analysis and interpretation of data. DDG had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

  • Funding The University of Toronto Psoriatic Arthritis Program is supported by a grant from the Krembil Foundation.

  • Competing interests None declared.

  • Patient consent for publication Obtained.

  • Ethics approval This study was approved by the University Health Network Research Ethics Board according to the principles of the Declaration of Helsinki.

  • Provenance and peer review Not commissioned; externally peer reviewed.