Fingerprint biomarkers of type I and III collagen in axial spondyloarthropathy (axspa) and psoriatic arthritis (psa). Association with disease activity and diagnostic capacity

N. S. Gudman, A. F. Christensen, G. L. Sorensen, Anne-Christine Bay Jensen, A. S. Siebuhr, M. A. Karsdal, H. L. Munk, L. Ejstrup, A. G. Loft, P. Junker

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Background/Purpose: AxSpA and PsA are core members of the spondyloarthritis complex. One cardinal characteristic shared by these two conditions is increased remodeling of bone and soft connective tissue in and around peripheral joints, axial skeleton and entheseal insertions leading to synovitis, enthesitis and ankylosis in advanced disease. Studies using seromarkers which reflect extracellular matrix constituent metabolism may provide insight into the activity and dynamics of connective remodeling and thereby pave the way for improved diagnostics and management. The aims of this investigation were to study C1M and C3M, which reflect the turnover of collagen I and III, in order to assess their utility as diagnostic and disease activity markers. Methods: Ninety-nine patients with PsA, 110 with axSpA and 120 healthy control subjects were included. Demographic and clinical disease measures were recorded.C1M and C3M were quantified using in house competitive ELISAs. Biomarker results are presented as median with 95% CI. Mann Whitney test was applied for inter-group comparisons and correlations were studied using Spearmans test. Receiver operator characteristics (ROC) curve analysis was carried out to evaluate the diagnostic potential of the biomarkers. Results: C1M and C3M were significantly increased in both axSpA and PsA as compared with healthy controls (Figure). Thus, in axSPA C1M and C3M amounted to 77.6 (71.3-84.6)ng/ml and 27.7 (26.2-29.7)ng/ml respectively, in PsA to 85.6 (78.2-96.2)ng/ml and 28.7 (26.7-31.0)ng/ml versus controls 48.3(43.3-53.2) and 20.9 (20.0-21.7) respectively. C1M and C3M levels did not differ significantly between axSpA and PsA. Serum levels of C1M and C3M were not affected by treatment, or smoking status, but SpA HLA-B27+ patients had significantly higher levels of both C1M (p=0.001) and C3M (p=0.006) compared to HLAB-27- SpA patients. C1M was significantly correlated with DAS28 (PsA: r=0.22, p=0.028, SpA: r=0.40, p0.0001 in all groups) but they did not correlate with demographics including age, BMI or gender. Segregation between healthy and diseased based on C1M levels resulted in an AUC of 0.83 for PsA (0.76-0.86) and 0.79 (0.73-0.84) for SpA. C3M could also segregate between healthy and diseased with an AUC of 0.77 (0.71-0.82) for PsA and 0.78 (0.72-0.83) for SpA. Conclusion: These findings indicate that soft connective tissue remodeling is equally increased in axSpA and PsA reflecting disease activity and that collagen type I and III turnover are mediated by closely coupled mechanisms. ROC curve analyses suggest that both C1M and C3M may be useful for diagnostic purposes in axSpA and PsA. (Figure Presented).
Original languageEnglish
Article number1742
JournalArthritis & Rheumatology
Issue numberS10
Publication statusPublished - 2015
EventACR/ARHP: American College of Rheumatology - San Francisco, United States
Duration: 7. Nov 201511. Nov 2015


Country/TerritoryUnited States
CitySan Francisco

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