Blood-based biomarkers for detecting mild osteoarthritis in the human knee  K.W. Marshall, M.D., Ph.D., F.R.C.S. (C), H. Zhang, M.D., Ph.D., T.D. Yager, Ph.D., N. Nossova, M.D., Ph.D., A. Dempsey, Ph.D., R. Zheng, M.D., M. Han, M.D., Ph.D., H. Tang, M.Sc., S. Chao, M.A.Sc., C.C. Liew, Ph.D.  Osteoarthritis and Cartilage  Volume 13, Issue 10, Pages 861-871 (October 2005) DOI: 10.1016/j.joca.2005.06.002 Copyright © 2005 OsteoArthritis Research Society International Terms and Conditions

Fig. 1 Comparison of blood gene expression profiles from 25 controls and 32 subjects with mild knee OA. A total of 25 controls and 32 patients were clustered according to the expression of 632 significantly (P<0.05) differentially expressed genes identified from a set of 4083 filtered genes. Samples: control (green), patients (red). The columns indicate gene expression profiles for each sample and each row represents the expression level of a single gene in each of the samples. The color of each row indicates the relative level of gene expression (blue to red=low to high in expression). Osteoarthritis and Cartilage 2005 13, 861-871DOI: (10.1016/j.joca.2005.06.002) Copyright © 2005 OsteoArthritis Research Society International Terms and Conditions

Fig. 2 Blood mRNA levels for HSPCA, IKBKAP, IL13RA1, LAMC1, PF4 and TNFAIP6 in control and mild OA patients. Steady-state mRNA levels were quantitated by two-step SYBR Green real-time RT-PCR. Comparative Ct method was used for the calculation (relative to controls). Values (mean±SD) between controls (n=36) and mild OA (n=42) were 1.06±0.38 and 0.86±0.30 for HSPCA, 1.08±0.42 and 0.79±0.30 for IKBKAP, 1.07±0.43 and 0.82±0.38 for IL13RA1, 1.29±1.02 and 0.71±0.46 for LAMC1, 1.21±0.75 and 0.54±0.34 for PF4, 1.27±0.97 and 0.94±0.78 for TNFAIP6. The lines inside the boxes denote the medians. The boxes mark the interval between the 25th and 75th percentiles. The whiskers denote the interval between the 10th and 90th percentiles. The “•” indicates data points outside the 10th and 90th percentiles. The plots for EGR1, G2AN and MAFB are not shown as they did not reach statistical significance as single biomarkers. Osteoarthritis and Cartilage 2005 13, 861-871DOI: (10.1016/j.joca.2005.06.002) Copyright © 2005 OsteoArthritis Research Society International Terms and Conditions

Fig. 3 ROC curves for biomarker combinations. This figure presents the top five ROC curves for biomarker combinations that successfully discriminate mild OA from control samples in reference data set AD1f2. AUC=area under the curve. Osteoarthritis and Cartilage 2005 13, 861-871DOI: (10.1016/j.joca.2005.06.002) Copyright © 2005 OsteoArthritis Research Society International Terms and Conditions