Table 2 Osteoarthritis biomarkers assayed

Inflammatory Biomarkers

 IL-1ra, plasma heparin

Interleukin-1 receptor antagonist

Blocks IL-1 but is elevated in OA

[32]

R&D Systems Luminex FCSTM03,

1:3

 IL-2, plasma heparin

Interleukin-2

Anti-inflammatory, immunoregulatory cytokine

[22]

R&D Systems Luminex FCSTM09,

1:2

 IL-4, plasma heparin

Interleukin-4

Anti-inflammatory, immunoregulatory cytokine

[22]

R&D Systems Luminex FCSTM09,

1:2

 IL-6, plasma heparin

Interleukin-6

Pro-inflammatory cytokine, macrophage-derived

[33, 34]

R&D Systems Luminex FCSTM09,

1:2

 IL-8, plasma heparin

Interleukin-8

Chemotactic factor

[35]

R&D Systems Luminex FCSTM09,

1:2

 MCP-1, plasma heparin

Monocyte chemoattractant protein-1, aka C–C motif ligand 2 (CCL2)

Monocyte and memory T cell recruitment

[36]

R&D Systems Luminex FCSTM03,

1:3

 HA, Plasma EDTA

Hyaluronic acid or hyaluronan

Levels positively associated with OA severity, pain, progression & duration

[37]

Biovision E4626-100

1:100

 CRP, plasma heparin

C-reactive protein

Marker of systemic inflammation

[34, 38]

R&D Systems Luminex FCSTM08,

1:100

 Cortisol, serum

Marker of systemic inflammation

[39]

Abcam AB108665,

1:2

 Arg, serum

Arginine

Substrate for nitric oxide synthase

[40]

Aviva Systems OKEH02603,

1:2

 SDMA, serum

Symmetric dimethylarginine

Inhibitor of nitric acid synthase, cardiac risk factor

[40, 41]

Abcam AB213973,

neat

 ADMA, serum

Asymmetric dimethylarginine

Inhibitor of nitric acid synthase, cardiac risk factor

[40, 41]

Novus NBP2-66,728,

neat

 TBARS, serum

Thiobarbituric acid reactive substances

Biproducts of lipid peroxidation, a measure of systemic inflammation

[40]

Abcam AB233471,

1:2

Adipokines

 Leptin, plasma heparin

Pro-inflammatory, high levels causing cartilage degeneration

[33]

R&D Systems Luminex FCSTM08

1:4

 Resistin, plasma heparin

Upregulates synthesis of chemokines and cytokines by chondrocytes

[42]

R&D Systems Luminex FCSTM08

1:4

 Adiponectin, plasma heparin

Pro-inflammatory, positively correlates with MMP-3 & COMP

[43]

R&D Systems Luminex FCSTM08

1:100

Growth Factors

 VEGF plasma heparin

Vascular Endothelial Growth Factor

Angiogenesis during osteophyte formation; positively corelated with OA radiographic severity

[44]

R&D Systems Luminex FCSTM09,

1:2

Enzymes causing joint destruction

 MMP-1, plasma heparin

Matrix metalloproteinase-1

A collagenase

[36]

R&D Systems Luminex FCSTM07,

1:5

 MMP-3, plasma heparin

Matrix metalloproteinase-3

Hydrolysis of collagens and proteoglycans, activation of other MMPs

[36]

R&D Systems Luminex FCSTM07,

1:5

 ADAMTS4, serum

A disintegrin and metalloproteinase with thrombospondin motifs-4

An aggrecanase

[45]

Novus NBP2-66,443,

1:200

 ADAMTS5, serum

A disintegrin and metalloproteinase with thrombospondin motifs-5

An aggrecanase

[45]

Novus NBP2-66,444,

Serum neat

Molecule fragments resulting from joint destruction

 CTX-1, urine

C-terminal telopeptide of type I collagen (bone destruction)

Detected in urine, normalized for creatinine concentration

[21, 46]

Novus NBP2-69,073

Urine neat

 CTX-2, urine

C-terminal telopeptide of type II collagen (articular cartilage destruction)

Detected in urine, normalized for creatinine concentration

[21, 46]

Novus NBP2-76,435

Urine neat

 C2C, urine

Collagenase-generated type II collagen cleavage epitope (articular cartilage destruction)

Detected in urine, normalized for creatinine concentration

[21, 47, 48]

MyBiosource MBS730283

Urine neat