Table 3: Biomarkers associated with different PsA disease characteristics and phenotypes.

Disease characteristic, n (%) Biomarker Concentration, mean (pg/ml) Pc-value
Variables at clinical examination ≥ Moderate ≤ Low
≥ Moderate disease activity1, 87 (32)
vs. ≤ Low disease activity1, 185 (68)
CRP 16.5 × 106 6.76 × 106 0.0008
IL-6 2.35 1.24 0.001
IL-16 240 204 0.007
Calprotectin 1.24 × 106 0.86 × 106 0.014
IL-12/IL-23p40 157 121 0.02
ICAM-1 5.72 × 105 5.09 × 105 0.045
Polyarthritic disease pattern, 130 (52)
vs. Mono-/oligo arthritis disease pattern, 123 (49)
Polyarthritis Mono-/oligo arthritis
IL-6 2.13 1.02 0.0006
SAA 13.0 × 106 5.41 × 106 0.009
CRP 13.1 × 106 5.62 × 106 0.012
IL-8 16.8 10.1 0.04
Axial disease with or without peripheral disease, 45 (17)
vs. Peripheral disease only, 220 (83)
Axial Peripheral
IL-6 2.20 1.44 0.044
IL-16 245 209 0.044
MIP-1β 108 95 0.039
Measurable inflammation when clinically active PsA disease 126 (52)
vs. Not measurable inflammation when clinically active PsA disease 117 (48)
Measurable inflammation Not measurable inflammation
CRP 15.5 × 106 4.16 × 106 0.0001
SAA 13.9 × 106 5.20 × 106 0.003
IL-6 2.10 1.12 0.003
VCAM 7.85 × 105 6.91 × 105 0.017
Calprotectin 1.15 × 106 0.80 × 106 0.020
IL-17A 4.02 3.11 0.022
TNF-β 0.534 0.307 0.022
IL-16 225 198 0.025
IL-12/IL-23p40 139 114 0.040
bDMARD2, ever 42 (16)
vs. Never bDMARD 221 (84)
bDMARD ever Never bDMARD
TNF-β 0.864 0.338 0.0001
TNF-α 14.5 2.91 0.0003
Calprotectin 1.76 × 106 0.885 × 106 0.0009
CRP 21.5 × 106 8.39 × 106 0.016
Tie-2 (lower level) 3290 3530 0.027

1Upon clinical investigation and collection of blood; 2Etanercept, Adalimumab, Infliximab, Certolizumab, Golimumab, Abatacept, Ustekinumab or Infliximab.