Angiogenic gene expression and vascular density are reflected in ultrasonographic features of synovitis in early rheumatoid arthritis: an observational study

Table 2 Correlation matrix of ultrasound parameters with angiogenic, lymphangiogenic cytokine expression and cellular infiltration

US parameter	PSS	SQuant	PQuant	PDHi	PQuant/SQuant
TNF-α	0.46*	0.74*	0.61*	0.60*	0.59*
IL-6	0.30	0.69*	0.59*	0.56*	0.57*
IL-1β	0.47*	0.81*	0.68*	0.64*	0.67*
Podoplanin	0.19	0.71*	0.43	0.15	0.32
Angiopoietin 1	0.4	0.37	0.22	0.11	0.23
Angiopoietin 2	0.5	0.74*	0.61*	0.46	0.56*
VEGF-R3	0.50*	0.61*	0.55*	0.36	0.47
VEGF-C	0.2	0.62*	0.39	0.14	0.29
VEGF-A	0.5	0.56*	0.52*	0.48*	0.54*
Tie-2	0.3	0.51*	0.44	0.19	0.34
Synovitis score	0.25	0.18	0.27	0.48*	0.31
CD68SL	0.29	0.35*	0.40*	0.51*	0.40*
CD68L	0.12	0.46*	0.18	0.33	0.09
CD20	0.02	0.24	0.25	0.38*	0.22

Correlation was analysed using Spearman's rho. *Significant values (P <0.05). SQuant correlated with the majority of pro-inflammatory cytokines, angiogenic, lymphangiogenic gene expression and macrophage lining and sublining infiltration. PSS, power Doppler semiquantitative score; SQuant, quantitative synovial thickness area; PQuant, quantitative power Doppler area; PDHi, quantitative thresholded power Doppler area; VEGF, vascular endothelial growth factor, Tie, Tyrosine kinase (predominant endothelial cell expression), CD68SL, macrophage marker (synovial sublining layer), CD68L, macrophage marker (synovial lining layer).