Figure 4.

Expression of CCL21 in synovial fluid and tissue. (a) CCL21 concentrations in sera from 15 age-matched healthy controls, paired sera (Sera) and synovial fluids (SF) from 28 patients with juvenile idiopathic arthritis (JIA). Lines represent median values. Boxes contain values falling between the 25th and 75th centiles; whiskers show lines that extend from the boxes represent the highest and lowest values for each subgroup. The heterogeneity test among the three subgroups was highly significant (Kruskal–Wallis analysis of variance test, P = 0.0045). At post hoc analysis, differences between paired sera and SF were evaluated by the Wilcoxon rank test. Difference between JIA sera and healthy controls were evaluated by the Mann–Whitney U-test. (b) Expression of CCL21 in perivascular aggregates and vascular endothelium in synovial tissue with diffuse lymphocytic infiltration from 10-year-old girl with persistent oligoarticular JIA. (c, d) Double staining with anti-CCR7 (red) and anti-CCL21 (brown) monoclonal antibodies at different magnifications (×10 and ×40, respectively) shows CCL21 expression by endothelial cells of vessels located in the sublining zone of the superficial subintima.