Fig. 4

The neutrophil phenotype shift is not explained by exposure to synovial fluid or transmigration. a Healthy control blood neutrophils were challenged with 20% JIA synovial fluid (n = 12) or 20% serum from the healthy blood donor for 1 h followed by the analysis of surface marker expression. Control serum-stimulated neutrophils are represented by the dotted line. Data are presented as fold change of median fluorescence intensity (MFI) in synovial fluid stimulated compared to control neutrophils. b–i Neutrophils in JIA synovial fluid (SF) were compared to neutrophils from the oral cavity (OC) of healthy controls, to investigate the alterations in surface markers between the blood and tissue in paired samples of blood and SF or blood and OC. Blood values are represented by the dotted line. Data are presented as fold change of MFI values of b CD66b, c CD11b, d S100A8/A9, e CD62L, f CD16, g CD14, h CD206, and i CD10 in tissue neutrophils compared to paired blood neutrophils. Line at the median. **p < 0.01, ***p < 0.001, Mann-Whitney U test