Fig. 3.

Synovial fluid alone does not induce the observed in vivo polarization pattern. a Paired SF and plasma samples were used to induce polarization in in vitro cultured monocytes from healthy donors and analyzed by flow cytometry. The fold change of the markers between SF and plasma was calculated. SF induced an M2-like pattern as compared to paired plasma, with a significant MFI fold change in all markers, except CD163. *Unpaired SF samples. Data from these patients was calculated against the geometric mean of the patients with plasma samples (paired SF and plasma, n = 9; unpaired SF, n = 4). b Cytokines in the synovial fluid were analyzed by a cytometric bead assay and contained measurable levels of IL-1β, IL-6, IL-8, and IL-10 compared to paired plasma that contained none to very low detectable levels. SF n = 13, plasma n = 9. Statistics was performed on paired data using Wilcoxon matched-pair signed rank test. Data are shown as median and interquartile range. MFI-median fluorescence intensity. SF: synovial fluid