Levels of soluble receptor for advanced glycation end products (soluble RAGE) in blood and synovial fluid (SF) of rheumatoid arthritis (RA) patients and in patients with degenerative/traumatic joint diseases (non-inflammatory joint disease [NID]). In addition, blood levels of soluble RAGE were assessed in healthy controls. Box plots show the 25th and 75th percentiles. Horizontal lines in bold within boxes indicate medians, and dashed lines indicate means. Vertical bars indicate the 5th and 95th percentiles. Statistical differences with respect to soluble RAGE levels between groups were calculated using the Mann–Whitney U test, and differences between paired samples were calculated by the Wilcoxon signed rank test. Mean ± standard error of the mean (median) values are shown. NS, not significant.