CD14⁺CD16⁺ monocytes are more expanded in synovial fluid (SF), which is the site of inflammation in RA patients.

<p>(<b>A</b>) Representative contour plot of CD14 and CD16 expression on paired peripheral (left) and synovial monocytes (right) from RA patients. Number in rectangular gate indicates the frequency of CD14^dimCD16⁺ monocytes. (<b>B</b>) Frequencies (%) of different monocyte subsets which were subdivided by differential expression of CD14 and CD16, in paired peripheral blood and synovial fluid RA patient samples (n = 18) (<b>C</b>) Frequencies (%) of CD14⁺HLA-DR⁺ monocytes in peripheral blood and synovial fluid derived from the same RA patients (n = 18) (<b>D</b>) Relative gene expression of CD16 in monocytes purified from peripheral blood and synovial fluid of the same RA patients (n = 5). Each data point represents an individual subject; horizontal bars and error bars show the mean ± SEM. * = <i>P<</i>0.05; ** = <i>P<</i>0.01 by paired <i>t</i>-test in (<b>B and C</b>). Bars show the mean ± SEM. * = <i>P<</i>0.05 by paired <i>t</i>-test in (<b>D</b>). PBMO (peripheral blood monocytes) and SFMO (synovial fluid monocytes).